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Background: Urban neighbourhood environments may impact older adults’ cognitive health. However, longitudinal studies examining key environmental correlates of cognitive health are lacking. We estimated cross-sectional and longitudinal associations of neighbourhood built and natural environments and ambient air pollution with multiple cognitive health outcomes in Australian urban dwellers aged 60+ years. Methods: The study included 1160 participants of the PATH Through Life study (60+ cohort) who were followed up for 12 years (four assessments; 2001/02 to 2013/15) and with data on socio-demographics, health, cognitive functions and diagnoses, and full residential address. Neighbourhood environmental features encompassed population and street-intersection densities, non-commercial land use mix, transit points, presence of blue space, percentages of commercial land, parkland and tree cover, and annual average PM2.5 and NO2 concentrations. All exposures except for tree cover were assessed at two time points. Generalised additive mixed models estimated associations of person-level average, and within-person changes in, exposures with cognitive functions. Multi-state hidden Markov models estimated the associations of neighbourhood attributes with transitions to/from mild cognitive impairment (MCI). Results: Dense, destination-rich neighbourhoods were associated with a lower likelihood of transition to MCI and reversal to no MCI. Positive cross-sectional and longitudinal associations of non-commercial land use mix, street intersection density and percentage of commercial land were observed especially with global cognition and processing speed. While access to parkland and blue spaces were associated with a lower risk of transition to MCI, the findings related to cognitive functions were mixed and supportive of an effect of parkland on verbal memory only. Higher levels of PM2.5 and NO2 were consistently associated with steeper declines and/or decreases in cognitive functions and worse cognitive states across time. Conclusion: To support cognitive health in ageing populations, neighbourhoods need to provide an optimal mix of environmental complexity, destinations and access to the natural environment and, at the same time, minimise ambient air pollution.

Background: Potential effect of greenspace exposure on human microbiota have been explored by a number of observational and interventional studies, but the results remained mixed. We comprehensively synthesized these studies by performing a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Methods: Comprehensive literature searches in three international databases (PubMed, Embase, and Web of Science) and three Chinese databases (China National Knowledge Infrastructure, Wanfang, and China Biology Medicine disc) were conducted from inception to November 1, 2023. Observational and interventional studies that evaluated associations between greenspace exposure and human microbiota at different anatomical sites were included. Studies were assessed using the National Toxicology Program’s office of Health Assessment and Translation risk of bias tool and certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation framework. Two authors independently performed study selection, data extraction, and risk of bias assessment, and evidence grading. Study results were synthesized descriptively. Results: Twenty studies, including 11 observational studies and 9 interventional studies, were finally included into the systematic review. The microbiota of the included studies was from gut (n = 13), skin (n = 10), oral cavity (n = 5), nasal cavity (n = 5) and eyes (n = 1). The majority of studies reported the associations of greenspace exposure with increased diversity (e.g., richness and Shannon index) and/or altered overall composition of human gut (n = 12) and skin microbiota (n = 8), with increases in the relative abundance of probiotics (e.g., Ruminococcaceae) and decreases in the relative abundance of pathogens (e.g., Streptococcus and Escherichia/Shigella). Due to limited number of studies, evidence concerning greenspace and oral, nasal, and ocular microbiota were still inconclusive. Conclusion: The current evidence suggests that greenspace exposure may diversify gut and skin microbiota and alter their composition to healthier profiles. These findings would be helpful in uncovering the potential mechanisms underlying greenspace and human health and in promoting a healthier profile of human microbiota.

Background: Evidence suggests that maternal exposure to heat might increase the risk of preterm birth (PTB), but no study has investigated the effect from urban heat island (UHI) at individual level. Aims: Our study aimed to investigate the association between individual UHI exposure and PTB. Methods: We utilized data from the ongoing China Birth Cohort Study (CBCS), encompassing 103,040 birth records up to December 2020. UHI exposure was estimated for each participant using a novel individual assessment method based on temperature data and satellite-derived land cover data. We used generalized linear mixed-effects models to estimate the association between UHI exposure and PTB, adjusting for potential confounders including maternal characteristics and environmental factors. Results: Consistent and statistically significant associations between UHI exposure and PTB were observed up to 21 days before birth. A 5 °C increment in UHI exposure was associated with 27 % higher risk (OR = 1.27, 95 % confident interval: 1.20, 1.34) of preterm birth in lagged day 1. Stratified analysis indicated that the associations were more pronounced in participants who were older, had higher pre-pregnancy body mass index level, of higher socioeconomic status and living in greener areas. Conclusion: Maternal exposure to UHI was associated with increased risk of PTB. These findings have implications for developing targeted interventions for susceptible subgroups of pregnant women. More research is needed to validate our findings of increased risk of preterm birth due to UHI exposure among pregnant women.

Despite an increasing number of studies demonstrating the potential mental health benefits of greenspace, few longitudinal studies have been reported. We aimed to assess associations between two metrics of residential greenspace exposure and anxiety symptoms in a cohort of Australian women living in major cities.Our study comprised 3,938 women, born between 1973 and 78. Anxiety symptoms in the previous month were assessed at follow-up every three years during 2003–2018, using the anxiety subscale of the Goldberg Anxiety and Depression Scale. The three-month seasonal average normalized difference vegetation index (NDVI) was estimated from 30 m Landsat satellite images in a 500 m buffer (NDVI500m) around participants’ address at each survey (higher NDVI indicates more green vegetation). The annual fractional cover of non-photosynthesising vegetation was estimated (fNPV500m, with higher values indicating greater levels of dead leaf litter or dry grass).A generalised estimating equation assessed associations between greenspace measures and anxiety symptoms (as odds ratios [ORs]), adjusting for repeated outcomes and individual-level covariates. Additional analyses focused on women experiencing substantial changes in between-survey exposure due to moving, and adjusting for nitrogen dioxide (NO2) and fine particulate matter (PM2.5) exposure, among others.A standard deviation (SD) (0.12 units) increase in NDVI500m was significantly associated with lower odds of anxiety symptoms (OR: 0.96, 95% CI: 0.93–0.99) in the adjusted model. An SD (5.2%) increase in annual fNPV500m was consistent with the direction expected for that exposure, but not significant in the adjusted model (OR: 1.03, 95% CI: 0.99–1.07). NDVI500m was modestly attenuated when air pollutants were adjusted for, while fNPV500m only became significant when PM2.5 was adjusted for. Between-survey contrasts had no clear effect for NDVI500m. Moving to a higher fNPV500m area, compared with a similar fNPV500m area, was consistently associated with anxiety symptoms (OR: 1.15, 95% CI: 1.02–1.31). NDVI500m was generally associated with lower odds of anxiety symptoms, while fNPV500m was generally associated with higher odds of anxiety, depending on the covariates considered.

Background: Accumulating evidence indicates early life exposure to air pollution, a suspected neurotoxicant, is negatively associated with children’s neurodevelopment. Objectives: To explore the role of multiple exposure periods to ambient particulate matter with diameter

Background: Evidence from developed countries suggests that fine particulate matter (≤2.5 µm [PM2.5]) contributes to childhood respiratory morbidity and mortality. However, few analyses have focused on resource-limited settings, where much of this burden occurs. We aimed to investigate the cross-sectional associations between annual average exposure to ambient PM2.5 and acute respiratory infection (ARI) in children aged

Can mitigating only particle mass, as the existing air quality measures do, ultimately lead to reduction in ultrafine particles (UFP)? The aim of this study was to provide a broader urban perspective on the relationship between UFP, measured in terms of particle number concentration (PNC) and PM2.5 (mass concentration of particles with aerodynamic diameter 1 for roadside sites and

Background: Living in greener areas has many health benefits, but evidence concerning the effects on blood pressure remains mixed. We sought to assess associations between community greenness and both blood pressure and hypertension in Chinese urban dwellers, and whether the associations were mediated by air pollution, body mass index, and physical activity. Methods: We analyzed data from 24,845 adults participating in the 33 Communities Chinese Health Study, which was conducted in Northeastern China during 2009. We measured each participant's blood pressure according to a standardized protocol. We assessed community greenness using two satellite-derived vegetation indexes – the Normalized Difference Vegetation Index (NDVI) and the Soil Adjusted Vegetation Index (SAVI). Particulate matter ≤2.5 μm and nitrogen dioxide were used as proxies of ambient air pollution. We applied generalized linear mixed models to investigate the association between greenness and blood pressure. We also performed mediation analyses. Results: Living in greener areas was associated with lower blood pressure and hypertension prevalence; an interquartile range increase in both NDVI500-m and SAVI500-m were significantly associated with reductions in systolic blood pressure of 0.82 mm Hg (95% CI: −1.13, −0.51) and 0.89 mm Hg (95% CI: −1.21, −0.57), respectively. The same increases in greenness were also significantly associated with a 5% (95% CI: 1%, 8%) and 5% (95% CI: 1%, 9%) lower odds of having hypertension, respectively. These associations remained consistent in sensitivity analyses. The associations were stronger among women than men. Air pollutants and body mass index partly mediated the associations, but there was no evidence of mediation effects for physical activity. Conclusions: Our findings indicate beneficial associations between community greenness and blood pressure in Chinese adults, especially for women. Air pollution and body mass index only partly mediated the associations. Keywords: Greenness, Hypertension, Blood pressure, Mediation, Cross-sectional study, Chinese adults

Background: Epidemiological studies show that long-term exposure to ambient air pollution reduces life expectancy. Most studies have been in environments with relatively high concentrations such as North America, Europe and Asia. Associations at the lower end of the concentration-response function are not well defined. Objectives: We assessed associations between all-cause mortality and exposure to annual average particulate matter

Backgrounds: Evidence on the association between long-term exposure to particulate matter with aerodynamic diameter ≤2.5 μm (PM2.5) and cardiovascular disease (CVD) is scarce in developing countries. Moreover, few studies assessed the role of the PM1 (≤1.0 μm) size fraction and CVD. We investigated the associations between PM1 and PM2.5 and CVD prevalence in Chinese adults. Methods: In 2009, we randomly recruited 24,845 adults at the age of 18–74 years from 33 communities in Northeastern China. CVD status was determined by self-report of doctor-diagnosed CVD. Three-year (2006–08) average concentrations of PM1 and PM2.5 were assigned using a satellite-based exposure. We used spatial Generalized Linear Mixed Models to evaluate the associations between air pollutants and CVD prevalence, adjusting for multiple covariates. Stratified and interaction analyses and sensitivity analyses were also performed. Results: A 10 μg/m3 increase in long-term exposure to ambient PM1 levels was associated a 12% higher odds for having CVD (OR = 1.12; 95% CI = 1.05–1.20). Compared to PM1, association between PM2.5 and CVD was lower (OR = 1.06; 95% CI = 1.01–1.11). No significant association was observed for PM1–2.5 (1–2.5 μm) size fraction (OR = 0.98; 95% CI = 0.85–1.13). Stratified analyses showed greater effect estimates in men and the elder. Conclusions: Long-term PM1 exposure was positively related to CVD, especially in men and the elder. In addition, PM1 may play a greater role than PM2.5 in associations with CVD. Further longitudinal studies are warranted to confirm our findings. Keywords: Particulate matter, Cardiovascular disease, Adults, Chinese, Cross-sectional study

Maternal exposure to ambient air pollution has been associated with preterm birth (PTB), however, entire pregnancy or trimester-specific associations were generally reported, which may not sufficiently identify windows of susceptibility. Using birth registry data from Guangzhou, a megacity of southern China (population ~14.5 million), including 469,975 singleton live births between January 2015 and July 2017, we assessed the association between weekly air pollution exposure and PTB in a retrospective cohort study. Daily average concentrations of PM2.5, PM10, NO2, SO2, and O3 from 11 monitoring stations were used to estimate district-specific exposures for each participant based on their district residency during pregnancy. Distributed lag models (DLMs) incorporating Cox proportional hazard models were applied to estimate the association between weekly maternal exposure to air pollutant and PTB risk (as a time-to-event outcome), after controlling for temperature, seasonality, and individual-level covariates. We also considered moderate PTB (32–36 gestational weeks) and very PTB (28–31 gestational weeks) as outcomes of interest. Hazard ratios (HRs) and 95% confidential intervals (95% CIs) were calculated for an interquartile range (IQR) increase in air pollutants during the study period. An IQR increase in PM2.5 exposure during the 20th to 28th gestational weeks (27.0 μg/m3) was significantly associated with PTB risk, with the strongest effect in the 25th week (HR = 1.034, 95% CI:1.010–1.059). The significant exposure windows were the 19th–28th weeks for PM10, the 18th–31st weeks for NO2, and the 23rd–31st weeks for O3, respectively. The strongest associations were observed in the 25th week for PM10 (IQR = 37.0 μg/m3; HR = 1.048, 95% CI:1.034–1.062), the 26th week for NO2 (IQR = 29.0 μg/m3; HR = 1.060, 95% CI:1.028–1.094), and in the 28th week for O3 (IQR = 90.0 μg/m3; HR = 1.063, 95% CI:1.046–1.081). Similar patterns were observed for moderate PTB (32–36 gestational weeks) and very PTB (28–31 gestational weeks) for PM2.5, PM10, NO2 exposure, but the effects were greater for very PTB. We did not observe any association between pregnancy SO2 exposure and the risk of PTB. Our results suggest that middle to late pregnancy is the most susceptible air pollution exposure window for air pollution and PTB among women in Guangzhou, China. Keywords: Air pollution, Preterm birth, Distributed lag model, Susceptible exposure window

Background: Ozone pollution keeps deteriorating in the context of climate change. Maternal ozone exposure may be associated with low birth weight (LBW), but the results are still inconsistent. The identification of the critical exposure windows, a specific period of particular susceptibility during pregnancy, remains unresolved. We aimed to evaluate whether ozone exposure was associated with term LBW and further identify the susceptible exposure windows. Methods: A retrospective cohort study was conducted in Guangzhou, a megacity in the most populous and economically developed city clusters in China. We included 444,096 singleton live births between January 2015 and July 2017. From 11 fixed stations, we collected daily 1-h maximum and 8-h maximum moving average ozone level (O3-1 h and O3-8 h) and calculated exposures for each participant based on their district of residence during pregnancy. We used traditional Logistic regression to estimate the trimester-specific association between ozone exposure and term LBW, and further estimated monthly- and weekly association by distributed lag models (DLMs) with Logistic regression. Odds ratios (ORs) and 95% confidence intervals (CIs) of term LBW were calculated for an interquartile range (IQR) increase in ozone exposure. Stratified analyses and heterogeneity tests were conducted by maternal age and infant sex. Results: The incidence of term LBW was 1.9%. During the study period, the mean O3-1 h and O3-8 h levels were 112.6 µg/m3 and 84.5 µg/m3, respectively. Increased O3-1 h (IQR: 90 µg/m3) and O3-8 h (73 µg/m3) exposure during the second trimester were associated with increased risk of term LBW. At a monthly level, the term LBW risk was associated with O3-1 h exposure during the 4th-6th month and O3-8 h exposure during the 6th month. By estimating the weekly-specific association, we observed that critical exposure windows were the 15th- 26th gestational weeks for O3-1 h, and the 20th-26th weeks for O3-8 h, respectively. Estimated ORs and 95% CIs ranged from 1.012 (1.000, 1.024) to 1.023 (1.007, 1.039). When examined by subgroups, the effects were present among women ≥ 35 years or

Background: Residing in greener areas has several health benefits, but no study to date has examined the effects of greenness on metabolic syndrome (MetS). We aimed to assess associations between residential greenness and MetS prevalence in China, and to explore whether air pollution and physical activity mediated any observed associations. Methods: We analyzed data from 15,477 adults who participated in the 33 Communities Chinese Health Study during 2009. We defined MetS according to standard guidelines for Chinese populations. Residential greenness was estimated using the Normalized Difference Vegetation Index (NDVI), the Soil Adjusted Vegetation Index (SAVI), and the Vegetation Continuous Field (VCF). We used generalized linear mixed models to assess the associations between greenness and MetS, and mediation analyses to explore potential mechanisms underlying the associations. Results: Higher greenness levels were associated with lower odds of MetS [e.g., for every interquartile range increase of NDVI500-m, SAVI500-m, and VCF500-m, the adjusted odds ratio of MetS was 0.81 (95% confidence interval: 0.70–0.93), 0.80 (95% confidence interval: 0.69–0.93), and 0.91 (95% confidence interval: 0.83–1.00), respectively]. The direction and the magnitude of the associations persisted in several sensitivity analyses. Stratified analyses showed that age and household income modified the associations, with greater effect estimates observed in participants younger than 65 years old or those with higher household income. Particulate matter with an aerodynamic diameter ≤10 μm, nitrogen dioxide, and ozone mediated 2.1–20.3% of the associations between greenness and MetS; no evidence of mediation was observed for physical activity. Conclusions: Our findings suggest a beneficial association for residential greenness and MetS in Chinese urban dwellers, especially for participants younger than 65 years old and those with higher household income. Particulate matter with an aerodynamic diameter ≤10 μm, nitrogen dioxide and ozone, but not physical activity, may only partially mediate the association. Keywords: Greenness, Metabolic syndrome, Mediation, Chinese adults, Cross-sectional study