Alterations in plasma short-chain fatty acids in preadolescence children: The Hokkaido study
Yonghan Li, Siddabasave Gowda B. Gowda, Divyavani Gowda, Atsuko Ikeda, Yu Ait Bamai, Rahel Mesfin Ketema, Reiko Kishi, Hitoshi Chiba, Shu-Ping Hui
Journal of Chromatography B, 1242, 124191, 124191, Elsevier BV, Jul. 2024
Scientific journal

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, Elsevier BV, Jan. 2024
Scientific journal

Exposure to organophosphate flame retardants and plasticizers is positively associated with wheeze and FeNO and eosinophil levels among school-aged children: The Hokkaido study
Yi Zeng, Houman Goudarzi, Yu Ait Bamai, Rahel Mesfin Ketema, Maarten Roggeman, Fatima den Ouden, Celine Gys, Chihiro Miyashita, Sachiko Ito, Satoshi Konno, Adrian Covaci, Reiko Kishi, Atsuko Ikeda-Araki
Environment International, 181, 108278, 108278, Elsevier BV, Nov. 2023
Scientific journal

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, Springer Science and Business Media {LLC}, Dec. 2021
English, Scientific journal, Abstract
Background
The Hokkaido Study on Environment and Children’s Health is an ongoing study consisting of two birth cohorts of different population sizes: the Sapporo cohort and the Hokkaido cohort. Our primary objectives are to (1) examine the effects that low-level environmental chemical exposures have on birth outcomes, including birth defects and growth retardation; (2) follow the development of allergies, infectious diseases, and neurobehavioral developmental disorders, as well as perform a longitudinal observation of child development; (3) identify high-risk groups based on genetic susceptibility to environmental chemicals; and (4) identify the additive effects of various chemicals, including tobacco.

Methods
The purpose of this report is to provide an update on the progress of the Hokkaido Study, summarize recent results, and suggest future directions. In particular, this report provides the latest details from questionnaire surveys, face-to-face examinations, and a collection of biological specimens from children and measurements of their chemical exposures.

Results
The latest findings indicate different risk factors of parental characteristics on birth outcomes and the mediating effect between socioeconomic status and children that are small for the gestational age. Maternal serum folate was not associated with birth defects. Prenatal chemical exposure and smoking were associated with birth size and growth, as well as cord blood biomarkers, such as adiponectin, leptin, thyroid, and reproductive hormones. We also found significant associations between the chemical levels and neuro development, asthma, and allergies.

Conclusions
Chemical exposure to children can occur both before and after birth. Longer follow-up for children is crucial in birth cohort studies to reinforce the Developmental Origins of Health and Disease hypothesis. In contrast, considering shifts in the exposure levels due to regulation is also essential, which may also change the association to health outcomes. This study found that individual susceptibility to adverse health effects depends on the genotype. Epigenome modification of DNA methylation was also discovered, indicating the necessity of examining molecular biology perspectives. International collaborations can add a new dimension to the current knowledge and provide novel discoveries in the future.

Secular trends of urinary phthalate metabolites in 7-year old children and association with building characteristics: Hokkaido study on environment and children's health
Rahel Mesfin Ketema, Yu Ait Bamai, Atsuko Ikeda-Araki, Takeshi Saito, Reiko Kishi
International Journal of Hygiene and Environmental Health, 234, 113724, 113724, Elsevier {BV}, May 2021
English, Scientific journal

Lifestyle behaviors and home and school environment in association with sick building syndrome among elementary school children: a cross-sectional study
Rahel Mesfin Ketema, Atsuko Araki, Yu Ait Bamai, Takeshi Saito, Reiko Kishi
Environmental Health and Preventive Medicine, 25, 1, Springer Science and Business Media {LLC}, Dec. 2020
English, Scientific journal, Abstract
Background
Sick building syndrome (SBS) refers to the combination of symptoms experienced by occupants of specific building characteristics. This study investigated the associations of children’s lifestyle behaviors, allergies, home, and school environment with SBS symptoms.

Methods
A total of 4408 elementary school children living in Sapporo City, Japan participated in this study. SBS was determined on parental answers to MM080 standardized school questionnaires on symptoms that were weekly experienced by these children, and if the symptom is attributed to their home or school environment. The Japanese version of the International Study of Asthma and Allergies in Childhood questionnaire was used to assess wheeze, rhino-conjunctivitis, and eczema. A logistic regression analysis was conducted to evaluate the associations between SBS symptoms and variables by controlling the potential confounders (gender, grade, school, and parental history of allergies). A stepwise backward elimination was conducted to assess independent variables related to SBS.

Results
Participants revealed mucosal (6.9%), skin (2.0%), and general (0.8%) symptoms. The presence of one or more allergy was associated with increased mucosal and skin symptoms. Children who skipped breakfast, displayed faddiness (like/dislike of food), had constipation, have insufficient sleep, did not feel refreshed after sleep, and lacked deep sleep showed significantly high odds ratios with SBS symptoms. The stepwise analysis showed faddiness for mucosal symptoms and not feeling refreshed after sleep for mucosal and skin symptoms, whereas constipation and lacking deep sleep for general symptoms were independent variables in increasing the symptoms. We found no significant relationship between SBS in children and schools. Considering children’s home, old building, no ventilation, wall-to-wall carpet, and heavy nearby traffic were associated with elevated mucosal symptom, while living in a multifamily home increased general symptoms. Home dampness was an independent variable in increasing all SBS symptoms.

Conclusions
Allergies and lifestyle behaviors were associated with increased SBS in children, including skipping breakfast, displaying faddiness, constipation, insufficient sleep, not feeling refreshed after sleep, and the lack of deep sleep. Further, dampness at home was associated with increase in all SBS symptoms. Lifestyle (e.g., eating and sleeping habits) and home (i.e., dampness) improvements might alleviate SBS symptoms in children.

Long-term effects of maternal resveratrol intake during lactation on cholesterol metabolism in male rat offspring
Shojiro Yamasaki, Tomomi Tomihara, Goh Kimura, Yukako Ueno, Rahel Mesfin Ketema, Shin Sato, Yuuka Mukai, Tajuddin Sikder, Masaaki Kurasaki, Toshiyuki Hosokawa, Takeshi Saito
International Journal of Food Sciences and Nutrition, 71, 2, 226, 234, Informa {UK} Limited, 17 Feb. 2020
English, Scientific journal

Polyphenol-enriched azuki bean (Vina angularis) extract reduces the oxidative stress and prevents DNA oxidation in the hearts of streptozotocin-induced early diabetic rats
Tomomi Kita-Tomihara, Shin Sato, Shojiro Yamasaki, Yukako Ueno, Goh Kimura, Rahel M. Ketema, Tae Kawahara, Masaaki Kurasaki, Takeshi Saito
International Journal of Food Sciences and Nutrition, 70, 7, 845, 855, Informa {UK} Limited, 03 Oct. 2019
English, Scientific journal

Associations between allergic symptoms and phosphate flame retardants in dust and their urinary metabolites among school children
Atsuko Araki, Michiel Bastiaensen, Yu Ait Bamai, Nele Van den Eede, Toshio Kawai, Tazuru Tsuboi, Rahel Mesfin Ketema, Adrian Covaci, Reiko Kishi
Environment International, 119, 438, 446, Elsevier {BV}, Oct. 2018
English, Scientific journal

Indoor environmental pollutants and their association with sick house syndrome among adults and children in elementary school
Reiko Kishi, Rahel Mesfin Ketema, Yu Ait Bamai, Atsuko Araki, Toshio Kawai, Tazuru Tsuboi, Ikue Saito, Eiji Yoshioka, Takeshi Saito
Building and Environment, 136, 293, 301, Elsevier {BV}, May 2018
English, Scientific journal

House Dust and Its Adverse Health Effects
Atsuko ARAKI, Yu AIT BAMAI, Rahel Mesfin KETEMA, Reiko KISHI
Nippon Eiseigaku Zasshi (Japanese Journal of Hygiene), 73, 2, 130, 137, Japanese Society for Hygiene, 2018
English, Scientific journal

Indoor environmental quality and health risk toward healthier environment for all
Kishi, Reiko, Norbäck, Dan, Araki, Atsuko
Springer, 2020, 9789813291812, viii, 333 p., English