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.
Subject(s)
Child , Child, Preschool , Female , Humans , Infant , Male , Pregnancy , Biomarkers/blood , Child Health , Cohort Studies , Environmental Exposure/adverse effects , Environmental Health , Environmental Pollutants/adverse effects , Fetal Blood/chemistry , Follow-Up Studies , Growth/drug effects , Hypersensitivity/etiology , Japan/epidemiology , Neurodevelopmental Disorders/etiology , Prenatal Exposure Delayed Effects/etiology , Prevalence , Smoking/adverse effectsABSTRACT
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.