Exposure to ambient PM2.5 associated with overall and domain-specific disability among adults in six low- and middle-income countries

The interaction between physical activity and ambient particulate matters on cognitive function among Chinese community-dwelling older adults

BACKGROUND

The interaction between physical activity (PA) and ambient particulate matters (PMs) on cognition is rarely investigated. Our study aimed to assess the interactions of PA and PMs on cognitive function in older adults.

METHODS

Our study comprised 3937 Chinese community-dwelling older adults. Cognition was evaluated using the Mini-Mental State Examination. PA information was gathered using the International Physical Activity Questionnaire. The data of PMs were obtained from China High Air Pollutants (CHAP). Linear regressions model and interaction plots were applied to assess and visualize the interaction of PA and PMs on cognition, respectively. Bayesian kernel machine regression (BKMR) method was employed to visualize discernible thresholds for the interaction.

RESULTS

PMs were negatively associated with MMSE scores (PM1: β = -0.40, 95 % CI: -0.58, -0.28; PM2.5: β = -0.46, 95 % CI: -0.64, -0.29; PM10: β = -0.44, 95 % CI: -0.61, -0.26), and PA was positively affiliated with MMSE scores (β = 0.18, 95 % CI: -0.01, 0.38). Interaction plots and BKMR demonstrated that adverse connotations of PMs with MMSE increased with the elevated PA levels, and the positive associations of PA with MMSE scores were attenuated by increased PMs (all Pinteraction < 0.20). Discernible thresholds for the interaction between PMs and PA on MMSE were found.

CONCLUSIONS

Our findings suggest that PA should not be taken at higher PMs concentrations, and that low level of PA could be performed in PMs polluted environment to improve cognitive function. Further experimental and cohort researches are required to reproduce our discovery.

Examining individual and contextual predictors of disability in Chinese older adults: A machine learning approach

BACKGROUND

There is a large gap of understanding the determinants of disability, especially the contextual characteristics. Therefore, this study aimed to examine the important predictors of disability in Chinese older adults based on the social ecological framework.

METHODS

We used the China Health and Retirement Longitudinal Study to examine predictors of disability, defined as self-report of any difficulty for six activity of daily living items. We restricted analytical sample to older adults aged 65 or above (N=1816). We considered 44 predictors, including personal-, behavioral-, interpersonal-, community-, and policy-level characteristics. The built-in variable importance measure (VIM) of random forest and SHapley Additive exPlanations (SHAP) were applied to assess key predictors of disability. A multilevel logit regression was further used to examine the associations of individual and contextual characteristics with disability.

RESULTS

The mean age of study sample was 72.62 years old (standard deviation: 5.77). During a 2-year of follow-up, 518 (28.52 %) of them developed into disability. Walking speed, age, and peak expiratory flow were the top important predictors in both VIM and SHAP. Contextual characteristics such as humidity, PM2.5, temperature, normalized difference vegetation index, and landscape also showed promise in predicting disability. Multilevel logit regression showed that people with male gender, arthritis, vision impairment, unable to finish semi tandem, no social activity, lower grip strength, and higher waist circumference, had much higher risk of disability.

CONCLUSION

Disability prevention strategies should specifically focus on multilevel factors such as individual and contextual characteristics, although the latter is warranted to be verified in future studies.

Severer air pollution, poorer cognitive function: Findings from 176,345 elders in Northwestern China

BACKGROUND

Limited evidence exists regarding the link between air pollution exposure and cognitive function in developing countries, particularly in areas with abundant natural sources of particulate matter.

OBJECTIVES

To investigate this association in a large representative sample of the elderly in northwestern China.

METHODS

We performed a cross-sectional study among 176,345 participants aged 60-100 years in northwestern China in 2020. A satellite-based spatiotemporal model was applied to assess three-year annual averages of particulate matter with an aerodynamic diameter ≤ 2.5 µm (PM2.5), ≤ 10 µm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3) at residential address. Poor cognitive function was assessed using the Mini-Mental State Examination (MMSE). Generalized linear mixed models were used to assess associations.

RESULTS

Compared with participants with the lowest quartiles of PM2.5, PM10, and O3 levels, those with the second, third, and highest quartiles of air pollutants consistently showed increased odds of poor cognitive function and decreased MMSE scores. The odds ratios of poor cognitive function associated with a 10 μg/m3 increment in PM2.5, PM10, and O3 were 1.26 (95 % confidence interval [CI]: 1.17, 1.36), 1.06 (95 %CI: 1.04, 1.08), and 2.76 (95 %CI: 2.11, 3.62), respectively. Subgroup analyses suggested stronger associations between air pollution exposures and poor cognitive function among participants who were younger, were non-Uyghur and were physically active.

CONCLUSION

Long-term exposures to PM2.5, PM10 and O3 were associated with poor cognitive function in elders. Our results suggest that reducing air pollution may alleviate the burden of poor cognitive function in the elderly.

Glaucoma in rural China (the Rural Epidemiology for Glaucoma in China (REG-China)): a national cross-sectional study

OBJECTIVE

This study aimed to investigate the prevalence of glaucoma with associated factors in the rural populations of 10 provinces in China.

DESIGN

A population-based cross-sectional study.

METHODS

All participants aged 6 years or older from 10 provinces completed visual acuity testing, slit-lamp examination, ophthalmoscopy and non-contact tonometry. Glaucoma suspects underwent fundus photography, Goldmann applanation tonometry, visual field testing and gonioscopy. Glaucoma was determined according to the International Society of Geographical and Epidemiological Ophthalmology classification scheme. Associations of demographics and medical factors with glaucoma were assessed using multiple logistic regression models.

RESULTS

From June 2017 to October 2018, 48 398 of 52 041 participants were included in the final analyses. The age-standardised prevalence of glaucoma was 1.7% (95% CI 1.55% to 1.78%) among the participants older than 6 years, which was 2.1% (95% CI 1.93% to 2.23%) in participants aged over 40 years. The constituent ratios of glaucoma were: 44.4% primary angle-closure glaucoma (PACG), 34.7% primary open-angle glaucoma, 2.6% congenital glaucoma and 18.3% other types of glaucoma. Increasing age, smoking, cerebral stroke, type 2 diabetes, higher education (college or more) and higher personal income were significant risk factors for PACG. The unilateral and bilateral blindness rates in the entire study population were 4.692% and 1.068%, respectively. A family history of glaucoma was a significant risk factor for the prevalence of glaucoma and blindness in at least one eye.

CONCLUSIONS

Rural populations have a high prevalence of glaucoma, which should be included in chronic disease management programmes in China for long-term care.

Leisure-time physical activity mitigated the cognitive effect of PM2.5 and PM2.5 components exposure: Evidence from a nationwide longitudinal study

BACKGROUND

Exposure to fine particulate matter (PM2.5) impairs cognition, while physical activity (PA) improves cognitive function. However, whether taking PA with PM2.5 exposure is still beneficial to cognition remains unknown.

METHODS

We utilized national representative longitudinal data from the China Family Panel Study (CFPS), comprising a total sample of 108,099 from 2010 to 2018 in three waves. Cognitive performance and leisure-time PA were measured using the standard cognitive module and Godin-Shephard Leisure-Time Physical Activity Questionnaire. Gridded overall PM2.5 and major chemical components of PM2.5 were estimated using a two-stage machine learning model and matched to each participant based on their residential location. Mixed-effect models and difference-in-difference models were employed to investigate the individual and joint effects of total PM2.5, PM2.5 components, and leisure-time PA on cognition.

RESULTS

Every 1 μg/m3 increase in PM2.5 was associated with a -0.035 (95% confidence interval [CI] = -0.052, -0.018) point change in cognitive score. All PM2.5 components exhibited negative associations with cognitive change, with black carbon (BC) contributing the most significant cognitive decline (β = -1.025, 95% CI = -1.367, -0.683). Every one-time (or one-hour) increase in leisure-time PA frequency (or PA time) per week was associated with an increase in cognitive score by 0.576 (0.270) points (PA frequency: 95% CI = 0.544, 0.608, PA time: 95% CI = 0.248, 0.293). PA frequency (β = -0.005, 95% CI = -0.006, -0.003) and PA time (β = -0.002, 95% CI = -0.003, -0.001) exhibited interactive effects with PM2.5. Increased PA frequency and time were more beneficial to cognitive function in the low PM2.5 exposure group compared to those exposed to high PM2.5 levels. Moreover, relative to lower PM2.5 exposure, the cognitive benefits of physically active individuals with higher PM2.5 exposure were attenuated but still improved cognition when compared to those with no PA.

CONCLUSION

Engaging in leisure-time PA provides cognitive benefits even under PM2.5 exposure, although PM2.5 exposure attenuates these benefits. Among all PM2.5 components, BC demonstrated the most significant cognitive hazard and interaction with leisure-time PA. Promoting PA as a preventive measure may offer a cost-effective and convenient strategy to mitigate the negative impact of PM2.5 exposure on cognition. There is no excuse to avoid PA under PM2.5 exposure, as its cognitive benefits persist even in polluted environments.

Exposure to quasi-ultrafine particulate matter accelerates memory impairment and Alzheimer's disease-like neuropathology in the AppNL-G-F knock-in mouse model

Exposure to traffic-related air pollution consisting of particulate matter (PM) is associated with cognitive decline leading to Alzheimer's disease (AD). In this study, we sought to examine the neurotoxic effects of exposure to ultrafine PM and how it exacerbates neuronal loss and AD-like neuropathology in wildtype (WT) mice and a knock-in mouse model of AD (AppNL-G-F/+-KI) when the exposure occurs at a prepathologic stage or at a later age with the presence of neuropathology. AppNL-G-F/+-KI and WT mice were exposed to concentrated ultrafine PM from local ambient air in Irvine, California, for 12 weeks, starting at 3 or 9 months of age. Particulate matter-exposed animals received concentrated ultrafine PM up to 8 times above the ambient levels, whereas control animals were exposed to purified air. Particulate matter exposure resulted in a marked impairment of memory tasks in prepathologic AppNL-G-F/+-KI mice without measurable changes in amyloid-β pathology, synaptic degeneration, and neuroinflammation. At aged, both WT and AppNL-G-F/+-KI mice exposed to PM showed a significant memory impairment along with neuronal loss. In AppNL-G-F/+-KI mice, we also detected an increased amyloid-β buildup and potentially harmful glial activation including ferritin-positive microglia and C3-positive astrocytes. Such glial activation could promote the cascade of degenerative consequences in the brain. Our results suggest that exposure to PM impairs cognitive function at both ages while exacerbation of AD-related pathology and neuronal loss may depend on the stage of pathology, aging, and/or state of glial activation. Further studies will be required to unveil the neurotoxic role of glial activation activated by PM exposure.

Does physical activity attenuate the association between ambient PM2.5 and physical function?

BACKGROUND

Physical function (PF), such as muscle strength, performing daily activities, has gradually declined with the increase of age, causing the occurrence of disability and diseases burden. Air pollution exposure and physical activity (PA) were both linked to PF. We aimed to explore the individual and joint effects of particulate matter <2.5 μm (PM_2.5) and PA on PF.

METHODS

A total of 4537 participants and 12,011 observations aged ≥45 years old from the China Health and Retirement Longitudinal Study (CHARLS) cohort from 2011 to 2015 were included into the study. PF was assessed by a combined score of four tests, including grip strength, walking speed, sense of balance, and chair standing tests. Air pollution exposure data was from The ChinaHighAirPollutants (CHAP) dataset. The annual PM_2.5 exposure for each individual was estimated based on county-level resident addresses. We estimated the volume of moderate-to-vigorous physical activity (MVPA) by quoting metabolic equivalent (MET). Multivariate linear model was conducted for baseline analysis, and linear mixed model with random participant intercepts was constructed for cohort longitudinal analysis.

RESULTS

PM_2.5 was negatively associated with PF, while PA was positively associated with PF in baseline analysis. In cohort longitudinal analysis, a 10 μg/m³ increase in PM_2.5 was associated to a 0.025 point (95 % CI: -0.047, -0.003) decrease in PF score, and a 10-MET-h/week increase in PA was related to a 0.004 point (95 % CI: 0.001, 0.008) increase in PF score. The association between PM_2.5 and PF decreased by increased PA intensity, and PA reversed the detrimental effects between PM_2.5 and PF.

CONCLUSION

PA attenuated the association of air pollution with PF at both high and low levels of air pollution, implying that PA may be an effective behavior to reduce the adverse effects of poor air quality on PF.

The effect of PM2.5 levels on continuum functional capability among older adults: Potential cause-effect or statistical associations

BACKGROUND

Since there is limited knowledge about health effects of the clean air policy (CAP, i.e., a series of emission-control actions) on continuum functional capacity (CFC) among the older adults on a large representative data, our research was to fill this gap.

METHODS

We used a continuous variable of airborne fine particulate matter (PM_2.5) particles as a proxy for the CAP to evaluate the linear and non-linear effect of PM_2.5 exposure on CFC of older adults, under the quasi-experimental framework of the temporal contrast between 2011 (before the CAP) and 2015 (after the CAP). Multiple environmental factors were considered and spline function was utilized to fit the spatial autocorrelations. A competing risk model was constructed to qualify the impact of PM_2.5 on multidimensional disability.

RESULTS

After adjusting for potential confounders, a J-shaped association was found between PM_2.5 concentration increase on CFC, with a threshold 2μg/m³. We also demonstrated that a 10-µg/m³ increase in PM_2.5 concentration was related to a 14.0% (95% CI:0.00, 19.00%) increment risk in the functional decline. Similarly, the competing risk model presented a hazard ratio of multidimensional disability ranging from 1.707(0.928-4.141) at 40μg/m³ concentration of PM_2.5 to 4.384 (1.970-9.755) over 80μg/m³. Stratified analyses showed that married men less than 80 years old in rural areas are more likely to be affected by PM_2.5 exposure, where the influencing mechanism of air pollutant to outdoor and indoor activities might be the potential cause.

CONCLUSION

Implementing CAP might improve CFC, prevent the occurrence of disability, and update the air policy.

The impact of air pollution on physical disability in a middle-aged and older Chinese population using regression discontinuity design

Emerging evidence has shown the association between ambient air pollution exposure and comorbid chronic diseases, which can subsequently impair physical function. However, less is known about the causal and contextual effect of air pollution on physical disability. Using data from the China Health and Retirement Longitudinal Study (CHARLS), this study employs a geographical regression discontinuity design based on the Huai River Policy to estimate the impact of ambient air pollution on physical disability in activities of daily living (ADL) in China. We find that a 10 μg/m³ increase in particulate matter [particulate matter smaller than 10 μm (PM₁₀)] leads to a 5.4% increase in the incidence of physical disability among middle-aged and older adults. This result is robust to using alternative measurement of key variables, different bandwidths and polynomial functions, and adjustment for a set of sociodemographic covariates. Stroke might be one of the potential pathological pathways linking air pollution and physical disability, with a 10 μg/m³ increase in PM₁₀ leading to a 4.7% increase in the incidence of stroke. In heterogeneity analyses, we find that older adults, males, urban residents, and people with lower socioeconomic status are more vulnerable to air pollution. These results contribute to the limited evidence on the causal and contextual effect of air pollution on physical health, and further provide policy implications for air quality control and health protection for vulnerable populations.

The path to healthy ageing in China: a Peking University-Lancet Commission

Around the world, populations are ageing at a faster pace than in the past and this demographic transition will have impacts on all aspects of societies. In May 2020, the UN General Assembly declared 2021–2030 the Decade of Healthy Ageing, highlighting the importance for policymakers across the world to focus policy on improving the lives of older people, both today and in the future. While rapid population ageing poses challenges, China’s rapid economic growth over the last forty years has created space for policy to assist older persons and families in their efforts to improve health and well-being at older ages. As China is home to 1/5 of the world’s older people, China is often held up as an example for other middle-income countries. This Commission Report aims to help readers to understand the process of healthy ageing in China as a means of drawing lessons from the China experience. In addition, with the purpose of informing the ongoing policy dialogue within China, the Commission Report highlights the policy challenges on the horizon and draws lessons from international experience.

Associations between household solid fuel use and activities of daily living trajectories: A nationwide longitudinal study of middle and older adults in China

BACKGROUND

More studies focus on reporting the effects of ambient air pollution on physical activity while ignoring the hazards of indoor air pollution caused by household solid fuel use. Moreover, the impact of individual cognitive and depressive status on the health effects of air pollution is often overlooked.

OBJECTIVE

We examined the association between household solid fuel and activities of daily living (ADL) trajectories, and further examined this association in homogeneous subgroups of cognitive or depressive trajectories.

METHODS

Participants were from the China Health and Retirement Longitudinal Study, which conducted four waves of surveys from 2011 to 2018. We collected information on participants' household fuel use, then the ADL, cognitive and depressive performances were assessed in each wave. The latent growth mixture model (LGMM) was used to identify the optimal trajectory class for ADL, cognition, and depression. Then, the multinomial logistic regression was used to assess the association between solid fuel use and ADL trajectories in total population, as well as subgroups with different cognitive or depression trajectories. Furthermore, we examined the association between switching household fuel types and ADL trajectories across the four-wave survey.

RESULTS

The study sample included 7052 participants. We identified three ADL trajectory classes in total population: "Low-stable", "Moderate-anterior rise", and "Moderate-posterior rise". The multinomial logistic regression results showed that solid fuel use was associated with elevated odds for the adverse ADL trajectories, and this association was still shown in homogeneous subgroups of cognitive or depressive trajectories, while some effects were less significant. In addition, the risk of adverse ADL trajectories generally increases with the times of solid fuel use across the four-wave survey.

CONCLUSIONS

For middle and older adults in China, household solid fuel use was not conducive to physical activity development, which inspires that a further transformation to cleaner fuels is an important intervention.

Perfluoroalkyl substances (PFASs) as risk factors for breast cancer: a case-control study in Chinese population

BACKGROUND

Perfluoroalkyl substances (PFASs) are a large family of synthetic chemicals, some of which are mammary toxicants and endocrine disruptors. Recent studies have implicated exposure to PFASs as a risk factor for breast cancer in Europe and America. Little is known about the role of PFASs with respect to breast cancer in the Chinese population.

METHODS

Participants who were initially diagnosed with breast cancer at Tianjin Medical University Cancer Institute and Hospital between 2012 and 2016 were recruited as cases. The controls were randomly selected from the participants with available blood samples in the Chinese National Breast Cancer Screening Program (CNBCSP) cohort. Ultimately, we enrolled 373 breast cancer patients and 657 controls. Plasma PFASs were measured by an ultra-performance liquid chromatography (UPLC) system coupled to a 5500 Q-Trap triple quadrupole mass spectrometer. A logistic regression model with least absolute shrinkage and selection operator (LASSO) regularization was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) to assess the relationships between PFASs and breast cancer. The three most predictive variables in the LASSO model were selected from 17 PFASs, which was based on the optimal penalty coefficient (λ = 0.0218) identified with the minimum criterion. Additionally, Bayesian kernel machine regression (BKMR) and quantile g-computation models were applied to evaluate the associations between separate and mixed exposure to PFASs and breast cancer.

RESULTS

Perfluorooctanesulfonic acid (PFOS) exhibited the highest concentration in both the cases and controls. Perfluorooctanoic acid (PFOA) and perfluoro-n-decanoic acid (PFDA) were positively associated with breast cancer, and perfluoro-n-tridecanoic acid (PFTrDA) was negatively associated with breast cancer according to both the continuous-PFASs and the quartile-PFASs logistic regression models. Of note, PFOA was associated with the occurrence of estrogen receptor (ER)-, progesterone receptor (PR)-, and human epidermal growth factor receptor 2 (HER2)-positive breast cancer (OR_ER+  = 1.47, 95% CI: 1.19, 1.80; OR_PR+  = 1.36, 95% CI: 1.09, 1.69; OR_HER2 = 1.62, 95% CI: 1.19, 2.21).

CONCLUSIONS

Overall, we observed that PFASs were associated with breast cancer in Chinese women. Prospective cohort studies and mechanistic experiments are warranted to elucidate whether these associations are causal.

Neighborhood characteristics as confounders and effect modifiers for the association between air pollution exposure and subjective cognitive functioning

BACKGROUND

Air pollution has been associated with cognitive function in the elderly. Previous studies have not evaluated the simultaneous effect of neighborhood-level socioeconomic status (N-SES), which can be an essential source of bias.

OBJECTIVES

We explored N-SES as a confounder and effect modifier in a cross-sectional study of air pollution and subjective cognitive function.

METHODS

We included 12,058 participants age 50+ years from the Emory Healthy Aging Study in Metro Atlanta using the Cognitive Function Instrument (CFI) score as our outcome, with higher scores representing worse subjective cognitive function. We estimated 9-year average ambient carbon monoxide (CO), nitrogen oxides (NOx), and fine particulate matter (PM2.5) concentrations at residential addresses using a fusion of dispersion and chemical transport models. We collected census-tract level N-SES indicators and created two composite measures via principal component analysis and k-means clustering. Associations between pollutants and CFI and effect modification by N-SES were estimated via linear regression models adjusted for age, education, race and N-SES.

RESULTS

N-SES confounded the association between air pollution and CFI, independent of individual characteristics. We found significant effect modifications by N-SES for the association between air pollution and CFI (p-values<0.001) suggesting that effects of air pollution differ depending on N-SES. Participants living in areas with low N-SES were most vulnerable to air pollution. In the lowest N-SES urban areas, interquartile range (IQR) increases in CO, NOx, and PM2.5 were associated with 5.4% (95%-confidence interval, -0.2,11.3), 4.9% (-0.4,10.4), and 9.8% (2.2,18.0) changes in CFI, respectively. In lowest N-SES suburban areas, IQR increases in CO, NOx, and PM2.5 were associated with higher changes in CFI, namely 13.0% (0.9,26.5), 13.0% (-0.1,27.8), and 17.3% (2.5,34.2), respectively.

DISCUSSION

N-SES is an important confounder and effect modifier in our study. This finding could have implications for studying health effects of air pollution and identifying susceptible populations.

Association of Air Pollution and Weather Factors with Traffic Injury Severity: A Study in Taiwan

Exposure to air pollutants may elevate the injury severity scores (ISSs) for road traffic injuries (RTIs). This multicenter cross-sectional study aimed to investigate the associations between air pollution, weather conditions, and RTI severity. This retrospective study was performed in Taiwan in 2018. The location of each road traffic accident (RTA) was used to determine the nearest air quality monitoring and weather station, and the time of each RTA was matched to the corresponding hourly air pollutant concentration and weather factors. Five multiple logistic regression models were used to compute the risk of sustaining severe injury (ISS ≥ 9). Of the 14,973 patients with RTIs, 2853 sustained severe injury. Moderate or unhealthy air quality index, higher exposure to particulate matter ≤2.5 μm in diameter, bicyclists or pedestrians, greater road width, nighttime, and higher temperature and relative humidity were significant risk factors for severe injury. Exposure to nitrogen oxide and ozone did not increase the risk. Auto occupants and scene-to-hospital time were the protective factors. Sensitivity analyses showed consistent results between air pollutants and the risk of severe injury. Poor air quality and hot and humid weather conditions were associated with severe RTIs. Active commuters were at higher risk of sustaining severe RTI.

Residential proximity to major roadway and progression in physical disability in older adults in China

Evidence of a connection between living near major roadway and adverse health outcome has come to light. However, little is known about the effect of residential traffic exposure on aging-related physical disability and whether this effect can be modified. We used data derived from Chinese Longitudinal Healthy Longevity Surveys in 2018, with a total of 15,771 participants aged ≥ 65. Residential proximity to major roadway was used as a surrogate for traffic-related air pollution and physical function was measured using basic and instrumental activities of daily living. Logistic regression models were adopted for the analyses. Compared with those living > 300 m from major road, participants living within 200 m had higher risk of poorer physical functioning. The peak odds ratio was observed in severe disability caused by 101-200 m distance (OR = 1.34, 95% CI: 1.08, 1.66). And this association got stronger with longer duration of living close to major road. In dichotomized analyses using 200 m as a cutoff point, the effect associated with living close to major road was greater in male and current smoker. Specially, poor physical function appears earlier in female, but less severe than that in male. The result emphasizes the adverse effect of residential proximity to major roadways to aging-related declines in health-especially for basic living ability. This association was more pronounced in male and current smokers, which cannot be reversed by lowering the indoor air pollution.

An investigation for airflow and deposition of PM2.5 contaminated with SAR-CoV-2 virus in healthy and diseased human airway

This study is motivated by the amplified transmission rates of the SAR-CoV-2 virus in areas with high concentrations of fine particulates (PM_2.5) as reported in northern Italy and Mexico. To develop a deeper understanding of the contribution of PM_2.5 in the propagation of the SAR-CoV-2 virus in the population, the deposition patterns and efficiencies (DEs) of PM_2.5 laced with the virus in healthy and asthmatic airways are studied. Physiologically correct 3-D models for generations 10-12 of the human airways are applied to carry out a numerical analysis of two-phase flow for full breathing cycles. Two concentrations of PM_2.5 are applied for the simulation, i.e., 30 μg⋅m^-3 and 80 μg⋅m^-3 for three breathing statuses, i.e., rest, light exercise, and moderate activity. All the PM_2.5 injected into the control volume is assumed to be 100% contaminated with the SAR-CoV-2 virus. Skewed air-flow phenomena at the bifurcations are proportional to the Reynolds number at the inlet, and their intensity in the asthmatic airway exceeded that of the healthy one. Upon exhalation, two peak air-flow vectors from daughter branches combine to form one big vector in the parent generation. Asthmatic airway models has higher deposition efficiencies (DEs) for contaminated PM_2.5 as compared to the healthy one. Higher DEs arise in the asthmatic airway model due to complex secondary flows which increase the impaction of contaminated PM_2.5 on airways' walls.

A critical review of the epidemiological evidence of effects of air pollution on dementia, cognitive function and cognitive decline in adult population

Dementia is arguably the most pressing public health challenge of our age. Since dementia does not have a cure, identifying risk factors that can be controlled has become paramount to reduce the personal, societal and economic burden of dementia. The relationship between exposure to air pollution and effects on cognitive function, cognitive decline and dementia has stimulated increasing scientific interest in the past few years. This review of the literature critically examines the available epidemiological evidence of associations between exposure to ambient air pollutants, cognitive performance, acceleration of cognitive decline, risk of developing dementia, neuroimaging and neurological biomarker studies, following Bradford Hill guidelines for causality. The evidence reviewed has been consistent in reporting associations between chronic exposure to air pollution and reduced global cognition, as well as impairment in specific cognitive domains including visuo-spatial abilities. Cognitive decline and dementia incidence have also been consistently associated with exposure to air pollution. The neuro-imaging studies reviewed report associations between exposure to air pollution and white matter volume reduction. Other reported effects include reduction in gray matter, larger ventricular volume, and smaller corpus callosum. Findings relating to ischemic (white matter hyperintensities/silent cerebral infarcts) and hemorrhagic (cerebral microbleeds) markers of cerebral small vessel disease have been heterogeneous, as have observations on hippocampal volume and air pollution. The few studies available on neuro-inflammation tend to report associations with exposure to air pollution. Several effect modifiers have been suggested in the literature, but more replication studies are required. Traditional confounding factors have been controlled or adjusted for in most of the reviewed studies. Additional confounding factors have also been considered, but the inclusion of these has varied among the different studies. Despite all the efforts to adjust for confounding factors, residual confounding cannot be completely ruled out, especially since the factors affecting cognition and dementia are not yet fully understood. The available evidence meets many of the Bradford Hill guidelines for causality. The reported associations between a range of air pollutants and effects on cognitive function in older people, including the acceleration of cognitive decline and the induction of dementia, are likely to be causal in nature. However, the diversity of study designs, air pollutants and endpoints examined precludes the attribution of these adverse effects to a single class of pollutant and makes meta-analysis inappropriate.

Protocol to assess the efficacy of carnosine supplementation in mitigating the adverse cardiovascular responses to particulate matter (PM) exposure: the Nucleophilic Defense Against PM Toxicity (NEAT) trial

INTRODUCTION

Exposure to airborne particulate matter (PM) is associated with cardiovascular disease. These outcomes are believed to originate from pulmonary oxidative stress and the systemic delivery of oxidised biomolecules (eg, aldehydes) generated in the lungs. Carnosine is an endogenous di-peptide (β-alanine-L-histidine) which promotes physiological homeostasis in part by conjugating to and neutralising toxic aldehydes. We hypothesise that an increase of endogenous carnosine by dietary supplementation would mitigate the adverse cardiovascular outcomes associated with PM exposure in humans.

METHODS AND ANALYSIS

To test this, we designed the Nucleophilic Defense Against PM Toxicity trial. This trial will enroll 240 participants over 2 years and determine if carnosine supplementation mitigates the adverse effects of PM inhalation. The participants will have low levels of endogenous carnosine to facilitate identification of supplementation-specific outcomes. At enrollment, we will measure several indices of inflammation, preclinical cardiovascular disease and physical function. Participants will be randomly allocated to carnosine or placebo groups and instructed to take their oral supplement for 12 weeks with two return clinical visits and repeated assessments during times of peak PM exposure (June-September) in Louisville, Kentucky, USA. Statistical modelling approaches will be used to assess the efficacy of carnosine supplementation in mitigating adverse outcomes.

ETHICS AND DISSEMINATION

This study protocol has been approved by the Institutional Review Board at the University of Louisville. Results from this study will be disseminated at scientific conferences and in peer-reviewed publications.Trial registration: NCT03314987; Pre-results.

Characteristics of airborne bacterial communities in indoor and outdoor environments during continuous haze events in Beijing: Implications for health care

There is solid evidence that haze pollution threatens human health owing to the abiotic pollutants it contains. However, the characteristics of airborne bacterial communities in indoor and outdoor environments exhibiting haze occurrence are still unknown. Thus, we examined variations in both indoor and outdoor airborne bacterial communities in Beijing from December 9-27, 2016, a period which included three haze events. The outdoor airborne bacterial communities were clustered into two main groups (Groups I and II), and they shifted between two typical bacterial communities regardless of the haze event. The Chao1, Shannon, and phylogenetic diversity indexes and abundance of dominant classes changed significantly, as did airborne bacterial community type. The indoor airborne bacterial community closely tracked the outdoor bacterial community type, forming two obvious groups supported by Adonis analysis, changes in dominant classes, and bacterial diversity compared to the outdoor group. Furthermore, we found that the airborne bacterial community type could affect the morbidity of respiratory diseases. Daily pneumonia cases were significantly higher in Group I (p = 0.035), whereas daily amygdalitis cases were significantly higher in Group II (p = 0.025). Interestingly, the enriched classes in the indoor environment were quite different from those in the typical airborne bacterial community environment, except for Clostridia, which had significantly higher abundance in both indoor environments. In conclusion, we found that the two indoor and outdoor airborne bacterial community types changed independently of haze events, and the special airborne bacterial community type was closely related to the incidence of pneumonia in the heavy haze season.

Long-term exposure to PM2.5 and incidence of disability in activities of daily living among oldest old

Currently the Chinese government has adopted World Health Organization interim target-1 values as the national ambient air quality standards values. However, the population-based evidence was insufficient, especially for the oldest old (aged 80+). We evaluated the association of fine particulate matters (PM_2.5) exposure and incidence of disability in activities of daily living (ADL) in 15 453 oldest old in 886 counties/cities in China from 2002 to 2014 using Cox model with penalized splines and competing risk models to evaluate the linear or non-linear association. After adjusting for potential confounders, a J-shaped association existed between PM_2.5 exposure with a threshold concentration of 33 μg/m³, and incident disability in ADL. Above this threshold, the risk magnitude significantly increased with increase of PM_2.5 concentrations; compared to 33 μg/m³, the hazard ratio ranged from 1.03 (1.00-1.06) at 40 μg/m³ to 2.25 (1.54-3.29) at 110 μg/m³. The risk magnitude was not significantly changed below this threshold. Each 10 μg/m³ increase in PM_2.5 exposure corresponded to a 7.7% increase in the risk of disability in ADL (hazard ratio 1.077, 95% CI 1.051-1.104). Men, smokers, and participants with cognitive impairment might be more vulnerable to PM_2.5 exposure. The study provided limited population-based evidence for the oldest old and detected a threshold of 33 μg/m³, and supported that reduction to current World Health Organization interim target-1value (35 μg/m³) and Chinese national ambient air quality standards (35 μg/m³) or lower may be associated with lower risk of disability in ADL.

Association of Indoor and Outdoor Air Pollution With Hand-Grip Strength Among Adults in Six Low- and Middle-Income Countries

BACKGROUND

Air pollution has been associated with various health outcomes. Its effect on hand-grip strength, a measurement of the construct of muscle strength and health status, remains largely unknown.

METHODS

We used the survey data from 31,209 adults ≥ 50 years of age within Wave 1 of the Study on Global AGEing and Adult Health in six low- and middle-income countries. The outdoor concentration of fine particulate matter pollution (PM2.5) was estimated using satellite data. Domestic fuel type and ventilation were used as indicators of indoor air pollution. We used multilevel linear regression models to examine the association between indoor and outdoor air pollution and hand-grip strength, as well as the potential effect modifiers.

RESULTS

We found inverse associations between both indoor and outdoor air pollution and hand-grip strength. Each 10 μg/m3 increase in 3 years' averaged concentrations of outdoor PM2.5 corresponded to 0.70 kg (95% CI: -1.26, -0.14) lower hand-grip strength; and compared with electricity/liquid/gas fuel users, those using solid fuels had lower hand-grip strength (β = -1.25, 95% CI: -1.74, -0.75). However, we did not observe a statistically significant association between ventilation and hand-grip strength. We further observed that urban residents and those having a higher education level had a higher association between ambient PM2.5 and hand-grip strength, and men, young participants, smokers, rural participants, and those with lower household income had higher associations between indoor air pollution and hand-grip strength.

CONCLUSION

This study suggests that both indoor and outdoor air pollution might be important risk factors of poorer health and functional status as indicated by hand-grip strength.

Air Pollution (Particulate Matter) Exposure and Associations with Depression, Anxiety, Bipolar, Psychosis and Suicide Risk: A Systematic Review and Meta-Analysis

BACKGROUND

Particulate air pollution's physical health effects are well known, but associations between particulate matter (PM) exposure and mental illness have not yet been established. However, there is increasing interest in emerging evidence supporting a possible etiological link.

OBJECTIVES

This systematic review aims to provide a comprehensive overview and synthesis of the epidemiological literature to date by investigating quantitative associations between PM and multiple adverse mental health outcomes (depression, anxiety, bipolar disorder, psychosis, or suicide).

METHODS

We undertook a systematic review and meta-analysis. We searched Medline, PsycINFO, and EMBASE from January 1974 to September 2017 for English-language human observational studies reporting quantitative associations between exposure to PM < 1.0 μ m in aerodynamic diameter (ultrafine particles) and PM < 2.5 and < 10 μ m in aerodynamic diameter (PM 2.5 and PM 10 , respectively) and the above psychiatric outcomes. We extracted data, appraised study quality using a published quality assessment tool, summarized methodological approaches, and conducted meta-analyses where appropriate.

RESULTS

Of 1,826 citations identified, 22 met our overall inclusion criteria, and we included 9 in our primary meta-analyses. In our meta-analysis of associations between long-term (> 6   months ) PM 2.5 exposure and depression (n = 5 studies), the pooled odds ratio was 1.102 per 10 - μ g / m 3 PM 2.5 increase (95% CI: 1.023, 1.189; I 2 = 0.00 % ). Two of the included studies investigating associations between long-term PM 2.5 exposure and anxiety also reported statistically significant positive associations, and we found a statistically significant association between short-term PM 10 exposure and suicide in meta-analysis at a 0-2 d cumulative exposure lag.

DISCUSSION

Our findings support the hypothesis of an association between long-term PM 2.5 exposure and depression, as well as supporting hypotheses of possible associations between long-term PM 2.5 exposure and anxiety and between short-term PM 10 exposure and suicide. The limited literature and methodological challenges in this field, including heterogeneous outcome definitions, exposure assessment, and residual confounding, suggest further high-quality studies are warranted to investigate potentially causal associations between air pollution and poor mental health. https://doi.org/10.1289/EHP4595.

Metal-containing Particulate Matter and Associated Reduced Olfactory Identification Ability in Children from an Area of High Atmospheric Exposure in Mexico City

Air pollution has been linked to poor olfactory function in human adults. Among pollutants, particulate matter (PM) is especially relevant, as it may contain toxic metal ions that can reach the brain via olfactory pathways. Our purpose was to investigate the relation between atmospheric PM and olfactory identification performance in children. Using a validated method, we tested the olfactory identification performance of 120 children, 6–12 years old, from two locations in Mexico City: a focal group (n = 60) from a region with high PM levels and a control group of equal size and similar socioeconomic level from a region with markedly lower PM concentrations. Groups were matched for age and sex. Concentrations of manganese and lead in the hair of participants were determined as biomarkers of exposure. Daily outdoor PM levels were obtained from official records, and indoor PM levels were measured in the children’s classrooms. Official records confirmed higher levels of outdoor PM in the focal region during the days of testing. We also found higher classroom PM concentrations at the focal site. Children from the focal site had on average significantly lower olfactory identification scores than controls, and hair analysis showed significantly higher levels of manganese for the focal children but no difference in lead. Children appear to be vulnerable to the effects of air pollution on olfactory identification performance, and metal-containing particles likely play a role in this. Olfactory tests provide a sensitive, noninvasive means to assess central nervous function in populations facing poor air quality.

Short-term and long-term effects of PM2.5 on acute nasopharyngitis in 10 communities of Guangdong, China

OBJECTIVES

We aimed to assess the effects of short-term and long-term exposure to ambient fine particle matter (PM_2.5) on acute nasopharyngitis.

METHODS

A total of 9468 participants aged 18 years and above were recruited from 10 communities in four cities of Guangdong, China during the baseline survey in 2014, and they were followed-up from January 2015 to December 2016. Air pollution exposure was assessed based on the daily concentrations (short-term) and annual concentrations (long-term) of the nearby air monitoring station and the survey date. A mixed-effect logistic model and Cox proportional hazards model were used to quantify the short-term and long-term associations after adjustment for potential confounding factors.

RESULTS

Significantly positive associations were found between both short-term and long-term exposures of PM_2.5 and acute nasopharyngitis. The adjusted odds ratio was 1.15 (95% CI: 1.07, 1.23) for each 10 μg/m³ increase in daily PM_2.5 at lag2 day (short-term effects), and the hazard risk was 1.18 (95% CI: 1.10, 1.25) for each 10 μg/m³ increase in annual PM_2.5 (long-term effects). Stronger associations between short-term PM_2.5 exposure and acute nasopharyngitis were observed among men (OR = 1.10; 95% CI: 1.04, 1.17) and participants aged above 65 years (OR = 1.13; 95% CI: 1.04, 1.23) in the stratified analyses. No significant association was found in women (OR = 1.00; 95% CI: 0.92, 1.10) or young participants ≤65 years (OR = 0.96; 95% CI: 0.88, 1.04). However, for the long-term exposure, the hazard risk was higher for participants younger than 65 years (OR = 1.22; 95% CI: 1.12, 1.32) than the older group (OR = 1.11; 95% CI: 1.00, 1.24).

CONCLUSION

This study indicates that both short-term and long-term exposures to higher concentrations of PM_2.5 could increase the risk of acute nasopharyngitis.

What is the health cost of haze pollution? Evidence from China

INTRODUCTION

Haze pollution has become a serious threat to the health of residents and has brought about considerable economic costs. The objectives of this study are to examine the relationship between haze pollution and residents' health and to estimate the health cost of haze pollution.

METHODS

Using macro data on 74 major Chinese cities, this study employs a static panel data model and a dynamic panel generalized method of moments model to investigate the impact of haze pollution on the mortality of residents. On the basis of the estimation results, the value of a statistical life (VOSL) method is used to evaluate the economic cost of haze pollution on residents' health.

RESULTS

In 74 major cities of China, an increase in concentration of PM_2.5 pollutants by 1 μg/m³ may cause the mortality rate to rise by 25 per million people. The VOSL of haze pollution in China is about 1.53 million yuan. The health cost of residents from haze in 74 major cities of China in 2016 was about 888 billion yuan, equivalent to about 2% of the these cities' GDP.

CONCLUSIONS

Haze pollution has serious damage to the health of urban residents and therefore brings about considerable economic losses.

Estimating the spatial distribution of environmental suitability for female lung cancer mortality in China based on a novel statistical method

Lung cancer as one of the major causes of cancer mortality has been demonstrated to be closely related to the ambient atmospheric environment, but little has been done in the synthetic evaluation of the linkage between cancer mortality and combined impact of ambient air pollution and meteorological conditions. The present study determined the environmental suitability for female lung cancer mortality associated with air contaminants and meteorological variables. A novel fuzzy matter-element method was applied to identify the spatial distribution and regions for the environmental suitability for the female lung cancer mortality across China in 2013. The membership functions between the cancer mortality and 6 environmental factors, including PM_2.5, NO₂, SO₂, PM₁₀, the annual mean wind speed, and mean temperature, were generated and the weights of each of the environmental factors were established by the maximum entropy (MaxEnt) model. We categorized the environmental suitability combined with GIS spatial analysis into three zones, including low-suitable, medium-suitable, and high-suitable region where the cancer mortality ranging from low to high rate was identified. These three zones were quantified by the MaxEnt model taking different air pollutants and meteorological variables into consideration. We identified that NO₂ was a most significant factor among the 6 environmental factors with the weight of 24.88%, followed by the annual mean wind speed, SO₂, and PM_2.5. The high-suitable area, mainly in the North China Plain which is a most heavily contaminated region by air pollution in China, covers 1.6195 million square kilometers, accounting for 17.85% of the total area investigated in this study. Identification of the impact of various environmental factors on cancer mortality in the different suitable area provides a scientific basis for the environmental management, risk assessment, and lung cancer control.

Chemical and Biological Components of Urban Aerosols in Africa: Current Status and Knowledge Gaps

Aerosolized particulate matter (PM) is a complex mixture that has been recognized as the greatest cause of premature human mortality in low- and middle-income countries. Its toxicity arises largely from its chemical and biological components. These include polycyclic aromatic hydrocarbons (PAHs) and their nitro-derivatives (NPAHs) as well as microorganisms. In Africa, fossil fuel combustion and biomass burning in urban settings are the major sources of human exposure to PM, yet data on the role of aerosols in disease association in Africa remains scarce. This review is the first to examine studies conducted in Africa on both PAHs/NPAHs and airborne microorganisms associated with PM. These studies demonstrate that PM exposure in Africa exceeds World Health Organization (WHO) safety limits and carcinogenic PAHs/NPAHs and pathogenic microorganisms are the major components of PM aerosols. The health impacts of PAHs/NPAHs and airborne microbial loadings in PM are reviewed. This will be important for future epidemiological evaluations and may contribute to the development of effective management strategies to improve ambient air quality in the African continent.

Ambient fine particulate pollution associated with diabetes mellitus among the elderly aged 50 years and older in China

The linkage between ambient air pollution exposure and occurrence of diabetes mellitus is not well defined. This study examined the association between exposure to fine particles (PM_2.5) and the prevalence of diabetes among Chinese elderly people. We surveyed 11,504 adults aged ≥50 years in China, estimated the annual concentrations of ambient PM_2.5 using a satellite-based model of aerosol optical depth information. We employed a generalized mixed effects model to examine the association between PM_2.5 and the prevalence of diabetes and explored potential effect modifiers. We estimated diabetes burden attributable to ambient PM_2.5 if the observed association is indeed causal. The diabetes prevalence among the participants was 6.5% (n = 745). Our analysis found a statistically significant association between PM_2.5 and diabetes. The adjusted odds ratio was 1.27 (95% confidence interval (CI), 1.12, 1.43) for each 10 μg/m³ increment in ambient PM_2.5. Stratified analyses found a lower association among the participants with higher consumption of fruit. We estimated that 22.02% (95% CI: 8.59%, 43.29%) of the diabetes cases could be ascribable to ambient PM_2.5. Our finding suggests that PM_2.5 exposures could increase the risk of diabetes, and if causal, could be responsible for substantial burden of diabetes among the Chinese elderly; and higher intakes of fruit might reduce the harmful effects of PM_2.5, however, due to the limitation of the cross-sectional study design, more studies are warranted to confirm this observation.

Mortality and morbidity for cardiopulmonary diseases attributed to PM2.5 exposure in the metropolis of Rome, Italy

The aim of the study was to evaluate the health effects associated with the exposure to ground-level of particulate matters with aerodynamic diameter ≤ 2.5 μm (PM_2.5) on citizens in Rome (Italy) in 2015 and 2016. Based on the new version of the World Health Organization's AirQ+ model, we have estimated the short- and long-term effects of PM_2.5 on hospital admissions due to cardiovascular (HA-CVD) and respiratory diseases (HA-RD) as well as on mortality for ischemic heart disease (M-IHD) and chronic obstructive pulmonary disease (M-COPD). In this study, city-specific relative risk values and baseline incidence rates were used to calculate the association between PM_2.5 and daily counts of emergency hospitalizations and mortality. The annual mean PM_2.5 concentrations were 18 μg m^-3 and 14 μg m^-3 in 2015 and 2016, respectively. In Rome, the citizens are mostly exposed to daily mean PM_2.5 concentrations of 10-20 μg m^-3 during the study period. In 2015-2016, 0.4-0.6% for HA-CVD, 1.1-1.5% for HA-RD, 16.5-18.1% for M-IHD and 8.5-9.2% for M-COPD are attributed to PM_2.5. In 2015-2016, 134-186 HA-CVD, 126-175 HA-RD, 947-1037 M-IHD and 244-279 M-COPD, caused by PM_2.5 exposure, could be "avoided" if PM_2.5 concentrations would not exceed 10 μg m^-3, i.e. the threshold recommended by the World Health Organization. Thus, a consistent air quality management and sustainable city planning are needed, urgently, to mitigate the adverse effects of PM_2.5 exposure in Rome.

Exposure to ambient PM2.5 concentrations and cognitive function among older Mexican adults

BACKGROUND

Recent epidemiological research has shown that exposure to fine particulate pollution (PM_2.5) is associated with a reduction in cognitive function in older adults. However, primary evidence comes from high-income countries, and no specific studies have been conducted in low and middle-income countries where higher air pollution levels exist.

OBJECTIVES

To estimate the association between the exposure to PM_2.5 and cognitive function in a nationally representative sample of older Mexican adults and the associated effect modifiers.

METHODS

Data for this study were taken from the National Survey of Health and Nutrition in Mexico carried out in 2012. A total of 7986 older adults composed the analytical sample. Cognitive function was assessed using two tests: semantic verbal fluency and three-word memory. The annual concentration of PM_2.5 was calculated using satellite data. Association between exposure to PM_2.5 and cognitive function was estimated using two-level logistic and linear regression models.

RESULTS

In adjusted multilevel regression models, each 10 μg/m³ increase in ambient PM_2.5 raised the odds of a poorer cognitive function using the three-word memory test (OR = 1.37, 95% CI: 1.08, 1.74), and reduced the number of valid animal named in the verbal fluency test (β = -0.72, 95% CI: -1.05, -0.40). Stratified analyses did not yield any significant modification effects of age, sex, indoor pollution, urban/rural dwelling, education, smoking and other factors.

CONCLUSIONS

This study supports an association between exposure to PM_2.5 concentrations and cognitive function in older adults. This is particularly relevant to low- and middle-income countries, which are marked by a rapid growth of their aging population and high levels of air pollution.

The emerging risk of exposure to air pollution on cognitive decline and Alzheimer's disease - Evidence from epidemiological and animal studies

As incidence of Alzheimer's disease (AD) and other neurodegenerative diseases rise, there is increasing interest in environmental factors which may contribute to disease onset and progression. Air pollution has been known as a major health hazard for decades. While its effects on cardiopulmonary morbidity and mortality have been extensively studied, growing evidence has emerged that exposure to polluted air is associated with impaired cognitive functions at all ages and increased risk of AD and other dementias in later life; this association is particularly notable with traffic related pollutants such as nitrogen dioxide, nitrous oxide, black carbon, and small diameter airborne solids and liquids known as particulate matter. The exact mechanisms by which air pollutants mediate neurotoxicity in the central nervous system (CNS) and lead to cognitive decline and AD remain largely unknown. Studies using animal and cell culture models indicate that amyloid-beta processing, anti-oxidant defense, and inflammation are altered following the exposure to constituents of polluted air. In this review, we summarize recent evidence supporting exposure to air pollution as a risk for cognitive decline at all ages and AD at later lifetime. Additionally, we review the current body of work investigating the molecular mechanisms by which air pollutants mediate damage in the CNS. Understanding of the neurotoxic effects of air pollution and its constituents is still limited, and further studies will be essential to better understand the cellular and molecular mechanisms linking air pollution and cognitive decline.

Long-term exposure to ambient PM2.5 associated with fall-related injury in six low- and middle-income countries

Exposure to ambient air pollution has been linked with adverse health outcomes of the circulatory and nervous systems. Given that falls are closely related to circulatory and nervous health, we hypothesize that air pollution may adversely affect fall-related injury. We employed Wave 1 data from 36,662 participants aged ≥50 years in WHO's Study on Global AGEing and Adult Health in six low- and middle-income countries. Ambient annual concentration of PM_2.5 was estimated using satellite data. A three-level logistic regression model was applied to examine the long-term association between ambient PM_2.5 and the prevalence of fall-related injury, and associated disease burden, as well as the potential effect modification of consumption of fruit and vegetables. Ambient PM_2.5 was found to be significantly associated with the risk of fall-related injury. Each 10 μg/m³ increase corresponded to 18% (OR = 1.18, 95% CI: 1.09, 1.28) increase in fall-related injury after adjusting for various covariates. The association was relatively stronger among participants with lower consumption of fruit (OR = 1.22, 95% CI: 1.12, 1.33) than higher consumption (OR = 1.06, 95% CI: 0.92, 1.23), and among those with lower vegetable consumption (OR = 1.18, 95% CI: 1.08, 1.28) than higher consumption (OR = 1.08, 95% CI: 0.91, 1.27). Our study suggests that ambient PM_2.5 may be one risk factor for fall-related injury and that higher consumption of fruit and vegetables could alleviate this effect.

A Narrative Review on the Human Health Effects of Ambient Air Pollution in Sub-Saharan Africa: An Urgent Need for Health Effects Studies

An important aspect of the new sustainable development goals (SDGs) is a greater emphasis on reducing the health impacts from ambient air pollution in developing countries. Meanwhile, the burden of human disease attributable to ambient air pollution in sub-Saharan Africa is growing, yet estimates of its impact on the region are possibly underestimated due to a lack of air quality monitoring, a paucity of air pollution epidemiological studies, and important population vulnerabilities in the region. The lack of ambient air pollution epidemiologic data in sub-Saharan Africa is also an important global health disparity. Thousands of air pollution health effects studies have been conducted in Europe and North America, rather than in urban areas that have some of the highest measured air pollution levels in world, including urban areas in sub-Saharan Africa. In this paper, we provide a systematic and narrative review of the literature on ambient air pollution epidemiological studies that have been conducted in the region to date. Our review of the literature focuses on epidemiologic studies that measure air pollutants and relate air pollution measurements with various health outcomes. We highlight the gaps in ambient air pollution epidemiological studies conducted in different sub-regions of sub-Saharan Africa and provide methodological recommendations for future environmental epidemiology studies addressing ambient air pollution in the region.

Air Pollution and Performance-Based Physical Functioning in Dutch Older Adults

BACKGROUND

Functional limitations are a major cause for needing care and institutionalization among older adults. Exposure to air pollution has been suggested to be associated with increased functional limitations in older people.

OBJECTIVE

Our objective was to assess the association between air pollution and physical functioning in Dutch older adults.

METHODS

We analyzed data on performance-based (walking speed, ability to rise from a chair, putting on and taking off a cardigan, balance test) and self-reported physical functioning for 1,762 participants of the Longitudinal Aging Study Amsterdam, who participated in measurement cycles performed in 2005/2006, 2008/2009, and 2011/2012. Annual average outdoor air pollution concentrations [nitrogen dioxide (NO₂), nitrogen oxides (NO_x), particulate matter with diameters ≤2.5μm (PM_2.5), ≤10μm (PM₁₀), and 2.5-10μm (PM_coarse), and PM_2.5 absorbance] at the home address at the start of the first measurement cycle were estimated using land-use regression models. Analyses were performed using mixed models with random participant intercepts adjusting for potential confounders.

RESULTS

Exposure to most air pollutants was associated with reduced performance-based physical functioning; for example, an interquartile range increase in NO₂ exposure was associated with a 0.22 (95% confidence interval: 0.03, 0.42) lower performance test score in fully adjusted models, equivalent to the difference in performance score between participants who differed by 9 mo in age. Exposure to air pollution was generally not statistically significantly associated with self-reported functional limitations, and not associated with a faster decline in performance-based physical functioning over the study period.

CONCLUSION

This study suggests that exposure to air pollution may adversely affect physical performance of older adults in the Netherlands. https://doi.org/10.1289/EHP2239.

Consumption of fruit and vegetables might mitigate the adverse effects of ambient PM2.5 on lung function among adults

BACKGROUND

Evidence on the effects of ambient PM_2.5 on lung function is limited among adults and the effect modification by dietary fruit and vegetables remains largely unknown.

METHODS

We interviewed 29,032 participants aged 50 years and older from the WHO Study on global AGEing and adult health. Annual average PM_2.5 levels were estimated for each community using satellite data. We applied multi-level linear regressions to examine the association between ambient PM_2.5 and lung function (forced vital capacity (FVC), forced expiratory volume in 1-sec (FEV₁), FEV₁/FVC ratio, peak expiratory flow (PEF), and forced expiratory flow between 25th and 75th percentiles of FVC (FEF_25-75)).

RESULTS

We found that ambient PM_2.5 was associated with lower lung functions. Each 10μg/m³ increase in PM_2.5 corresponded to reductions of 123.58ml in FVC (95% CI: -185.21, -61.95), 126.64ml in FEV₁ (95% CI: -186.04, -67.23) and 178.93ml/s FEV_25-75 (95% CI: -249.20, -108.66). Lower effect estimates were observed among those with higher consumption of fruit and vegetables.

CONCLUSION

Our study suggests that exposure to ambient PM_2.5 might be one risk factor of reduced lung function in adults and that higher consumption of fruit and vegetables may mitigate this effect.

Forecasting PM2.5 induced male lung cancer morbidity in China using satellite retrieved PM2.5 and spatial analysis

The present study predicts a spatial distribution of lung cancer morbidity in Chinese males due to exposure to PM_2.5 concentration from 2010 to 2015. A spatial autocorrelation method was used to evaluate the spatial relationship between the lung cancer morbidities from 2006 to 2009 and satellite-derived PM_2.5 atmospheric levels. A comprehensive grey correlation degree analysis was carried out to assess the simultaneous and lag associations between the lung cancer morbidity and PM_2.5 concentration. These relationships were subsequently applied to predict male lung cancer morbidity in a specific year. Annual mean PM_2.5 levels in this specific year and previous 8years were used as 9 independent variables to establish four statistical models. These models include ridge regression (RR), partial least squares regression (PLSR), support vector regression (SVR), and the combined forecasting model (CFM) to predict the male lung cancer morbidity in China from 2010 to 2015. The model error evaluations suggested that the partial least squares regression model performed the best in the male lung cancer morbidity forecast. We calculated the male lung cancer morbidity by the optimal method among the established statistical forecasting models at 1948 sites in China. The gridded morbidity distribution from 2010 to 2015 across the country was obtained by Kriging interpolation method. Results showed that the male lung cancer morbidity increased significantly from western to eastern China, except for the far north region. This spatial pattern is in line with the spatial distribution of PM_2.5 concentration, manifesting a significant relationship between PM_2.5 concentration level and lung cancer morbidity in Chinese males.

Exposure to air pollution and tobacco smoking and their combined effects on depression in six low- and middle-income countries

BackgroundLittle is known about the joint mental health effects of air pollution and tobacco smoking in low- and middle-income countries.AimsTo investigate the effects of exposure to ambient fine particulate matter pollution (PM2.5) and smoking and their combined (interactive) effects on depression.MethodMultilevel logistic regression analysis of baseline data of a prospective cohort study (n = 41 785). The 3-year average concentrations of PM2.5 were estimated using US National Aeronautics and Space Administration satellite data, and depression was diagnosed using a standardised questionnaire. Three-level logistic regression models were applied to examine the associations with depression.ResultsThe odds ratio (OR) for depression was 1.09 (95% C11.01-1.17) per 10 μg/m3 increase in ambient PM2.5, and the association remained after adjusting for potential confounding factors (adjusted OR = 1.10, 95% CI 1.02-1.19). Tobacco smoking (smoking status, frequency, duration and amount) was also significantly associated with depression. There appeared to be a synergistic interaction between ambient PM2.5 and smoking on depression in the additive model, but the interaction was not statistically significant in the multiplicative model.ConclusionsOur study suggests that exposure to ambient PM2.5 may increase the risk of depression, and smoking may enhance this effect.

The Association of Domestic Incense Burning with Hypertension and Blood Pressure in Guangdong, China

Domestic incense burning is a common activity in China. Although it generates serious air pollution and has been linked to various health outcomes, it remains unknown whether it is associated with blood pressure and hypertension. A community-based survey including 1153 hypertensive subjects and 4432 normotensive participants in Guangdong (China) was used to examine this question. Two-level logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (CI). The analyses showed that, compared with non-users, OR of hypertension was 1.24 (95% CI: 1.03–1.50) for users, and 1.37 (95% CI: 1.04–1.80) for daily users with a clear dose-response relationship. The estimated increases in systolic and diastolic blood pressures were 1.02 mmHg (95% CI: 0.06–1.99) and 1.26 mmHg (95% CI: 0.69–1.83) for users, 0.67 mmHg (95% CI: −0.35–1.68) and 1.25 mmHg (95% CI: 0.66–1.85) for occasional users, and 2.09 mmHg (95% CI: 0.79–3.39) and 1.28 mmHg (95% CI: 0.52–2.05) for daily users, respectively. The results remained after adjusting for potential confounders and more pronounced associations were found among females. This study suggests that domestic incense burning may increase the risk of hypertension and blood pressure in the study population, and women are more vulnerable to these effects than men.