Search

Background: Previous studies have revealed that current secondhand smoke exposure showed highly suggestive evidence for increased risk of simultaneous sleep problems in children. Data on the associations between early-life exposure to SHS with subsequent sleep problems in children were scarce. We aimed to evaluate the associations of early-life SHS exposure with sleep problems in children. Methods: In this cross-sectional study, children were recruited from elementary and middle schools in Liaoning Province, China between April 2012 and January 2013. We assessed early-life SHS exposure (pregnancy and the first 2 years of life) via questionnaires. Sleep problems and different types of sleep-related symptoms were measured based on the validated tool of the Sleep Disturbance Scale for Children (SDSC). Generalized linear mixed models were applied to estimate the associations of early-life SHS exposure with sleep problems. Results: We included a total of 45,562 children (22,657 [49.7%] males; mean [SD] age, 11.0 [2.6] years) and 6167 of them (13.5%) were exposed to early-life SHS during both pregnancy and the first 2 years of life. Compared with unexposed counterparts, children exposed to early-life SHS had higher total T-scores of SDSC (β = 4.32; 95%CI: 4.06, 4.58) and higher odds of increased sleep problems (OR = 2.14; 95%CI: 1.89, 2.42). When considering different sleep-related symptoms, the associations between early-life SHS exposure and symptom of sleep-wake transition disorders (i.e., bruxism) were the strongest in all analyses. Conclusions: Early-life SHS exposure was associated with higher odds of global sleep problems and different sleep-related symptoms in children aged 6–18 years. Our findings highlight the importance to strengthen efforts to support the critical importance of maintaining a smoke-free environment especially in early life. [ABSTRACT FROM AUTHOR]

Although ozone exposure has neurological toxicity, it remains unclear whether it was associated with an increased risk of attention-deficit/hyperactivity disorders (ADHD) among childhood. We matched the four-year average ozone concentration with questionnaire data for 35,103 children aged 3–12 years from seven cities in Liaoning, China, 2012–2013. Using mixed-effect logistic regression models, we assessed the association of ozone concentration with multiple ADHD indicators using the Conners Abbreviated Symptom Questionnaire (C-ASQ), including explicit attention-deficit/hyperactivity symptoms (ADHD; score ≥15), attention-deficit/hyperactivity disorder tendencies (ADHD-T; 11 ≤ score ≤14), and attention-deficit/hyperactivity problems (ADHP; score ≥11). Results were also stratified by sociodemongraphics. After adjusting for covariates, we found that each interquartile range (IQR) increase in ozone concentration was associated with an increased risk of ADHD, ADHD-T, and ADHP (P < 0.001) with an odds ratio of 1.12 (95% confidence interval, 1.04–1.21), 1.08 (1.03–1.13), and 1.09 (1.05–1.14), respectively. Additionally, we found greater effect estimates in children who reported longer exercise time (vs those with limited exercise time) with odds ratio of 1.18 (1.07–1.31) vs 1.06 (0.96–1.17) for ADHD, 1.13 (1.06–1.21) vs 1.03 (0.96–1.10) for ADHD-T, and 1.15 (1.08–1.21) vs 1.04 (0.98–1.10) for ADHP. Non-breastfed children were also shown to be more vulnerable to ADHD with an odds ratio of 1.22 (1.09–1.36) compared with 1.06 (0.96–1.16) among the rest. Long-term ozone exposure may be associated with increased ADHD among children. Additional studies are needed to validate our findings and support policies and interventions to address this growing public health concern. [Display omitted] • Ozone was associated with children attention-deficit/hyperactivity disorders (ADHD). • Children with symptoms but not reaching the diagnostic criteria had similar results. • Non-breastfed children and those who exercise frequently are the most vulnerable. [ABSTRACT FROM AUTHOR]