Researcher basic information

• 博士（保健科学）, Hokkaido University, Jun. 2018

• https://researchmap.jp/naomitamura?lang=en

• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201801020916827848

• 201801020916827848

• Life Science, Hygiene and public health: excluding laboratory approach
• Life Science, Hygiene and public health: including laboratory approach
• Humanities & Social Sciences, Childhood and nursery/pre-school education
• Informatics, Statistical science
• Life Science, Medical management and medical sociology

Research activity information

• May 2014, 北海道大学環境健康科学研究教育センター, 日本衛生学会若手優秀演題賞
  児の出生体重と母親の社会経済要因との関連についての疫学研究．
  田村菜穂美, 受賞形態: 個人、国内外区分: 国内の賞、専門分野: 衛生学

• Impact of prenatal manganese and selenium exposure on childhood thyroid hormone parameters up to 4 years of age: Japan environment and children’s study
  Takeshi Yamaguchi; Hiroyoshi Iwata; Sachiko Itoh; Yu Ait Bamai; Atsuko Ikeda; Keitaro Makino; Mariko Itoh; Rahel Mesfin Ketema; Naomi Tamura; Rieko Yamamoto; Maki Tojo; Kensuke Oba; Shuntaro Morikawa; Yasuaki Saijo; Yoshiya Ito; Reiko Kishi
  Environment International, 110353, 110353, Elsevier BV, Jun. 2026
  Scientific journal
• Latent class analysis of mobile phone usage patterns and association with sleep problems in children: Findings from the Hokkaido Birth Cohort Study
  Ammara Ajmal; Naomi Tamura; Yu Ait Bamai; Keiko Yamazaki; Toshio Yoshikawa; Rieko Yamamoto; Mariko Itoh; Keitaro Makino; Takashi Hikage; Tatsuya Kashiwa; Toshihiko Nishimura; Atsuko Ikeda; Reiko Kishi
  Computers in Human Behavior Reports, 22, 101077, 101077, Elsevier BV, May 2026
  Scientific journal
• Associations of prenatal exposure to organophosphate pesticides with eczema and allergic rhinoconjunctivitis in 4-year-old children: The Japan Environment and Children's Study
  Megasari Marsela; Hiroyoshi Iwata; Yu Ait Bamai; Mariko Itoh; Rahel Mesfin Ketema; Takeshi Yamaguchi; Yasuaki Saijo; Yoshiya Ito; Sachiko Itoh; Keiko Yamazaki; Naomi Tamura; Keitaro Makino; Maki Tojo; Reiko Kishi; Atsuko Ikeda
  Environmental Research, 123839, 123839, Elsevier BV, Feb. 2026
  Scientific journal
• Effects of maternal occupation on low birth weight and preterm birth: A prospective birth cohort study in the first trimester, the Japan environment and Children's study.
  Sumitaka Kobayashi; Hiroyoshi Iwata; Takeshi Yamaguchi; Naomi Tamura; Mariko Itoh; Maki Tojo; Keiko Yamazaki; Yasuaki Saijo; Yoshiya Ito; Reiko Kishi
  International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics, 172, 2, 991, 1008, Feb. 2026, [International Magazine]
  English, Scientific journal, OBJECTIVE: Although there are some reports that maternal occupation during pregnancy decreases birth size, the results are inconsistent. Hence, we examined the association of maternal occupation during pregnancy with infant low birth weight (LBW) and preterm birth (PB). METHODS: We used data from 53 932 participants of the prospective birth cohort of the Japan Environment and Children's Study. During the first trimester, information on maternal occupational major and minor groups, type of employment, and average weekly working hours was obtained using a self-administered questionnaire. Information on LBW and PB was obtained from medical records transcribed by physicians, midwives/nurses, and/or research coordinators at birth. Associations between maternal occupation and birth outcomes were examined using logistic regression models adjusted for confounding factors. RESULTS: In the major occupational group, the odds ratio (95% confidence interval) of LBW in administrative and managerial workers (0.52; 0.32-0.84) was lower than that in professional and engineering workers. Among administrative and managerial workers, the percentages of LBW among management government officials (4.6%), officers of companies and organizations (4.0%), and management staff of companies and organizations (7.1%) were lower than the overall average of 8.2%. Similar results were found for LBW at full-term (Term-LBW; ≥37 weeks of gestational age). However, there were no associations between the maternal major occupational groups on PB. We observed the association of maternal occupation in the first trimester on infant LBW and Term-LBW. CONCLUSION: The results suggest that medical professionals need to advise considering maternal occupation when performing pregnancy checkups.
• Childhood obesity and DNA methylation in an epigenome-wide association study: findings from the Hokkaido Birth Cohort
  Hiroyoshi Iwata; Chihiro Miyashita; Takeshi Yamaguchi; Atsuko Ikeda; Ryu Miura; Machiko Minatoya; Naomi Tamura; Yu Ait Bamai; Sachiko Itoh; Keiko Yamazaki; Rahel Mesfin Ketema; Mariko Itoh; Maki Tojo; Rieko Yamamoto; Keitaro Makino; Reiko Kishi
  Clinical Epigenetics, Springer Science and Business Media LLC, 01 Dec. 2025
  Scientific journal
• Toxic metals and trace elements in maternal blood and urinary tract infection during the first 2 years of life: The Japan Environment and Children's Study
  Keitaro Makino; Hiroyoshi Iwata; Takeshi Yamaguchi; Atsuko Ikeda; Yu Ait Bamai; Sachiko Itoh; Mariko Itoh; Maki Tojo; Naomi Tamura; Rieko Yamamoto; Rahel Mesfin Ketema; Yasuaki Saijo; Yoshiya Ito; Reiko Kishi
  Science of The Total Environment, 1006, 180895, 180895, Elsevier BV, Dec. 2025
  Scientific journal
• The impact of pediatric constipation on appendicitis: a prospective birth cohort in the Japan Environment and Children's Study.
  Hiroyoshi Iwata; Takeshi Yamaguchi; Sachiko Itoh; Yu Ait Bamai; Atsuko Ikeda; Keitaro Makino; Mariko Itoh; Maki Tojo; Rieko Yamamoto; Naomi Tamura; Rahel Mesfin Ketema; Yasuaki Saijo; Yoshiya Ito; Reiko Kishi
  BMC pediatrics, 25, 1, 962, 962, 26 Nov. 2025, [International Magazine]
  English, Scientific journal, BACKGROUND: This study aimed to examine the association between constipation and appendicitis in children using data from a nationwide birth cohort, the Japan Environment and Children's Study (JECS). METHODS: Data were obtained from 64,772 children and their mothers participating in JECS, which included over 100,000 pregnancies across 15 regional centres in Japan. Pediatric constipation was assessed at age three using the Rome III criteria, while appendicitis cases were identified between ages three to four. Logistic regression analyses, including univariable and multivariable models, were conducted to evaluate associations. Additional analyses were stratified by sex. RESULTS: Among the 64,772 children analyzed, 156 cases of appendicitis were identified between the ages of 3 and 4 years. Logistic regression suggested a possible association between constipation and an increased risk of appendicitis (univariable odds ratio [OR]: 1.38, 95% confidence interval [CI]: 0.87–2.10; multivariable OR: 1.36, 95% CI: 0.86–2.06). Although the associations did not reach statistical significance, the point estimates consistently indicated a trend toward increased risk. CONCLUSION: Although our analyses of children aged 3–4 years did not yield statistically significant associations, the observed trends may suggest a potential link between constipation and appendicitis. These findings should be interpreted only as exploratory, and further studies in different age groups, including older children and adults, are warranted to confirm or refute this possible association. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12887-025-06263-7.
• 出生体重500gごとの成長曲線 エコチル調査より
  山口 健史; 田村 菜穂美; 岩田 啓芳; 中村 明枝; 伊藤 善也; 山内 太郎; 岸 玲子
  日本成長学会雑誌, 31, 2, 65, 65, 日本成長学会, Nov. 2025
  Japanese
• Whole-Body SAR Evaluation under Far-Field Exposure with Daily Posture Variability: Toward an Epidemiologically Relevant Assessment
  Koki Kusakabe; Takashi Hikage; Toshihiko Nishimura; Tatsuya Kashiwa; Naomi Tamura; Yu Ait Bamai; Atsuko Ikeda; Reiko Kishi
  2025 International Symposium on Antennas and Propagation (ISAP), 1, 2, IEEE, 27 Oct. 2025
  International conference proceedings
• Small for gestational age as a predictor of developmental coordination disorders: Exploring early risk from Japan birth cohort consortium
  Hiroyoshi Iwata; Maki Tojo; Kenji J. Tsuchiya; Mami Ishikuro; Geng Chen; Satoshi Suyama; Akio Nakai; Naomi Tamura; Toshio Yoshikawa; Toyoki Yamagata; Tomoko Nishimura; Takeshi Yamaguchi; Keiko Yamazaki; Taku Obara; Kazue Ishitsuka; Naho Morisaki; Keitaro Makino; Shinichi Kuriyama; Reiko Kishi
  Brain and Development, 47, 5, 104435, 104435, Elsevier BV, Oct. 2025
  Scientific journal
• Prediction of Kawasaki disease coronary artery lesions in the Japan Environment and Children’s Study
  Hiroyoshi Iwata; Takeshi Yamaguchi; Naomi Tamura; Yu Ait Bamai; Atsuko Ikeda; Mariko Itoh; Rieko Yamamoto; Maki Tojo; Rahel Mesfin Ketema; Keiko Yamazaki; Sachiko Itoh; Keitaro Makino; Satoru Shida; Yasuaki Saijo; Yoshiya Ito; Reiko Kishi
  Annals of Pediatric Cardiology, 18, 5, 437, 446, Ovid Technologies (Wolters Kluwer Health), Sep. 2025
  Scientific journal, Objective:
  
  This study aimed to validate a composite of previously identified risk factors for predicting coronary artery lesions in Japanese children with Kawasaki Disease (KD).
  
  Materials and Methods:
  
  Children diagnosed with KD from the Japan Environment and Children’s Study (JECS) cohort were included. We assessed the discriminative ability of the model using the area under the curve (AUC) and evaluated its calibration using calibration plots. Based on clinical insights, we derived our original model, which consisted of variables established in previous score models or studies. Using the bootstrap method, internal validation was assessed with the AUC and calibration slope.
  
  Results:
  
  Our analysis included 959 children with KD, derived from 104,062 pediatric records contained in the JECS. Our model comprised the following variables: sex, hematocrit, platelet count, C-reactive protein, and serum sodium levels. The mean and 95% confidence intervals of the AUCs for the Harada, Egami, and Kobayashi models were 0.66 (0.59–0.72), 0.59 (0.52–0.66), and 0.64 (0.56–0.72), respectively. Our score model with bootstrap analyses produced an AUC of 0.80 (0.68–0.91) and a calibration slope of 1.01.
  
  Conclusions:
  
  We built and evaluated our score model using indicators that were easily accessible with a moderate-to-high AUC and stable calibration results, indicating the high reliability of the model for clinical application. Further studies are required to validate our model in other cohorts.
• Impact of prenatal exposure to per- and polyfluoroalkyl substances on developmental delays in 4-year-old children: The Japan Environment and Children’s study
  Mariko Itoh; Sumitaka Kobayashi; Hiroyoshi Iwata; Yu Ait Bamai; Rahel Mesfin Ketema; Takeshi Yamaguchi; Keiko Yamazaki; Naomi Tamura; Maki Tojo; Satoshi Suyama; Sachiko Itoh; Chihiro Miyashita; Yasuaki Saijo; Yoshiya Ito; Shoji F. Nakayama; Michihiro Kamijima; Reiko Kishi
  Environment International, 198, 109434, 109434, Elsevier BV, Apr. 2025
  Scientific journal
• Mediation of prenatal cotinine and 8-hydroxy-2’-deoxyguanosine levels on infant birth size in the Japan Environment and Children’s Study (JECS)
  Sumitaka Kobayashi; Hiroyoshi Iwata; Takeshi Yamaguchi; Naomi Tamura; Mariko Itoh; Maki Tojo; Keiko Yamazaki; Sachiko Itoh; Chihiro Miyashita; Yu Ait Bamai; Yukihiro Sato; Yasuaki Saijo; Yoshiya Ito; Reiko Kishi
  Reproductive Toxicology, 108905, 108905, Elsevier BV, Apr. 2025
  Scientific journal
• Association between prenatal exposure to maternal metal and trace elements and Streptococcus infection: A prospective birth cohort in the Japan Environment and Children’s Study
  Hiroyoshi Iwata; Atsuko Ikeda; Mariko Itoh; Rahel Mesfin Ketema; Naomi Tamura; Takeshi Yamaguchi; Keiko Yamazaki; Rieko Yamamoto; Maki Tojo; Yu Ait Bamai; Yasuaki Saijo; Yoshiya Ito; Reiko Kishi
  PLOS ONE, 20, 2, e0319356, e0319356, Public Library of Science (PLoS), 27 Feb. 2025
  Scientific journal, Background
  
  Streptococcus infection is a common and potentially severe bacterial infection which remains a global public health challenge, underscoring the necessity of investigating potential risk factors.
  
  Aims
  
  The present study aims to assess the association between metal and trace element exposure and Streptococcus infection using a prospective nationwide birth cohort, the Japan Environment and Children’s Study (JECS).
  
  Methods
  
  The JECS obtained data from over 100,000 pregnancies through 15 Regional Centres across Japan. We assessed toxic metal and trace element levels among pregnant mothers and Streptococcus infection among their children, born between 2011 and 2014, at age three to four. Analysis was performed using univariable and multivariable logistic regressions, as well as Quantile g-computation. We also conducted quartile regressions to assess the effects of higher serum selenium levels and potential interactions between selenium and mercury.
  
  Results
  
  Among 74,434 infants and their mothers, univariable and multivariable regression analyses found that selenium and mercury each had an inverse association with Streptococcus infection incidence. Quantile g-computation analysis yielded results consistent with the primary regression analyses. Quartile regression suggested that serum selenium levels above the third quartile were inversely associated with later Streptococcus infection incidence, but no interaction between selenium and mercury was found.
  
  Conclusions
  
  These findings imply that maternal selenium exposure may have protective effects on Streptococcus infection among children. Further studies should explore the role of pediatric selenium in immune responses to infectious diseases, especially Streptococcus infection.
• Association between small for gestational age and neurodevelopmental disability at 5 years in the Hokkaido study.
  Satoshi Suyama; Mariko Itoh; Naomi Tamura; Hiroyoshi Iwata; Takeshi Yamaguchi; Sumitaka Kobayashi; Chihiro Miyashita; Takuya Saito; Reiko Kishi
  Pediatrics international : official journal of the Japan Pediatric Society, 67, 1, e70137, 2025, [International Magazine]
  English, Scientific journal, BACKGROUND: Low birth weight is a known risk factor for delayed growth and disability in children. It is assessed using a measure called small for gestational age (SGA). SGA children have an increased risk of neurodevelopmental disabilities, regardless of gestational age. We conducted this study to evaluate the effects of SGA on neurodevelopmental disability, particularly in SGA full-term newborns (term-SGA). METHODS: This study was conducted using a prospective birth cohort from the Hokkaido Study on Environment and Children's Health. The mothers of 4851 children who reached the age of 5 years between April 2008 and November 2011 received questionnaires, including the strengths and difficulties questionnaire (SDQ). Neurodevelopmental disability was assessed using the SDQ. SGA infants, including term-SGA, were assessed by referring to the birth weight database of the Japan Pediatric Society. RESULTS: We received 3484 responses from the parents. Univariate analysis revealed a significant difference in hyperactivity/inattention and the total difficulties score (TDS) between groups defined as normal and borderline/clinical based on the TDS, for both SGA and term-SGA infants. In the multivariate analysis, sex, household income, and SGA and term-SGA status were significantly associated with TDS (term-SGA: odds ratio [OR] = 1.72; 95% confidence interval [CI], 1.07-2.76; SGA, OR = 1.75; 95% CI: 1.10-2.78). However, SGA and term-SGA status were not associated with hyperactivity/inattention. CONCLUSIONS: SGA, even at term, may predispose children to neurodevelopmental disability.
• Association between children's intended screen time use and behavior problems in Japan: the Hokkaido Study on Environmental and Children's Health.
  Naomi Tamura; Keiko Yamazaki; Chihiro Miyashita; Atsuko Ikeda; Ammara Ajmal; Satoshi Suyama; Takashi Hikage; Manabu Omiya; Masahiro Mizuta; Reiko Kishi
  Environmental health and preventive medicine, 30, 82, 82, 2025, [Domestic magazines]
  English, Scientific journal, BACKGROUND: Long screen time hours may be associated with behavioral problems in children. To better understand the relationship between children's behavioral problems and screen time, it the associated risk factors must be subdivided based on the purpose underlying screen use. This study examined the relationship between screen time based on intended usage and behavioral problems in Japan. METHODS: This study included 3,332 children aged between 7-17 years from the Hokkaido Study on Environment and Children's Health. From October 2020 to October 2021, the children and their parents answered questionnaires on the children's screen use duration (never used, <30 min, ≥30 min & <1 hour, ≥1 h & <2 h, ≥2 h) based on seven intended usage categories: watching television/video, video gaming, reading books/comics, sending/receiving e-mail/messages, browsing/posting on social networking services, studying for classes/homework, drawing/editing pictures/photos/videos, along with the Strengths and Difficulties Questionnaire (SDQ). Logistic regression was used to analyze the association between screen time, purpose of children's screen use, and behavioral problems across the 13 SDQ total scores. RESULTS: The mean ± standard deviation age of the participants was 12.4 ± 2.4-years-old, 487 (14.6%) children were determined to have behavioral problems, and the duration of screen time increased with their age. The children's primary purposes for screen use were watching television/video, video gaming, sending/receiving e-mail/messages, and browsing/posting on social networking services. Children who reported playing video games for ≥2 hours on weekdays had higher odds of problematic total difficulties scores than never user (Odds Ratio: 2.10, 95% confidence interval: 1.45-3.06). CONCLUSION: Long video gaming screen time is associated with behavioral issues, hyperactivity/inattention, and prosocial behaviors in children. Conversely, watching television and videos for 30 min-1 h per day, using e-mail or messaging, and using social networking services were significantly association with reduced odds ratio for peer relationship problems as compared to children who never engaged in these activities. Longitudinal follow-up is needed to further examine screen time and problem behaviors.
• Japanese growth charts stratified by birth weight in 500-gram increments: findings from the Japan environment and children’s study
  Takeshi Yamaguchi; Naomi Tamura; Hiroyoshi Iwata; Sachiko Itoh; Mariko Itoh; Maki Tojo; Keitaro Makino; Yasuaki Saijo; Akie Nakamura; Yoshiya Ito; Kazutoshi Cho; Akinori Moriichi; Yumi Kono; Taro Yamauchi; Reiko Kishi
  Clinical Pediatric Endocrinology, Japanese Society for Pediatric Endocrinology, 2025
  Scientific journal
• Association between prenatal tobacco exposure and attention-deficit/hyperactivity disorder related characteristics at 6 and 8 years: a birth cohort in Japan
  Mariko Itoh; Sumitaka Kobayashi; Shinkichi Nishihara; Chihiro Miyashita; Keiko Yamazaki; Naomi Tamura; Satoshi Suyama; Atsuko Ikeda; Sachiko Itoh; Yu Ait Bamai; Takeshi Yamaguchi; Hideyuki Masuda; Sharon Hanley; Reiko Kishi
  BMJ Open, 14, 12, e087406, e087406, BMJ, 26 Dec. 2024
  Scientific journal, Objectives
  
  To examine the association between maternal plasma cotinine concentrations during pregnancy and attention-deficit/hyperactivity disorder (ADHD) related characteristics in children.
  
  Design
  
  Prospective birth cohort study from the Hokkaido Study on Environment and Children’s Health.
  
  Setting
  
  Hokkaido, Japan.
  
  Participants
  
  A total of 7217 children were included in the analysis. Their mothers were recruited to this study between 2003 and 2012 during early pregnancy. Blood samples of mothers in their third trimester of pregnancy were obtained.
  
  Main outcome measures
  
  ADHD-related characteristics screened by the ADHD-Rating Scale (ADHD-RS) in children at 6 and 8 years of age.
  
  Results
  
  The mothers were classified into three groups according to plasma cotinine levels (median=0.22 ng/mL)—non-smokers (≤0.21 ng/mL), passive smokers (0.22–11.48 ng/mL) and active smokers (≥11.49 ng/mL). ADHD was suspected in 302 (8.6%), 334 (10.9%) and 90 (14.5%) children in the non-smoker, passive smoker and active smoker groups, respectively. Children born to mothers in the smoking group had a statistically significant increased risk of ADHD-related characteristics (adjusted RR=1.49, 95% CI=1.19–1.86 and adjusted RR=1.20, 95% CI=1.03–1.40 for the active and passive smoking groups, respectively).
  
  Conclusion
  
  This large Japanese cohort study suggests an association between smoking during pregnancy and the risk of ADHD in children 6 and 8 years of age.
• Effects of the maternal work environment on psychological distress during pregnancy: A cross-sectional research-The Japan Environment and Children’s Study
  Sumitaka Kobayashi; Yasuaki Saijo; Mariko Itoh; Naomi Tamura; Maki Tojo; Hiroyoshi Iwata; Takeshi Yamaguchi; Yoshiya Ito; Reiko Kishi
  Journal of Occupational & Environmental Medicine, Ovid Technologies (Wolters Kluwer Health), 19 Nov. 2024
  Scientific journal, Abstract
  
  Objectives
  
  As part of the “Japan Environment and Children’s Study (JECS),” a national prospective birth cohort study, we examined the association between the maternal work environment and psychological distress during pregnancy in Japan.
  
  Methods
  
  Employing a cross-sectional design, we analyzed data from 42,797 participants, originally collected between 2011 and 2014. Associations between the maternal work environment and psychological distress (Kessler 6) were examined using generalized estimation equation models adjusted for confounding factors.
  
  Results
  
  Pregnant women who worked ≥51 h/week had a 1.19-fold higher odds ratio (OR) of psychological distress than those who worked 36-40 h/week (95% confidence intervals [CI], 1.07-1.32). Pregnant women who worked ≥5 days/month of shift work had a 1.11-fold higher OR of psychological distress than those who worked 0 days/month (1.00-1.24).
  
  Conclusions
  
  We observed an association between the maternal work environment and psychological distress during pregnancy.
• Association between the occupation of pregnant women’s partners and risks of infant low birth weight and preterm birth in a prospective birth cohort: the Japan Environment and Children’s Study
  Sumitaka Kobayashi; Yasuaki Saijo; Hiroyoshi Iwata; Takeshi Yamaguchi; Naomi Tamura; Mariko Itoh; Maki Tojo; Yoshiya Ito; Reiko Kishi
  Journal of Occupational & Environmental Medicine, Ovid Technologies (Wolters Kluwer Health), 19 Nov. 2024
  Scientific journal, Abstract
  
  Objective
  
  We examined the association between the occupations of pregnant women’s partners and infant low birth weight (LBW) and preterm birth (PB).
  
  Methods
  
  Birth outcome data were collected from 46,540 participants enrolled in the Japan Environment and Children’s Study. Participants were recruited from January 2011 to March 2014. Associations between the occupations of pregnant women’s partners and birth outcomes were examined using logistic regression models adjusted for confounding factors.
  
  Results
  
  LBW and PB incidences were 7.5% and 4.1%, respectively. In the major occupational group, the odds ratios (95% confidence intervals) of LBW for clerical (1.19; 1.03-1.37) and service workers (1.21; 1.05-1.39) were higher than those for professional and engineering workers. However, no associations existed between the major occupational groups of the pregnant women’s partners and PB.
  
  Conclusion
  
  Partner’s employment in clerical and service work increases the risk for LBW.
• Association between small for gestational age and motor coordination difficulties in children aged 5-6 years: Insights from the Hokkaido Study on Environment and Children's Health.
  Maki Tojo; Hiroyoshi Iwata; Naomi Tamura; Takeshi Yamaguchi; Kenji J Tsuchiya; Satoshi Suyama; Taku Obara; Akio Nakai; Toshio Yoshikawa; Toyoki Yamagata; Mariko Itoh; Keiko Yamazaki; Sumitaka Kobayashi; Reiko Kishi
  Brain & development, 47, 1, 104296, 104296, 14 Nov. 2024, [International Magazine]
  English, Scientific journal, BACKGROUND: Developmental coordination disorder (DCD) presents motor skill delays in early childhood and has been associated with later maladaptation, necessitating early intervention. However, research on the potential risk factors, particularly in preschool-aged children, remains scarce. AIMS: We aimed to explore the association between small for gestational age (SGA) and other factors and motor coordination problems in 5-6-year-olds from the Hokkaido Study on Environment and Children's Health Cohort. STUDY DESIGN: Prospective. SUBJECTS: We analyzed data from >3500 participants from the Hokkaido Study, a prospective birth cohort, and assessed children aged 5-6 years. OUTCOME MEASURES: Participants underwent assessment with the Developmental Coordination Disorder Questionnaire Japanese version (DCDQ-J). We conducted linear regression analyses adjusted for variables such as the child's sex, maternal age, and maternal smoking history during pregnancy, while also examining the independent associations of each risk factor. RESULTS: Among the 3883 children analyzed for SGA, children with SGA exhibited significantly lower DCDQ-J total scores than non-SGA children (mean difference: -2.25, 95 % confidence interval [-4.19, -0.30], p = 0.02). On the subscales, children with SGA demonstrated significantly lower "Control During Movement" scores than non-SGA children (mean difference: -0.96, 95 % confidence interval [-1.78, -0.13], p = 0.02). Furthermore, the child's sex, maternal smoking, maternal age, and preterm birth were independently associated with DCD. CONCLUSIONS: SGA was shown to be one of the risk factors for the manifestation of motor coordination difficulties in 5-6-years old children. In combination with other factors, screening for motor coordination difficulties in SGA children will be an important means of initiating appropriate interventions.
• 子どもの肥満とDNAメチル化に関するエピゲノム・ワイド関連研究 北海道スタディ
  田村 菜穂美; 岩田 啓芳; 宮下 ちひろ; 山口 健史; 岸 玲子
  日本成長学会雑誌, 30, 2, 87, 87, 日本成長学会, Sep. 2024
  Japanese
• 北海道妊婦の血中ビタミンD濃度の実態調査
  中西 康; 武藤 麻未; 伊藤 佐智子; 小林 澄貴; 山口 健史; 岩田 啓芳; 田村 菜穂美; 岸 玲子; 佐藤 嘉晃
  日本成長学会雑誌, 30, 2, 91, 91, 日本成長学会, Sep. 2024
  Japanese
• Link between Wi-Fi, cordless devices, mobile phone usage patterns, and behavioral problems among Japanese children: A prospective cohort study.
  Ammara Ajmal; Keiko Yamazaki; Naomi Tamura; Yu Ait Bamai; Toshio Yoshikawa; Takashi Hikage; Atsuko Ikeda; Reiko Kishi
  Environmental research, 261, 119715, 119715, 02 Aug. 2024, [International Magazine]
  English, Scientific journal, BACKGROUND: With the recent advent of technology, it is important to confirm the health and safety of the youth. This study aimed to prospectively evaluate the relationship between Wi-Fi, cordless phones, and mobile phone usage patterns and behavioral problems. METHODS: This study involved 2465 children aged 8-17 years from the Hokkaido Study on Environment and Children's Health from October 2020 to January 2021, with a follow-up from September 2021 to March 2022. The mother-child dyad provided information on the presence of residential Wi-Fi and cordless phones, cordless phone call duration, and mobile phone usage pattern (duration of calls using mobile network and internet, online audio streaming, online video streaming, and playing online games) via a baseline questionnaire. Based on the scores on Strength and Difficulties Questionnaire at baseline and follow-up, the children were categorized into four groups: normal, persistent, improved, and concurrent. RESULTS: No significant association was found between Wi-Fi, mobile phone calls via mobile networks, and behavioral problems. Cordless phone at home had higher odds for improvement in total difficulty scores, and cordless phone for calling more than 4 min per week had lower odds of persistent problematic prosocial behavior. Longer duration of mobile phone calling via the internet (>40 min/week) had higher odds of concurrent total difficulties. Mobile phone calling via mobile network for <5 min per week had higher odds for improved total difficulty scores. Audio streaming via mobile phones for 60-120 min had lower odds of persistent total difficulties. CONCLUSION: Our results showed sporadic findings between residential RF-EMF indoor sources and mobile phone usage pattern. These observed findings could be affected by residual confounding and chance findings. Ongoing follow-up studies are necessary to further explore this association through detailed exposure assessment and addressing the potential limitations of our study.
• Correction to: Prenatal metal concentrations and physical abnormalities in the Japan Environment and Children’s Study (Pediatric Research, (2023), 10.1038/s41390-023-02851-4)
  Yuichi Nakamura; Sumitaka Kobayashi; Kazutoshi Cho; Sachiko Itoh; Chihiro Miyashita; Takeshi Yamaguchi; Hiroyoshi Iwata; Naomi Tamura; Yasuaki Saijo; Yoshiya Ito; Yoshitaka Seto; Ryota Honjo; Akiko Ando; Yuta Furuse; Atsushi Manabe; Reiko Kishi; Michihiro Kamijima; Shin Yamazaki; Yukihiro Ohya; Reiko Kishi; Nobuo Yaegashi; Koichi Hashimoto; Chisato Mori; Shuichi Ito; Zentaro Yamagata; Hidekuni Inadera; Takeo Nakayama; Tomotaka Sobue; Masayuki Shima; Hiroshige Nakamura; Narufumi Suganuma; Koichi Kusuhara; Takahiko Katoh
  Pediatric Research, 95, 6, 1659, 1661, May 2024
  Scientific journal
• small-for-gestational-age(SGA)と就学前の協調運動の問題との関連
  東條 真希; 岩田 啓芳; 山口 健史; 田村 菜穂美; 土屋 賢治; 須山 聡; 小原 拓; 石塚 一枝; 西村 倫子; 石黒 真美; 中井 昭夫; 小林 澄貴; 山縣 豊樹; 栗山 進一; 岸 玲子
  日本衛生学雑誌, 79, Suppl., S263, S263, (一社)日本衛生学会, Mar. 2024
  Japanese
• Vitamin D concentration in maternal serum during pregnancy: Assessment in Hokkaido in adjunct study of the Japan Environment and Children's Study (JECS).
  Ko Nakanishi; Mami Mutoh; Sachiko Itoh; Sumitaka Kobayashi; Takeshi Yamaguchi; Hiroyoshi Iwata; Naomi Tamura; Momoko Koishi; Machiko Kasai; Emi Kikuchi; Nanae Yasuura; Reiko Kishi; Yoshiaki Sato
  PloS one, 19, 11, e0312516, 2024, [International Magazine]
  English, Scientific journal, BACKGROUND: Vitamin D is an essential nutrient for maintaining blood calcium and phosphorus levels and controlling bone density. Deficiency in it leads to rickets, osteomalacia, osteoporosis, and various other diseases. Recently, it has gained attention for reportedly reducing the risk of COVID-19 severity. However, there are no reports evaluating pregnant women in the Hokkaido region of Japan. This study aims to elucidate the current status of vitamin D levels in pregnant women in the Hokkaido region. METHODS: This study measured the serum concentrations of Vitamin D2 and D3 in 206 pregnant women participating in the Japan Environment and Children's Study-Hokkaido sub-cohort at the Hokkaido Regional Center. It analyzed the relationship between these concentrations and the months, seasons, and sunshine hours. RESULTS: The mean maternal age was 31.7 ± 4.7 years, and the mean prepregnancy BMI was 21.0 ± 2.5 kg/m2. Only two women have given birth at least once. Regarding sunscreen use, 65 participants (31.6%) responded "often" or "sometimes." Five women used the supplement containing Vitamin D. The value of 25(OH)D2 was above 1 ng/ml in four of them. The average 25(OH)D3 level was 12.1 ng/ml, with a median of 11.0 ng/ml. Four participants (1.9%) had levels below 5 ng/ml. The highest median of 25(OH)D3 was in July, and the lowest was in April. The concentration of 25(OH)D3 was significantly higher in summer than in winter. A correlation was found between 25(OH)D3 and sunshine hours, with 25(OH)D3 concentrations gradually increasing as sunshine hours increase. CONCLUSION: It was found that almost all pregnant women in Hokkaido were deficient in vitamin D. It is necessary to implement measures to enhance vitamin D levels in pregnant women to safeguard the health of women and fetuses in Hokkaido.
• Heavy metals and trace elements in maternal blood and prevalence of congenital limb abnormalities among newborns: the Japan Environment and Children's Study.
  Atsuko Ikeda; Megasari Marsela; Chihiro Miyashita; Takeshi Yamaguchi; Yasuaki Saijo; Yoshiya Ito; Hiroyoshi Iwata; Sachiko Itoh; Mariko Itoh; Keiko Yamazaki; Naomi Tamura; Sumitaka Kobayashi; Reiko Kishi
  Environmental health and preventive medicine, 29, 36, 36, 2024, [Domestic magazines]
  English, Scientific journal, BACKGROUND: Heavy metals such as lead (Pb) and cadmium (Cd) have been associated with adverse pregnancy and developmental outcomes, including congenital abnormalities. This study investigated the association between exposure to heavy metals and trace elements during fetal life and congenital limb abnormalities in infants. METHODS: This study is based on a prospective ongoing nationwide birth cohort from the Japan Environment and Children's Study (JECS). The concentrations of Cd, Pb, mercury (Hg), selenium (Se), and manganese (Mn) were measured in maternal blood collected during the mid-late trimesters. Inclusion criteria were available from questionnaires filled in during pregnancy, including information about congenital limb abnormalities at birth or at one month. To examine the associations with limb anomalies and individual chemicals, logistic regression models were applied following log-transformation or division into quartiles of Cd, Pb, Hg, Se, and Mn concentrations. To assess the associations with the heavy metals and trace elements mixture, quantile g-computation was employed. All models were adjusted for age, maternal smoking history, maternal alcohol intake, history of smoking, and infant sex. RESULTS: Data from 90,163 participants were included in the analysis, of whom 369 had congenital limb abnormalities in any of the collected information, and 89,794 had none. Among the 369 cases of congenital limb abnormalities, there were 185 and 142 cases of polydactyly and syndactyly, respectively. The median concentrations of Pb, Cd, Hg, Se, and Mn were 5.85, 0.66, 3.64, 168, and 15.3 ng/g, respectively. There were no associations between maternal blood concentrations of Pb [adjusted odd ratio = 0.83; 95% confidence interval = 0.61, 1.11], Cd [0.87; 0.68, 1.10], Hg [0.88; 0.73, 1.07], Se [1.07; 0.44, 2.59], and Mn [0.91; 0.64, 1.30] with congenital limb abnormalities. No significant association was observed between the mixture of heavy metals and trace elements [0.85; 0.72, 1.02] and any congenital limb abnormalities. Moreover, there was no association with all polydactylies and all syndactylies, or any type of abnormality as a subdivision. CONCLUSION: At the maternal exposure levels of Cd, Pb, Hg, Se, and Mn assessed in the present study, no association was identified with the risk of developing congenital limb abnormalities in children.
• The association between flooring materials and childhood asthma: A prospective birth cohort in the Japan Environment and Children's Study.
  Hiroyoshi Iwata; Atsuko Ikeda; Mariko Itoh; Sachiko Itoh; Rahel Mesfin Ketema; Naomi Tamura; Chihiro Miyashita; Takeshi Yamaguchi; Keiko Yamazaki; Rieko Yamamoto; Maki Tojo; Yasuaki Saijo; Yoshiya Ito; Reiko Kishi
  PloS one, 19, 7, e0305957, 2024, [International Magazine]
  English, Scientific journal, BACKGROUND: Childhood asthma is known to be affected by a range of factors, including conditions in the indoor environment. While flooring material influences indoor air conditions, the potential association between flooring materials and childhood asthma remains poorly understood in Japan. OBJECTIVE: The present study aims to assess the association between childhood asthma incidence and the primary flooring material with the ongoing prospective nationwide birth cohort data of the Japan Environment and Children's Study (JECS). METHODS: The JECS gathered data on mothers and children through 15 Regional Centres across Japan. The present study assessed flooring materials used in the home and asthma incidence at age four among children born between 2011 and 2014. We implemented logistic regressions, setting asthma incidence among the children as the outcome and home floor type as the exposure. Additional analyses were conducted, stratifying the home's age as a proxy for tatami age, to assess whether the potential effect of tatami flooring on asthma risk is influenced by its age. RESULTS: The present study included total of 75,629 infants. For tatami flooring, the main multivariable regression and additional sub-group regression for homes over ten years old produced odds ratios of 1.09; 95% Confidence Interval (CI) [1.01-1.17] and 1.10; 95% CI [1.00-1.21] compared with flooring, respectively. CONCLUSION: These results imply that exposure to tatami flooring, particularly in older homes, may be associated with childhood asthma incidence. Moreover, our study highlights the importance of evaluating the relationship between regional and cultural differences between asthma and flooring materials.
• Hokkaido birth cohort study in Japan on the growth trajectory of children born with low birth weight until 7 years of age
  Kritika Poudel; Sumitaka Kobayashi; Hiroyoshi Iwata; Maki Tojo; Takeshi Yamaguchi; Keiko Yamazaki; Naomi Tamura; Mariko Itoh; Taku Obara; Shinichi Kuriyama; Reiko Kishi
  Early Human Development, 105925, 105925, Elsevier BV, Dec. 2023
  Scientific journal
• Estimation of Human Body Blockage Considering Elevation Angle of Exposure Plane-waves in Wireless LAN Frequency Band for Epidemiological Research on RF Exposure and Children’s Health
  Sakura Tsuruga; Kaito Sugimura; Takashi Hikage; Manabu Omiya; Keiko Yamazaki; Atuko Ikeda-Araki; Chihiro Miyashita; Naomi Tamura; Reiko Kishi
  IEICE Proceeding Series, 79, P2-26, The Institute of Electronics, Information and Communication Engineers, 29 Nov. 2023
  English, In recent years, due to the spread of smartphones and other wireless devices, the age at which children start using these devices has been declining. Consequently, it becomes imperative to investigate the effects of radiofrequency (RF) exposure on children's health, particularly with regard to higher nerve functions. In this study, we evaluate the effects of human body blockage on personal exposure assessment tools in wireless LAN frequency band, using the FDTD method to investigate the dosimetry protocol for epidemiologic research.
• The association between prenatal per-and polyfluoroalkyl substance levels and Kawasaki disease among children of up to 4 years of age: A prospective birth cohort of the Japan Environment and Children's study.
  Hiroyoshi Iwata; Sumitaka Kobayashi; Mariko Itoh; Sachiko Itoh; Rahel Mesfin Ketema; Naomi Tamura; Chihiro Miyashita; Takeshi Yamaguchi; Keiko Yamazaki; Hideyuki Masuda; Yu Ait Bamai; Yasuaki Saijo; Yoshiya Ito; Shoji F Nakayama; Michihiro Kamijima; Reiko Kishi
  Environment international, 183, 108321, 108321, 11 Nov. 2023, [International Magazine]
  English, Scientific journal, Kawasaki disease (KD) is common among pediatric patients and is associated with an increased risk of later cardiovascular complications, though the precise pathophysiology of KD remains unknown. Per- and polyfluoroalkyl substances (PFAS) have gathered notoriety as the causal pathogens of numerous diseases as well as for their immunosuppressive effects. The present epidemiological study aims to assess whether PFAS may affect KD risk. We evaluated research participants included in the ongoing prospective nationwide birth cohort of the Japan Environment and Children's Study (JECS). Among the over 100,000 pregnant women enrolled in the JECS study, 28 types of PFAS were measured in pregnancy in a subset of participants (N = 25,040). The JECS followed their children born between 2011 and 2014 (n total infants = 25,256; n Kawasaki disease infants = 271), up to age four. Among the 28 types of PFAS, those which were detected in >60 % of participants at levels above the method reporting limit (MRL) were eligible for analyses. Multivariable logistic regressions were implemented on the seven eligible PFAS, adjusting for multiple comparison effects. Finally, we conducted Weighted Quantile Sum (WQS) and Bayesian kernel machine regression (BKMR) to assess the effects of the PFAS mixture on KD. Therefore, we ran the BKMR model using kernel mechanical regression equations to examine PFAS exposure and the outcomes of KD. Upon analysis, the adjusted multivariable regression results did not reach statistical significance for the seven eligible substances on KD, while odds ratios were all under 1.0. WQS regression was used to estimate the mixture effect of the seven eligible PFAS, revealing a negative correlation with KD incidence; similarly, BKMR implied an inverse association between the PFAS mixture effect and KD incidence. In conclusion, PFAS exposure was not associated with increased KD incidence.
• 携帯電話等による電磁波への胎児期曝露に関する最近の研究動向 文献調査
  山崎 圭子; 田村 菜穂美; Ajmal Ammara; 日景 隆; 岸 玲子
  北海道公衆衛生学雑誌, 37, 1特別付録, 47, 47, 北海道公衆衛生学会, Nov. 2023
  Japanese
• 研究プロトコール発表 北海道の小学校6年生におけるエキノコックス症抗体保有率の調査
  岩田 啓芳; 山口 健史; 田村 菜穂美; 山本 理恵子; 東條 真希; 伊藤 真利子; 山崎 圭子; 宮下 ちひろ; 伊藤 佐智子; Ketema Rahel; 池田 敦子; 村林 宏; 伊藤 善也; 野中 成晃; 岸 玲子
  北海道公衆衛生学雑誌, 37, 1特別付録, 44, 44, 北海道公衆衛生学会, Nov. 2023
  Japanese
• Prenatal metal concentrations and physical abnormalities in the Japan Environment and Children's Study.
  Yuichi Nakamura; Sumitaka Kobayashi; Kazutoshi Cho; Sachiko Itoh; Chihiro Miyashita; Takeshi Yamaguchi; Hiroyoshi Iwata; Naomi Tamura; Yasuaki Saijo; Yoshiya Ito; Yoshitaka Seto; Ryota Honjo; Akiko Ando; Yuta Furuse; Atsushi Manabe; Reiko Kishi
  Pediatric research, 19 Oct. 2023, [International Magazine]
  English, Scientific journal, BACKGROUND: The association between prenatal metal exposure and congenital anomalies is unclear. We aimed to examine the association between exposure to cadmium, lead, mercury, selenium, and manganese and physical abnormalities. METHODS: Data from 89,887 pregnant women with singleton pregnancies who participated in the Japan Environment and Children's Study (JECS) were used. The correlation between maternal blood metal concentrations and physical abnormalities during the second or third trimester was investigated using logistic regression models. Physical anomalies included those observed at birth or at 1 month, primarily from ICD-10 Chapter 17, particularly congenital anomalies associated with environmental factors (e.g., hypospadias, cryptorchidism, cleft lip and palate, digestive tract atresia, congenital heart disease, and chromosomal abnormalities) and minor abnormalities. RESULTS: After adjusting for covariates, the OR (95% CIs) of physical abnormalities for a one-unit rise in Mn concentrations in all individuals were 1.26 (1.08, 1.48). The OR (95% CIs) of physical abnormalities in the 4th quartile (≥18.7 ng/g) were 1.06 (1.01, 1.13) (p-value for the trend = 0.034) compared with those in the 1st quartile (≤12.5 ng/g). CONCLUSION: In Japan, maternal blood Mn concentrations above threshold during pregnancy may slightly increase the incidence of physical abnormalities. IMPACT: Physical abnormalities (including minor anomalies and congenital anomalies) are associated with prenatal manganese concentrations. They are not associated with cadmium, lead, mercury, and selenium concentrations.
• 子どものスクリーンタイムと聴覚・視覚ワーキングメモリーとの関連 北海道スタディ
  田村 菜穂美; 山崎 圭子; 宮下 ちひろ; 池田 敦子; 日景 隆; 水田 正弘; 大宮 学; 竹鼻 美月; 赤坂 梨莉花; 岸 玲子
  日本衛生学雑誌, 78, Suppl., S172, S172, (一社)日本衛生学会, Mar. 2023
  Japanese
• 学童期の子どもの電磁波曝露実態の変化 北海道スタディ
  山崎 圭子; 宮下 ちひろ; 田村 菜穂美; 池田 敦子; 日景 隆; 水田 正弘; 大宮 学; 岸 玲子
  日本衛生学雑誌, 78, Suppl., S215, S215, (一社)日本衛生学会, Mar. 2023
  Japanese
• 妊婦の母体血中水銀・セレン濃度と4歳までの児の神経発達との関連 エコチル調査
  小林 澄貴; 伊藤 佐智子; 宮下 ちひろ; アイツバマイ ゆふ; 山口 健史; 増田 秀幸; 伊藤 真利子; 山崎 圭子; 田村 菜穂美; ハンリー・シャロン; 池田 敦子; 西條 泰明; 伊藤 善也; 岸 玲子
  日本衛生学雑誌, 78, Suppl., S173, S173, (一社)日本衛生学会, Mar. 2023
  Japanese
• 3.5歳と7歳の子どもの行動チェックリスト得点と関連要因の探索 北海道スタディ
  宮下 ちひろ; 山崎 圭子; 伊藤 佐智子; 田村 菜穂美; 岩田 啓芳; 岸 玲子
  日本衛生学雑誌, 78, Suppl., S221, S221, (一社)日本衛生学会, Mar. 2023
  Japanese
• Change of radiofrequency electromagnetic exposure of children from 2020 to 2021: A report from Hokkaido Study
  Keiko Yamazaki; Naomi Tamura; Chihiro Miyashita; Toshio Yoshikawa; Atsuko Ikeda-Araki; Takashi Hikage; Manabu Omiya; Masahiro Mizuta; Miwa Ikuyo; Kazuhiro Tobita; Teruo Onishi; Masao Taki; Soichi Watanabe; Reiko Kishi
  2023 35th General Assembly and Scientific Symposium of the International Union of Radio Science, URSI GASS 2023, 2023
  International conference proceedings
• Human Body Blockage Effects on Personal Exposimeter Device in 4G/5G Frequency Bands for Epidemiological Research on Children's Health
  Sakura Tsuruga; Manabu Omiya; Chihiro Miyashita; Kaito Sugimura; Keiko Yamazaki; Naomi Tamura; Takashi Hikage; Atsuko Ikeda-Araki; Reiko Kishi
  2023 IEEE International Symposium on Antennas and Propagation, ISAP 2023, 2023
  International conference proceedings
• Cross-sectional associations between early mobile device usage and problematic behaviors among school-aged children in the Hokkaido Study on Environment and Children's Health.
  Chihiro Miyashita; Keiko Yamazaki; Naomi Tamura; Atsuko Ikeda-Araki; Satoshi Suyama; Takashi Hikage; Manabu Omiya; Masahiro Mizuta; Reiko Kishi
  Environmental health and preventive medicine, 28, 22, 22, 2023, [Domestic magazines]
  English, Scientific journal, BACKGROUND: Concerns have been raised about the adverse health impacts of mobile device usage. The objective of this cross-sectional study was to examine the association between a child's age at the first use of a mobile device and the duration of use as well as associated behavioral problems among school-aged children. METHODS: This study focused on children aged 7-17 years participating in the Hokkaido Study on Environment and Children's Health. Between October 2020 and October 2021, the participants (n = 3,021) completed a mobile device use-related questionnaire and the strengths and difficulties questionnaire (SDQ). According to the SDQ score (normal or borderline/high), the outcome variable was behavioral problems. The independent variable was child's age at first use of a mobile device and the duration of use. Covariates included the child's age at the time of survey, sex, sleep problems, internet addiction, health-related quality of life, and history of developmental concerns assessed at health checkups. Logistic regression analysis was performed for all children; the analysis was stratified based on the elementary, junior high, and senior high school levels. RESULTS: According to the SDQ, children who were younger at their first use of a mobile device and used a mobile device for a longer duration represented more problematic behaviors. This association was more pronounced among elementary school children. Moreover, subscale SDQ analysis showed that hyperactivity, and peer and emotional problems among elementary school children, emotional problems among junior high school children, and conduct problems among senior high school children were related to early and long usage of mobile devices. CONCLUSIONS: Elementary school children are more sensitive to mobile device usage than older children, and early use of mobile devices may exacerbate emotional instability and oppositional behaviors in teenagers. Longitudinal follow-up studies are needed to clarify whether these problems disappear with age.
• Measurement of personal radio frequency exposure in Japan: The Hokkaido Study on the Environment and Children's health.
  Keiko Yamazaki; Atsuko Ikeda-Araki; Chihiro Miyashita; Naomi Tamura; Toshio Yoshikawa; Takashi Hikage; Manabu Omiya; Masahiro Mizuta; Miwa Ikuyo; Kazuhiro Tobita; Teruo Onishi; Masao Taki; Soichi Watanabe; Reiko Kishi
  Environmental research, 216, Pt 1, 114429, 114429, 26 Sep. 2022, [International Magazine]
  English, Scientific journal, The opportunities for exposure to radiofrequency electromagnetic fields (RF-EMF) among children are increasing. Children's exposure to RF-EMF in Japan was recorded using a personal exposure meter (ExpoM-RF), and factors associated with the exposure examined. A total of 101 children, aged 10-15 years old, participated in the prospective birth cohort "Hokkaido study". RF-EMF data were recorded in the 700 MHz-5.8 GHz frequency range for 3 days. The recorded data were summarized into six groups of frequency bands: downlink from mobile phone base stations (DL), uplink from mobile phones to a base station (UL), Wireless Local Area Network (LAN), terrestrial digital TV broadcasting (digital TV), 2.5 GHz and 3.5 GHz Time Division Duplex (TDD), 1.9 GHz TDD, and total (the summation of power density in all measured frequency bands). A questionnaire was used to document the internet environment (at home) and mobile phone usage. Personal RF-EMF exposure in Japanese children was lower than that reported in studies in Europe. The DL signals from mobile phone base stations were the most significant contributors to total exposure, while Wireless LAN and digital TV were only higher at home. The urban residence was consistently associated with increases in the four groups of frequency bands (DL, UL, digital TV, and TDD). TDD level has several associations with mobile phone usage (calls using mobile phones, video viewing, text message service, and online game). The association between inattention/hyperactivity subscale of the Strengths and Difficulties Questionnaire (SDQ) and higher Wireless LAN exposure at nighttime was also noted. Further studies with additional data will shed light on factors involved in RF-EMF exposure among Japanese children.
• Impact of prenatal exposure to mercury and selenium on neurodevelopmental delay in children in the Japan Environment and Children’s Study using the ASQ-3 questionnaire: a prospective birth cohort
  Sumitaka Kobayashi; Sachiko Itoh; Chihiro Miyashita; Yu Ait Bamai; Takeshi Yamaguchi; Hideyuki Masuda; Mariko Itoh; Keiko Yamazaki; Naomi Tamura; Sharon J.B. Hanley; Atsuko Ikeda-Araki; Yasuaki Saijo; Yoshiya Ito; Miyuki Iwai-Shimada; Shin Yamazaki; Michihiro Kamijima; Reiko Kishi
  Environment International, 168, 107448, 107448, Elsevier BV, Aug. 2022, [International Magazine]
  English, Scientific journal, Neurodevelopmental delay is associated with neurodevelopmental disorders. Prenatal metal exposure can potentially cause neurodevelopmental delays in children. This study examines whether prenatal exposure to mercury (Hg) and selenium (Se) is associated with the risk of neurodevelopmental delays in children up to 4 years of age. Children enrolled in a prospective birth cohort of the Japan Environment and Children's Study were examined. Hg and Se levels in maternal (nchild = 48,731) and cord (nchild = 3,083) blood were analyzed by inductively coupled plasma-mass spectrometry. Neurodevelopmental delays were assessed in children between the ages of 0.5 to 4 years using the Ages and Stages Questionnaires, Third Edition. The association between exposure and outcomes was examined using the generalized estimation equation models. In maternal blood, compared to participants with Se levels in the first quartile (83.0 to < 156 ng/g), the odds ratio (95 % confidence intervals) for problem-solving ability in children of mothers in the third (168 to < 181 ng/g) and fourth quartiles (181 to 976 ng/g) were 1.08 (1.01 to 1.14) and 1.10 (1.04 to 1.17), respectively. Furthermore, communication, gross and fine motor skills, and problem-solving delays were also observed. However, prenatal Hg levels in maternal and cord blood and Se levels in the latter were not associated with neurodevelopmental delays in children. Thus, the findings of this study suggest an association between Se levels in maternal blood and slightly increased risks of neurodevelopmental delays in children up to the age of 4 years.
• Association between maternal caffeine intake during pregnancy and child development at 6 and 12 months: The Japan Environment and Children's Study
  Shinkichi Nishihara; Sumitaka Kobayashi; Atsuko Ikeda-Araki; Chihiro Miyashita; Sachiko Itoh; Keiko Yamazaki; Yu Ait Bamai; Naomi Tamura; Hideyuki Masuda; Mariko Itoh; Yasuaki Saijo; Yoshiya Ito; Reiko Kishi
  Early Human Development, 171, 105607, 105607, Elsevier BV, Jun. 2022, [International Magazine]
  English, Scientific journal, BACKGROUND: Caffeine intake by pregnant women may have neurodevelopmental effects on the fetus due to adenosine antagonism. However, there are insufficient data and inconsistent results from epidemiological studies on the effect of maternal caffeine intake on child development. AIMS: This study examined the association between mothers' estimated caffeine intake during pregnancy and their children's score on the Japanese version of the Ages & Stages Questionnaires™ (J-ASQ) at 6 and 12 months of age. STUDY DESIGN: The study is a part of nationwide prospective birth-cohort study: the Japan Environment and Children's Study. SUBJECTS: In total, 87,106 participants with the Food Frequency Questionnaire (FFQ) data and J-ASQ at 6 or 12 months of age were included in the study. OUTCOME MEASURES: The data were analyzed by logistic regression analysis to determine whether the scores of the five subscales on the J-ASQ were below the cutoff point as the dependent variable. RESULTS: The results showed that children born to mothers who consumed >300 mg caffeine per day had a 1.11-fold increased odds of gross motor developmental delay at 12 months of age (adjusted odds ratio [AOR] = 1.114 [95 % CI: 1.013-1.226]). CONCLUSIONS: Issues in gross motor development can emerge prior to future developmental issues. Therefore, further studies on developmental outcomes in older children, including the future outcomes of the children who participated in this study, are needed.
• 小児の携帯情報端末の使用開始年齢と問題行動の程度との関連 北海道スタディ
  宮下 ちひろ; 山崎 圭子; 田村 菜穂美; 池田 敦子; 福永 久典; 日景 隆; 水田 正弘; 大宮 学; 岸 玲子
  日本衛生学雑誌, 77, Suppl., S189, S189, (一社)日本衛生学会, Mar. 2022
  Japanese
• 子どものスクリーンタイムおよび問題行動との関連 北海道スタディ
  田村 菜穂美; 山崎 圭子; 宮下 ちひろ; 池田 敦子; 福永 久典; 日景 隆; 水田 正弘; 大宮 学; 岸 玲子
  日本衛生学雑誌, 77, Suppl., S189, S189, (一社)日本衛生学会, Mar. 2022
  Japanese
• 学童期における携帯電話等の電磁波曝露の実態調査 北海道スタディ
  山崎 圭子; 田村 菜穂美; 宮下 ちひろ; 池田 敦子; 福永 久典; 日景 隆; 水田 正弘; 大宮 学; 岸 玲子
  日本衛生学雑誌, 77, Suppl., S199, S199, (一社)日本衛生学会, Mar. 2022
  Japanese
• Hokkaido birth cohort study on environment and children’s health: cohort profile 2021
  Reiko Kishi; Atsuko Ikeda-Araki; Chihiro Miyashita; Sachiko Itoh; Sumitaka Kobayashi; Yu Ait Bamai; Keiko Yamazaki; Naomi Tamura; Machiko Minatoya; Rahel Mesfin Ketema; Kritika Poudel; Ryu Miura; Hideyuki Masuda; Mariko Itoh; Takeshi Yamaguchi; Hisanori Fukunaga; Kumiko Ito; Houman Goudarzi
  Environmental Health and Preventive Medicine, 26, 1, 59, 59, Springer Science and Business Media LLC, Dec. 2021, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Hypertensive Disorders during Pregnancy and Anthropometric Measurement of Children up to 7 Years of Age: The Hokkaido Birth Cohort Study in Japan.
  Kritika Poudel; Sumitaka Kobayashi; Chihiro Miyashita; Takeshi Yamaguchi; Naomi Tamura; Atsuko Ikeda-Araki; Yu Ait Bamai; Sachiko Itoh; Keiko Yamazaki; Hideyuki Masuda; Mariko Itoh; Reiko Kishi
  International journal of environmental research and public health, 18, 20, 18 Oct. 2021, [International Magazine]
  English, Scientific journal, Hypertensive disorders during pregnancy (HDP) increase the risk of offspring with a low birth weight, preterm birth and small-for-gestational age; however, evidence of the anthropometric measurements during early childhood remains limited. We aimed to understand the associations between maternal HDP and anthropometric measurements of children aged up to seven years in a Japanese cohort. In total, 20,926 mother-infant pairs participated in the Hokkaido Study on Environment and Children's Health, Japan, from 2002 to 2013. Medical reports were used to confirm HDP exposure, while weight, height, height z score, and weight z score were the outcomes. The prevalence of HDP in the study population was 1.7%. The birth height of male children born to HDP mothers was smaller as compared to those born to non-HDP mothers. When adjusted with covariates, the linear regressions showed significant changes in birth weight (β: -79.3; 95% confidence interval [CI]: -154.8, -3.8), birth height (-0.67; 95% CI: -1.07, -0.26), weight at seven years (1.21; 95% CI: 0.13, 2.29), and weight gain between four and seven years (1.12; 95% CI: 0.28, 1.96) of male children exposed to HDP. Differences were more significant in male children than female. Our study showed that despite low birth weight, male children exposed to HDP caught up with their growth and gained more weight by seven years of age compared with male children not exposed to HDP, whereas no such differences were observed in female children; however, this finding requires replication.
• Association between the Concentrations of Metallic Elements in Maternal Blood during Pregnancy and Prevalence of Abdominal Congenital Malformations: The Japan Environment and Children’s Study
  Chihiro Miyashita; Yasuaki Saijo; Yoshiya Ito; Atsuko Ikeda-Araki; Sachiko Itoh; Keiko Yamazaki; Sumitaka Kobayashi; Yu Ait Bamai; Hideyuki Masuda; Naomi Tamura; Mariko Itoh; Takeshi Yamaguchi; Shin Yamazaki; Reiko Kishi
  International Journal of Environmental Research and Public Health, 18, 19, 10103, 10103, MDPI AG, 26 Sep. 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Abdominal congenital malformations are responsible for early mortality, inadequate nutrient intake, and infant biological dysfunction. Exposure to metallic elements in utero is reported to be toxic and negatively impacts ontogeny. However, no prior study has sufficiently evaluated the effects of exposure to metallic elements in utero on abdominal congenital malformations. The aim of the present study was to evaluate associations between metallic elements detected in maternal blood during pregnancy and congenital abdominal malformations. Data from participants in the Japan Environment and Children’s Study was used in the present study, and contained information on singleton and live birth infants without congenital abnormalities (control: n = 89,134) and abdominal malformations (case: n = 139). Heavy metals such as mercury (Hg), lead (Pb), cadmium (Cd), and trace elements of manganese (Mn) and selenium (Se) were detected in maternal serum samples during mid- and late-gestation. Infant congenital abnormalities were identified from delivery records at birth or one month after birth by medical doctors. In a multivariate analysis adjusted to account for potential confounders, quartiles of heavy metals and trace elements present in maternal blood were not statistically correlated to the prevalence of abdominal congenital malformations at birth. This study is the first to reveal the absence of significant associations between exposure levels to maternal heavy metals and trace elements in utero and the prevalence of abdominal congenital malformations in a large cohort of the Japanese population. Further studies are necessary to investigate the impact of exposure to heavy metals and trace elements via maternal blood in offspring after birth.
• The protocol for the study about association between radio frequency wave and children's health: The Hokkaido study on environment and children's health
  Keiko Yamazaki; Atsuko Araki; Chihiro Miyashita; Naomi Tamura; Takashi Hikage; Manabu Omiya; Masahiro Mizuta; Reiko Kishi
  2021 34th General Assembly and Scientific Symposium of the International Union of Radio Science, URSI GASS 2021, 28 Aug. 2021
  International conference proceedings
• Hypertensive Disorders during Pregnancy (HDP), Maternal Characteristics, and Birth Outcomes among Japanese Women: A Hokkaido Study
  Kritika Poudel; Sumitaka Kobayashi; Chihiro Miyashita; Atsuko Ikeda-Araki; Naomi Tamura; Yu Ait Bamai; Sachiko Itoh; Keiko Yamazaki; Hideyuki Masuda; Mariko Itoh; Kumiko Ito; Reiko Kishi
  International Journal of Environmental Research and Public Health, 18, 7, 3342, 3342, MDPI AG, 24 Mar. 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Hypertension during pregnancy causes a greater risk of adverse birth outcomes worldwide; however, formal evidence of hypertensive disorders during pregnancy (HDP) in Japan is limited. We aimed to understand the association between maternal characteristics, HDP, and birth outcomes. In total, 18,833 mother-infant pairs were enrolled in the Hokkaido study on environment and children’s health, Japan, from 2002 to 2013. Medical records were used to identify hypertensive disorders and birth outcomes, namely, small for gestational age (SGA), SGA at full term (term-SGA), preterm birth (PTB), and low birth weight (LBW). The prevalence of HDP was 1.9%. Similarly, the prevalence of SGA, term-SGA, PTB, and LBW were 7.1%, 6.3%, 7.4%, and 10.3%, respectively. The mothers with HDP had increased odds of giving birth to babies with SGA (2.13; 95% Confidence Interval (CI): 1.57, 2.88), PTB (3.48; 95%CI: 2.68, 4.50), LBW (3.57; 95%CI: 2.83, 4.51) than normotensive pregnancy. Elderly pregnancy, low and high body mass index, active and passive smoking exposure, and alcohol consumption were risk factors for different birth outcomes. Therefore, it is crucial for women of reproductive age and their families to be made aware of these risk factors through physician visits, health education, and various community-based health interventions.
• 電波へのばく露による児の精神神経発達への影響に関する最近の研究動向:文献調査
  山崎圭子; 荒木敦子; 田村菜穂美; 寺岡友里; 日景隆; 水田正弘; 大宮学; 岸玲子
  Hokkaido Journal of Public Health, 34, 2, 14, 21, Mar. 2021, [Peer-reviewed]
  Japanese, Scientific journal
• Mediating Factors Between Parental Socioeconomic Status and Small for Gestational Age in Infants: Results from the Hokkaido Study on Environment and Children’s Health
  Naomi Tamura; Tomoyuki Hanaoka; Kumiko Ito; Atsuko Araki; Chihiro Miyashita; Sachiko Ito; Sumitaka Kobayashi; Yoichi Ito; Hisanori Minakami; Kazutoshi Cho; Toshiaki Endo; Tsuyoshi Baba; Kazuo Sengoku; Toshinobu Miyamoto; Katsuhiko Ogasawara; Reiko Kishi
  Maternal and Child Health Journal, 25, 4, 645, 655, Springer Science and Business Media LLC, 03 Jan. 2021, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal, OBJECTIVES: Previous studies indicated a significant association between small for gestational age (SGA) in infants and their parents' socioeconomic status (SES). Thus, this study aimed to examine if parental factors, such as maternal smoking, and the pre-pregnancy body mass index (BMI) could mediate the associations between parental SES and SGA. METHODS: The participants of this study were pregnant women who enrolled in an ongoing birth cohort study, the Hokkaido study, during the first trimester of their pregnancies. A total of 14,593 live singleton births were included in the statistical analysis, of which 1011 (6.9%) were SGA. Two structural equation models were employed to evaluate the associations between parental SES, parental characteristics, and SGA. RESULTS: The effect of low SES on SGA was directly mediated by maternal pre-pregnancy BMI, smoking during the third trimester, and alcohol consumption during the first trimester in the first model, which was based the assumption of independent associations between mediating factors. In the second model, which additionally considered the mediating factors from the first model, smoking during pregnancy mediated decline in parental SES, consequently increased SGA. Moreover, an increase in pregnancy smoking status increased the prevalence of lower maternal pre-pregnancy BMI and its effect on SGA. CONCLUSIONS FOR PRACTICE: In this study, we observed the independent mediating effect of maternal pre-pregnancy BMI, smoking, and alcohol consumption during pregnancy on low SES and, consequently, SGA, with the additional mediating pathway of SES to smoking to low BMI on SGA.
• Exposure to Radiofrequency Electromagnetic Field in the High-Frequency Band and Cognitive Function in Children and Adolescents: A Literature Review
  Toru Ishihara; Keiko Yamazaki; Atsuko Araki; Yuri Teraoka; Naomi Tamura; Takashi Hikage; Manabu Omiya; Masahiro Mizuta; Reiko Kishi
  International Journal of Environmental Research and Public Health, 17, 24, 9179, 9179, MDPI AG, 08 Dec. 2020, [Peer-reviewed], [International Magazine]
  English, Scientific journal, With increasing use of mobile phones, exposure to radiofrequency electromagnetic field (RF-EMF) in the high-frequency band associated with mobile phones has become a public concern, with potentially adverse effects on cognitive function in children and adolescents. However, findings regarding the relation of RF-EMF and cognitive function in children and adolescents have been inconsistent due to a number of study design-related factors, such as types of exposure and outcome measures, age of participants, and the era of study conduction. The present literature review focused on these possible factors that could explain this inconsistency. This review identified 12 eligible studies (participants ages 4 to 17 years) and extracted a total 477 relations. In total, 86% of the extracted relations were not statistically significant; in the remaining 14%, a negative relation between RF-EMF and cognitive performance was detected under limited conditions: when (1) RF-EMF was assessed using objective measurement not subjective measurement (i.e., questionnaire), (2) participants were relatively older (12 years and above) and had greater opportunity of exposure to RF-EMF, and (3) the collection of cognitive function data was conducted after 2012. Given that 86% of the extracted relations in this analysis were not statistically significant, the interpretation should be approached with caution due to the possibility of the 14% of significant relationships, extracted in this review, representing chance findings.
• Risk factors for motor coordination problems in preschool-age children.
  Satoshi Suyama; Kazuyori Yagyu; Atsuko Araki; Chihiro Miyashita; Sachiko Itoh; Machiko Minatoya; Keiko Yamazaki; Naomi Tamura; Akio Nakai; Takuya Saito; Reiko Kishi
  Pediatrics international : official journal of the Japan Pediatric Society, 62, 10, 1177, 1183, Oct. 2020, [Peer-reviewed], [International Magazine]
  English, Scientific journal, BACKGROUND: Motor coordination problems (MCP) in children can sometimes be diagnosed as developmental coordination disorder. Early intervention for developmental coordination disorder is necessary because it often continues into adolescence, causing mental and physical complications. Few studies have investigated the prevalence of childhood MCP in the Japanese population, examining the risk factors for MCP. We therefore investigated the prenatal factors associated with MCP in preschool-age children. METHODS: This study was based on a prospective cohort study, the Hokkaido Study on Environment and Children's Health. Mothers of 4,851 children who reached the age of 5 years within the study-period received questionnaires, including the Japanese version of the Developmental Coordination Disorder Questionnaire (DCDQ-J). We examined the risk factors associated with MCP using logistic regression analysis. RESULTS: Of 3,402 returned DCDQ-J questionnaires, 3,369 were answered completely. From the 3,369 children, we categorized having MCP by using two cut-off scores: that of the DCDQ'07 and the cut-off at the 5th percentile of a total DCDQ-J score. Comparing children with and without MCP, we found significant differences in the education level of the mothers, annual household income during pregnancy, maternal alcohol consumption and smoking during pregnancy, and sex and age of the children at the time of completing the DCDQ-J by both categorizations. Adjusted logistic regression analysis revealed that maternal smoking during the first trimester of pregnancy and male sex were significantly associated with MCP. CONCLUSIONS: Our results suggest that maternal smoking during pregnancy is the main factor associated with MCP in preschool-age children.
• Factors Influencing the Intention to Improve Lifestyle Habits and Visualization of Regionality
  Suzuki T; Tamura N; Enomoto H; Nagai W; Ogasawara K
  Japan Journal of Medical Informatics, 39, 2, 85, 98, Oct. 2019, [Peer-reviewed]
  Japanese, Scientific journal
• Association between maternal passive smoking and increased risk of delivering small-for-gestational-age infants at full-term using plasma cotinine levels from The Hokkaido Study: a prospective birth cohort.
  Sumitaka Kobayashi; Fumihiro Sata; Tomoyuki Hanaoka; Titilola Serifat Braimoh; Kumiko Ito; Naomi Tamura; Atsuko Araki; Sachiko Itoh; Chihiro Miyashita; Reiko Kishi
  BMJ open, 9, 2, e023200, 19 Feb. 2019, [Peer-reviewed], [International Magazine]
  English, Scientific journal, OBJECTIVES: To investigate the association between plasma cotinine level measured at the 8th gestational month and the delivery of small-for-gestational-age (SGA) infants, using a highly sensitive ELISA method. DESIGN: Prospective birth cohort study from The Hokkaido Study on Environment and Children's Health. SETTING: Hokkaido, Japan. PARTICIPANTS: Our sample included 15 198 mother-infant pairs enrolled in 2003-2012. MAIN OUTCOME MEASURES: SGA, defined as a gestational age-specific weight Z-score below -2. RESULTS: The number of SGA infants was 192 (1.3%). The cotinine cut-off level that differentiated SGA infants from other infants was 3.03 ng/mL for both the total population and the full-term births subgroup (sensitivity 0.307; positive predictive value 2.3%). Compared with infants of mothers with a plasma cotinine level of <3.03 ng/mL, infants of mothers with a plasma cotinine level of ≥3.03 ng/mL showed an increased OR for SGA in the total population and the full-term infant group (2.02(95% CI 1.45 to 2.83) and 2.44(95% CI 1.73 to 3.44), respectively). CONCLUSION: A plasma cotinine level of ≥3.03 ng/mL, which included both passive and active smokers, was associated with an increased risk of SGA. This finding is of important relevance when educating pregnant women about avoiding prenatal passive and active smoking due to the adverse effects on their infants, even those born at full-term.
• Prenatal exposure to bisphenol A and phthalates and behavioral problems in children at preschool age: the Hokkaido Study on Environment and Children's Health.
  Machiko Minatoya; Sachiko Itoh; Keiko Yamazaki; Atsuko Araki; Chihiro Miyashita; Naomi Tamura; Jun Yamamoto; Yu Onoda; Kazuki Ogasawara; Toru Matsumura; Reiko Kishi
  Environmental health and preventive medicine, 23, 1, 43, 43, 07 Sep. 2018, [Peer-reviewed], [International Magazine]
  English, Scientific journal, BACKGROUND: Studies reported adverse behavioral development including internalizing and externalizing problems in association with prenatal exposure to bisphenol A (BPA) and phthalates; however, findings were not sufficient due to using different assessment tools and child ages among studies. This study aimed to examine associations between maternal serum levels of BPA and phthalate metabolites and behavioral problems at preschool age. METHODS: The Strengths and Difficulties Questionnaire (SDQ) was used to assess behavioral problems at 5 years of age. BPA and phthalate metabolite levels in the first trimester maternal serum was determined by LC-MS/MS for 458 children. Variables used for adjustment were parental ages, maternal cotinine levels, family income during pregnancy, child sex, birth order, and age at SDQ completed. RESULTS: The median concentrations of BPA, MnBP, MiBP, MEHP, and MECPP, primary and secondary metabolites of phthalates, were 0.062, 26.0, 7.0, 1.40, and 0.20 ng/ml, respectively. MECPP level was associated with increase conduct problem risk (OR = 2.78, 95% CI 1.36-5.68) overall and the association remained after child sex stratification, and odds ratios were increased with wider confidence interval (OR = 2.85, 95% CI 1.07-7.57 for boys, OR = 4.04, 95% CI 1.31-12.5 for girls, respectively). BPA, ∑DBPm (MnBP + MiBP), and ∑DEHPm (MEHP+MECPP) levels were not associated with any of the child behavioral problems. CONCLUSIONS: Our analyses found no significant association between BPA or summation of phthalate metabolite levels and any of the behavioral problems at 5 years of age but suggested possible association between MECPP levels and increased risk of conduct problems.
• Association between maternal serum folate concentrations in the first trimester and the risk of birth defects: the Hokkaido Study of Environment and Children’s Health.
  Ito; Kumiko, Hanaoka; Tamura, Naomi; Naomi, Sasaki; Seiko, Miyashita; Chihiro, Araki; Atsuko, Itoh; Sachiko, Minakami; Hisanori, Cho; Kazutoshi, Endo; Toshiaki, Baba; Tsuyoshi, Miyamoto; Toshinobu, Sengoku; Kazuo, Tamakoshi; Akiko, Kishi; Reiko.
  Journal of Epidemiology., 29, 4, 164, 171, Apr. 2018, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, BACKGROUND: Low red blood cell folate concentrations during early pregnancy might cause neural tube defects. However, the association between folate concentrations and birth defects of other neural crest cell-derived organs remains unknown. We investigated the associations between birth defects and first-trimester serum folate concentrations in a birth-cohort study in Japan. METHODS: In total, 14,896 women who were prior to 13 weeks of gestation were enrolled from 2003 through 2012. Birth defect information was obtained from medical records and questionnaires. The association between folate levels in the first trimester and birth defects categorized as ICD-10 cord defects and neural crest cell-derived organ defects was examined. The crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) per log-transformed folate concentration were calculated using logistic regression. RESULTS: Blood samples were obtained at a mean of 10.8 weeks of gestation. Median serum folate level was 16.5 (interquartile range, 13.4-21.5) nmol/L, and the deficiency level (less than 6.8 nmol/L) was 0.7%. There were 358 infants with birth defects. The adjusted odds ratio for any birth defect, ventricular septal defects, and cleft lip was 0.99 (95% CI, 0.74-1.32), 0.63 (95% CI, 0.30-1.33), and 4.10 (95% CI, 0.96-17.58), respectively. There were no significant associations between first-trimester maternal serum folate and the risk of birth defects. CONCLUSIONS: We were unable to demonstrate a relationship between maternal serum folate in the first trimester and birth defects. Potential confounding factors may have influenced our results.
• 両親の教育歴と児のSmall for gestational ageとの媒介要因分析 北海道スタディ
  田村 菜穂美; 花岡 知之; 伊藤 久美子; 伊藤 佐智子; 宮下 ちひろ; 荒木 敦子; 小笠原 克彦; 岸 玲子
  日本衛生学雑誌, 73, Suppl., S244, S244, (一社)日本衛生学会, Mar. 2018
  Japanese
• Different risk factors for very low birth weight, term-small-for-gestational-age, or preterm Birth in Japan
  Naomi Tamura; Tomoyuki Hanaoka; Kumiko Ito; Atsuko Araki; Chihiro Miyashita; Sachiko Ito; Hisanori Minakami; Kazutoshi Cho; Toshiaki Endo; Kazuo Sengoku; Katsuhiko Ogasawara; Reiko Kishi
  International Journal of Environmental Research and Public Health, 15, 2, 369, MDPI AG, 21 Feb. 2018, [Peer-reviewed], [Lead author]
  English, Scientific journal
• 環境省「エコチル調査」開始4年を経ての集計結果の報告 全国と北海道の参加者の喫煙・食物アレルギー等について
  土川 陽子; 西條 泰明; 伊藤 善也; 吉岡 英治; 川西 康之; 堤 裕幸; 遠藤 俊明; 馬場 剛; 小林 正樹; 水上 尚典; 有賀 正; 長 和俊; 白石 秀明; 千石 一雄; 宮本 敏伸; 東 寛; 荒木 敦子; 池野 多美子; 宮下 ちひろ; 伊藤 佐智子; 湊屋 街子; 小林 澄貴; アイツバマイ ゆふ; 山崎 圭子; 西原 進吉; 田村 菜穂美; 岸 玲子
  北海道母性衛生学会誌, 45, 33, 38, 北海道母性衛生学会, Aug. 2016
  Japanese
• A Pilot Study Measuring Changes in Student Impressions before and after Clinical Training Using a Questionnaire Based on the Semantic Differential Technique
  Naomi Tamura; Takayoshi Terashita; Katsuhiko Ogasawara
  MEDINFO 2013: PROCEEDINGS OF THE 14TH WORLD CONGRESS ON MEDICAL AND HEALTH INFORMATICS, PTS 1 AND 2, 192, 1038, 1038, 2013, [Peer-reviewed]
  English, International conference proceedings

• Editor’s Focus: Prenatal metal concentrations and physical abnormalities
  Yuichi Nakamura; Sumitaka Kobayashi; Kazutoshi Cho; Sachiko Itoh; Chihiro Miyashita; Takeshi Yamaguchi; Hiroyoshi Iwata; Naomi Tamura; Yasuaki Saijo; Yoshiya Ito; Yoshitaka Seto; Ryota Honjo; Akiko Ando; Yuta Furuse; Atsushi Manabe; Reiko Kishi; The Japan Environment and Children’s Study (JECS) Group, Pediatric Research, 95, 7, 1663, 1663, Jun. 2024, [Invited], [International Magazine]
  掲載論文（責任著者）が、Pediatric Research Volume 95 No.7 June 2024のEditor's Focusに選出され紹介された。掲載論文：Nakamura Y, Kobayashi S, et al. Prenatal metal concentrations and physical abnormalities in the Japan Environment and Children’s Study. Pediatric Research. 2024; 95 (7): 1875-1882. https://doi.org/10.1038/s41390-023-02851-4, Springer Sciences and Business Media LLC, English, Introduction scientific journal
• SAR Evaluation for 5G Smartphones Using Child Phantom Models
  篭橋みのり; 日景隆; 西村寿彦; 柏達也; 山崎圭子; 田村菜穂美; 岸玲子, 電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM), 2024, 2024
• Numerical Estimation of Wi-Fi Frequency Band Receiving Characteristics for Portable Exposimeter for Epidemiological Research on High-Frequency Exposure and Child Health
  敦賀桜; 杉村海渡; 日景隆; 山崎圭子; 宮下ちひろ; 田村菜穂美; 荒木敦子; 岸玲子, 電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM), 2023, 2023
• 子どものスクリーンタイムと聴覚・視覚ワーキングメモリーとの関連:北海道スタディ
  田村菜穂美; 山崎圭子; 宮下ちひろ; 池田敦子; 池田敦子; 日景隆; 水田正弘; 大宮学; 竹鼻美月; 赤坂梨莉花; 岸玲子, 日本衛生学雑誌(Web), 78, Supplement, 2023
• 学童期の子どもの電磁波曝露実態の変化-北海道スタディ
  山崎圭子; 宮下ちひろ; 田村菜穂美; 池田敦子; 池田敦子; 日景隆; 水田正弘; 大宮学; 岸玲子, 日本衛生学雑誌(Web), 78, Supplement, 2023
• Human Body Blockage Characteristics Estimation on Personal Exposure Meter for Epidemiologic Research on RF Exposure and Adolescent Health
  杉村海渡; 山本康平; 日景隆; 山崎圭子; 田村菜穂美; 宮下ちひろ; 岸玲子, 電子情報通信学会論文誌 B(Web), J106-B, 8, 2023
• Estimation of Human Body Blockage Effects on Portable Exposure Meter for Epidemiological Studies on Radio Wave Exposure and Health Effects in Adolescents
  山本康平; 日景隆; 大宮学; 山崎圭子; 池田敦子; 宮下ちひろ; 田村菜穂美; 岸玲子, 電子情報通信学会大会講演論文集(CD-ROM), 2022, 2022
• Estimation of Human Body Blockage Characteristics Considering Elevation Angle of Plane-wave for RF Dosimetry of Adolescent
  杉村海渡; 山本康平; 日景隆; 山崎恵子; 宮下ちひろ; 田村菜穂美; 荒木敦子; 岸玲子, 電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM), 2022, 2022
• 小児の携帯情報端末の使用開始年齢と問題行動の程度との関連-北海道スタディ
  宮下ちひろ; 山崎圭子; 田村菜穂美; 池田敦子; 池田敦子; 福永久典; 日景隆; 水田正弘; 大宮学; 岸玲子, 日本衛生学雑誌(Web), 77, Supplement, 2022
• 学童期における携帯電話等の電磁波曝露の実態調査-北海道スタディ
  山崎圭子; 田村菜穂美; 宮下ちひろ; 池田敦子; 池田敦子; 福永久典; 日景隆; 水田正弘; 大宮学; 岸玲子, 日本衛生学雑誌(Web), 77, Supplement, 2022
• 子どものスクリーンタイムおよび問題行動との関連:北海道スタディ
  田村菜穂美; 山崎圭子; 宮下ちひろ; 池田敦子; 池田敦子; 福永久典; 日景隆; 水田正弘; 大宮学; 岸玲子, 日本衛生学雑誌(Web), 77, Supplement, 2022
• 胎児期の受動喫煙曝露が正期産のSmall-for-gestational-age（SGA）に及ぼす影響：前向き出生コーホート研究（北海道スタディ）
  小林澄貴; 佐田文宏; 花岡知之; チチローラ・ブライモー; 伊藤久美子; 田村菜穂美; 荒木敦子; 伊藤佐智子; 宮下ちひろ; 岸玲子, 北海道公衆衛生学雑誌, 33, 2, 10, 12, 2019, [Invited], [Domestic magazines]
  Japanese, Introduction scientific journal
• 両親の教育歴と児のSmall for gestational ageとの媒介要因分析 北海道スタディ
  田村 菜穂美; 花岡 知之; 伊藤 久美子; 伊藤 佐智子; 宮下 ちひろ; 荒木 敦子; 小笠原 克彦; 岸 玲子, 日本衛生学雑誌, 73, Suppl., S244, S244, Mar. 2018
  (一社)日本衛生学会, Japanese
• 両親の教育歴と児のSmall for gestational ageとの媒介要因分析:北海道スタディ
  田村菜穂美; 田村菜穂美; 花岡知之; 伊藤久美子; 伊藤久美子; 伊藤佐智子; 宮下ちひろ; 荒木敦子; 小笠原克彦; 小笠原克彦; 岸玲子, 日本衛生学雑誌(Web), 73, Supplement, S244, Mar. 2018
  Japanese
• [Importance of Two Birth Cohorts (n=20,926 and n=514): 15 Years' Experience of the Hokkaido Study on Environment and Children's Health: Malformation, Development and Allergy].
  Reiko Kishi; Atsuko Araki; Chihiro Miyashita; Sachiko Itoh; Machiko Minatoya; Sumitaka Kobayashi; Keiko Yamazaki; Yu Ait Bamai; Ryu Miura; Naomi Tamura, Nihon eiseigaku zasshi. Japanese journal of hygiene, 73, 2, 164, 177, 2018, [Peer-reviewed], [Domestic magazines]
  Since "Our Stolen Future" by Theo Colborn was published in 1996, global interest on the impact of chemical substances, such as the endocrine-disrupting action of chemicals, has increased. In Japan, "The Hokkaido Study on Environment and Children's Health: Malformation, Development and Allergy" was launched in 2001. It was a model of Japan Environment and Children's Study of the Ministry of the Environment. In a large-scale, Hokkaido cohort, we obtained the consent of 20,926 mothers at the organogenesis stage with the cooperation of 37 obstetrics clinics in Hokkaido. We tracked the effects of endocrine disruptors on developmental disorders. In a small-scale Sapporo cohort, we observed in detail the neuropsychiatric development of children with the consent of 514 mothers in their late pregnancy. We examined how prenatal exposure to low concentrations of environmental chemicals affect the development of organs and the postnatal development of children. Maternal exposure to POPs, such as PCB/dioxins and perfluorinated alkyl substances, has affected not only children's birth size, thyroid functions, and sex hormone levels, but also postnatal neurodevelopment, infection, and allergy among others. The associations of short-half-life substances, such as DEHP and BPA, with obesity, ASD, and ADHD have been investigated. Gene-environment interactions have been found for smoking, caffeine, folic acid, and PCB/dioxin. In 2015, our center was officially designated as the WHO Collaborating Centre for Environmental Health and Prevention of Chemical Hazards, and we continue to the contribute to the global perspectives of child health., Japanese
• 北海道のエコチル調査の集計結果 生後2歳までの食物アレルギーの頻度および食品の摂食状況について
  アイツバマイ ゆふ; 西條 泰明; 伊藤 善也; 村林 宏; 吉岡 英治; 川西 康之; 水上 尚典; 有賀 正; 長和 俊; 白石 秀明; 千石 一雄; 宮本 敏伸; 東 寛; 堤 裕幸; 遠藤 俊明; 馬場 剛; 小林 正樹; 荒木 敦子; 池野 多美子; 宮下 ちひろ; 伊藤 佐智子; 土川 陽子; 湊屋 街子; 小林 澄貴; 山崎 圭子; 西原 進吉; 田村 菜穂美; 岸 玲子, 北海道公衆衛生学雑誌, 29, 1特別付録, 36, 36, Nov. 2015
  北海道公衆衛生学会, Japanese
• 児の出生体重と母親の社会経済要因との関連についての疫学研究 北海道スタディ
  田村 菜穂美; 伊藤 久美子; 花岡 知之; 喜多 歳子; 西原 進吉; 宮下 ちひろ; 荒木 敦子; 小笠原 克彦; 岸 玲子, 日本衛生学雑誌, 70, Suppl., S190, S190, Mar. 2015
  (一社)日本衛生学会, Japanese
• 環境省「エコチル調査」北海道ユニットセンターにおけるこれまでの活動報告
  荒木 敦子; 伊藤 善也; 西條 泰明; 池野 多美子; 宮下 ちひろ; 伊藤 佐智子; 土川 陽子; 田村 菜穂美; 湊屋 街子; 吉岡 英治; 川西 康之; 村林 宏; 岸 玲子, 環境ホルモン学会研究発表会要旨集, 17回, 65, 65, Dec. 2014
  環境ホルモン学会(日本内分泌撹乱化学物質学会), Japanese
• 胎児期の有機塩素系農薬が小児アレルギー発症に与える影響 環境と子どもの健康北海道スタディ
  宮下 ちひろ; 金澤 文子; 池野 多美子; 荒木 敦子; 伊藤 佐智子; 小林 澄貴; 湊屋 街子; Goudarzi Houman; 小林 祥子; 田村 菜穂美; 水谷 太; 苣木 洋一; 岸 玲子, 北海道公衆衛生学雑誌, 28, 1特別付録, 44, 44, Dec. 2014
  北海道公衆衛生学会, Japanese
• 北海道3地区における妊婦の食習慣・運動習慣の実態について 環境省「子どもの健康と環境に関する全国調査(エコチル調査)」 北海道ユニットセンター登録者のデータから
  湊屋 街子; 西條 泰明; 伊藤 善也; 荒木 敦子; 池野 多美子; 宮下 ちひろ; 伊藤 佐智子; 小林 澄貴; 土川 陽子; 田村 菜穂美; 吉岡 英治; 川西 康之; 村林 宏; 岸 玲子; エコチル調査北海道ユニットセンター事務局, 北海道公衆衛生学雑誌, 28, 1特別付録, 57, 57, Dec. 2014
  北海道公衆衛生学会, Japanese
• 児の出生体重と母親の社会経済要因との関連についての疫学研究
  田村 菜穂美; 伊藤 久美子; 小林 澄貴; 岡田 恵美子; 喜多 歳子; ホウマヌ・ゴウダルジ; 宮下 ちひろ; 荒木 敦子; 池野 多美子; 岸 玲子, 日本衛生学雑誌, 69, Suppl., S204, S204, May 2014
  (一社)日本衛生学会, Japanese

• 日本における両親の社会経済要因と子どもの在胎週数および出生体重：共分散構造分析で何がわかったか？
  田村 菜穂美; 統計数理研究所医療健康データ科学研究センター
  第90回日本衛生学会学術総会, 28 Mar. 2020, Japanese, Others
  盛岡市 日本, [Domestic Conference]
• エコチル調査北海道ユニットセンターに登録した両親の特徴と出生アウトカムの集計結果.
  田村 菜穂美; 北海道大学環境健康科学研究教育センター; 西條 泰明; 旭川; 伊藤 善也; 日本赤十; 千石 一雄; 川; 吉岡 英二; 川; 川西 康之; 川; 遠藤 俊明; 幌; 馬場 剛; 札幌医; 村林 宏; 日本赤十字; 学; 水上 尚典; 北海; 長 和俊; 北海道; 荒木 敦子; 北海道大学環境健康科学研究教育センター; 伊藤 佐智子; 北海道大学環境健康科学研究教育センター; 宮下 ちひろ; 北海道大学環境健康科学研究教育センター; 湊屋 街子; 北海道大学環境健康科学研究教育センター; 小林 澄貴; 北海道大学環境健康科学研究教育センター; 山崎 圭子; 北海道大学環境健康科学研究教育センター; アイツバマイ ゆふ; 北海道大学環境健康科学研究教育センター; 三浦 りゅう; 北海道大学環境健康科学研究教育センター; 岸 玲子; 北海道大学環境健康科学研究教育センター
  第16回北海道周産期談話会., 18 Aug. 2018, Japanese, Oral presentation
  札幌市 日本, [Domestic Conference]

• 大学院共通授業科目（教育プログラム）：社会と健康, 2024年, 修士課程, 大学院共通科目

• Epidemiological Study on the Effects of Radio Frequency Electromagnetic Fields on Adolescents
  Studies and Evaluation Technologies for Ensuring the Security of Radio Waves
  Aug. 2024 - Mar. 2030
  Ministry of Internal Affairs and Communications of Japan, Hokkaido University, Principal investigator, JPMI10001
• Impact of Chemical Exposure on Reproductive Health from Fetal Life: Unraveling Molecular Mechanisms
  Grants-in-Aid for Scientific Research
  01 Apr. 2025 - 31 Mar. 2029
  岸 玲子; アイツバマイ ゆふ; 山口 健史; 伊藤 佐智子; 岩田 啓芳; 牧野 圭太郎; 田村 菜穂美; 馬場 剛; 齊藤 良玄; 江口 哲史; 今 雅史; 村西 雄貴; 平田 由里絵
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 25H01076
• Validation of a Japanese Version of a Screening Tool for Adolescent Depression Based on a Birth Cohort Study.
  Grants-in-Aid for Scientific Research
  01 Apr. 2025 - 31 Mar. 2028
  田村 菜穂美; 齊藤 卓弥; 須山 聡; 東條 真希
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 25K06793
• A Study of Social Norm Formation Mechanisms in Suicide Scarce Areas: A Natural Experimental Approach
  Grants-in-Aid for Scientific Research
  01 Apr. 2024 - 31 Mar. 2027
  岡 檀; 織田澤 利守; 山内 慶太; 大塚 尚; 大平 悠季; 田村 菜穂美
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), The Institute of Statistical Mathematics, 24K13329
• 化学物質の次世代影響-出生から青年期の脂質代謝やエピゲノムの作用機序
  科学研究費助成事業
  01 Apr. 2023 - 31 Mar. 2026
  宮下 ちひろ; 池田 敦子; 田村 菜穂美; 山口 健史; 惠 淑萍
  日本学術振興会, 基盤研究(C), 北海道大学, 23K09641
• Effects of exposure to environmental chemicals on adolescent reproductive function, depression, and NCDs in the Hokkaido Study: Clarification of molecular mechanism
  Grants-in-Aid for Scientific Research
  01 Apr. 2022 - 31 Mar. 2026
  岸 玲子; 宮下 ちひろ; 小林 澄貴; 伊藤 佐智子; 山崎 圭子; アイツバマイ ゆふ; 山口 健史; 田村 菜穂美; 齊藤 卓弥
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 22H00489
• A longitudinal study for neurodevelopment in childhood and depression in adolescence: a prospective birth cohort
  Grants-in-Aid for Scientific Research
  01 Apr. 2022 - 31 Mar. 2025
  田村 菜穂美
  本研究は日本における子どもの幼少期・学童期の問題行動・発達障害傾向と思春期の抑うつ傾向との関連を縦断的に明らかにすることを目的とする。研究対象者は、前向き出生コホート研究である「環境と子どもの健康に関する研究・北海道スタディ」に参加者する子どもとその親に質問票調査を行う。14～15歳の子どもの抑うつ、不安、双極性障害の傾向を目的変数として、出生コホート研究にてそれ以前に収集した子どもの問題行動・発達障害傾向などの軌跡との関連を縦断的に一般化線形混合モデルで解析する予定である。思春期の抑うつ傾向とそれ以前の発達障害傾向との関連を検討することにより、青年期に継続する疾病と社会的予後の向上を図る。
  本対象集団では、子どもが5歳、6歳、8歳の時点での発達障害および問題行動の傾向に関する情報を質問票調査にて収集済みである。加えて12歳時点の発達障害の傾向を追跡するため、調査対象者の保護者に対して質問票調査を実施する。発達障害傾向は、標準化された調査票であるADHD-RS（Attention Deficit Hyperactivity Disorder-Rating Scale）を用いて評価する。
  抑うつ傾向については、14～15歳の子ども本人とその親に対して調査を実施する。子ども本人からは、標準化されたうつ病・不安障害などの精神疾患スクリーニングと、向社交性について質問票を用いて測定する。また、抑うつ傾向の予防因子として知られている身体的運動や相談できる相手の存在などの利用可能なソーシャルキャピタルの測定を検討している。親への質問項目としては、親から見た子どもの精神神経発達状況をSDQで測定する。また、子どもの抑うつ傾向の重要なリスク要因となる親本人の抑うつ傾向および健康状態についても測定する。
  Japan Society for the Promotion of Science, Grant-in-Aid for Early-Career Scientists, Hokkaido University, 22K17361
• Association between maternal passive smoking during pregnancy and delay of fetal growth with child growth after birth: Gene-environment interaction
  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
  Apr. 2020 - Mar. 2023
  KOBAYASHI Sumitaka
  Using a prospective birth cohort study of the Hokkaido Study on Environment and Children's Health in Japan, we examined the associations between prenatal passive smoking and child growth until 12 years, including gene-environment interactions. There was a small difference in weight gain between children born to passive and active smokers during pregnancy from the third and fourth grade of elementary school. In addition, it was suggested that metabolizing-enzyme gene polymorphisms in children may be involved to a slight in the mechanism by which prenatal passive smoking affects weight gain in elementary school children.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 20K10445
• Trajectory of children's neurodevelopment from preschool to post-school and developmental support
  Grants-in-Aid for Scientific Research
  Apr. 2019 - Mar. 2022
  Tamura Naomi
  The purpose of this study was to provide epidemiological evidence for early diagnosis and support in children with developmental disabilities in Japan. A birth cohort study was used to examine the relationship between children's developmental disabilities and support systems. We sent the Strength and Difficulties Questionnaire (SDQ) as well as a questionnaire on developmental support received to date to 5,221 children aged 7-17 years in FY2020. Of these 3,332 were returned, response rate 63.8%. IN FY 2021, we also sent the Attention Deficit Hyperactivity Disorder (ADHD) questionnaire to 2,325 eligible children aged 12 years and 1,502 were returned, response rate 64.6%. Of the children determined as having a possible need for support based on the results of the SDQ, 93 (33.0%) boys and 39 (19.1%) girls utilized support. This difference was significant (p < 0.01).
  Japan Society for the Promotion of Science, Grant-in-Aid for Early-Career Scientists, Competitive research funding, 19K14169
• Development and evaluation of program to improve nurse's assessment ability cooperating with hospital at home health consultation
  Grants-in-Aid for Scientific Research
  01 Apr. 2015 - 31 Mar. 2018
  Yoshimura Sadako; SUZUKI Teppei; TSUTSUMI Kaori; TAKAHASHI Noriko; SAMUKAWA Mina; TAMURA Naomi; SATOH Hitomi; FUNAKI Noriko; NIIOKA Ikuko
  In order to improve the assessment ability of nurses, it is necessary to progress the ability to collect information on health consultation applicants and to improve accurate analytical skills. We developed a data management system that protects personal information. In this study, the data collected were BMI of local residents who need to have remote health consultation, body composition such as muscle mass, self-collected blood data and daily life habits etc. These data were shared by home nurse in charge of consultation and resident through the screen. The simulation training of analysis of each data by home nurse was efficient and effective in interview and inspection by home nurse while sharing data with remote health consultation applicant.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 15H05062