Fatemeh Mayvaneh

Growing evidence has linked environmental exposures to preterm birth (PTB), yet the interplay between greenness, air pollution, and PTB remains understudied in middle-income settings. This study aimed to evaluate the association between surrounding greenness and the odds of PTB and to examine whether ambient air pollution mediates this association. We analyzed a national retrospective cohort of 3.98 million singleton live births from 31 provinces of Iran between 2013 and 2018. Prenatal exposure to surrounding greenness was characterized by normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI) within 500–3000 m buffers around geocoded delivery hospital locations. Multivariable logistic regression models were used to assess the associations of greenness with overall PTB and its subtypes, adjusting for demographic, reproductive, and environmental covariates. Causal mediation analysis was applied to quantify mediation by fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂), and analyses were stratified by maternal age, education, and residential area. Among 3,976,387 singleton live births included in the analysis, 256,612 (6.45%) were PTB. Higher prenatal greenness, assessed by NDVI and EVI across buffers, was consistently associated with lower odds of PTB and its subtypes. Compared with the lowest NDVI_-3000 m tertile, the highest tertile was associated with approximately 14–26% lower odds of overall PTB, moderate PTB, and very PTB. Mediation analyses indicated that PM_2.5 and NO₂ together explained about 15–25% of the greenness–PTB association, with smaller mediated proportions for PTB subtypes. Findings were broadly consistent when using EVI-based metrics, and mediation effects of PM_2.5 and NO₂ were more pronounced among rural-dwelling mothers. Greenness exposure was associated with lower odds of PTB, and this association was partially mediated by reduced ambient PM_2.5 and NO₂ pollution. These results underscored the importance of green space as a modifiable environmental determinant to mitigate PTB burden in middle-income countries.

Despite extensive population-based evidence linking air pollution with adverse birth outcomes, the potential interactive effects of ambient ozone (O₃

Despite accumulating evidence linking greenness with the decreased risk of low birthweight (LBW), the potential modification and mediation effects of ambient air pollution remain unstudied. We conducted a nationwide birth cohort analysis using nearly 3.9 million registry-based mother-infant records across 31 provinces in Iran during 2013–2018. Greenness exposure during pregnancy was assessed utilizing the normalized difference vegetation index (NDVI) within multiple buffers (500–3000 m). Logistic regression model was used to analyze the associations of maternal greenness exposure with LBW and small for gestational age (SGA). Modification effects of PM2.5 and O3 levels were checked via comparing greenness-related risks in stratified analyses by grouping maternal air pollution exposure into low, medium, and high levels based on cut-points at tertiles. Mediation analysis was adopted to quantify the degree to which PM2.5 and O3 exposure mediated the associations of greenness exposure with LBW and SGA. We observed consistently lower LBW and SGA risks in relation to greater greenness within buffers of 500–3000 m. Each 0.1-unit rise of NDVI within the 3000-m buffer (NDVI-3000 m) was associated with an estimated odds of 0.902 (95% confidence interval [CI]: 0.900–0.905) for LBW and 0.887 (95% CI: 0.886–0.889) for SGA. Stratified analyses provided consistent evidence for greater greenness-related protective effects in lowering LBW and SGA risks at higher PM2.5 and O3 levels in multiple age subgroups. Among the entire group with maternal age of 15–49 years, for instance, LBW risk for each 0.1-unit rise in NDVI-3000 m declined by 6.8% (95% CI: 6.4%–7.2%), 10.1% (95% CI: 9.7%–10.6%), and 10.9% (95% CI: 10.4%–11.3%) in the 1st to 3rd tertile stratum of PM2.5 levels, respectively. The mediation analysis suggested a significant mediating role of ambient air pollution in greenness-LBW/SGA association, where reduced PM2.5 and O3 mediated 2.2%–3.4% and 7.3%–12.1% risks during the pregnancy. This study provided national evidence for greater health benefits of greenness in alleviating LBW and SGA risks among pregnant women being exposed to higher PM2.5 and O3 pollution levels. Reduced PM2.5 and O3 may partially mediate the association of greenspace exposure with fetal growth.

To assess thermal comfort conditions in classrooms, a field study was conducted in Sabzevar. The thermal sensations reported by students regarding classroom conditions were documented at various times throughout the day during the 2009–2010 academic year across multiple classes. temperature and humidity data within the classrooms were recorded simultaneous using a data ...

The nexus between prenatal greenspace exposure and low birth weight (LBW) remains largely unstudied in low- and middle-income countries (LMICs). We investigated a nationwide retrospective cohort of 4,021,741 live births (263,728 LBW births) across 31 provinces in Iran during 2013–2018. Greenness exposure during pregnancy was assessed using satellite-based normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI). We estimated greenness-LBW associations using multiple logistic models, and quantified avoidable LBW cases under scenarios of improved greenspace through counterfactual analyses. Association analyses provide consistent evidence for approximately L-shaped exposure-response functions, linking 7.0–11.5% declines in the odds of LBW to each 0.1-unit rise in NDVI/EVI with multiple buffers. Assuming causality, 3931–5099 LBW births can be avoided by achieving greenness targets of mean NDVI/EVI, amounting to 4.4–5.6% of total LBW births in 2015. Our findings suggest potential health benefits of improved greenspace in lowering LBW risk and burden in LMICs.

Background: Cardiovascular disease is the leading cause of death worldwide. Existing studies on the association between temperatures and cardiovascular deaths have been limited in geographic zones and have generally considered associations with total cardiovascular deaths rather than cause-specific cardiovascular deaths. Methods: We used unified data collection protocols within the Multi-Country Multi-City Collaborative Network to assemble a database of daily counts of specific cardiovascular causes of death from 567 cities in 27 countries across 5 continents in overlapping periods ranging from 1979 to 2019. City-specific daily ambient temperatures were obtained from weather stations and climate reanalysis models. To investigate cardiovascular mortality associations with extreme hot and cold temperatures, we fit case-crossover models in each city and then used a mixed-effects meta-analytic framework to pool individual city estimates. Extreme temperature percentiles were compared with the minimum mortality temperature in each location. Excess deaths were calculated for a range of extreme temperature days. Results: The analyses included deaths from any cardiovascular cause (32 154 935), ischemic heart disease (11 745 880), stroke (9 351 312), heart failure (3 673 723), and arrhythmia (670 859). At extreme temperature percentiles, heat (99th percentile) and cold (1st percentile) were associated with higher risk of dying from any cardiovascular cause, ischemic heart disease, stroke, and heart failure as compared to the minimum mortality temperature, which is the temperature associated with least mortality. Across a range of extreme temperatures, hot days (above 97.5th percentile) and cold days (below 2.5th percentile) accounted for 2.2 (95% empirical CI [eCI], 2.1–2.3) and 9.1 (95% eCI, 8.9–9.2) excess deaths for every 1000 cardiovascular deaths, respectively. Heart failure was associated with the highest excess deaths proportion from extreme hot and cold days with 2.6 (95% eCI, 2.4–2.8) and 12.8 (95% eCI, 12.2–13.1) for every 1000 heart failure deaths, respectively. Conclusions: Across a large, multinational sample, exposure to extreme hot and cold temperatures was associated with a greater risk of mortality from multiple common cardiovascular conditions. The intersections between extreme temperatures and cardiovascular health need to be thoroughly characterized in the present day—and especially under a changing climate.