Effect of Personal Exposure to PM2.5 on Respiratory Health in a Mexican Panel of Patients with COPD

Impacts from air pollution on respiratory disease outcomes: a meta-analysis

Introduction

Air pollution is widely acknowledged as a significant factor in respiratory outcomes, including coughing, wheezing, emergency department (ED) visits, and even death. Although several literature reviews have confirmed the association between air pollution and respiratory outcomes, they often did not standardize associations across different studies and overlooked other increasingly impactful pollutants such as trace metals. Recognizing the importance of consistent comparison and emissions of non-exhaust particles from road traffic, this study aims to comprehensively evaluate the standardized effects of various criteria pollutants and trace metals on respiratory health.

Methods

We conducted a comprehensive meta-analysis of peer-reviewed journal articles on air pollution and respiratory outcomes published between 1 January 2000, and 1 June 2024. The study included children (age < 18 years), adults (age ≥ 18 years), and all age groups exposed to criteria pollutants established by the US Environmental Protection Agency National Ambient Air Quality Standards and over 10 trace metals. Using databases, such as PubMed, MEDLINE, Web of Science Core Collection, and Google Scholar, we identified 579 relevant articles. After rigorous screening and quality assessment using the Newcastle-Ottawa Scale, 50 high-quality studies were included. We converted various reported outcomes (e.g., odds ratios, relative risk, and percent increase) to a standardized odds ratio (OR) for comparability and performed meta-analyses using R 4.4.0 and related packages, ensuring the robustness of our findings.

Results

Our meta-analysis indicated significant associations between air pollutants and respiratory outcomes. For particulate matter with diameter ≤ 2.5 μm (PM2.5), the overall ORs for children, adults, and combined age groups were 1.31, 1.10, and 1.26, respectively, indicating a consistent positive association. Similar positive associations were observed for particulate matter with diameter ≤ 10 μm (PM10) and other pollutants, with children showing higher susceptibility than adults. The analysis of trace metals also showed significant associations; however, these findings require cautious interpretation due to the small number of studies.

Conclusion

Our study supports associations between air pollutants, including non-exhaust trace metals, and respiratory outcomes across different age groups. The findings underscore the need for stringent environmental health policies and further research, especially in regions with higher pollution levels. The future studies should consider long-term and short-term exposures separately and include diverse populations to improve the accuracy and generalizability of the results.

Air pollution and respiratory health in patients with COPD: should we focus on indoor or outdoor sources?

INTRODUCTION

While associations between ambient air pollution and respiratory health in chronic obstructive pulmonary disease (COPD) patients are well studied, little is known about individuals' personal exposure to pollution and associated health effects by source.

AIM

To separate measured total personal exposure into indoor-generated and outdoor-generated pollution and use these improved metrics in health models for establishing more reliable associations with exacerbations and respiratory symptoms.

METHODS

We enrolled a panel of 76 patients with COPD and continuously measured their personal exposure to particles and gaseous pollutants and location with portable monitors for 134 days on average. We collected daily health information related to respiratory symptoms through diary cards and peak expiratory flow (PEF). Mixed-effects models were applied to quantify the relationship between total, indoor-generated and outdoor-generated personal exposures to pollutants with exacerbation and symptoms occurrence and PEF.

RESULTS

Exposure to nitrogen dioxide from both indoor and outdoor sources was associated with exacerbations and respiratory symptoms. We observed an increase of 33% (22%-45%), 19% (12%-18%) and 12% (5%-20%) in the odds of exacerbation for an IQR increase in total, indoor-generated and outdoor-generated exposures. For carbon monoxide, health effects were mainly attributed to indoor-generated pollution. While no associations were observed for particulate matter2.5 with COPD exacerbations, indoor-generated particles were associated with a significant decrease in PEF.

CONCLUSIONS

Indoor-generated and outdoor-generated pollution can deteriorate COPD patients' health. Policy-makers, physicians and patients with COPD should note the importance of decreasing exposure equally to both source types to decrease risk of exacerbation.

Assessing the Impact of Spatial and Temporal Variability in Fine Particulate Matter Pollution on Respiratory Health Outcomes in Asthma and COPD Patients

Ambient air pollution's health impacts are well documented, yet the domestic environment remains underexplored. We aimed to compare indoor versus outdoor (I/O) air quality and estimate the association between indoor/ambient fine particulate matter (PM2.5) exposure and lung function in asthma and chronic obstructive pulmonary disease (COPD) patients. The study involved 24 h monitoring of PM2.5 levels indoors and outdoors, daily peak expiratory flow (PEF), and biweekly symptoms collection from five patients with asthma and COPD (average age of 50 years, 40% male) over a whole year. Data analysis was performed with linear mixed effect models for PEF and generalized estimating equations (GEE) for exacerbations. More than 5 million PM2.5 exposure and meteorological data were collected, demonstrating significant I/O PM2.5 ratio variability with an average ratio of 2.20 (±2.10). Identified indoor PM2.5 sources included tobacco use, open fireplaces, and cooking, resulting in average indoor PM2.5 concentrations of 63.89 μg/m3 (±68.41), significantly exceeding revised World Health Organization (WHO) guidelines. Analysis indicated a correlation between ambient PM2.5 levels and decreased PEF over 0-to-3-day lag, with autumn indoor exposure significantly impacting PEF and wheezing. The study underscores the need to incorporate domestic air quality into public health research and policy-making. A personalized approach is required depending on the living conditions, taking into account the exposure to particulate pollution.

piR-27222 mediates PM2.5-induced lung cancer by resisting cell PANoptosis through the WTAP/m6A axis

PM2.5 pollution has been associated with the incidence of lung cancer, but the underlying mechanism is still unclear. PIWI-interacting RNAs (piRNAs), initially identified in germline cells, have emerged as a novel class of small non-coding RNAs (26 - 32 nucleotides) with diverse functions in various diseases, including cancer. However, the role and mechanism of piRNAs in the development of PM2.5-induced lung cancer remain to be clarified. In the presented study, we used a PM2.5-induced malignant transformation cell model to analyze the change of piRNA profiles. Among the disturbed piRNAs, piR-27222 was identified as an oncogene that inhibited cell death in a m6A-dependent manner. Mechanistically, we found that piR-27222 could deubiquitinate and stabilize eIF4B by directly binding to eIF4B and reducing its interaction with PARK2. The enhanced expression of eIF4B, in turn, promoted the expression of WTAP, leading to increased m6A modification in the Casp8 transcript. Consequently, the stability of Casp8 transcripts was reduced, rendering lung cancer cells resistant to PANoptosis. Collectively, our findings reveal that PM2.5 exposure up-regulated piR-27222 expression, which could affect EIF4B/WTAP/m6A axis, thereby inhibiting PANoptosis of cells and promoting lung cancer. Our study provides new insights into understanding the epigenetic mechanisms underlining PM2.5-induced lung cancer.

Fine particulate matter aggravates smoking induced lung injury via NLRP3/caspase-1 pathway in COPD

BACKGROUND

Exposure to noxious particles, including cigarette smoke and fine particulate matter (PM2.5), is a risk factor for chronic obstructive pulmonary disease (COPD) and promotes inflammation and cell death in the lungs. We investigated the combined effects of cigarette smoking and PM2.5 exposure in patients with COPD, mice, and human bronchial epithelial cells.

METHODS

The relationship between PM2.5 exposure and clinical parameters was investigated in patients with COPD based on smoking status. Alveolar destruction, inflammatory cell infiltration, and pro-inflammatory cytokines were monitored in the smoking-exposed emphysema mouse model. To investigate the mechanisms, cell viability and death and pyroptosis-related changes in BEAS-2B cells were assessed following the exposure to cigarette smoke extract (CSE) and PM2.5.

RESULTS

High levels of ambient PM2.5 were more strongly associated with high Saint George's respiratory questionnaire specific for COPD (SGRQ-C) scores in currently smoking patients with COPD. Combined exposure to cigarette smoke and PM2.5 increased mean linear intercept and TUNEL-positive cells in lung tissue, which was associated with increased inflammatory cell infiltration and inflammatory cytokine release in mice. Exposure to a combination of CSE and PM2.5 reduced cell viability and upregulated NLRP3, caspase-1, IL-1β, and IL-18 transcription in BEAS-2B cells. NLRP3 silencing with siRNA reduced pyroptosis and restored cell viability.

CONCLUSIONS

PM2.5 aggravates smoking-induced airway inflammation and cell death via pyroptosis. Clinically, PM2.5 deteriorates quality of life and may worsen prognosis in currently smoking patients with COPD.

Short-term effects of air pollution and weather on physical activity in patients with chronic obstructive pulmonary disease (COPD)

INTRODUCTION

Patients with chronic obstructive pulmonary disease (COPD) accumulate low levels of physical activity. How environmental factors affect their physical activity in the short-term is uncertain.

AIM

to assess the short-term effects of air pollution and weather on physical activity levels in COPD patients.

METHODS

This multi-center panel study assessed 408 COPD patients from Catalonia (Spain). Daily physical activity (i.e., steps, time in moderate-to-vigorous physical activity (MVPA), locomotion intensity, and sedentary time) was recorded in two 7-day periods, one year apart, using the Dynaport MoveMonitor. Air pollution (nitrogen dioxide (NO2), particulate matter below 10 μm (PM10) and a marker of black carbon (absorbance of PM2.5: PM2.5ABS), and weather (average and maximum temperature, and rainfall) were estimated the same day (lag zero) and up to 5 days prior to each assessment (lags 1-5). Mixed-effect distributed lag linear regression models were adjusted for age, sex, weekday, public holidays, greenness, season, and social class, with patient and city as random effects.

RESULTS

Patients (85% male) were on average (mean ± SD) 68 ± 9 years old with a post-bronchodilator forced expiratory volume in 1 s (FEV1) of 57 ± 18% predicted. Higher NO2, PM10 and PM2.5ABS levels at lag four were associated with fewer steps, less time in MVPA, reduced locomotion intensity, and longer sedentary time (e.g., coefficient (95% CI) of -60 (-105, -15) steps per 10 μg/m3 increase in NO2). Higher average and maximum temperatures at lag zero were related to more steps and time in MVPA, and less sedentary time (e.g., +85 (15, 154) steps per degree Celsius). Higher rainfall at lag zero was related to fewer steps and more sedentary time.

CONCLUSION

Air pollution affects the amount and intensity of physical activity performed on the following days in COPD patients, whereas weather affects the amount of physical activity performed on the same day.

Analysis of PM2.5 inorganic and organic constituents to resolve contributing sources in Seoul, South Korea and Beijing, China and their possible associations with cytokine IL-8

China and South Korea are the most polluted countries in East Asia due to significant urbanization and extensive industrial activities. As neighboring countries, collaborative management plans to maximize public health in both countries can be helpful in reducing transboundary air pollution. To support such planning, PM2.5 inorganic and organic species were determined in simultaneously collected PM2.5 integrated filters. The resulting data were used as inputs to positive matrix factorization, which identified nine sources at the ambient air monitoring sites in both sites. Secondary nitrate, secondary sulfate/oil combustion, soil, mobile, incinerator, biomass burning, and secondary organic carbon (SOC) were found to be sources at both sampling sites. Industry I and II were only identified in Seoul, whereas combustion and road dust sources were only identified in Beijing. A subset of samples was selected for exposure assessment. The expression levels of IL-8 were significantly higher in Beijing (167.7 pg/mL) than in Seoul (72.7 pg/mL). The associations between the PM2.5 chemical constituents and its contributing sources with PM2.5-induced inflammatory cytokine (interleukin-8, IL-8) levels in human bronchial epithelial cells were investigated. For Seoul, the soil followed by the secondary nitrate and the biomass burning showed increase with IL-8 production. However, for the Beijing, the secondary nitrate exhibited the highest association with IL-8 production and SOC and biomass burning showed modest increase with IL-8. As one of the highest contributing sources in both cities, secondary nitrate showed an association with IL-8 production. The soil source having the strongest association with IL-8 production was found only for Seoul, whereas SOC showed a modest association only for Beijing. This study can provide the scientific basis for identifying the sources to be prioritized for control to provide effective mitigation of particulate air pollution in each city and thereby improve public health.

Impact of Climate Change on Indoor Air Quality

Climate change may affect the quality of the indoor environment through heat and mass transfer between indoors and outdoors: first by a direct response to global warming itself and related extreme weather phenomena and second by indirect actions taken to reduce greenhouse gas emissions that can lead to increased concentrations of indoor air contaminants. Therefore, both indoor and outdoor air pollution contribute to poor indoor air quality in this context. Exposures to high concentrations of these pollutants contribute to inflammatory respiratory diseases. Climate change adaptation and mitigation measures could minimize these risks and bring associated health benefits.

The impact of fine particulate matter on chronic obstructive pulmonary disease deaths in Pudong New Area, Shanghai, during a long period of air quality improvement

Chronic obstructive pulmonary disease (COPD) deaths attributed to fine particulate matter (with an aerodynamic equivalent diameter <2.5 μm, PM2.5) exposure are a common global public health concern. Recent improvements in air quality and the corresponding health benefits have received much attention. Thus, we have explored the trends of PM2.5 pollution improvement on COPD deaths during an important period of air pollution control (2008-2017) in Pudong New Area, Shanghai, China. Data, including daily COPD death counts, meteorological variables, and ambient air pollutants, were collected from 2008 to 2017. Generalized additive models were fitted to evaluate the percent change (%) in pollution-related COPD deaths. The results showed that the number of days with daily PM2.5 concentrations <35 μg/m3 increased from 19 days (5.19%) in 2008 to 166 days (45.48%) in 2017, and PM2.5 concentrations >75 μg/m3 decreased from 222 days (60.66%) in 2008 to 33 days (9.04%) in 2017. The associations in the overall period between 2008 and 2017 was significant. In subperiod analysis, each 10 μg/m3 increment in PM2.5 was associated with a percent change (%) of 0.89 (95% confidence interval [CI], 0.37, 1.42) at lag 5 and 0.78 (95% CI, 0.26, 1.30) at lag 6 during 2008-2013. Significant results were also found at lag 0-5 [percent change (%), 1.12 (95% CI, 0.09, 2.17)], lag 0-6 [percent change (%), 1.52 (95% CI, 0.43, 2.62)] and lag 0-7 [percent change (%), 1.72 (95% CI, 0.57, 2.88)] during 2008-2013. By contrast, no significant association was found between 2014 and 2017. In conclusion, the decreased COPD deaths associated with PM2.5 exposure were found, especially after the air quality improvement turning point in 2014.

Analytical method for urinary homovanillic acid and 5-hydroxyindoleacetic acid levels using HPLC with electrochemical detection applied to evaluate children environmentally exposed to manganese

Homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) are the urinary metabolites of dopamine (DA) and serotonin (5-HA), respectively. We aimed to develop an extraction method for the determination of HVA and 5-HIAA, using strong anionic exchange cartridges combined with HPLC with electrochemical detection, and apply it to measure the levels of HVA and 5-HIAA in children living near a ferro-manganese alloy plant in Simões Filho, Brazil. The validated method showed good selectivity, sensitivity, precision, and accuracy. The limits of detection (LOD) were 4 and 8 μmol/L for 5-HIAA and HVA, respectively, in urine. Recoveries ranged from 85.8 to 94%. The coefficients of determination (R2 ) of the calibration curves were greater than 0.99. Spot urine samples of 30 exposed children and 20 nonexposed ones were processed accordingly. The metabolite levels in exposed and reference children were within the physiological ranges. The medians (range) for 5-HIAA and HVA of the exposed ones were 36.4 μmol/L (18.4-58.0) and 32.9 μmol/L ( Collapse

Key Words

• 5-HIAA
• HPLC-ECD
• HVA
• dopamine
• manganese exposure
• serotonin

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MESH Headings

• Humans
• Child
• Homovanillic Acid/urine
• Hydroxyindoleacetic Acid
• Chromatography, High Pressure Liquid/methods
• Manganese
• Dopamine/metabolism

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Grants

• JCB0029/2015 Fundação de Amparo à Pesquisa do Estado da Bahia

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Affiliation(s)

Mariana Silva Cardoso Graduate Program in Pharmacy, College of Pharmacy, Federal University of Bahia, Salvador, Brazil
Andrea Rebouças Rocha Graduate Program in Food Science, College of Pharmacy, Federal University of Bahia, Salvador, Brazil
José Antônio Souza-Júnior Laboratory of Toxicology, College of Pharmacy, Federal University of Bahia, Salvador, Brazil
José Antonio Menezes-Filho Graduate Program in Pharmacy, College of Pharmacy, Federal University of Bahia, Salvador, Brazil Graduate Program in Food Science, College of Pharmacy, Federal University of Bahia, Salvador, Brazil Laboratory of Toxicology, College of Pharmacy, Federal University of Bahia, Salvador, Brazil

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Short-term effect of particulate matter on lung function and impulse oscillometry system (IOS) parameters of chronic obstructive pulmonary disease (COPD) in Beijing, China

OBJECTIVE

This study aimed to evaluate the associations between particulate matter (PM), lung function and Impulse Oscillometry System (IOS) parameters in chronic obstructive pulmonary disease (COPD) patients and identity effects between different regions in Beijing, China.

METHODS

In this retrospective study, we recruited 1348 outpatients who visited hospitals between January 2016 and December 2019. Ambient air pollutant data were obtained from the central monitoring stations nearest the participants' residential addresses. We analyzed the effect of particulate matter with aerodynamic diameter ≤ 2.5 μm (PM_2.5) exposure on lung function and IOS parameters using a multiple linear regression model, adjusting for sex, smoking history, education level, age, body mass index (BMI), mean temperature, and relative humidity .

RESULTS

The results showed a relationship between PM_2.5, lung function and IOS parameters. An increase of 10 µg/m³ in PM_2.5 was associated with a decline of 2.083% (95% CI: -3.047 to - 1.103) in forced expiratory volume in one second /predict (FEV₁%pred), a decline of 193 ml/s (95% CI: -258 to - 43) in peak expiratory flow (PEF), a decline of 0.932% (95% CI: -1.518 to - 0.342) in maximal mid-expiratory flow (MMEF); an increase of 0.732 Hz (95% CI: 0.313 to 1.148) in resonant frequency (F_res), an increase of 36 kpa/(ml/s) (95% CI: 14 to 57) in impedance at 5 Hz (Z₅) and an increase of 31 kpa/(ml/s) (95% CI: 2 to 54) in respiratory impedance at 5 Hz (R₅). Compared to patients in the central district, those in the southern district had lower FEV₁/FVC, FEV₁%pred, PEF, FEF_75%, MMEF, X₅, and higher F_res, Z₅ and R₅ (p < 0.05).

CONCLUSION

Short-term exposure to PM_2.5 was associated with reductions in lung function indices and an increase in IOS results in patients with COPD. The heavier the PM_2.5, the more severe of COPD.

Hospitalisations for cardiovascular and respiratory disease among older adults living near unconventional natural gas development: a difference-in-differences analysis

BACKGROUND

During 2008-15, the Marcellus shale region of the US state of Pennsylvania experienced a boom in unconventional natural gas development (UNGD) or "fracking". However, despite much public debate, little is known about the effects of UNGD on population health in local communities. Among other mechanisms, air pollution from UNGD might affect individuals living nearby through cardiovascular or respiratory disease, and older adults could be particularly susceptible.

METHODS

To study the health impacts of Pennsylvania's fracking boom, we exploited the ban on UNGD in neighbouring New York state. Using 2002-15 Medicare claims, we conducted difference-in-differences analyses over multiple timepoints to estimate the risk of living near UNGD for hospitalisation with acute myocardial infarction (AMI), chronic obstructive pulmonary disease (COPD) and bronchiectasis, heart failure, ischaemic heart disease, and stroke among older adults (aged ≥65 years).

FINDINGS

Pennsylvania ZIP codes that started UNGD in 2008-10 were associated with more hospitalisations for cardiovascular diseases in 2012-15 than would be expected in the absence of UNGD. Specifically, in 2015, we estimated an additional 11·8, 21·6, and 20·4 hospitalisations for AMI, heart failure, and ischaemic heart disease, respectively, per 1000 Medicare beneficiaries. Hospitalisations increased even as UNGD growth slowed. Results were robust in sensitivity analyses.

INTERPRETATION

Older adults living near UNGD could be at high risk of poor cardiovascular outcomes. Mitigation policies for existing UNGD might be needed to address current and future health risks. Future consideration of UNGD should prioritise local population health.

FUNDING

University of Chicago and Argonne National Laboratories.

Fine particulate matter induces METTL3-mediated m6A modification of BIRC5 mRNA in bladder cancer

Long-term exposure to fine particulate matter (PM_2.5) is reportedly related to a variety of cancers including bladder cancer. However, little is known about the biological mechanism underlying this association. In the present study, PM_2.5 exposure was significantly associated with increased levels of m⁶A modification in bladder cancer patients and bladder cells. METTL3 expression was aberrantly upregulated after PM_2.5 exposure, and METTL3 was involved in PM_2.5-induced m⁶A methylation. Higher METTL3 expression was observed in bladder cancer tissues and METTL3 knockdown dramatically inhibited bladder cancer cell proliferation, colony formation, migration and invasion, inducing apoptosis and disrupting the cell cycle. Mechanistically, PM_2.5 enhanced the expression of METTL3 by inducing the promoter hypomethylation of its promoter and increasing the binding affinity of the transcription factor HIF1A. BIRC5 was identified as the target of METTL3 through m⁶A sequencing (m⁶A-Seq) and KEGG analysis. The methylated BIRC5 transcript was subsequently recognized by IGF2BP3, which increased its mRNA stability. In particular, PM_2.5 exposure promoted the m⁶A modification of BIRC5 and its recognition by IGF2BP3. In addition, BIRC5 was involved in bladder cancer proliferation and metastasis, as well as VEGFA-regulated angiogenesis_. This comprehensive study revealed that PM_2.5 exposure exerts epigenetic regulatory effects on bladder cancer via the HIF1A/METTL3/IGF2BP3/BIRC5/VEGFA network.

Personal and household PM2.5 and black carbon exposure measures and respiratory symptoms in 8 low- and middle-income countries

BACKGROUND

Household air pollution (HAP) from cooking with solid fuels has been associated with adverse respiratory effects, but most studies use surveys of fuel use to define HAP exposure, rather than on actual air pollution exposure measurements.

OBJECTIVE

To examine associations between household and personal fine particulate matter (PM_2.5) and black carbon (BC) measures and respiratory symptoms.

METHODS

As part of the Prospective Urban and Rural Epidemiology Air Pollution study, we analyzed 48-h household and personal PM_2.5 and BC measurements for 870 individuals using different cooking fuels from 62 communities in 8 countries (Bangladesh, Chile, China, Colombia, India, Pakistan, Tanzania, and Zimbabwe). Self-reported respiratory symptoms were collected after monitoring. Associations between PM_2.5 and BC exposures and respiratory symptoms were examined using logistic regression models, controlling for individual, household, and community covariates.

RESULTS

The median (interquartile range) of household and personal PM_2.5 was 73.5 (119.1) and 65.3 (91.5) μg/m³, and for household and personal BC was 3.4 (8.3) and 2.5 (4.9) x10^-5 m^-1, respectively. We observed associations between household PM_2.5 and wheeze (OR: 1.25; 95%CI: 1.07, 1.46), cough (OR: 1.22; 95%CI: 1.06, 1.39), and sputum (OR: 1.26; 95%CI: 1.10, 1.44), as well as exposure to household BC and wheeze (OR: 1.20; 95%CI: 1.03, 1.39) and sputum (OR: 1.20; 95%CI: 1.05, 1.36), per IQR increase. We observed associations between personal PM_2.5 and wheeze (OR: 1.23; 95%CI: 1.00, 1.50) and sputum (OR: 1.19; 95%CI: 1.00, 1.41). For household PM_2.5 and BC, associations were generally stronger for females compared to males. Models using an indicator variable of solid versus clean fuels resulted in larger OR estimates with less precision.

CONCLUSIONS

We used measurements of household and personal air pollution for individuals using different cooking fuels and documented strong associations with respiratory symptoms.

Comparing human exposure to fine particulate matter in low and high-income countries: A systematic review of studies measuring personal PM2.5 exposure

BACKGROUND

Due to the adverse health effects of air pollution, researchers have advocated for personal exposure measurements whereby individuals carry portable monitors in order to better characterise and understand the sources of people's pollution exposure.

OBJECTIVES

The aim of this systematic review is to assess the differences in the magnitude and sources of personal PM2.5 exposures experienced between countries at contrasting levels of income.

METHODS

This review summarised studies that measured participants personal exposure by carrying a PM2.5 monitor throughout their typical day. Personal PM2.5 exposures were summarised to indicate the distribution of exposures measured within each country income category (based on low (LIC), lower-middle (LMIC), upper-middle (UMIC), and high (HIC) income countries) and between different groups (i.e. gender, age, urban or rural residents).

RESULTS

From the 2259 search results, there were 140 studies that met our criteria. Overall, personal PM2.5 exposures in HICs were lower compared to other countries, with UMICs exposures being slightly lower than exposures measured in LMICs or LICs. 34% of measured groups in HICs reported below the ambient World Health Organisation 24-h PM2.5 guideline of 15 μg/m3, compared to only 1% of UMICs and 0% of LMICs and LICs. There was no difference between rural and urban participant exposures in HICs, but there were noticeably higher exposures recorded in rural areas compared to urban areas in non-HICs, due to significant household sources of PM2.5 in rural locations. In HICs, studies reported that secondhand smoke, ambient pollution infiltrating indoors, and traffic emissions were the dominant contributors to personal exposures. While, in non-HICs, household cooking and heating with biomass and coal were reported as the most important sources.

CONCLUSION

This review revealed a growing literature of personal PM2.5 exposure studies, which highlighted a large variability in exposures recorded and severe inequalities in geographical and social population subgroups.

Indoor Air Pollution and the Health of Vulnerable Groups: A Systematic Review Focused on Particulate Matter (PM), Volatile Organic Compounds (VOCs) and Their Effects on Children and People with Pre-Existing Lung Disease

Air pollution affects health, but much of the focus to this point has been on outdoor air. Higher indoor pollution is anticipated due to increasingly energy-efficient and less leaky buildings together with more indoor activities. Studies of indoor air pollution focusing on children and people with respiratory disease from the database Web of Science (1991–2021) were systemically reviewed according to the PRISMA guidelines, with 69 studies included in the final selection. Emissions from building materials affected indoor air quality, and ventilation also had an influence. The main indoor air pollutants are Volatile Organic Compounds (VOCs) and Particulate Matter (PM). PM sources included smoking, cooking, heating, candles, and insecticides, whereas sources of coarse particles were pets, housework and human movements. VOC sources included household products, cleaning agents, glue, personal care products, building materials and vehicle emissions. Formaldehyde levels were particularly high in new houses. Personal exposure related to both indoor and outdoor pollutant levels, highlighting home characteristics and air exchange rates as important factors. Temperature, humidity, educational level, air purifiers and time near sources were also related to personal exposure. There was an association between PM and Fractional exhaled Nitric Oxide (FeNO), lung function, oxygen saturation, childhood asthma and symptoms of chronic obstructive pulmonary disease (COPD) patients. High VOCs were associated with upper airways and asthma symptoms and cancer. Effective interventional studies for PM in the future might focus on human behavior together with air purifiers and increased ventilation, whereas VOC interventions might center more on building materials and household products, alongside purification and ventilation.

Reduction in daily ambient PM2.5 pollution and potential life gain by attaining WHO air quality guidelines in Tehran

BACKGROUND

Fine particulate matter pollution (PM_2.5) is widely considered to be a top-ranked risk factor for premature mortality and years of life lost (YLL). However, evidence regarding the effect of daily air quality improvement on life expectancy is scarce, especially in the Middle East such as Iran. This study aimed to investigate the potential benefits in life expectancy at concentrations meeting the daily PM_2.5 standards during 2012-2016 in Tehran, Iran.

METHODS

We collected daily non-accidental mortality and data on air pollutants and weather conditions from Tehran, Iran, 2012-2016. A quasi-Poisson or Gaussian time-series regression was employed to fit the associations between ambient PM_2.5 and mortality or YLL. Potential gains in life expectancy (PGLE) and attributable fraction (AF) were estimated by assuming that daily PM_2.5 concentrations attained the World Health Organization air quality guidelines (WHO AQG) 2005 (25 μg/m³) and 2021 (15 μg/m³).

RESULTS

During the study period, a total of 221,231 non-accidental deaths were recorded in Tehran, resulting in 3.6 million YLL. The mean concentration of ambient PM_2.5 was 34.7 μg/m³ (standard deviation: 15.3 μg/m³). For a 10-μg/m³ rise in 4-day moving average (lag 03-day) in PM_2.5 concentration, non-accidental mortality and YLL increased by 1.12% (95% confidence interval: 0.60, 1.65) and 20.73 (7.08, 34.39) person years, respectively. A relatively higher effect was observed in males and young adults aged 18-64 years. We estimated that 39830 [AF = 1.1%] and 74284 [AF = 2.1%] YLL could potentially be avoided if daily PM_2.5 concentrations attained the WHO AQG 2005 and 2021, respectively, which corresponded to potential gains in life expectancy of 0.18 (0.06, 0.30) and 0.34 (0.11, 0.56) years for each deceased person. PM_2.5-associated PGLE estimates were largely robust when performing sensitivity analyses.

CONCLUSIONS

Our findings indicated that short-term exposure to PM_2.5 is associated with increased non-accidental YLL and mortality. Prolonged life expectancy could be achieved if the particulate matter air pollution level were kept under a stricter standard.

COPD in Smoking and Non-Smoking Community Members Exposed to the World Trade Center Dust and Fumes

Background: The characteristics of community members exposed to World Trade Center (WTC) dust and fumes with Chronic Obstructive Pulmonary Disease (COPD) can provide insight into mechanisms of airflow obstruction in response to an environmental insult, with potential implications for interventions. Methods: We performed a baseline assessment of respiratory symptoms, spirometry, small airway lung function measures using respiratory impulse oscillometry (IOS), and blood biomarkers. COPD was defined by the 2019 GOLD criteria for COPD. Patients in the WTC Environmental Health Center with <5 or ≥5 pack year smoking history were classified as nonsmoker-COPD (ns-COPD) or smoker-COPD (sm-COPD), respectively. Main Results: Between August 2005 and March 2018, 467 of the 3430 evaluated patients (13.6%) fit criteria for COPD. Among patients with COPD, 248 (53.1%) were ns-COPD. Patients with ns-COPD had measures of large airway function (FEV1) and small airway measures (R5−20, AX) that were less abnormal than those with sm-COPD. More ns-COPD compared to sm-COPD had a bronchodilator (BD) response measured by spirometry (24 vs. 14%, p = 0.008) or by IOS (36 vs. 21%, p = 0.002). Blood eosinophils did not differ between ns-COPD and sm-COPD, but blood neutrophils were higher in sm-COPD compared to ns-COPD (p < 0.001). Those with sm-COPD were more likely to be WTC local residents than ns-COPD (p = 0.007). Conclusions: Spirometry findings and small airway measures, as well as inflammatory markers, differed between patients with ns-COPD and sm-COPD. These findings suggest potential for differing mechanisms of airway injury in patients with WTC environmental exposures and have potential therapeutic implications.

Fine Particulate Matter and Lung Function among Burning-Exposed Deepwater Horizon Oil Spill Workers

BACKGROUND

During the 2010 Deepwater Horizon (DWH) disaster, controlled burning was conducted to remove oil from the water. Workers near combustion sites were potentially exposed to increased fine particulate matter [with aerodynamic diameter ≤2.5μm (PM2.5)] levels. Exposure to PM2.5 has been linked to decreased lung function, but to our knowledge, no study has examined exposure encountered in an oil spill cleanup.

OBJECTIVE

We investigated the association between estimated PM2.5 only from burning/flaring of oil/gas and lung function measured 1-3 y after the DWH disaster.

METHODS

We included workers who participated in response and cleanup activities on the water during the DWH disaster and had lung function measured at a subsequent home visit (n=2,316). PM2.5 concentrations were estimated using a Gaussian plume dispersion model and linked to work histories via a job-exposure matrix. We evaluated forced expiratory volume in 1 s (FEV1; milliliters), forced vital capacity (FVC; milliliters), and their ratio (FEV1/FVC; %) in relation to average and cumulative daily maximum exposures using multivariable linear regressions.

RESULTS

We observed significant exposure-response trends associating higher cumulative daily maximum PM2.5 exposure with lower FEV1 (p-trend=0.04) and FEV1/FVC (p-trend=0.01). In comparison with the referent group (workers not involved in or near the burning), those with higher cumulative exposures had lower FEV1 [-166.8mL, 95% confidence interval (CI): -337.3, 3.7] and FEV1/FVC (-1.7, 95% CI: -3.6, 0.2). We also saw nonsignificant reductions in FVC (high vs. referent: -120.9, 95% CI: -319.4, 77.6; p-trend=0.36). Similar associations were seen for average daily maximum PM2.5 exposure. Inverse associations were also observed in analyses stratified by smoking and time from exposure to spirometry and when we restricted to workers without prespill lung disease.

CONCLUSIONS

Among oil spill workers, exposure to PM2.5 specifically from controlled burning of oil/gas was associated with significantly lower FEV1 and FEV1/FVC when compared with workers not involved in burning. https://doi.org/10.1289/EHP8930.

Prenatal exposure to residential PM2.5 and its chemical constituents and weight in preschool children: A longitudinal study from Shanghai, China

BACKGROUND

Studies have reported that prenatal exposure to fine particulate matter (PM_2.5) might be associated with adverse birth outcomes in offspring. However, evidence with regard to the effects of prenatal exposure to PM_2.5 and, especially, its main chemical constituents on offspring's weight in childhood is limited and inconsistent.

OBJECTIVES

The present study aimed to examine associations of prenatal exposure to PM_2.5 total mass and its chemical constituents in each trimester with children's weight from birth to 6 years of age using data from Shanghai-Minhang Birth Cohort Study.

METHODS

A total of 1,084 mother-infant pairs were included with both PM_2.5 exposure data and at least one measurement of weight and height. Weight-for-Length (WLZ), BMI-for-Age (BMIz), and Weight-for-Age (WAZ) z-scores were generated according to the World Health Organization guidelines. Exposure to PM_2.5 total mass and its chemical constituents [organic carbon (OC), black carbon (BC), ammonium (NH₄⁺), nitrate (NO₃^-), sulfate (SO₄^2-), and soil dust (SOIL)] during pregnancy was estimated from a satellite based modelling framework. We used multiple informant model to estimate the associations of trimester-specific PM_2.5 total mass and its specific constituents concentrations with WLZ/BMIz and WAZ of offspring at birth and 1, 4, and 6 years of age.

RESULTS

In multiple informant model, we observed consistent patterns of associations between exposure to PM_2.5 total mass, OC, BC, NH₄⁺, NO₃^-, and SO₄^2- during the 2^nd and 3^rd trimesters and decreased WLZ/BMIz and WAZ at 1, 4, and 6 years of age in boys. We observed associations between prenatal exposure to PM_2.5 total mass, NH₄⁺, and NO₃^- during the 1^st and 2^nd trimesters and increased WLZ/BMIz and WAZ in girls at birth. However, there were null associations at 1 and 4 years of age and inverse associations at 6 years of age.

CONCLUSIONS

Prenatal exposure to PM_2.5 total mass and its main chemical constituents was associated with decreased weight in boys from 1 to 6 years of age, with increased weight at birth and decreased weight at 6 years of age in girls. Our findings suggest that prenatal exposure to PM_2.5 and its chemical constituents may have a lasting effect on offspring's weight in childhood.

Effects of PM2.5 on Chronic Airway Diseases: A Review of Research Progress

The adverse effects of polluted air on human health have been increasingly appreciated worldwide. It is estimated that outdoor air pollution is associated with the death of 4.2 million people globally each year. Accumulating epidemiological studies indicate that exposure to ambient fine particulate matter (PM2.5), one of the important air pollutants, significantly contributes to respiratory mortality and morbidity. PM2.5 causes lung damage mainly by inducing inflammatory response and oxidative stress. In this paper, we reviewed the research results of our group on the effects of PM2.5 on chronic obstructive pulmonary disease, asthma, and lung cancer. And recent research progress on epidemiological studies and potential mechanisms were also discussed. Reducing air pollution, although remaining a major challenge, is the best and most effective way to prevent the onset and progression of respiratory diseases.

Personal exposure to air pollution and respiratory health of COPD patients in London

Previous studies have investigated the effects of air pollution on chronic obstructive pulmonary disease (COPD) patients using either fixed-site measurements or a limited number of personal measurements, usually for one pollutant and a short time period. These limitations may introduce bias and distort the epidemiological associations as they do not account for all the potential sources or the temporal variability of pollution.

We used detailed information on individuals’ exposure to various pollutants measured at fine spatiotemporal scale to obtain more reliable effect estimates. A panel of 115 patients was followed up for an average continuous period of 128 days carrying a personal monitor specifically designed for this project that measured temperature, nitrogen dioxide (NO₂), ozone (O₃), nitric oxide (NO), carbon monoxide (CO), and particulate matter with aerodynamic diameter <2.5 and <10 μm at 1-min time resolution. Each patient recorded daily information on respiratory symptoms and measured peak expiratory flow (PEF). A pulmonologist combined related data to define a binary variable denoting an “exacerbation”. The exposure–response associations were assessed with mixed effects models.

We found that gaseous pollutants were associated with a deterioration in patients’ health. We observed an increase of 16.4% (95% CI 8.6–24.6%), 9.4% (95% CI 5.4–13.6%) and 7.6% (95% CI 3.0–12.4%) in the odds of exacerbation for an interquartile range increase in NO₂, NO and CO, respectively. Similar results were obtained for cough and sputum. O₃ was found to have adverse associations with PEF and breathlessness. No association was observed between particulate matter and any outcome.

Our findings suggest that, when considering total personal exposure to air pollutants, mainly the gaseous pollutants affect COPD patients’ health.

Significant adverse associations were found between the respiratory health of COPD patients and their personal exposure to gaseous pollutants measured using portable sensors over 6 months. No significant associations were found for particulate pollutants.https://bit.ly/3aqMT6O

Food Security, Environmental Health, and the Economy in Mexico: Lessons Learned with the COVID-19

The COVID-19 pandemic showed an impact mainly on the health of people and the economy of households. The levels of food security in the world’s households, especially in Mexico, have decreased. When people do not have food security, their health is compromised and they have financial problems; on the other hand, environmental deterioration has a link with food security. The purpose of this review is to analysis of the current situation in Mexico of food security, environmental health and economy, the main lessons learned in these areas and their proposals integrating public policies. A review was carried out in the main databases (MEDLINE, Embase, CINAHL Plus, Web of Science, CAB Abstracts y PAIS Index) with the following keywords and according to the MeSH terms: Food security, food insecurity, environmental health, public policies, environmental, production, integrating the word COVID-19 in English and Spanish. Only 44.5% of Mexican households presented food security. For food insecurity, 22.6% had moderate and severe food insecurity, while 32.9% had mild insecurity. Food insecurity and the health impacts of environmental origin (waste management during the coronavirus pandemic, water contaminated by bacteria, viruses, and toxins; air pollution) generates impacts on economic activity by not offering food that meets health regulations. Without the application of cost-effective measures and interventions for the prevention and control of patients with obesity, the direct costs for 2023 will amount to 9 million dollars, which worsens the household economy. Despite having laws and policies on the right to food, a healthy environment (water), and opportunities for economic growth, these human rights are not fulfilled. The conclusion is that it is necessary to use a health and agroecological model to promote public policies (health, environment, and economy) that aims to prevent the discussed issues, with multidisciplinary and intersectoral interventions (government, academia, researchers, civil society organizations, industry, and population). This upholds the human right that all people should enjoy an adequate, healthy environment and have access to high-quality food.

Application and evaluation of a low-cost PM sensor and data fusion with CMAQ simulations to quantify the impacts of prescribed burning on air quality in Southwestern Georgia, USA

Prescribed burning (PB) is a prominent source of PM_2.5 in the southeastern US and exposure to PB smoke is a health risk. As demand for burning increases and stricter controls are implemented for other anthropogenic sources, PB emissions tend to be responsible for an increasing fraction of PM_2.5 concentrations. Here, to quantify the effect of PB on air quality, low-cost sensors are used to measure PM_2.5 concentrations in Southwestern Georgia. The feasibility of using low-cost sensors as a supplemental measurement tool is evaluated by comparing them with reference instruments. A chemical transport model, CMAQ, is also used to simulate the contribution of PB to PM_2.5 concentrations. Simulated PM_2.5 concentrations are compared to observations from both low-cost sensors and reference monitors. Finally, a data fusion method is applied to generate hourly spatiotemporal exposure fields by fusing PM_2.5 concentrations from the CMAQ model and all observations. The results show that the severe impact of PB on local air quality and public health may be missed due to the dearth of regulatory monitoring sites. In Southwestern Georgia PM_2.5 concentrations are highly non-homogeneous and the spatial variation is not captured even with a 4-km horizontal resolution in model simulations. Low-cost PM sensors can improve the detection of PB impacts and provide useful spatial and temporal information for integration with air quality models. R² of regression with observations increases from an average of 0.09 to 0.40 when data fusion is applied to model simulation withholding the observations at the evaluation site. Adding observations from low-cost sensors reduces the underestimation of nighttime PM_2.5 concentrations and reproduces the peaks that are missed by the simulations. In the future, observations from a dense network of low-cost sensors could be fused with the model simulated PM_2.5 fields to provide better estimates of hourly exposures to smoke from PB.Implications: Prescribed burning emissions are a major cause of elevated PM_2.5 concentrations, posing a risk to human health. However, their impact cannot be quantified properly due to a dearth of regulatory monitoring sites in certain regions of the United States such as Southwestern Georgia. Low-cost PM sensors can be used as a supplemental measurement tool and provide useful spatial and temporal information for integration with air quality model simulations. In the future, data from a dense network of low-cost sensors could be fused with model simulated PM_2.5 fields to provide improved estimates of hourly exposures to smoke from prescribed burning.

Joint association of cigarette smoking and PM2.5 with COPD among urban and rural adults in regional China

Background

Cigarette smoking and PM_2.5 are important risk factors of Chronic Obstructive Pulmonary Disease (COPD). However, the joint association of cigarette smoking and PM_2.5 with COPD is unknown.

Methods

A community-based study was conducted among urban and rural adults aged 40 + years between May and December of 2015 in Jiangsu Province, China. The outcome variable was spirometry-defined COPD. Explanatory measures were smoking status (non-smokers or smokers) and PM_2.5 exposure [low level (< 75 μg/m³) or high level (≥ 75 μg/m³)]. Mixed-effects logistic regression models were applied to calculate the odds ratio (OR) and 95% confidence interval (CI) to investigate the associations of cigarette smoking and PM_2.5 with COPD.

Results

The prevalence of COPD was 11.9% (95% CI = 10.9%, 13.0%) within the overall 3407 participants in this study. After adjustment for potential confounders and community-level clustering effect, smokers tended to develop COPD relative to non-smokers (OR = 2.46, 95% CI 1.76, 3.43), while only smokers exposed to high level PM_2.5 were more likely to experience COPD (OR = 1.36; 95% CI 1.01, 1.83) compared to their counterparts exposed to low level PM_2.5. Meanwhile, compared to non-smokers who exposed to low level PM_2.5, non-smokers who exposed to high level PM_2.5 (OR = 1.10, 95% CI 0.74, 1.64), smokers who exposed to low (OR = 2.22, 95% CI 1.51, 3.27) or high level PM_2.5 (OR = 3.14, 95% CI 2.15, 4.59) were, respectively, more like to develop COPD.

Conclusions

Cigarette smoking was positively associated with COPD among overall participants, while PM_2.5 was in positive relation to COPD among smokers only. Moreover, cigarette smoking and PM_2.5 might have an additive effect on the risk of COPD among adult smokers aged 40 years or older in China.

Effect of Particulate Matter Exposure on Respiratory Health of e-Waste Workers at Agbogbloshie, Accra, Ghana

Background: Direct and continuous exposure to particulate matter (PM), especially in occupational settings is known to impact negatively on respiratory health and lung function. Objective: To determine the association between concentrations of PM (2.5, 2.5–10 and 10 µm) in breathing zone and lung function of informal e-waste workers at Agbogbloshie. Methods: To evaluate lung function responses to PM (2.5, 2.5–10 and 10 µm), we conducted a longitudinal cohort study with three repeated measures among 207 participants comprising 142 healthy e-waste workers from Agbogbloshie scrapyard and 65 control participants from Madina-Zongo in Accra, Ghana from 2017–2018. Lung function parameters (FVC, FEV1, FEV1/FVC, PEF, and FEF 25-75) and PM (2.5, 2.5–10 and 10 µm) concentrations were measured, corresponding to prevailing seasonal variations. Socio-demographic data, respiratory exposures and lifestyle habits were determined using questionnaires. Random effects models were then used to examine the effects of PM (2.5, 2.5–10 and 10 µm) on lung function. Results: The median concentrations of PM (2.5, 2.5–10 and 10 µm) were all consistently above the WHO ambient air standards across the study waves. Small effect estimates per IQR of PM (2.5, 2.5–10 and 10 µm) on lung function parameters were observed even after adjustment for potential confounders. However, a 10 µg increase in PM (2.5, 2.5–10 and 10 µm) was associated with decreases in PEF and FEF 25–75 by 13.3% % [β = −3.133; 95% CI: −0.243, −0.022) and 26.6% [β = −0.266; 95% CI: −0.437, 0.094]. E-waste burning and a history of asthma significantly predicted a decrease in PEF by 14.2% [β = −0.142; 95% CI: −0.278, −0.008) and FEV1 by 35.8% [β = −0.358; 95% CI: −0.590, 0.125] among e-waste burners. Conclusions: Direct exposure of e-waste workers to PM predisposes to decline in lung function and risk for small airway diseases such as asthma and COPD.

Establishment of Regional Concentration-Duration-Frequency Relationships of Air Pollution: A Case Study for PM2.5

Poor air quality usually leads to PM2.5 warnings and affects human health. The impact of frequency and duration of extreme air quality has received considerable attention. The extreme concentration of air pollution is related to its duration and annual frequency of occurrence known as concentration-duration-frequency (CDF) relationships. However, the CDF formulas are empirical equations representing the relationship between the maximum concentration as a dependent variable and other parameters of interest, i.e., duration and annual frequency of occurrence. As a basis for deducing the extreme CDF relationship of PM2.5, the function assumes that the extreme concentration is related to the duration and frequency. In addition, the spatial pattern estimation of extreme PM2.5 is identified. The regional CDF identifies the regional extreme concentration with a specified duration and return period. The spatial pattern of extreme air pollution over 8 h duration shows the hotspots of air quality in the central and southwestern areas. Central and southwestern Taiwan is at high risk of exposure to air pollution. Use of the regional CDF analysis is highly recommended for efficient design of air quality management and control.

Indoor PM2.5, tobacco smoking and chronic lung diseases: A narrative review

The lung is one of the most important organs exposed to environmental agents. People spend approximately 90% of their time indoors, and risks to health may thus be greater from exposure to poor air quality indoors than outdoors. Multiple indoor pollutants have been linked to chronic respiratory diseases. Environmental tobacco smoke (ETS) is known as an important source of multiple pollutants, especially in indoor environments. Indoor PM_2.5 (particulate matter with aerodynamic diameter < 2.5 μm) was reported to be the most reliable marker of the presence of tobacco smoke. Recent studies have demonstrated that PM_2.5 is closely correlated with chronic lung diseases. In this paper, we reviewed the relationship of tobacco smoking and indoor PM_2.5 and the mechanism that underpin the link of tobacco smoke, indoor PM_2.5 and chronic lung diseases.

Participation of the miR-22-HDAC4-DLCO Axis in Patients with COPD by Tobacco and Biomass

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation and systemic inflammation. The main causes of COPD include interaction between genetic and environmental factors associated with tobacco smoking (COPD-TS) and/or exposure to biomass smoke (COPD-BS). Several microRNAs (miRNAs) control posttranscriptional regulation of COPD-TS associated gene expression. The miR-22-HDAC4-IL-17 axis was recently characterized. It is still unknown, however, whether this axis, participates in COPD-BS. To investigate, 50 patients diagnosed with severe-to-very severe COPD GOLD (Global Initiative for Chronic Obstructive Lung Disease) stages III/IV, were recruited, 25 women had COPD-BS (never smokers, exposed heavily to BS) and 25 had COPD-TS. Serum levels of miRNA-22-3p were measured by RT (Reverse Transcription)-qPCR, while the concentration of HDAC4 (Histone deacetylase 4) was detected by ELISA. Additionally, we looked for association between serum HDAC4 and DLCOsb (Single-breath diffusing capacity of the lung for carbon monoxide), as % of predicted by age, height, and gender, one of the main differences described between COPD-BS and COPD-TS. Women with COPD-BS were older and shorter and had a higher DLCOsb %P (percent predicted) compared to COPD-TS. Serum miR-22-3p was downregulated in COPD-BS relative to COPD-TS. In contrast, the concentration of HDAC4 was higher in COPD-BS compared to COPD-TS. Furthermore, a positive correlation between serum HDAC4 levels and DLCOsb %P was observed. We concluded that the miR-22-HDAC4-DLCO axis behaves differently in patients with COPD-BS and COPD-TS.

Association between outdoor PM2.5 and prevalence of COPD: a systematic review and meta-analysis

There were conflictions and differences among the results of cross-sectional studies association between PM_2.5 and COPD prevalence. We aimed to explore the real association between outdoor PM_2.5 and COPD prevalence, analyze the possible cause to the differences and conflictions in previous cross-sectional studies. Cross-sectional literatures about the association between outdoor PM_2.5 and COPD prevalence were selected up to 12 September 2018. Subgroup analysis was performed to explore the source of the heterogeneity. Publication bias was tested via funnel plot. Leave-one-out method was used to conduct influential analysis. Variance analysis was used to analyze the influence of concentration, literature quality and age (over 60 or not) on the ln (aOR) values. The initial search revealed 230 studies, of which 8 were selected. The heterogeneity in this study was significant (I²=62, P<0.01), and random effects model was used. The pooled OR for the association between PM_2.5 and COPD prevalence is 2.32(95%CI, 1.91-2.82). There was no evidence of publication bias. Subgroup analysis showed the subgroup of age seemed to be the source of heterogeneity (P=0.0143, residual I²=0%). Variance analysis showed that the differences of ln (aOR) among each concentration group(p=0.0075) were statistically significant, the same as age groups(P=0.0234). This meta-analysis study demonstrated a conclusive association between PM_2.5 and prevalence of COPD (OR: 2.32, 95%CI 1.91-2.82). The significant heterogeneity among selected studies was mainly caused by age (over 60 or not). High PM_2.5 concentration should be needed in further research of the relationship between PM_2.5 and chronic diseases.

Stronger association between particulate air pollution and pulmonary function among healthy students in fall than in spring

Previous studies have reported the short-term effects of particulate air pollution on health. However, most of those studies were relatively short in duration, with only a few, in healthy adolescents. We investigated the short-term effects of particulate air pollution on pulmonary function in healthy adolescents over a long period. A panel study was repeatedly conducted twice a year for about one month each, in spring and fall from 2014 to 2016, in an isolated island in the Seto Inland Sea, Japan. Daily measurements of peak expiratory flow (PEF) and forced expiratory volume in 1 s (FEV₁) were performed in a total of 48 healthy college students aged 15-19 years. The ambient concentrations of particulate matter with diameter ≤2.5 μm (PM_2.5) and between 2.5 and 10 μm (PM_10-2.5), and black carbon (BC) were continuously measured. A mixed-effects model was used to investigate the relationships between air pollutants and pulmonary function. In the overall analyses of the six study periods, decreases in the PEF and FEV₁ were significantly associated with increases in the PM_2.5 and BC concentrations. The greatest decrease was found in FEV₁ (-1.97% [95% confidence interval (CI): -2.90, -1.04]), which was associated with an interquartile range (IQR) increase in the 0-72-h average concentrations of PM_2.5 (14.1 μg/m³). Neither PEF nor FEV₁ were associated with PM_10-2.5 concentrations. In the analyses by season, both the PEF and FEV₁ values decreased significantly in relation to increases in the PM_2.5, PM_10-2.5 and BC concentrations in the fall. However, in spring, both PEF and FEV₁ showed weak associations with each of the pollutants. In conclusion, relatively low increases in the ambient particulate matter levels were associated with reduced pulmonary function among healthy adolescents. This association was stronger in fall than in spring.

The global DNA and RNA methylation and their reversal in lung under different concentration exposure of ambient air particulate matter in mice

Particulate matter (PM) in air pollution is a pervasive risk factor in pulmonary diseases that are always associated with gene expression level alterations in many specific-genes. DNA methylation (5-methylcytosine [5mC]) and RNA methylation (N6-methyladenine [6 mA]) influence the gene expression from transcription and post-transcription level, and the DNA hydroxymethylation (5-hydroxymethylcytosine [5hmC]) is the oxidized form of 5mC. In the present study, the levels of global 5mC, 5hmC and 6 mA of lungs in experimental mice were investigated. We divided the animals into 3 groups randomly, the group 1 was exposed to heavy PM for 24 h in the unfiltered chamber, the group 2 was exposed to filtered air in the filtered chamber, and the group 3 was 10 of the mice in the group 1 after 24 h exposure and then being moved to the filtered chamber for further 120 h exposure. The morphology of lungs showed that acute PM exposure impaired the structure of pulmonary alveolus. Meanwhile, the global level of DNA methylation was decreased, and DNA hydroxymethylation and RNA methylation levels were increased in lungs after PM exposure for only 24 h. Very notably, after being exposed in purified air for 120 h, the pulmonary morphology, the global levels of DNA methylation, DNA hydroxymethylation and RNA methylation of lungs were all reversed. The present study clearly demonstrated the alteration of DNA and RNA methylation after acute heavy PM exposure and emphasized the reversal of the symptoms caused by PM exposure after the air purification, which provided us a new idea for the intervention of the adverse health effects from air pollution. CAPSULE: Acute PM exposure resulted in reduced global DNA methylation and increased global DNA hydroxymethylcytosine and RNA methylation, and air purification reversed these alterations.

Fine-particulate matter aggravates cigarette smoke extract-induced airway inflammation via Wnt5a-ERK pathway in COPD

Background

Exposure to environmental particulate matter (PM) ≤2.5 μm in diameter (PM_2.5) and smoking are common contributors to COPD, and pertinent research implicates both factors in pulmonary inflammation. Using in vivo mouse and in vitro human cellular models, we investigated the joint impact of PM_2.5 pollution, and cigarette smoke (CS) in mice or cigarette-smoke extract (CSE) in cells on COPD inflammation, and explored potential mechanisms.

Methods

Tissue changes in lungs of C57BL/6 mice exposed to PM_2.5 and CS were studied by light microscopy, H&E, immunochemistry, and immunofluorescence-stained sections. Levels of inflammatory factors induced by PM_2.5/CS in mice and PM_2.5/CSE in 16HBE cells were also monitored by quantitative reverse-transcription (qRT)-PCR and ELISA. Expression of genes related to the Wnt5a-signaling pathway was assessed at transcriptional and protein levels using immunofluorescence, qRT-PCR, and Western blotting.

Results

Inflammatory response to combined exposure of PM_2.5 and CS or CSE in mouse and 16HBE cells surpassed responses incited separately. Although separate PM_2.5 and CS/CSE exposure upregulated the expression of Wnt5a (a member of the Wnt-secreted glycoprotein family), combined PM_2.5 and CS/CSE exposure produced a steeper rise in Wnt5a levels. Use of a Wnt5a antagonist (BOX5) successfully blocked related inflammatory effects. ERK phosphorylation appeared to mediate the effects of Wnt5a in the COPD model, promoting PM_2.5 aggravation of CS/CSE-induced airway inflammation.

Conclusion

Our findings suggest that combined PM_2.5 and CS/CSE exposure induce airway inflammation and Wnt5a expression in vivo in mice and in vitro in 16HBE cells. Furthermore, PM_2.5 seems to aggravate CS/CSE-induced inflammation via the Wnt5a–ERK pathway in the context of COPD.

Acute Effects of Air Pollution and Noise from Road Traffic in a Panel of Young Healthy Adults

Panel studies are an efficient means to assess short-term effects of air pollution and other time-varying environmental exposures. Repeated examinations of volunteers allow for an in-depth analysis of physiological responses supporting the biological interpretation of environmental impacts. Twenty-four healthy students walked for 1 h at a minimum of four separate occasions under each of the following four settings: along a busy road, along a busy road wearing ear plugs, in a park, and in a park but exposed to traffic noise (65 dB) through headphones. Particle mass (PM_2.5, PM₁), particle number, and noise levels were measured throughout each walk. Lung function and exhaled nitrogen oxide (NO) were measured before, immediately after, 1 h after, and approximately 24 h after each walk. Blood pressure and heart rate variability were measured every 15 min during each walk. Recorded air pollution levels were found to correlate with reduced lung function. The effects were clearly significant for end-expiratory flows and remained visible up to 24 h after exposure. While immediate increases in airway resistance could be interpreted as protective (muscular) responses to particulate air pollution, the persisting effects indicate an induced inflammatory reaction. Noise levels reduced systolic blood pressure and heart rate variability. Maybe due to the small sample size, no effects were visible per specific setting (road vs. park).

Influence of Particulate Matter during Seasonal Smog on Quality of Life and Lung Function in Patients with Chronic Obstructive Pulmonary Disease

The impact of outdoor air pollution on the quality of life (QoL) of chronic obstructive pulmonary disease (COPD) patients, as measured by the COPD assessment test (CAT) questionnaire, is limited. The aim of this study was to determine the impact of a short-term increase in outdoor particulate matter in which the particles are less than 10 microns in diameter (PM₁₀) during a seasonal smog period on QoL, symptoms, and lung function in COPD patients. This prospective observational study was conducted at Chiang Dao Hospital, Chiang Mai, Thailand between March and August 2016. Measurement of QoL, severity of dyspnea, forced vital capacity (FVC), and forced expiratory volume in the first second (FEV₁) were performed at both high and low PM₁₀ periods. Fifty-nine patients met the inclusion criteria for enrollment into the study, with the mean age being 71.5 ± 8.0 years. Total CAT score, but not mMRC score, was statistically higher during the high PM₁₀ period. The two lung function parameters, FVC and FEV₁, were significantly lower at the high PM₁₀ compared to the low PM₁₀ period. We concluded that exposure to PM₁₀ during the seasonal smog period resulted in short-term negative impact on the quality of life and lung function in COPD patients.

Ambient fine particulate pollution and daily morbidity of stroke in Chengdu, China

Introduction

Association has been reported between ambient fine particulate matter (PM) and adverse outcomes of cerebrovascular events. However, it remains unclear that whether short-term exposure to PM relates to stroke and the lag of health effects. This triggers us to examine the relationship between PM and population stroke morbidity in Chengdu.

Methods

The daily average concentration of atmospheric pollutants and meteorological factors and daily morbidity of stroke in Chengdu (2013–2015) were collected. Based on time series analysis-generalized additive models (GAM), single-pollutant, two-pollutant and multi-pollutant model were established. The effects of atmospheric PM_2.5 (defined as PM less than 2.5μm in aerodynamic diameter), PMc(defined as PM less than 10μm and more than 2.5μm in aerodynamic diameter) and PM₁₀ (defined as PM less than 10μm in aerodynamic diameter) concentration on the daily mortality of stroke were analyzed, respectively.

Results

The three-year mean concentrations of PM_2.5, PMc and PM₁₀ for air pollutants were 75.9, 43.9 and 119.7 μg/m³, respectively. PM_2.5 on the current day (lag0) and with a moving average of 0–1 days were significantly associated with the increasing risk of stroke morbidity, and PM_2.5 with a lag of 0–1 days had greater association, whereas for PMc and PM₁₀ there were no significant association observed. In our study, every 10μg/m³ increase of PM_2.5 was associated with 0.69% percent change in stroke morbidity (95%CI: 0.01~1.38). For females, every 10μg/m³ increase of PM_2.5 contributes to 0.80% percent change of onset. And for the group of age less than 65, we observed 0.78% higher risk every 10μg/m³ increase of PM_2.5.

Conclusions

These findings suggest that short-term exposure to PM_2.5 within 1 day is associated with the onset of stroke, and the younger people (age<65) and females are more sensitive than older people and males.

COPD rat model is more susceptible to cold stress and PM2.5 exposure and the underlying mechanism

The purpose of this study is to verify the hypothesis that chronic obstructive pulmonary disease (COPD) model rat is more susceptible to cold stress and fine particulate matter (PM_2.5) exposure than the healthy rat, and explore the related mechanism. COPD rat model, established with cigarette smoke and lipopolysaccharide intratracheal instillation, were exposed to cold stress (0 °C) and PM_2.5 (0, 3.2, 12.8 mg/ml). After that, the levels of superoxide dismutase, inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-α), monocyte chemotactic protein 1 (MCP-1) and angiotensin Ⅱ (Ang-Ⅱ) in lung were measured, as well as the expression levels of lung 8-hydroxy-2-deoxyguanosine (8-OHdG), nuclear factor kappa B (NF-κB), heme-oxygenase-1 (HO-1) and nuclear factor erythroid-2-related factor 2 (Nrf2). There were significant positive relationships between PM_2.5 and lung level of iNOS, TNF-α, MCP-1 and Ang-Ⅱ, lung function and pathologic damage in COPD rats. The HO-1, NF-κB and 8-OHdG were found highly expressed in COPD rat lung, particularly at the higher PM_2.5 dose of cold stress groups, while Nrf2 was found declined. Thus, COPD rats may be more susceptible to cold stress and PM_2.5 exposure. Cold stress may aggravate PM_2.5-induced toxic effects in the lung of COPD rats through increasing Ang-Ⅱ/NF-κB signaling pathway and suppressing Nrf2 signaling pathway.

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.

Function of PM2.5 in the pathogenesis of lung cancer and chronic airway inflammatory diseases

Previous research has identified that air pollution is associated with various respiratory diseases, but few studies have investigated the function served by particulate matter 2.5 (PM2.5) in these diseases. PM2.5 is known to cause epigenetic and microenvironmental alterations in lung cancer, including tumor-associated signaling pathway activation mediated by microRNA dysregulation, DNA methylation, and increased levels of cytokines and inflammatory cells. Autophagy and apoptosis of tumor cells may also be detected in lung cancer associated with PM2.5 exposure. A number of mechanisms are involved in triggering and aggravating asthma and COPD, including PM2.5-induced cytokine release and oxidative stress. The present review is an overview of the underlying molecular mechanisms of PM2.5-induced pathogenesis in lung cancer and chronic airway inflammatory diseases.

[Protective effect of paeoniflorin against PM2.5-induced damage in BEAS-2B cells]

OBJECTIVE

To investigate the protective effects of paeoniflorin against PM2.5-induced damage in BEAS-2B cells and explore the possible mechanism.

METHODS

With a factorial design, this study was performed to observe the protective effects of different doses of paeoniflorin against PM2.5-induced BEAS-2B cell growth inhibition and the effects of paeoniflorin on the contents of malondialdehyde (MDA) and intracellular reactive oxygen species (ROS) in the cell cultures.

RESULTS

Exposure to increased PM2.5 concentrations caused significant decrease in the cell survival rate (P<0.05) with a clear dose-response relationship (r=-0.759, P<0.05). Treatment of the cells with paeoniflorin significantly attenuated PM2.5-induced inhibition of BEAS-2B cell survival (P<0.05), but the effect of paeoniflorin was not dose-dependent (P>0.05). PM2.5 exposure also significantly increased the contents of MDA and intracellular ROS (P<0.05), and paeoniflorin obviously antagonized these effects of PM2.5.

CONCLUSION

Paeoniflorin can protect BEAS-2B cells from PM2.5-induced growth inhibition, and the mechanism might be related to the anti-oxidant effects of paeoniflorin.

Synergistic effects of temperature and humidity on the symptoms of COPD patients

This panel study investigates how temperature, humidity, and their interaction affect chronic obstructive pulmonary disease (COPD) patients' self-reported symptoms. One hundred and six COPD patients from Shanghai, China, were enrolled, and age, smoking status, St. George Respiratory Questionnaire (SGRQ) score, and lung function index were recorded at baseline. The participants were asked to record their indoor temperature, humidity, and symptoms on diary cards between January 2011 and June 2012. Altogether, 82 patients finished the study. There was a significant interactive effect between temperature and humidity (p < 0.0001) on COPD patients. When the indoor humidity was low, moderate, and high, the indoor temperature ORs were 0.969 (95% CI 0.922 to 1.017), 0.977 (0.962 to 0.999), and 0.920 (95% CI 0.908 to 0.933), respectively. Low temperature was a risk factor for COPD patients, and high humidity enhanced its risk on COPD. The indoor temperature should be kept at least on average at 18.2 °C, while the humidity should be less than 70%. This study demonstrates that temperature and humidity were associated with COPD patients' symptoms, and high humidity would enhance the risk of COPD due to low temperature.

Association between environmental factors and hospitalisations for bronchiectasis in Badalona, Barcelona, Spain (2007-2015)

INTRODUCTION

The relationship between environmental factors and the exacerbation of respiratory diseases has been widely studied. However, there are no studies examining the relationship between these factors and bronchiectasis exacerbations. Our objective was to analyse the association between various environmental factors and hospitalisation for bronchiectasis.

MATERIAL AND METHODS

This was a retrospective observational study conducted at two hospitals in Badalona (Barcelona). The number of hospital admissions for exacerbation of bronchiectasis between 2007 and 2015 was obtained. Through multiple regression we analysed the relationship between the number of exacerbations and mean monthly values of temperature, SO₂, NO, NO₂, O₃ and CO.

RESULTS

Temperature, SO₂, NO, NO₂, O₃ and CO were significantly associated with an increase in admissions due to exacerbation of bronchiectasis. By controlling the effect of temperature on the pollution variables, only SO₂ maintained statistical significance (P=.008).

CONCLUSION

We have detected an increase in hospital admissions for exacerbation of bronchiectasis with increases in the atmospheric concentration of SO₂ and the decrease in temperature. Prospective studies with different geographical locations to confirm these results are needed.

Air pollution alters Staphylococcus aureus and Streptococcus pneumoniae biofilms, antibiotic tolerance and colonisation

Air pollution is the world's largest single environmental health risk (WHO). Particulate matter such as black carbon is one of the main components of air pollution. The effects of particulate matter on human health are well established however the effects on bacteria, organisms central to ecosystems in humans and in the natural environment, are poorly understood. We report here for the first time that black carbon drastically changes the development of bacterial biofilms, key aspects of bacterial colonisation and survival. Our data show that exposure to black carbon induces structural, compositional and functional changes in the biofilms of both S. pneumoniae and S. aureus. Importantly, the tolerance of the biofilms to multiple antibiotics and proteolytic degradation is significantly affected. Additionally, our results show that black carbon impacts bacterial colonisation in vivo. In a mouse nasopharyngeal colonisation model, black carbon caused S. pneumoniae to spread from the nasopharynx to the lungs, which is essential for subsequent infection. Therefore our study highlights that air pollution has a significant effect on bacteria that has been largely overlooked. Consequently these findings have important implications concerning the impact of air pollution on human health and bacterial ecosystems worldwide.

Occupation exposed to road-traffic emissions and respiratory health among Congolese transit workers, particularly bus conductors, in Kinshasa: a cross-sectional study

Objectives

Road-traffic emissions (RTE) induce adverse health effects, notably respiratory symptoms and respiratory diseases, as a result of pollutants deposited into the respiratory tract. The aim of this study was to evaluate the association between occupation groups of Congolese transit workers exposed to RTE, particularly bus conductors and respiratory health, in Kinshasa.

Methods

A cross-sectional study was conducted from 2015 April 20^th to May 14^th, whose participants were bus conductors (n = 110), bus drivers (n = 107), taxi-motorcyclists (n = 102) and high school teachers (control group; n = 106). Subjects had completed the American Thoracic Society respiratory symptom questionnaire. Lung function test was performed by spirometry. Air pollutants levels of PM_2.5, NO₂ and SO₂ were measured between 7:30 and 8:30 and 16:30–17:30 using a portable gas monitor.

Multivariate analysis was performed to evaluate the association between occupation exposed to RTE and impaired pulmonary function, after adjustment by plausible confounders.

Results

The prevalence of mixed syndrome was 21.9% for bus conductors, 10.9% for bus drivers, 15.4% for taxi-motorcyclists and 7.1% for high school teachers with (p < 0.05). The risk of developing a mixed syndrome was seven times higher among bus conductors [OR = 7.64; 95% CI: 1.83–31.67; p < 0.05] than other groups. Additionally, the prevalence of respiratory syndromes increased with the duration of exposure.

Conclusions

Occupation exposed to RTE is associated with impaired pulmonary function and the prevalence of respiratory symptoms among transit workers, especially bus conductors. Furthermore, this association increases with the duration of exposure suggesting the necessity to regulate these categories of occupations and to apply preventives measures.

Panel studies of air pollution in patients with COPD: Systematic review and meta-analysis

BACKGROUND

Epidemiological studies have shown an increase in morbidity and mortality rates in patients with chronic obstructive pulmonary disease (COPD) following exposure to elevated levels of air pollution. Panel studies have been used to assess short-term effects of air pollution which are not detected by registry studies, specifically lung function and symptoms. The aim of this systematic review was to assess the evidence of panel studies on acute effects of air pollution among patients with COPD.

METHODS

We searched the PubMed database, and identified additional studies by inspecting reference lists and literature reviews. We identified and summarized 25 panel studies that were published between 1993 and February 2016. Results were presented in forest plots and effect estimates of sufficiently comparable outcomes and pollutants were summarized by a random-effects meta-analysis.

RESULTS

Meta-analysis showed that a 10µg/m³ increase in ambient levels of particles less than 10µm in diameter (PM₁₀) had a small, but statistically significant impact on FEV₁ (-3.38mL, 95% CI -6.39 to -0.37) and PEF (-0.61L/min, -1.20 to -0.01). There was significant heterogeneity across the included studies. A forest plot showing associations between PM₁₀ and respiratory symptoms was also suggestive of an adverse effect of particulate air pollution, but this was not formally tested in a meta-analysis due to the heterogeneity of outcomes. Results for gaseous pollutants were inconsistent for lung function or symptoms.

CONCLUSIONS

Evidence from the identified panel studies indicated statistically significant associations of particulate matter air pollution with lung function in patients with COPD.

Mutagenic and genotoxic potential of native air borne particulate matter from industrial area of Rourkela city, Odisha, India

In this study, we examined potential adverse health effect of particulate matter (PM) collected from industrial areas of Rourkela, Odisha, India. Results indicate that PM in these areas contains benzo[a]pyrene in addition to other unidentified molecules. Ames test revealed the above PM to be highly mutagenic. Further studies of PM in HaCaT cells suggest its DNA damaging potential which may lead to apoptosis. Generation of reactive oxygen and nitrogen species following PM exposure may be an early event in the PM induced apoptosis. In addition, the activity of cytochrome P450 (CYP450), the key xenobiotic metabolism enzyme, was found to be increased following PM exposure indicating its role in PM induced toxicity. To confirm this, we used genetic and pharmacological inhibitors of CYP450 like CYP1B1 siRNA and Clotrimazole. Interestingly, we found that the use of these inhibitors significantly suppressed the PM induced apoptosis in HaCaT cells, which confirm the crucial role of CYP1B1 in the toxic manifestation of PM. For further analysis, blood samples were collected from the volunteer donor and analyzed for immunophenotypes and comet assay to survey any change in immune cells and DNA damage in blood cells respectively. The study was performed with 55 blood samples including 32 from industrial areas and 23 people from non-industrial zone of Rourkela city. Samples had a mean±SD age of 35±6.2years (35 men and 20 women). Our investigation did not observe any significant alteration in lymphocytes (P=0.671), B cell (P=0.104), cytotoxic T cell (P=0.512), helper T cell (P=0.396), NK cell (P=0.675) and monocytes (P=0.170) of blood cells from these two groups. Taken together; this study first time reports the possible health hazards of PM from industrial areas of Odisha, India.