Accumulating exposure to quality green space over time is posited to influence child health, yet longitudinal studies are scarce. This study aimed to examine the associations between trajectories of perceived green space quality and child health-related outcomes. We used data from 1874 childrenin the B-cohort of the Longitudinal Study of Australian Children who participated in the Child Health Checkpoint module at 11–12 years. Data on caregiver perceived green space quality measured biennially was assessed using discrete trajectory mixture models to group children by contrasting distributions in green space quality over time. Examination of associations between trajectory groups of perceived green space quality and child biomarkers (i.e., albumin-to-creatinine ratio, total, cholesterol, total triglycerides, and glucose), physical health and behavioural assessments (i.e., anthropometric measurements, blood pressure, sedentary behaviour, physical activity, sleep, aerobic work capacity, and general wellbeing), and health care use were assessed using multilevel models, adjusted for sociodemographic variables. Four perceived green space quality trajectories were identified: “decreasing quality from high to moderate”; “increasing quality from low to high”; “consistently high quality”; “consistently low quality”. Compared with consistently low levels of quality green space, adjusted models indicated consistently high-quality green space was associated with lower total triglycerides (β −0.13; 95%CI -0.25, −0.01). Lower odds of hospital admission was observed among children who accumulated quality green space over time (OR 0.45; 95%CI 0.23, 0.87). These associations were observed in boys only in sex-stratified analyses. Moreover, boys accumulating quality green space through time tended to have lower diastolic blood pressure (β −2.76; 95%CI -5.17, −0.35) and girls who experienced loss in quality green space tended to have a higher percentage of body fat (β 2.81; 95%CI 0.43, 5.20). Accumulating quality green space over time is important for various aspects of child health, with contrasting benefits by sex.

We used real-world exposure scenarios to evaluate the effect of six ambient air pollutant (PM₂.₅, PM₁₀, NO₂, SO₂, CO, and O₃) exposure on renal function among older adults without chronic kidney disease (CKD). We recruited 169 older adults without CKD in Beijing, China, for a longitudinal study from 2016 to 2018. The Modification of Diet in Renal Disease (MDRD) and the Chronic Kidney Disease Epidemiology Collaboration (EPI) equations were employed to derive the estimated glomerular filtration rate (eGFR). A linear mixed-effects model with random intercepts for participants was employed to determine the effects of air pollutants on renal function evaluated on the basis of eGFR and urinary albumin/creatinine ratio at different exposure windows (1-, 2-, 3-, 5-, 7-, 14-, 28-, 45-, and 60-days moving averages). An interquartile range (IQR) increase in NO₂ for was associated with significant decreases of in eGFR (MDRD equation) [percentage changes: −4.49 (95% confidence interval: −8.44, −0.37), −5.51 (−10.43, −0.33), −2.26 (−4.38, −0.08), −3.71 (−6.67, −0.65), −5.44 (−9.58, −1.11), −5.50 (−10.24, −0.51), −6.15 (−10.73, −1.33), and −6.34 (−11.17, −1.25) for 1-, 2-, 5-, 7-, 14-, 28-, 45-, and 60-days moving averages, respectively] and in eGFR (EPI equation) [percentage changes: −5.04 (−7.09, −2.94), −6.25 (−8.81, −3.62), −5.16 (−7.34, −2.92), −5.10 (−7.85, −2.28), −5.83 (−8.23, −3.36), −6.04 (−8.55, −3.47) for 1-, 2-, 14-, 28-, 45-, and 60-days moving averages, respectively]. In two-pollutant model, only the association of NO₂ exposure with eGFR remained robust after adjustment for any other pollutant. This association was stronger for individuals with hypertension for the EPI equation or BMI <25 kg/m² for the MDRD equation at lags 1 and 1–2. Our findings suggest that NO₂ exposure is associated with eGFR reduction among older adults without CKD for short (1-, 2-days) and medium (14-, 28-, 45-, 60-days) term exposure periods; thus, NO₂ exposure may contribute to renal impairment.

Metabolic syndrome is an important risk factor for non-communicable diseases, particularly type 2 diabetes, coronary heart disease, and stroke. Long-term exposure to greenspace could be protective of metabolic syndrome, but evidence for such an association is lacking. Accordingly, we investigated the association between long-term exposure to greenspace and risk of metabolic syndrome.The present longitudinal study was based on data from four clinical examinations between 1997 and 2013 in 6076 participants of the Whitehall II study, UK (aged 45–69 years at baseline). Long-term exposure to greenspace was assessed by satellite-based indices of greenspace including Normalized Difference Vegetation Index (NDVI) and Vegetation Continuous Field (VCF) averaged across buffers of 500 and 1000 m surrounding the participants’ residential location at each follow-up. The ascertainment of metabolic syndrome was based on the World Health Organization (WHO) definition. Hazard ratios for metabolic syndrome were estimated using Cox proportional hazards regression models, controlling for age, sex, ethnicity, lifestyle factors, and socioeconomic status.Higher residential surrounding greenspace was associated with lower risk of metabolic syndrome. An interquartile range increase in NDVI and VCF in the 500 m buffer was associated with 13% (95% confidence interval (CI): 1%, 23%) and 14% (95% CI: 5%, 22%) lower risk of metabolic syndrome, respectively. Greater exposure to greenspace was also associated with each individual component of metabolic syndrome, including a lower risk of high levels of fasting glucose, large waist circumference, high triglyceride levels, low HDL cholesterol, and hypertension. The association between residential surrounding greenspace and metabolic syndrome may have been mediated by physical activity and exposure to air pollution.The findings of the present study suggest that middle-aged and older adults living in greener neighbourhoods are at lower risk of metabolic syndrome than those living in neighbourhoods with less greenspace.

A limited but emerging body of evidence is suggestive for a beneficial association between contact with green spaces and glucose homeostasis in adults; however, such an evidence for children is scarce. We evaluated the association between time spent in green spaces and fasting blood glucose (FBG) levels and impaired fasting glucose (IFG, FBG≥110 mg/dL) in a population-based multicentric sample of 3844 Iranian schoolchildren aged 7–18 years (2015). Participants were instructed to report the average hours per week spent in green spaces separately during each season and in each type of green space (parks, woods/other natural green spaces, and private gardens/agricultural field) for a 12-month period preceding the interview. We developed linear and logistic mixed effects models with centre as random effect to evaluate the association of time spent in green spaces (separately for each type as well as all types together) with FBG and IFG, respectively, controlled for a wide range of covariates including household indicators of socioeconomic status. We observed inverse associations between time spent in green spaces, especially in natural green spaces, and FBG levels. Specifically, 1.83 h increase in the total time spent in green spaces was associated with −0.5 mg/dl (95% confidence intervals: −0.9, −0.1) change in FBG levels. We also observed reduced risk of IFG associated with time spent in green spaces; however, the association was statistically significant only for the time spent in natural green spaces. There were suggestions for stronger associations for those residing in urban areas and those from lower socioeconomic status groups; however, the interaction terms for socioeconomic status and urbanity were not statistically significant. Further longitudinal studies are required to replicate our findings in other settings with different climates and population susceptibilities.

Triclosan (TCS) is a suspected endocrine disrupting chemical which is widely used in consumer products as an antibacterial agent. But findings in human studies focusing on the fetal developmental effects of prenatal TCS exposure were rare and inconsistent. This study aimed to determine maternal urinary TCS and investigate its association with birth outcomes. Pregnant women (n = 1006) were randomly selected from the prospective Healthy Baby Cohort (HBC) enrolled in 2014. TCS levels were determined in maternal urine samples collected at delivery and recorded birth outcomes were obtained from the medical records. Multiple linear regressions were applied to evaluate associations of maternal urinary TCS levels with birth outcomes including birth weight, birth length, and gestational age. Logistic regressions were used to evaluate associations with preterm birth, late term birth, and low birth weight. The geometric mean concentrations for TCS and specific gravity (SG) adjusted TCS in maternal urines were 0.73, 0.78 ng/mL, respectively. In the crude model, one ln-unit increase of urinary SG-adjusted TCS concentration was associated with a 0.30-day [95% confidence interval (CI): 0.00, 0.60] increase in gestational age; however, the associations were not statistically significant after adjustment for covariates. No significant associations of SG-adjusted TCS concentrations with birth weight and birth length were observed. Maternal SG-adjusted TCS concentrations were not related to preterm birth, late term birth, and low birth weight (all p > 0.10). Our findings reported a relatively low level of TCS among Chinese pregnant women. With such exposure level, we did not find strong evidence for associations between maternal TCS exposure and birth outcomes. Longitudinal studies concerning about different potential effects of TCS on perinatal health are necessary.

Data-driven machine learning methods present an opportunity to simultaneously assess the impact of multiple air pollutants on health outcomes. The goal of this study was to apply a two-stage, data-driven approach to identify associations between air pollutant exposure profiles and children's cognitive skills. Data from 6900 children enrolled in the Early Childhood Longitudinal Study, Birth Cohort, a national study of children born in 2001 and followed through kindergarten, were linked to estimated concentrations of 104 ambient air toxics in the 2002 National Air Toxics Assessment using ZIP code of residence at age 9 months. In the first-stage, 100 regression trees were learned to identify ambient air pollutant exposure profiles most closely associated with scores on a standardized mathematics test administered to children in kindergarten. In the second-stage, the exposure profiles frequently predicting lower math scores were included within linear regression models and adjusted for confounders in order to estimate the magnitude of their effect on math scores. This approach was applied to the full population, and then to the populations living in urban and highly-populated urban areas. Our first-stage results in the full population suggested children with low trichloroethylene exposure had significantly lower math scores. This association was not observed for children living in urban communities, suggesting that confounding related to urbanicity needs to be considered within the first-stage. When restricting our analysis to populations living in urban and highly-populated urban areas, high isophorone levels were found to predict lower math scores. Within adjusted regression models of children in highly-populated urban areas, the estimated effect of higher isophorone exposure on math scores was −1.19 points (95% CI −1.94, −0.44). Similar results were observed for the overall population of urban children. This data-driven, two-stage approach can be applied to other populations, exposures and outcomes to generate hypotheses within high-dimensional exposure data.

The negative health effects of water pollution remain a major source of morbidity and mortality in China. The Chinese government is making great efforts to strengthen water environment treatment; however, no studies have evaluated the effects of water treatment on human health by water pollution in China. This study evaluated the association between water pollution and health outcomes, and determined the extent to which environmental regulations on water pollution may lead to health benefits. Data were extracted from the 2011 and 2013 China Health and Retirement Longitudinal Study (CHARLS). Random effects model and random effects Logit model were applied to study the relationship between health and water pollution, while a Mediator model was used to estimate the effects of environmental water treatment on health outcomes by the intensity of water pollution. Unsurprisingly, water pollution was negatively associated with health outcomes, and the common pollutants in industrial wastewater had differential impacts on health outcomes. The effects were stronger for low-income respondents. Water environment treatment led to improved health outcomes among Chinese people. Reduced water pollution mediated the associations between water environment treatment and health outcomes. The results of this study offer compelling evidence to support treatment of water pollution in China.

As a highly toxic heavy metal, the pollution and exposure risks of lead are of widespread concern for human health. However, the collection of blood samples for use as an indicator of lead pollution is not always feasible in most cohort or longitudinal studies, especially those involving children health. To evaluate the potential use of urinary lead as an indicator of exposure levels and source apportionment, accompanying with environmental media samples, lead concentrations and isotopic measurements (expressed as 207Pb/206Pb, 208Pb/206Pb and 204Pb/206Pb) were investigated and compared between blood and urine from children living in the vicinities of a typical coking plant and lead-acid battery factory. The results showed urinary lead might not be a preferable proxy for estimating blood lead levels. Fortunately, urinary lead isotopic measurements could be used as an alternative for identifying the sources of children's lead exposure, which coincided well with the blood lead isotope ratio analysis.

Long-term exposure to air pollutants, especially particulates, in adulthood is related to cardiovascular diseases and vascular markers of atherosclerosis. However, whether vascular changes in children is related to exposure to air pollutants remains unknown. This study examined whether childhood exposure to air pollutants was related to a marker of cardiovascular risk, carotid intima–media thickness (CIMT) in children aged 11–12 years old. Longitudinal Study of Australian Children (LSAC) recruited parents and their children born in 2003–4. Among the participants, CheckPoint examination was conducted when the children were 11–12 years old. Ultrasound of the right carotid artery was performed using standardized protocols. Average and maximum far-wall CIMT, carotid artery distensibility, and elasticity were quantified using semiautomated software. Annual and life-time exposure to air pollutants was estimated using satellite-based land-use regression by residential postcodes. A total of 1063 children (50.4% girls) with CIMT data, serum cholesterol, and modeled estimates of NO₂ and PM₂.₅ exposure for the period 2003 to 2015 were included. The average and maximum CIMT, carotid distensibility, and elasticity were 497 μm (standard deviation, SD 58), 580 μm (SD 44), 17.4% (SD 3.2), and 0.48%/mmHg (SD 0.09), respectively. The life-time average concentrations of PM₂.₅ and NO₂ were 6.4 μg/m³ (SD 1.4) and 6.4 ppb (SD 2.4), respectively. Both average and maximum CIMT were significantly associated with average ambient PM₂.₅ concentration (average CIMT: +5.5 μm per μg/m³, 95% confidence interval, CI 2.4 to 8.5, and maximum CIMT: +4.9 μm per μg/m³, CI 2.3 to 7.6), estimated using linear regression, adjusting for potential confounders. CIMT was not significantly related to NO₂ exposure. Carotid artery diameter, distensibility, and elasticity were not significantly associated with air pollutants. We conclude that life-time exposure to low levels of PM₂.₅ in children might have measurable adverse impacts on vascular structure by age 11–12 years.

Evidence of the effects of long-term household air pollution (HAP) on human mental health is limited. This study aimed to explore the longitudinal relationship between long-term household air pollution exposure from solid fuel use and depression based on nationally representative follow-up dataset. A total of 7005 middle- and old-age adults from the latest four waves (2011, 2013, 2015, and 2018) of China Health and Retirement Longitudinal Study (CHARLS) were involved. The Center for Epidemiologic Studies Depression scale (CES-D 10) was used to measure depressive symptoms and individuals who got more than 12 points were considered to have depression symptoms. We conducted Cox proportional hazards regression models to examine the association between household air pollution and depression in overall population, and subgroup stratified by socio-demographic factors, lifestyle behaviors, chronic diseases, and residential environments. We found long-term household air pollution exposure from solid fuel use was significantly associated with higher depression risk among Chinese older adults (HR 1.27, 95% CI 1.14–1.42 in heating; 1.26, 1.13–1.40 in cooking). Longer duration of household air pollution exposure (1.47, 1.28–1.68 in heating; 1.36, 1.19–1.56 in cooking) and household air pollution from crop residue/wood burning (1.66, 1.41–1.94 in heating; 1.37, 1.23–1.53 in cooking) was correlated with higher depression risk. For subgroups analysis, the effect of household air pollution from solid fuel on depression varied. Compared with those who using clean fuel, older adults living in small size houses or houses with small number rooms had increasing depression risks if they used solid fuel for heating or cooking. Our findings indicate long-term household air pollution exposure from solid fuel use is associated with higher depression risk. Reducing household air pollution by restricting solid fuel use can be effective ways to prevent depression for Chinese older adults and decrease related public health burden.