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Background: Reported associations between particulate matter with aerodynamic diameter ≤2.5 μm (PM 2.5 ) and cognitive outcomes remain mixed. Differences in exposure estimation method may contribute to this heterogeneity., Objectives: To assess agreement between PM 2.5 exposure concentrations across 11 exposure estimation methods and to compare resulting associations between PM 2.5 and cognitive or MRI outcomes., Methods: We used Visit 5 (2011-2013) cognitive testing and brain MRI data from the Atherosclerosis Risk in Communities (ARIC) Study. We derived address-linked average 2000-2007 PM 2.5 exposure concentrations in areas immediately surrounding the four ARIC recruitment sites (Forsyth County, NC; Jackson, MS; suburbs of Minneapolis, MN; Washington County, MD) using 11 estimation methods. We assessed agreement between method-specific PM 2.5 concentrations using descriptive statistics and plots, overall and by site. We used adjusted linear regression to estimate associations of method-specific PM 2.5 exposure estimates with cognitive scores (n = 4678) and MRI outcomes (n = 1518) stratified by study site and combined site-specific estimates using meta-analyses to derive overall estimates. We explored the potential impact of unmeasured confounding by spatially patterned factors., Results: Exposure estimates from most methods had high agreement across sites, but low agreement within sites. Within-site exposure variation was limited for some methods. Consistently null findings for the PM 2.5 -cognitive outcome associations regardless of method precluded empirical conclusions about the potential impact of method on study findings in contexts where positive associations are observed. Not accounting for study site led to consistent, adverse associations, regardless of exposure estimation method, suggesting the potential for substantial bias due to residual confounding by spatially patterned factors., Discussion: PM 2.5 estimation methods agreed across sites but not within sites. Choice of estimation method may impact findings when participants are concentrated in small geographic areas. Understanding unmeasured confounding by factors that are spatially patterned may be particularly important in studies of air pollution and cognitive or brain health., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Melinda Power reports financial support was provided by National Institutes of Health.Melinda Power reports a relationship with National Institutes of Health that includes: funding grants. Melinda Power reports a relationship with U.S. Department of Defense that includes: funding grants. Melinda Power reports a relationship with DC DEPARTMENT OF HEALTH that includes: funding grants. Melinda Power reports a relationship with Biogen that includes: consulting or advisory. Erin Bennett reports a relationship with Massachusetts General Hospital that includes: consulting or advisory. Eun Sug Park reports a relationship with National Institutes of Health that includes: funding grants. Jeff D. Yanosky reports a relationship with National Institutes of Health that includes: funding grants. Duanping Liao reports a relationship with National Institutes of Health that includes: funding grants. Joel D. Kaufman reports a relationship with National Institutes of Health that includes: funding grants. Joel D. Kaufman reports a relationship with U.S. Environmental Protection Agency that includes: funding grants. Lianne Sheppard reports a relationship with National Institutes of Health that includes: funding grants. Lianne Sheppard reports a relationship with Health Effects Institute that includes: funding grants. Adam Szpiro reports a relationship with National Institutes of Health that includes: funding grants. Adam Szpiro reports a relationship with Health Effects Institute that includes: funding grants. Adam Szpiro reports a relationship with Health Effects Institute that includes: consulting or advisory. Eric Whitsel reports a relationship with National Institutes of Health that includes: funding grants. Eric Whitsel reports a relationship with USFederal Aviation Administration that includes: funding grants.If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Rationale: Evidence concerning the acute health effects of air pollution caused by fine particulate matter (PM 2.5 ) in developing countries is quite limited., Objectives: To evaluate short-term associations between PM 2.5 and daily cause-specific mortality in China., Methods: A nationwide time-series analysis was performed in 272 representative Chinese cities from 2013 to 2015. Two-stage Bayesian hierarchical models were applied to estimate regional- and national-average associations between PM 2.5 concentrations and daily cause-specific mortality. City-specific effects of PM 2.5 were estimated using the overdispersed generalized additive models after adjusting for time trends, day of the week, and weather conditions. Exposure-response relationship curves and potential effect modifiers were also evaluated., Measurements and Main Results: The average of annual mean PM 2.5 concentration in each city was 56 μg/m 3 (minimum, 18 μg/m 3 ; maximum, 127 μg/m 3 ). Each 10-μg/m 3 increase in 2-day moving average of PM 2.5 concentrations was significantly associated with increments in mortality of 0.22% from total nonaccidental causes, 0.27% from cardiovascular diseases, 0.39% from hypertension, 0.30% from coronary heart diseases, 0.23% from stroke, 0.29% from respiratory diseases, and 0.38% from chronic obstructive pulmonary disease. There was a leveling off in the exposure-response curves at high concentrations in most, but not all, regions. The associations were stronger in cities with lower PM 2.5 levels or higher temperatures, and in subpopulations with elder age or less education., Conclusions: This nationwide investigation provided robust evidence of the associations between short-term exposure to PM 2.5 and increased mortality from various cardiopulmonary diseases in China. The magnitude of associations was lower than those reported in Europe and North America.

Background: Practical approaches to protect individuals from ambient particulate matter (PM) are urgently needed in developing countries. Evidence on the health benefits of wearing particulate-filtering respirators is limited., Objectives: We evaluated the short-term cardiovascular health effects of wearing respirators in China., Methods: A randomized crossover trial was performed in 24 healthy young adults in Shanghai, China in 2014. The subjects were randomized into two groups and wore particulate-filtering respirators for 48 hr alternating with a 3-week washout interval. Heart rate variability (HRV) and ambulatory blood pressure (BP) were continuously monitored during the 2nd 24 hr in each intervention. Circulating biomarkers were measured at the end of each intervention. Linear mixed-effect models were applied to evaluate the effects of wearing respirators on health outcomes., Results: During the intervention periods, the mean daily average concentration of PM with an aerodynamic diameter < 2.5 μm (PM2.5) was 74.2 μg/m3. Compared with the absence of respirators, wearing respirators was associated with a decrease of 2.7 mmHg [95% confidence interval (CI): 0.1, 5.2 mmHg] in systolic BP and increases of HRV parameters, including 12.5% (95% CI: 3.8%, 21.2%) in high frequency (HF) power, 10.9% (95% CI: 1.8%, 20.0%) in the root mean square of the successive differences, and 22.1% (95% CI: 3.6%, 40.7%) in the percentage of normal RR intervals with duration > 50 msec different from the previous normal RR interval (pNN50). The presence of respirators was also associated with a decrease of 7.8% (95% CI: 3.5%, 12.1%) in the ratio of low frequency (LF)/HF power., Conclusions: Short-term wearing of particulate-filtering respirators may produce cardiovascular benefits by improving autonomic nervous function and reducing BP. Citation: Shi J, Lin Z, Chen R, Wang C, Yang C, Cai J, Lin J, Xu X, Ross JA, Zhao Z, Kan H. 2017. Cardiovascular benefits of wearing particulate-filtering respirators: a randomized crossover trial. Environ Health Perspect 125:175-180; http://dx.doi.org/10.1289/EHP73., Competing Interests: The authors declare they have no actual or potential competing financial interests.

Background: Ambient fine particulate matter (PM2.5) air pollution has been associated with increased airway inflammation, but the roles of various PM2.5 constituents remain to be determined., Objectives: To investigate the acute effects of PM2.5 constituents on fractional exhaled nitric oxide (FeNO), a well-established biomarker of respiratory inflammation., Methods: A longitudinal panel study was performed among 32 healthy young adults in Shanghai, China from January 12th to February 6th, 2015. FeNO was repeatedly measured, 6-8 times per subject. Real-time mass concentration of ambient PM2.5 and chemical constituents were obtained from a nearby monitoring station. Linear mixed-effect models were applied to evaluate the association between FeNO and PM2.5 constituents, with the adjustment of age, gender, body mass index, temperature, relative humidity and day of week. The robustness of constituents' effects was also evaluated., Results: A total of 234 effective measurements of FeNO were obtained with a geometric mean of 13.1 ppb. The PM2.5-FeNO associations were strongest at lags of 0-6h and diminished at lags longer than 12h. An interquartile range increase in PM2.5 constituents (NH4(+), NO3(-), K(+), SO4(2-) and elemental carbon) at lags of 0-6h were significantly associated with increments in FeNO by 12.3%, 11.3%, 11.1%, 9.6% and 10.7%, respectively. After controlling for PM2.5 total mass and the colinearity, only elemental carbon remained significant., Conclusion: Several chemical constituents of PM2.5 may impact FeNO following acute exposure. Elemental carbon in particular may be the primary component responsible for increased airway inflammation., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Ambient air pollution has been linked to the development of gestational diabetes mellitus (GDM). However, evidence of the association is very limited, and no study has estimated the effects of ozone., Objective: Our aim was to determine the association of prenatal exposures to particulate matter ≤ 2.5 μm (PM2.5) and ozone (O3) with GDM., Methods: We used Florida birth vital statistics records to investigate the association between the risk of GDM and two air pollutants (PM2.5 and O3) among 410,267 women who gave birth in Florida between 2004 and 2005. Individual air pollution exposure was assessed at the woman's home address at time of delivery using the hierarchical Bayesian space-time statistical model. We further estimated associations between air pollution exposures during different trimesters and GDM., Results: After controlling for nine covariates, we observed increased odds of GDM with per 5-μg/m3 increase in PM2.5 (ORTrimester1 = 1.16; 95% CI: 1.11, 1.21; ORTrimester2 = 1.15; 95% CI: 1.10, 1.20; ORPregnancy = 1.20; 95% CI: 1.13, 1.26) and per 5-ppb increase in O3 (ORTrimester1 = 1.09; 95% CI: 1.07, 1.11; ORTrimester2 = 1.12; 95% CI: 1.10, 1.14; ORPregnancy = 1.18; 95% CI: 1.15, 1.21) during both the first trimester and second trimester as well as the full pregnancy in single-pollutant models. Compared with the single-pollutant model, the ORs for O3 were almost identical in the co-pollutant model. However, the ORs for PM2.5 during the first trimester and the full pregnancy were attenuated, and no association was observed for PM2.5 during the second trimester in the co-pollutant model (OR = 1.02; 95% CI: 0.98, 1.07)., Conclusion: This population-based study suggests that exposure to air pollution during pregnancy is associated with increased risk of GDM in Florida, USA., Citation: Hu H, Ha S, Henderson BH, Warner TD, Roth J, Kan H, Xu X. 2015. Association of atmospheric particulate matter and ozone with gestational diabetes mellitus. Environ Health Perspect 123:853-859; http://dx.doi.org/10.1289/ehp.1408456.

Background: Short-term associations between size-fractionated particulate matter (PM) air pollution and circulating biomarkers are not well established, especially among diabetes patients., Methods: We conducted a longitudinal panel study involving 6 repeated measurements of 12 circulating biomarkers among 35 diabetes patients from April to June, 2013 in Shanghai, China. Real-time number and mass concentrations of PM with multiple size fractions between 0.25 and 10 μm were measured. Linear mixed-effect models were used to explore the associations between size-fractionated PM concentrations and blood biomarkers at different time windows., Results: Short-term exposure to PM was significantly associated with elevated levels of 5 biomarkers of inflammation, 3 biomarkers of coagulation and 1 vasoconstrictor. The effects varied considerably by particle size and time windows. Overall, PM with smaller size had stronger associations, and the most significant size fractions were 0.25-0.40 μm. Even 2 h exposure to PM can lead to a significant increase in biomarkers. The effects on biomarkers of inflammation and vasoconstriction were restricted to the first 12h after exposure, but the effects on coagulation persisted for 24-72 h. For example, an interquartile range increase in 2h average exposure to PM(0.25-0.40) was associated with 6-20% increase in biomarkers of inflammation, 19-38% in coagulation and 17% in vasoconstriction. PM had a stronger effect among male patients than female patients., Conclusions: Our results provided important evidence on the roles of the size and time windows of exposure in the PM-mediated effects on circulating biomarkers of inflammation, coagulation and vasoconstriction in diabetes patients in China., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Indoor exposure to fine particulate matter (PM2.5) from outdoor sources is a major health concern, especially in highly polluted developing countries such as China. Few studies have evaluated the effectiveness of indoor air purification on the improvement of cardiopulmonary health in these areas., Objectives: This study sought to evaluate whether a short-term indoor air purifier intervention improves cardiopulmonary health., Methods: We conducted a randomized, double-blind crossover trial among 35 healthy college students in Shanghai, China, in 2014. These students lived in dormitories that were randomized into 2 groups and alternated the use of true or sham air purifiers for 48 h with a 2-week washout interval. We measured 14 circulating biomarkers of inflammation, coagulation, and vasoconstriction; lung function; blood pressure (BP); and fractional exhaled nitric. We applied linear mixed-effect models to evaluate the effect of the intervention on health outcome variables., Results: On average, air purification resulted in a 57% reduction in PM2.5 concentration, from 96.2 to 41.3 μg/m3, within hours of operation. Air purification was significantly associated with decreases in geometric means of several circulating inflammatory and thrombogenic biomarkers, including 17.5% in monocyte chemoattractant protein-1, 68.1% in interleukin-1β, 32.8% in myeloperoxidase, and 64.9% in soluble CD40 ligand. Furthermore, systolic BP, diastolic BP, and fractional exhaled nitrous oxide were significantly decreased by 2.7%, 4.8%, and 17.0% in geometric mean, respectively. The impacts on lung function and vasoconstriction biomarkers were beneficial but not statistically significant., Conclusions: This intervention study demonstrated clear cardiopulmonary benefits of indoor air purification among young, healthy adults in a Chinese city with severe ambient particulate air pollution. (Intervention Study on the Health Impact of Air Filters in Chinese Adults; NCT02239744)., (Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Air pollution has been shown to have adverse effects on many health outcomes including cardiorespiratory diseases and cancer. However, evidence on the effects of prenatal exposure is still limited. The purpose of this retrospective cohort study is to evaluate the effects of prenatal exposure to air pollutants including particulate matter with aerodynamic diameter less than 2.5 μm (PM2.5) and ozone (O3) on the risk of adverse birth outcomes (ABOs) including term low birth weight (LBW), preterm delivery (PTD) and very PTD (VPTD)., Methods: singleton births from 2004 to 2005 in Florida were included in the study (N=423,719). Trimester-specific exposures to O3 and PM2.5 at maternal residence at delivery were estimated using the National Environmental Public Health Tracking Network data, which were interpolated using Hierarchical Bayesian models., Results: After adjustment for potential confounders such as demographics, medical and lifestyle factors PM2.5 exposures in all trimesters were found to be significantly and positively associated with the risk of all ABOs. Second-trimester exposure had the strongest effects. For an interquartile range (IQR) increase in PM2.5 during the second trimester, the risk of term LBW, PTD and VPTD increased by 3% [95% confidence interval (CI): 1-6%)], 12% (11-14%) and 22% (18-25%), respectively. O3 was also found to be positively associated with PTD and VPTD with the strongest effects over the whole pregnancy period [3% (1-5%) for PTD and 13% (7-19%) for VPTD for each IQR increase]. However, O3 was observed to have protective effects on term LBW. Results were consistent for multi-pollutant models., Conclusion: PM2.5 has consistent adverse effects on ABOs whereas O3 has inconsistent effects. These findings warrant further investigation., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Few prior cohort studies exist in developing countries examining the association of ambient particulate matter (PM) with mortality. We examined the association of particulate air pollution with mortality in a prospective cohort study of 71,431 middle-aged Chinese men. Baseline data were obtained during 1990-1991. The follow-up evaluation was completed in January, 2006. Annual average PM exposure between 1990 and 2005, including TSP and PM10, were estimated by linking fixed-site monitoring data with residential communities. We found significant associations between PM10 and mortality from cardiopulmonary diseases; each 10 μg/m(3) PM10 was associated with a 1.6% (95%CI: 0.7%, 2.6%), 1.8% (95%CI: 0.8%, 2.9%) and 1.7% (95%CI: 0.3%, 3.2%) increased risk of total, cardiovascular and respiratory mortality, respectively. For TSP, we observed significant associations only for cardiovascular morality. These data contribute to the scientific literature on long-term effects of particulate air pollution for high exposure settings typical in developing countries., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Air pollution has been accepted as an important contributor to asthma development and exacerbation. However, the evidence is limited in China. In this study, we investigated the acute effect of air pollution on asthma hospitalization in Shanghai, China. We applied over-dispersed generalized additive model adjusted for weather conditions, day of the week, long-term and seasonal trends. An interquartile range increase in the moving average concentrations of PM10, SO2, NO2 and BC on the concurrent day and previous day corresponded to 1.82%, 6.41%, 8.26% and 6.62% increase of asthmatic hospitalization, respectively. The effects of SO2 and NO2 were robust after adjustment for PM10. The associations appeared to be more evident in the cool season than in the warm season. Our results contribute to the limited data in the scientific literature on acute effects of air pollution on asthma in high exposure settings, which are typical in developing countries. [Copyright &y& Elsevier]

[Display omitted] Studies suggest associations between long-term ambient air pollution exposure and outcomes related to Alzheimer's disease (AD). Whether a link exists between pollutants and brain amyloid accumulation, a biomarker of AD, is unclear. We assessed whether long-term air pollutant exposures are associated with late-life brain amyloid deposition in Atherosclerosis Risk in Communities (ARIC) study participants. We used a chemical transport model with data fusion to estimate ambient concentrations of PM 2.5 and its components, NO 2 , NO x , O 3 (24-hour and 8-hour), CO, and airborne trace metals. We linked concentrations to geocoded participant addresses and calculated 10-year mean exposures (2002 to 2011). Brain amyloid deposition was measured using florbetapir amyloid positron emission tomography (PET) scans in 346 participants without dementia in 2012–2014, and we defined amyloid positivity as a global cortical standardized uptake value ratio ≥ the sample median of 1.2. We used logistic regression models to quantify the association between amyloid positivity and each air pollutant, adjusting for putative confounders. In sensitivity analyses, we considered whether use of alternate air pollution estimation approaches impacted findings for PM 2.5 , NO 2 , NO x , and 24-hour O 3. At PET imaging, eligible participants (N = 318) had a mean age of 78 years, 56% were female, 43% were Black, and 27% had mild cognitive impairment. We did not find evidence of associations between long-term exposure to any pollutant and brain amyloid positivity in adjusted models. Findings were materially unchanged in sensitivity analyses using alternate air pollution estimation approaches for PM 2.5 , NO 2 , NO x , and 24-hour O 3. Air pollution may impact cognition and dementia independent of amyloid accumulation, though whether air pollution influences AD pathogenesis later in the disease course or at higher exposure levels deserves further consideration. [ABSTRACT FROM AUTHOR]

Background: Few studies have evaluated the health benefits of omega-3 fatty acid supplementation against fine particulate matter (aerodynamic diameter <2.5 μm [PM2.5]) exposure in highly polluted areas.Objectives: The authors sought to evaluate whether dietary fish-oil supplementation protects cardiovascular health against PM2.5 exposure in China.Methods: This is a randomized, double-blinded, and placebo-controlled trial among 65 healthy college students in Shanghai, China. Participants were randomly assigned to either the placebo group or the intervention group with dietary fish-oil supplementation of 2.5 g/day from September 2017 to January 2018, and received 4 rounds of health examinations in the last 2 months of treatments. Fixed-site PM2.5 concentrations on campus were measured in real time. The authors measured blood pressure and 18 biomarkers of systematic inflammation, coagulation, endothelial function, oxidative stress, antioxidant activity, cardiometabolism, and neuroendocrine stress response. Acute effects of PM2.5 on these outcomes were evaluated within each group using linear mixed-effect models.Results: The average PM2.5 level was 38 μg/m3 during the study period. Compared with the placebo group, the fish-oil group showed relatively stable levels of most biomarkers in response to changes in PM2.5 exposure. Between-group differences associated with PM2.5 exposure varied by biomarkers and by lags of exposure. The authors observed beneficial effects of fish-oil supplementation on 5 biomarkers of blood inflammation, coagulation, endothelial function, oxidative stress, and neuroendocrine stress response in the fish-oil group at a false discovery rate of <0.05.Conclusions: This trial shows that omega-3 fatty acid supplementation is associated with short-term subclinical cardiovascular benefits against PM2.5 exposure among healthy young adults in China. (Effect of Dietary Supplemental Fish Oil in Alleviating Health Hazards Associated With Air Pollution; NCT03255187). [ABSTRACT FROM AUTHOR]

• The Navigation Guide review methodology is a transparent and rigorous approach. • Evidence supports an association between ambient PM and decreased birth weight. • High spatial resolution exposure assessment methods may help reduce heterogeneity. Low birth weight is an important risk factor for many co-morbidities both in early life as well as in adulthood. Numerous studies report associations between prenatal exposure to particulate matter (PM) air pollution and low birth weight. Previous systematic reviews and meta-analyses report varying effect sizes and significant heterogeneity between studies, but did not systematically evaluate the quality of individual studies or the overall body of evidence. We conducted a new systematic review to determine how prenatal exposure to PM 2.5 , PM 10 , and coarse PM (PM 2.5-10) by trimester and across pregnancy affects infant birth weight. Using the Navigation Guide methodology, we developed and applied a systematic review protocol [CRD42017058805] that included a comprehensive search of the epidemiological literature, risk of bias (ROB) determination, meta-analysis, and evidence evaluation, all using pre-established criteria. In total, 53 studies met our inclusion criteria, which included evaluation of birth weight as a continuous variable. For PM 2.5 and PM 10 , we restricted meta-analyses to studies determined overall as "low" or "probably low" ROB; none of the studies evaluating coarse PM were rated as "low" or "probably low" risk of bias, so all studies were used. For PM 2.5 , we observed that for every 10 µg/m3 increase in exposure to PM 2.5 in the 2nd or 3rd trimester, respectively, there was an associated 5.69 g decrease (I2: 68%, 95% CI: −10.58, −0.79) or 10.67 g decrease in birth weight (I2: 84%, 95% CI: −20.91, −0.43). Over the entire pregnancy, for every 10 µg/m3 increase in PM 2.5 exposure, there was an associated 27.55 g decrease in birth weight (I2: 94%, 95% CI: −48.45, −6.65). However, the quality of evidence for PM 2.5 was rated as "low" due to imprecision and/or unexplained heterogeneity among different studies. For PM 10 , we observed that for every 10 µg/m3 increase in exposure in the 3rd trimester or the entire pregnancy, there was a 6.57 g decrease (I2: 0%, 95% CI: −10.66, −2.48) or 8.65 g decrease in birth weight (I2: 84%, 95% CI: −16.83, −0.48), respectively. The quality of evidence for PM 10 was rated as "moderate," as heterogeneity was either absent or could be explained. The quality of evidence for coarse PM was rated as very low/low (for risk of bias and imprecision). Overall, while evidence for PM 2.5 and course PM was inadequate primarily due to heterogeneity and risk of bias, respectively, our results support the existence of an inverse association between prenatal PM 10 exposure and low birth weight. [ABSTRACT FROM AUTHOR]