Association Between Home Renovation and Sleeping Problems Among Children Aged 6-18 Years: A Nationwide Survey in China.

BACKGROUND: Although the indoor environment has been proposed to be associated with childhood sleep health, to our knowledge no study has investigated the association between home renovation and childhood sleep problems. METHODS: The study included 186,470 children aged 6-18 years from the National Chinese Children Health Study (2012-2018). We measured childhood sleeping problems via the Chinese version of the Sleep Disturbance Scale for Children (C-SDSC). Information on home renovation exposure within the recent 2 years was collected via parent report. We estimated associations between home renovation and various sleeping problems, defined using both continuous and categorized (binary) C-SDSC t-scores, using generalized mixed models. We fitted models with city as a random effect variable, and other covariates as fixed effects. RESULTS: Out of the overall participants, 89,732 (48%) were exposed to recent home renovations. Compared to the unexposed group, children exposed to home renovations had higher odds of total sleep disorder (odd ratios [OR] = 1.3; 95% confidence interval [CI] = 1.2, 1.4). Associations varied when we considered different types of home renovation materials. Children exposed to multiple types of home renovation had higher odds of sleeping problems. We observed similar findings when considering continuous C-SDSC t-scores. Additionally, sex and age of children modified the associations of home renovation exposure with some of the sleeping problem subtypes. CONCLUSIONS: We found that home renovation was associated with higher odds of having sleeping problems and that they varied when considering the type of renovation, cumulative exposure, sex, and age differences.

Association between long-term green space exposure and mortality in China: A difference-in-differences analysis of national data in 2000, 2010 and 2019.

BACKGROUND: Effects of green space on human health have been well-documented in western, high-income countries. Evidence for similar effects in China is limited. Moreover, the underlying mechanisms linking green space and mortality are yet to be established. We therefore conducted a nation-wide study to assess the association between green space and mortality in China using a difference-in-difference approach, which applied a causal framework and well controlled unmeasured confounding. In addition, we explored whether air pollution and air temperature could mediate the association. METHODS: In this analysis, we collected data on all-cause mortality and sociodemographic characteristics for each county in China from the 2000 and 2010 censuses and the 2020 Statistical Yearbook. Green space exposure was assessed using county-level normalized difference vegetation index (NDVI) and the percentage of green space (forest, grasslands, shrub land and wetland). We applied a difference-in-differences approach to evaluate the association between green space and mortality. We also performed mediation analysis (by air pollution and air temperature). RESULTS: Our sample consisted of 2726 counties in 2000 and 2010 as well as 1432 counties in 2019. In the 2000 versus 2019 comparison, a 0.1 unit increase in NDVI was associated with a 2.4 % reduction in mortality [95 % confidence interval (CI) 0.4-4.3 %], and a 10 % increase in percentage of green space was associated with a 4.7 % reduction (95 % CI 0-9.2 %) in mortality. PM2.5 and air temperature mediated 0.3 % to 12.3 % of the associations. CONCLUSIONS: Living in greener counties may be associated with lower risk of mortality in China. These findings could indicate the potential of a population-level intervention to reduce mortality in China, which has important public health implications at the county level.

The associations of particulate matter short-term exposure and serum lipids are modified by vitamin D status: A panel study of young healthy adults.

Particulate matter (PM) exposure is associated to the adverse change in blood lipids. Vitamin D is beneficial to lipid metabolism, but whether vitamin D levels modifies the impact of air pollutants on lipids is unclear. The purpose of the study was to investigate if vitamin D modifies the associations of PM and serum lipids in young healthy people. From December 2017 to January 2018, a panel study with five once weekly follow-ups was conducted on 88 healthy adults aged 21.09 (1.08) (mean (SD)) years on average in Guangzhou, China. We measured serum lipids, serum 25-hydroxyvitamin D (25(OH)D) concentrations (440 blood samples in total), mass concentrations of particulate matter with diameters ≤2.5 µm (PM2.5), ≤1.0 µm (PM1.0), and ≤0.5 µm (PM0.5), and number concentrations of particulate matter with diameters ≤0.2 µm (PN0.2) and ≤0.1 µm (PN0.1) at each follow-up. Linear mixed-effect models were applied to assess the interaction of vitamin D and size-fractionated PM short-term exposure on four lipid metrics. We found the interactions between 25(OH)D and size-fractionated PM exposure on blood lipids in different lags (lag 3 days and 4 days). An interquartile range increase in PM2.5, PM1.0, PM0.5 were significantly associated with increments of 12.30%, 12.99%, and 13.66% in triglycerides (TGs) at lag 4 days at vitamin D levels <15 ng/mL group, respectively. Similar results were found for PN0.2, PN0.1 and low-density lipoprotein cholesterol (LDL-C). All the associations between size-fractionated PM and blood lipids were found null statistically significant in vitamin D levels ≥15 ng/mL group.

Exposure to ambient particulate matter and hyperuricemia: An eight-year prospective cohort study on male traffic officers in China.

BACKGROUND AND OBJECTIVES: Studies on the effects of airborne particulates of diameter ≤ 1 µm (PM1), airborne particulates of diameter ≤ 2.5 µm (PM2.5) and airborne particulates of diameter ranges from 1 to 2.5 µm (PM1-2.5) on incidence of hyperuricemia are limited. We aimed to investigate the associations between PM1, PM2.5, and PM1-2.5 and hyperuricemia among male traffic officers. METHODS: We conducted a prospective cohort study of 1460 traffic officers without hyperuricemia in Guangzhou, China from 2009 to 2016. Exposures of PM1 and PM2.5 were estimated with a spatiotemporal model. PM1-2.5 concentrations were calculated by subtracting PM1 from PM2.5 concentrations. Cox's proportional hazards regressions models were used to examine the association between PM1, PM2.5, and PM1-2.5 and hyperuricemia, adjusted for potential confounders. Associations between PM1, PM2.5, and PM1-2.5 and serum uric acid (SUA) levels were evaluated with multiple linear regression models. RESULTS: Hazard ratios (HRs) and 95% confidence intervals (CIs) of hyperuricemia associated with 10 µg/m3 increment in PM1, PM2.5, and PM1-2.5 were 1.67 (95% CI:1.30-2.36), 1.49 (95% CI: 1.27-1.75), and 2.18 (95% CI: 1.58-3.02), respectively. The SUA concentrations increased by 12.23 µmol/L (95% CI: 5.91-18.56), 6.93 µmol/L (95% CI: 3.02-10.84), and 8.72 µmol/L (95% CI: 0.76-16.68) per 10 µg/m3 increase in PM1, PM2.5, and PM1-2.5, respectively. Stratified analyses indicated the positive associations of PM2.5 and PM1-2.5 with SUA levels were stronger in non-smokers, and PM1, PM2.5, and PM1-2.5 with SUA levels were stronger in non-drinkers. CONCLUSION: Long-term PM1, PM2.5, and PM1-2.5 exposures may increase the risk of hyperuricemia and elevate SUA levels among male traffic officers, especially in non-smokers and non-drinkers.

Living near greenness is associated with higher bone strength: A large cross-sectional epidemiological study in China.

BACKGROUND: Living near green spaces may benefit various health outcomes. However, no studies have investigated the greenness-bone linkage in the general population. Moreover, to which extent ambient air pollution (AAP), physical activity (PA), and body mass index (BMI) mediate this relationship remains unclear. We aimed to explore the association between greenness and bone strength and the potential mediating roles of AAP, PA, and BMI in Chinese adults. METHODS: This cross-sectional analysis enrolled 66,053 adults from the China Multi-Ethnic Cohort in 2018-2019. The normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI) were employed to define residential greenness. The calcaneus quantitative ultrasound index (QUI) was used to indicate bone strength. Multiple linear regression models and mediation analyses were used to estimate the residential greenness-bone strength association and potential pathways operating through AAP (represented by PM2.5 [particulate matter <2.5 µm in diameter]), PA, and BMI. Stratification analyses were performed to identify susceptible populations. RESULTS: Higher residential exposure to greenness was significantly associated with an increase in QUI, with changes (95% confidence interval) of 3.28 (3.05, 3.50), 3.57 (3.34, 3.80), 2.68 (2.46, 2.90), and 2.93 (2.71, 3.15) for every interquartile range increase in NDVI500m, NDVI1000m, EVI500m, and EVI1000m, respectively. Sex, urbanicity, annual family income, smoking, and drinking significantly modified the association of greenness-bone strength, with more remarkable associations in males, urban residents, subjects from wealthier families, smokers, and drinkers. For the NDVI500m/EVI500m-QUI relationship, the positive mediating roles of PM2.5 and PA were 6.70%/8.50 and 2.43%/2.69%, respectively, whereas those negative for BMI and PA-BMI were 0.88%/1.06% and 0.05%/0.05%, respectively. CONCLUSION: Living in a greener area may predict higher bone strength, particularly among males, urban residents, wealthier people, smokers, and drinkers. AAP, PA, BMI, and other factors may partially mediate the positive association. Our findings underscore the importance of optimizing greenness planning and management policies.

Outdoor light at night, overweight, and obesity in school-aged children and adolescents.

Previous studies have indicated that outdoor light at night (LAN) is associated with a higher prevalence of overweight or obesity in adults. However, the association of LAN levels with overweight or obesity in children is still unknown. This study utilized data from the Seven Northeastern Cities study, which included 47,990 school-aged children and adolescents (ages 6-18 years). Outdoor LAN levels were measured using satellite imaging data. Weight and height were used to calculate age-sex-specific body mass index (BMI) Z-scores based on the World Health Organization (WHO) growth standards. Overweight status and obesity were defined using the Chinese standard. Information regarding socioeconomic status, sleep-related characteristics, and obesogenic factors were obtained using a questionnaire. A generalized linear mixed model examined the associations of outdoor LAN levels (in quartiles) with the outcomes of interest. Compared to children in the lowest quartile of outdoor LAN levels, children exposed to higher outdoor LAN levels had larger BMI Z-scores and higher odds of being overweight (including obesity) or obese, with the largest estimates in the third quartile [BMI Z-score: ß = 0.26, 95% CI: 0.18-0.33; overweight (including obesity): OR = 1.40, 95% CI: 1.25-1.56; obesity: OR = 1.46, 95% CI: 1.29-1.65]. There was a significant sex difference (Pinteraction<0.001) in the association of outdoor LAN levels with BMI Z-scores, and the association was stronger in males. Results remained robust following multiple sensitivity analyses and the adjustment of sleep-related characteristics, obesogenic factors, and environmental exposures. Our findings suggest that higher outdoor LAN levels are associated with larger BMI Z-scores and greater odds of overweight (including obesity) and obesity in school-aged children and adolescents. Further, the association between outdoor LAN levels and BMI Z-scores is stronger in males. Future studies with exposure assessments that consider both outdoor and indoor LAN exposures are needed.

Long-term PM0.1 exposure and human blood lipid metabolism: New insight from the 33-community study in China.

Ambient particles with aerodynamic diameter <0.1 µm (PM0.1) have been suggested to have significant health impact. However, studies on the association between long-term PM0.1 exposure and human blood lipid metabolism are still limited. This study was aimed to evaluate such association based on multiple lipid biomarkers and dyslipidemia indicators. We matched the 2006-2009 average PM0.1 concentration simulated using the neural-network model following the WRF-Chem model with the clinical and questionnaire data of 15,477 adults randomly recruited from 33 communities in Northeast China in 2009. After controlling for social demographic and behavior confounders, we assessed the association of PM0.1 concentration with multiple lipid biomarkers and dyslipidemia indicators using generalized linear mixed-effect models. Effect modification by various social demographic and behavior factors was examined. We found that each interquartile range increase in PM0.1 concentration was associated with a 5.75 (95% Confidence interval, 3.24-8.25) mg/dl and a 6.05 (2.85-9.25) mg/dl increase in the serum level of total cholesterol and LDL-C, respectively. This increment was also associated with an odds ratio of 1.25 (1.10-1.42) for overall dyslipidemias, 1.41 (1.16, 1.73) for hypercholesterolemia, and 1.90 (1.39, 2.61) for hyperbetalipoproteinemia. Additionally, we found generally greater effect estimates among the younger participants and those with lower income or with certain behaviors such as high-fat diet. The deleterious effect of long-term PM0.1 exposure on lipid metabolism may make it an important toxic chemical to be targeted by future preventive strategies.

Street view greenness is associated with lower risk of obesity in adults: Findings from the 33 Chinese community health study.

BACKGROUND: Urban greenness may protect against obesity, but very few studies have assessed 'street view' (SV) greenness metrics, which may better capture people's actual exposure to greenness compared to commonly-used satellite-derived metrics. We aimed to investigate these associations further in a Chinese adult study. METHODS: Our analysis included 24,845 adults in the 33 Chinese Community Health Study in 2009. SV images from Tencent Map, segmented by machine learning algorithms, were used to determine the average proportion of green vegetation in SV images at community level in 800m road network buffer. Sensitivity analyses were performed with an alternative buffer size. Overall greenness was assessed as normalized difference vegetation index (NDVI) in 800 m buffer. We used predicted PM2.5 and monitored NO2 as proxies of air pollution. Body mass index (BMI), waist circumference (WC) and hip circumference (HC) were regressed on SV greenness by generalized linear mixed models, with adjustment for covariates. Mediation analyses were performed to assess the mediation effects of air pollution. RESULTS: Each interquartile range (IQR = 3.6%) increase in street view greenness was associated with a 0.15 kg/m2 (95% CI: -0.22, -0.09) decrease in BMI and 0.23 cm (95% CI: -0.35, -0.11) reduction in HC, and was associated with 7% lower odds of overweight (OR = 0.93, 95% CI:0.90, 0.96) and 18% lower odds of obesity (OR = 0.82, 95% CI:0.76, 0.89). Similar effect estimation was observed compared with commonly-used NDVI measures. PM2.5 and NO2 mediated 15.5% and 6.1% of the effects of SV greenness with BMI, respectively. CONCLUSIONS: Our findings suggest beneficial associations between community-level SV greenness and lower body weight in Chinese adults. The effects were observed in women but not in men. Air pollution may partially mediate the association. These findings may have implications to support efforts to promote greening in urban areas.

Association of Prenatal, Early Postnatal, or Current Exposure to Secondhand Smoke With Attention-Deficit/Hyperactivity Disorder Symptoms in Children.

Importance: Few studies have investigated the association between the exposure window (prenatal, early postnatal, and current period) of secondhand smoke (SHS) and attention-deficit/hyperactivity disorder (ADHD) symptoms and subtypes in children. Objective: To evaluate the associations of prenatal, early postnatal, or current SHS exposure with ADHD symptoms and subtypes among school-aged children. Design, Setting, and Participants: In this cross-sectional study, 48 612 children aged 6 to 18 years from elementary and middle schools in Liaoning province, China, between April 2012 and January 2013 were eligible for participation. Data on SHS exposure and ADHD symptoms and subtypes for each child were collected via questionnaires administered to parents or guardians by school teachers. Data were analyzed from September 14 to December 2, 2020. Main Outcomes and Measures: The ADHD symptoms and subtypes (inattention, hyperactivity-impulsivity, and combined) were measured based on a validated tool developed from the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition). Generalized linear mixed models were evaluated to estimate the association of SHS exposure with ADHD symptoms and subtypes. Results: A total of 45 562 participants completed the questionnaires and were included in this study (22 905 girls [50.3%]; mean [SD] age, 11.0 [2.6] years; 2170 [4.8%] with ADHD symptoms). Compared with their unexposed counterparts, children who were ever exposed (odds ratio [OR], 1.50; 95% CI, 1.36-1.66) or always exposed to SHS (OR, 2.88; 95% CI, 2.55-3.25) from pregnancy to childhood had higher odds of having ADHD symptoms and subtypes (ORs ranged from 1.46 [95% CI, 1.31-1.62] to 2.94 [95% CI, 2.09-4.13]). Compared with their unexposed counterparts, children with SHS exposure had higher odds of having ADHD symptoms when exposed in the prenatal period (OR, 2.28; 95% CI, 2.07-2.51), early postnatal period (OR, 1.47; 95% CI, 1.29-1.68), or current period (OR, 1.20; 95% CI, 1.09-1.31). Compared with their unexposed counterparts, children whose fathers smoked 10 or more cigarettes/d on both weekdays and weekends had higher odds of having ADHD symptoms and subtypes (ORs ranged from 1.48 [95% CI, 1.28-1.70] to 2.25 [95% CI, 1.29-3.93]). Conclusions and Relevance: Being exposed to SHS from pregnancy to childhood was associated with higher odds of having ADHD symptoms and subtypes among school-aged children, and the associations were somewhat stronger for SHS exposure during prenatal and early postnatal periods. Our findings highlight the important public health implications of reducing SHS exposure, which may decrease the health and economic burdens of individuals with ADHD.

Associations of ambient particulate matter with homocysteine metabolism markers and effect modification by B vitamins and MTHFR C677T gene polymorphism.

Evidence concerning effects of ambient air pollution on homocysteine (HCY) metabolism is scarce. We aimed to explore the associations between ambient particulate matter (PM) exposure and the HCY metabolism markers and to evaluate effect modifications by folate, vitamin B12, and methylenetetrahyfrofolate reductase (MTHFR) C677T gene polymorphism. Between December 1, 2017 and January 5, 2018, we conducted a panel study in 88 young college students in Guangzhou, China, and received 5 rounds of health examinations. Real-time concentrations of PMs with aerodynamic diameter ≤2.5 (PM2.5), ≤1.0 (PM1.0), and ≤0.1 (PM0.1) were monitored, and the serum HCY metabolism markers (i.e., HCY, S-Adenosylhomocysteine [SAH], and S-Adenosylmethionine [SAM]) were repeatedly measured. We applied linear mixed effect models combined with a distributed lag model to evaluate the associations of PMs with the HCY metabolism markers. We also explored effect modifications of folate, vitamin B12, and the MTHFR C677T polymorphism on the associations. We observed that higher concentrations of PM2.5 and PM1.0 were associated with higher serum levels of HCY, SAH, SAM, and SAM/SAH ratio (e.g., a 10 µg/m3 increase in PM2.5 during lag 0 day and lag 5 day was significantly associated with 1.3-19.4%, 1.3-28.2%, 6.2-64.4%, and 4.8-28.2% increase in HCY, SAH, SAM, and SAM/SAH ratio, respectively). In addition, we observed that the associations of PM2.5 with the HCY metabolism markers were stronger in participants with lower B vitamins levels. This study demonstrated that short-term exposure to PM2.5 and PM1.0 was deleteriously associated with the HCY metabolism markers, especially in people with lower B vitamins levels.