Associations between fine and coarse particles and mortality in Mediterranean cities: results from the MED-PARTICLES project

Dust Storms and Emergency Department Visits in 3 Southwestern States Using NWS Storm Reports

Importance

Dust storms are projected to increase with climate change. The short-term health outcomes associated with dust storms in the US are not well characterized, especially for morbidity outcomes.

Objective

To estimate associations between dust storms and diagnosis-specific emergency department (ED) visits during 2005 to 2018.

Design, Setting, and Participants

In this cross-sectional study using a time-stratified case-crossover design, short-term associations between dust storms and ED visits were estimated at the zip code level using conditional Poisson analysis with adjustment for meteorology and within-month trends. Same-day dust storm events and storm events within a lag period of up to 7 days were considered. State-wide patient-level ED visit records acquired from 3 state health departments (Arizona, California, and Utah) were analyzed. Data were analyzed between April 21 and November 12, 2024.

Exposures

Dust storm events were reported by the US National Weather Service and assigned to each patient zip code that had at least a 5% areal overlap with the National Weather Service forecast zone.

Main Outcomes and Measures

Patient-level ED visits for asthma, chronic obstructive pulmonary disease, culture-negative pneumonia, congestive heart failure (CHF), cerebrovascular disease, ischemic heart disease, and visits due to motor vehicle accidents.

Results

The analysis included 33 500 ED visits among the outcomes of interest (5717 children aged 0-17 years [17.1%] and 11 150 adults aged >65 years [33.3%]; 17 394 male [51.9%] and 16 104 female [48.1%]; 2829 Black [8.4%] and 22 537 White [67.2%]; 9256 Hispanic [27.6%]) and 206 dust-impacted zip codes. The strongest associations between dust storms and ED visits were found for asthma (lag 0-2 relative risk [RR], 1.06; 95% CI, 1.01-1.11; P = .03), culture-negative pneumonia (lag 0-7 RR, 1.06; 95% CI, 1.02-1.10; P = .002), CHF (lag 0-7 RR, 1.06; 95% CI, 1.01-1.10; P = .01), and motor vehicle accidents (lag 0 RR, 1.13; 95% CI, 1.04-1.23; P = .003). Associations of dust storm exposure with ischemic heart disease were mostly protective (eg, lag 0-2 RR, 0.89; 95% CI, 0.84-0.95; P < .001). Associations of dust storm exposure with risk of ED visits for CHF and motor vehicle accidents were robust against adjustment for ambient ozone (eg, CHF: RR, 1.08; 95% CI, 1.03-1.13; P = .003) and nitrogen dioxide (eg, CHF: RR, 1.08; 95% CI, 1.03-1.13; P = .003) air pollution.

Conclusions and Relevance

In this study, dust storms were positively associated with ED visits for asthma, pneumonia, heart failure, and motor vehicle accidents. These findings contribute to our understanding of the association of dust storms with morbidity in the US and potential outcomes under a changing climate.

Sand and dust storms: a growing global health threat calls for international health studies to support policy action

Sand and dust storms increasingly threaten global environmental and public health. To date, 150 countries are directly affected, with more than 100 classified as non-dust source regions. With climate change, these storms are expected to become more frequent and severe. Despite international awareness and initiatives, such as those led by the UN, crucial knowledge gaps continue to hinder effective, evidence-based public responses to sand and dust storms. In this Viewpoint, we review existing gaps in health research and highlight four key research priorities: the comprehensive health effects of sand and dust storms, including short-term and long-term exposures, diseases, regions, and health outcomes; the key particle sizes and toxic components of particles during sand and dust storms; the design of multicentre studies accounting for region-specific exposure patterns; and research on health outcomes attributable to particulate matter mixtures dominated by windblown dust versus other sources. We urgently call for international, collaborative, and multidisciplinary health studies considering sand and dust storm exposure characteristics and for the adoption of scientifically robust epidemiological methods in these studies.

The associations between exposure to ambient air pollution and coagulation markers and the potential effects of DNA methylation

Previous studies have illustrated the pivotal role of coagulation biomarkers in the link between air pollution and cardiovascular disease (CVD). However, inconsistencies remain in the conclusions, with limited studies conducted in rural areas of China. We conducted a panel study in rural areas of Henan Province, China. Considering the potential effect modifications of atherosclerotic cardiovascular disease (ASCVD) risks, 104 participants were enrolled, comprising two matched groups: 52 with high ASCVD risks and 52 with low ASCVD risks. DNA methylation at CpG sites and coagulation indices were measured for all participants. Linear mixed-effect regression models were used to evaluate the associations between ambient air pollution, coagulation biomarkers, and DNA methylation. We observed that for every 5-day standard deviation (SD) increment of PM2.5 (11.91 μg/m³) and PM10 (13.65 μg/m³), fibrinogen increased by 7.70 % (95 %CI: 2.27, 13.12) and 8.50 % (95 %CI: 2.46, 14.55), respectively. SO2 (6.95 μg/m³) was associated with 40.25 % (95 %CI: 14.83, 65.67) increase in plasminogen activator inhibitor-1 (PAI-1). Decreased methylation at CpG sites was associated with exposure to air pollution. However, DNA methylation did not mediate the association between ambient air pollution and coagulation. Our study revealed the harmful impact of ambient air pollution on coagulation function but found no significant mediation effects of DNA methylation.

Effects of ambient air pollution from shipping on mortality: A systematic review

BACKGROUND

Shipping contributes to air pollution causing adverse health effects. We conducted for the first time a systematic review on the health and economic impacts of ambient air pollution from shipping emissions.

METHODS

We performed a systematic search in PubMed, Web of Science, EBSCO (Medline), and Scopus of all time up to December 2023. We then inter-compared semi-quantitatively the results of the included eligible studies.

RESULTS

We identified 23 eligible studies, 22 applying health impact assessment, and 1 using epidemiological methods. These studies used different methods for the evaluation of emissions, dispersion, and exposure, and for the exposure-mortality risk functions for exposure to shipping emissions for 1-2 years. The estimated excess global all-cause mortality from six studies ranged between 1 and 5 deaths per 100,000 person-years. However, the heterogeneity of the methods and critical gaps in the reporting seriously limited the synthesis of the evidence on health and economic effects of shipping emissions. Sufficient spatial and temporal resolutions in both dispersion and exposure modeling, as well as presentation of uncertainties is needed. Health impact assessment should present the results with all the main risk functions and population attributable risks, and the magnitude of the effect should be expressed in excess number per a given person-time or per population size. Economic effects should also cover work productivity, mental well-being, and cognitive functions.

CONCLUSIONS

We recommend that future studies should properly evaluate and report the uncertainty ranges and the confidence limits of the results. Rigorous studies are needed on multipollutant exposures, exposures from various source categories, and exposures attributed to various particulate matter measures. Studies should report the health impact measures in a format that facilitates straightforward inter-study comparisons. Further research should also specifically report the used grid spacings and resolutions and evaluate whether these are optimal for the task.

Air quality challenges in Central Asian urban areas: a PM2.5 source apportionment analysis in Dushanbe, Tajikistan

This work presents the first comprehensive assessment of PM pollution sources in Dushanbe, Tajikistan. A total of 138 PM2.5 samples were collected during 2015-2016 and 2018-2019 and were analyzed through gravimetric, ED-XRF, and multi-wavelength absorption techniques. The results show that PM2.5 concentrations were substantially higher than the European annual limit value and WHO Air Quality Guidelines annual average value, with an average of 90.9 ± 68.5 μg m-3. The PMF application identified eight sources of pollution that influenced PM2.5 concentration levels in the area. Coal burning (21.3%) and biomass burning (22.3%) were the dominant sources during the winter, while vehicular traffic (7.7%) contributed more during the warm season. Power plant emissions (17.5%) showed enhanced contributions during the warm months, likely due to high energy demand. Cement industry emissions (6.9%) exhibited significant contribution during the cold period of 2018-2019, while soil dust (11.3%) and secondary sulphates (11.5%) displayed increased contribution during the warm and cold months, respectively. Finally, waste burning (1.5%) displayed the lowest contribution, with no significant temporal variation. Our results highlight the significant impact of anthropogenic activities, and especially the use of coal burning for energy production (both in power plants and for residential heating), and the significant contribution of biomass burning during both warm and cold seasons.

Heat exposure and chronic kidney disease: a temporal link in a Taiwanese agricultural county

Heat stress-related kidney injury has drawn public health attention. This study explored the temporal relationships between impaired kidney function and preceding outdoor heat exposure Taiwan. Data of participants collected through a health screening program was used to assess the association between chronic kidney disease (CKD) and average ambient temperature with various time lag structures. A total of 1,243 CKD cases and 38,831 non-CKD participants were included in the study. After adjusting for demographic, socioeconomic, lifestyle factors, and comorbidities, CKD was positively associated with the ambient temperature within 1-9 months. The 9-month average ambient temperature yielded the highest odds ratio of CKD (OR = 1.22; 95% CI = 1.09-1.37). Furthermore, females and farmers were found to be more vulnerable to CKD risk after outdoor heat exposure. These findings suggest that the prevention of heat stress-related kidney injury should consider relevant time frames and focus on vulnerable populations.

Influence of leaf morphological characteristics on the dynamic changes of particulate matter retention and grain size distributions

ABSTRACTPlant leaves can retain atmospheric particulate matter (PM) and thus alleviate air pollution. Herein, four plant species (Cerasus. serrulata, H. syriacus, H. tuberosus, and E. japonicus) from the central part of Shanxi Province, China, were investigated to analyse the dynamic changes in their PM retention capacity and grain size over five periods. The relationship between leaf morphological characteristics (leaf size and leaf surface microstructure) and dynamic changes were discussed in PM retention, revealing the influence of leaf morphological characteristics on the amount of PM retention and its composition. The results showed that amount and grain sizes of the retained PM differed significantly among the various studied species; however, the trends in PM retention of different species in the time series were the same. The grain size distributions of PM from the four species displayed a bimodal distribution, in which the main peak distribution range was 5-60 μm and the secondary peak distribution range was 0.4-1 μm. Leaves of smaller sizes and those with rough surfaces had a high PM retention capacity. Leaves with deep grooves are conductive to retaining PM2.5 and PM2.5-10, while leaves with hair are conductive to retaining PM>10. Therefore, the morphological characteristics of leaves should be considered when selecting the use of plant species to alleviate air pollution.Highlights Dynamics of PM retention capacity and grain size distributions of four plant species were analysed.Grain size distributions of PM retained on leaves had a bimodal distribution.Small leaves with grooves or hair are conductive to PM retention.Grooves are conductive to fine PM retention while hairs are conductive to coarse PM retention.

Particulate air pollution and cardiovascular disease mortality in Jiangsu Province, China: a time-series analysis between 2015 and 2021

Introduction

Previous time-series studies have revealed a positive association between particulate matter (PM) and acute cardiovascular effects. However, the evidence mostly comes from developed countries and regions, while the majority of air-pollution-related deaths occur in developing countries. To assess the effect of short-term exposure to PM on daily cause-specific cardiovascular disease (CVD) mortality in Jiangsu Province, China, we investigated 1,417,773 CVD deaths from 2015 to 2021 in Jiangsu.

Methods

The city-specific association was estimated using generalized additive models with quasi-Poisson regression, and then, random effects meta-analysis was performed to estimate the pooled provincial-average associations between acute exposure to PM2.5 and PM10 and cardiovascular disease mortality. To test the independence of PM from gaseous pollutants, we fitted two-pollutant models. Mortality data were also stratified by sex, age, and region to investigate the modification of associations. The exposure-response (E-R) curve from each city was combined using meta-analysis to drive the provincial-level E-R curve.

Results

The results showed that each 10-μg/m3 increase in the PM2.5 concentration was associated with a 0.723% [95% confidence interval (CI): 0.512, 0.935] increase in daily total CVD mortality, a 0.669% (95% CI: 0.461, 0.878) increase in CHD mortality, a 0.758% (95% CI: 0.584, 0.931) increase in stroke mortality, a 0.512% (95% CI: 0.245, 0.780) increase in ICH mortality, and a 0.876% (95% CI: 0.637, 1.116) increase in CI mortality. The corresponding increases in daily mortality rates for the same increase in the PM10 concentration were 0.424% (95% CI: 0.293, 0.556), 0.415% (95% CI: 0.228, 0.602), 0.444% (95% CI: 0.330, 0.559), 0.276% (95% CI: 0.026, 0.526), and 0.510% (95% CI: 0.353, 0.667), respectively. The association between PM and total CVD mortality remained significant after adjusting for gaseous pollutants. Females, older adults and districts with lower average PM levels are more sensitive, especially for PM10. The E-R curve for PM on CVD mortality is steeper at lower concentrations and flattens out at higher concentrations. The estimates remained generally consistent in sensitivity analyses when excluding the data during the COVID-19 pandemic period.

Discussion

Our time-series study provides evidence of positive associations between acute exposure to PM2.5 and PM10 and total and cause-specific cardiovascular disease mortality in developing countries.

Chronic Kidney Disease Among Agricultural Workers in Taiwan: A Nationwide Population-Based Study

Introduction

Chronic kidney disease (CKD) in agricultural communities is a significant public health issue. We aimed to investigate the epidemiology of CKD among Taiwanese farmers and its association with outdoor heat exposure.

Methods

A nested case-control study was conducted on participants in the National Adult Health Examination (NAHE) from 2012 to 2018. The farming occupation was identified through National Health Insurance data. The primary outcomes of interest were the development of CKD, defined as a decreased estimated glomerular filtration rate (eGFR) with diagnosis by physicians, and CKD of undetermined etiology (CKDu), defined as CKD excluding common traditional etiologies. We calculated the county-wide average ambient temperature from a climate reanalysis dataset (ERA5-Land). All CKD cases were matched 1:2 to non-CKD participants by age and biological sex. We estimated the odds ratios (ORs) of CKD and CKDu for farmers and changes in mean ambient temperature (°C) before the examination.

Results

We identified 844,412 farmers and 3,750,273 nonfarmers. Among 24.9% of farmers and 7.4% of nonfarmers with reduced kidney function, only 1 in 7 received a diagnosis of CKD. The farming occupation was independently predictive of CKDu (OR = 1.09, 95% confidence interval [CI] = 1.001-1.18) but not CKD. Increased ambient temperature (°C) was associated with a higher risk of CKD (OR = 1.023, 95% CI = 1.017-1.029), with particularly strong associations observed among middle-aged participants and diabetics.

Conclusions

Taiwanese farmers might have a higher risk of developing CKDu. Outdoor heat exposure is associated with the development of CKD, and middle-aged participants and those with diabetes are more vulnerable than the general population.

Short-term Exposure to Air Pollution and Ischemic Stroke: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Approximately 5 million fatalities occur annually due to stroke, along with its substantial effects on patient well-being and functional impairment. Research has established a connection between extended exposure to air pollutants and ischemic stroke. However, the link between short-term exposure to air pollutants and stroke remains less definitive.

METHODS

A comprehensive search was conducted on MEDLINE, Scopus, the Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Sciences databases up until February 2023, without any language restrictions. The inclusion criteria encompassed observational or interventional studies that examined the correlation between short-term exposure to air pollutants (carbon monoxide [CO], sulfur dioxide [SO2], nitrogen dioxide [NO2], ozone [O3]) and particulate matter with diameters of less than 1 µm, less than 2.5 µm, or less than 10 µm (PM1, PM2.5, and PM10), with the incidence and mortality of ischemic stroke. Short-term exposure was defined as exposure occurring within 5 days of the onset of stroke.

RESULTS

A total of 18,035,408 cases of ischemic stroke were included in the analysis, derived from 110 observational studies. Asia accounted for most included studies, representing 58.8% of the total. By contrast, Europe and the Americas contributed 24.6% and 16.7% of the studies, respectively. Notably, none of the included studies were conducted in Africa. Stroke incidence was significantly associated with an increase in the concentration of NO2 (RR = 1.28; 95% CI 1.21-1.36), O3 (RR = 1.05; 95% CI 1.03-1.07), CO (RR = 1.26; 95% CI 1.21-1.32), SO2 (RR = 1.15; 95% CI 1.11-1.19), PM1 (RR = 1.09; 95% CI 1.06-1.12), PM2.5 (RR = 1.15; 95% CI 1.13-1.17), and PM10 (RR = 1.14; 95% CI 1.12-1.16). Moreover, an increase in the concentration of NO2 (RR = 1.33; 95% CI 1.07-1.65), SO2 (RR = 1.60; 95% CI 1.05-2.44), PM2.5 (RR = 1.09; 95% CI 1.04-1.15), and PM10 (RR = 1.02; 95% CI 1.00-1.04) was associated with an increase in stroke mortality.

DISCUSSION

There is a strong and significant correlation between gaseous and particulate air pollutants and the occurrence and mortality rates of stroke. This close temporal association underscores the importance of implementing global initiatives to develop policies aimed at reducing air pollution. By doing so, alleviate the burden of ischemic stroke and its consequences.

Estimation of health risk and economic loss attributable to PM2.5 and O3 pollution in Jilin Province, China

Ambient pollutants, particularly fine particulate matter (PM2.5) and ozone (O3), pose significant risks to both public health and economic development. In recent years, PM2.5 concentration in China has decreased significantly, whereas that of O3 has increased rapidly, leading to considerable health risks. In this study, a generalized additive model was employed to establish the relationship of PM2.5 and O3 exposure with non-accidental mortality across 17 districts and counties in Jilin Province, China, over 2015-2016. The health burden and economic losses attributable to PM2.5 and O3 were assessed using high-resolution satellite and population data. According to the results, per 10 µg/m3 increase in PM2.5 and O3 concentrations related to an overall relative risk (95% confidence interval) of 1.004 (1.001-1.007) and 1.009 (1.005-1.012), respectively. In general, the spatial distribution of mortality and economic losses was uneven. Throughout the study period, a total of 23,051.274 mortalities and 27,825.015 million Chinese Yuan (CNY) in economic losses were attributed to O3 exposure, which considerably surpassing the 5,450.716 mortalities and 6,553,780 million CNY in economic losses attributed to PM2.5 exposure. The O3-related health risks and economic losses increased by 3.75% and 9.3% from 2015 to 2016, while those linked to PM2.5 decreased by 23.33% and 18.7%. Sensitivity analysis results indicated that changes in pollutant concentrations were the major factors affecting mortality rather than baseline mortality and population.

The association of long-term exposure to outdoor air pollution with all-cause GP visits and hospital admissions by ethnicity and country of birth in the United Kingdom

BACKGROUND

Air pollution is associated with poor health. Yet, more research is needed to reveal the association of long-term exposure to outdoor air pollution with less studied health outcomes like hospital admissions and general-practitioner (GP) visits and whether this association is stronger for ethnic minorities compared to the rest of population. This study investigates the association between air pollution and all-cause GP visits and hospital admissions by ethnicity in the United-Kingdom (UK).

METHODS

We used individual-level longitudinal data from the "UK Household Longitudinal Study" including 46,442 adult individuals who provided 140,466 responses across five years (2015-2019). This data was linked to yearly concentrations of NO2, SO2, and particulate-matter (PM10, PM2.5) outdoor pollution using the Lower Super Output Area (LSOA) of residence for each individual. Multilevel mixed-effects ordered logistic models were used to assess the association between air pollution and all-cause GP visits and hospital admissions.

RESULTS

We found higher odds of hospital admissions per 1 μg/m3 increase in annual concentrations of NO2 (OR = 1.008; 95%CI = 1.004-1.012), SO2 (OR = 1.048; 95%CI = 1.014-1.083), PM10 (OR = 1.011; 95%CI = 1.003-1.018), and PM2.5 (OR = 1.018; 95%CI = 1.007-1.029) pollutants. Higher odds of GP visits were also observed with increased exposure to NO2 (OR = 1.010; 95%CI = 1.006-1.014) and SO2 (OR = 1.114; 95%CI = 1.077-1.152) pollutants. The observed associations did not differ across ethnic groups, but by country of birth, they were more pronounced in individuals born outside UK than those born in UK.

CONCLUSION

This study supports an association between higher exposure to outdoor air pollution and increased all-cause hospital admissions and GP visits. Further longitudinal studies with longer follow-up time periods may be able to reveal more definite conclusions on the influence of ethnicity on the association between long-term outdoor air pollution and both hospital admissions and GP visits.

Associations of long-term joint exposure to various ambient air pollutants with all-cause and cause-specific mortality: evidence from a large population-based cohort study

The association between long-term joint exposure to all kinds of ambient air pollutants and the risk of mortality is not known. Our study prospectively assessed the joint associations of various air pollutants with cause-specific and all-cause mortality risk and identified potential modifying factors affecting these associations. A total of 400,259 individuals aged 40-70 years were included in this study. Information on PM10, PM2.5-10, PM2.5, NO2, and NOx was collected. A weighted air pollution score was calculated to assess joint exposure to the above air pollutants. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models. During a median of 12.0 years (4,733,495 person-years) of follow-up, 21,612 deaths were recorded, including 7097 deaths from cardiovascular disease and 11,557 deaths from cancer. The adjusted HRs of all-cause mortality were 1.39 (95% CI: 1.29-1.50), 1.86 (95% CI: 1.63-2.13), 1.12 (95% CI: 1.10-1.14), and 1.04 (95% CI: 1.03-1.05) for every 10-ug/m3 increase in PM10, PM2.5, NO2, and NOx, respectively. The adjusted HRs associated with the air pollution score (the highest quintile versus the lowest quintile) were 1.24 (95% CI: 1.19-1.30) for all-cause mortality, 1.33 (95% CI: 1.23-1.43) for cardiovascular mortality, and 1.16 (95% CI: 1.09-1.23) for cancer mortality. Furthermore, we found that the air pollution score was associated with a linear dose-response increase in mortality risk (all P for linearity < 0.001). The findings highlight the importance of a comprehensive assessment of various air pollutants.

Short-term effects of fine particulate matter constituents on mortality considering the mortality displacement in Zhejiang province, China

BACKGROUND

Evidence linking mortality and short-term exposure to particulate matter (PM_2.5) constituents was sparse. The mortality displacement was often unconsidered and may induce incorrect risk estimation.

OBJECTIVES

To assess the short-term effects of PM_2.5 constituents on all-cause mortality considering the mortality displacement.

METHODS

Daily data on all-cause mortality and PM_2.5 constituents, including sulfate (SO₄^2-), nitrate (NO₃^-), ammonium (NH₄⁺), organic matters (OM), and black carbon (BC), were collected from 2009 to 2020. The mortality effect of PM_2.5 and its constituents was estimated using a distributed lag non-linear model. Stratified analyses were performed by age, sex, and season.

RESULTS

Per interquartile range increases in SO₄^2-, NO₃^-, NH₄⁺, OM, and BC were associated with the 1.42% (95%CI: 0.98, 1.87), 3.76% (3.34, 4.16), 2.26% (1.70, 2.83), 2.36% (2.02, 2.70), and 1.26% (0.91, 1.61) increases in all-cause mortality, respectively. Mortality displacements were observed for PM_2.5, SO₄^2-, NH₄⁺, OM, and BC, with their overall effects lasting for 7-15 days. Stratified analyses revealed a higher risk for old adults (>65 years) and females, with stronger effects in the cold season.

CONCLUSIONS

Short-term exposures to PM_2.5 constituents were positively associated with increased risks of mortality. The mortality displacement should be considered in future epidemiological studies on PM constituents.

DATA AVAILABILITY

Data will be made available on request.

Exploring the impact of particulate matter on mortality in coastal Mediterranean environments

Air pollution is one of the most important problems the world is facing nowadays, adversely affecting public health and causing millions of deaths every year. Particulate matter is a criteria pollutant that has been linked to increased morbidity, as well as all-cause and cause-specific mortality. However, this association remains under-investigated in smaller-size cities in the Eastern Mediterranean, which are also frequently affected by heat waves and dust storms. This study explores the impact of particulate matter with an aerodynamic diameter ≤ 10 μm (PM₁₀) and ≤ 2.5 μm (PM_2.5) on mortality (all-cause, cardiovascular, respiratory) in two coastal cities in the Eastern Mediterranean; Thessaloniki, Greece and Limassol, Cyprus. Generalized additive Poisson models were used to explore overall and gender-specific associations, controlling for long- and short-term patterns, day of week and the effect of weather variables. Moreover, the effect of different lags, season, co-pollutants and dust storms on primary associations was investigated. A 10 μg/m³ increase in PM_2.5 resulted in 1.10 % (95 % CI: -0.13, 2.34) increase in cardiovascular mortality in Thessaloniki, and in 3.07 % (95 % CI: -0.90, 7.20) increase in all-cause mortality in Limassol on the same day. Additionally, significant positive associations were observed between PM_2.5 as well as PM₁₀ and mortality at different lags up to seven days. Interestingly, an association with dust storms was observed only in Thessaloniki, having a protective effect, while the gender-specific analysis revealed significant associations only for the males in both cities. The outcome of this study highlights the need of city- or county-specific public health interventions to address the impact of climate, population lifestyle behaviour and other socioeconomic factors that affect the exposure to air pollution and other synergistic effects that alter the effect of PM on population health.

Short-term effects of ambient particulate matter (PM1, PM2.5 and PM10) on influenza-like illness in Guangzhou, China

BACKGROUND

Particulate matter (PM) has been linked to respiratory infections in a growing body of evidence. Studies on the relationship between ILI (influenza-like illness) and PM₁ (particulate matter with aerodynamic diameter ≤1 μm) are, however, scarce. The purpose of this study was to investigate the effects of PM on ILI in Guangzhou, China.

METHODS

Daily ILI cases, air pollution records (PM₁, PM_2.5, PM₁₀ and gaseous pollutants), and metrological data between 2014 and 2019 were gathered from Guangzhou, China. To estimate the risk of ILI linked with exposure to PM pollutants, a quasi-Poisson regression was used. Additionally, subgroup analyses stratified by gender, age and season were carried out.

RESULTS

For each 10 μg/m³ increase of PM₁ and PM_2.5 over the past two days (lag01), and PM₁₀ over the past three days (lag02), the relative risks (RR) of ILI were 1.079 (95% confidence interval [CI]: 1.050, 1.109), 1.044 (95% CI: 1.027, 1.062) and 1.046 (95% CI: 1.032, 1.059), respectively. The estimated risks for men and women were substantially similar. The effects of PM pollutants between male and female were basically equivalent. People aged 15-24 years old were more susceptive to PM pollutants.

CONCLUSIONS

It implies that PM₁, PM_2.5 and PM₁₀ are all risk factors for ILI, the health impacts of PM pollutants vary by particle size. Reducing the concentration of PM₁ needs to be considered when generating a strategy to prevent ILI.

Meta analysis of health effects of ambient air pollution exposure in low- and middle-income countries

It is well established that exposure to ambient air pollution affects human health. A majority of literature concentrated on health effects of air pollution in high income countries. Only fewer studies analyzing health effects of air pollution in Low- and Middle-Income Countries (LMICs) are available. To bridge this gap in literature, this study investigated short term and long-term health impacts of ambient air pollutants focussed in LMICs. We evaluated Total Non-accidental mortality, Respiratory Mortality, Stroke Mortality, Cardio-vascular Mortality, Chronic Obstructive Pulmonary Disease (COPD), Ischemic Heart Disease (IHD) and Lung Cancer Mortality in LMICs particularly. Random Effects Model was utilised to derive overall risk estimate. Relative Risk (RR) estimates per 10 μg/m³ was used as input for model. Subgroup and Sensitivity Analysis by Design and Country was conducted. A total of 152 studies were included for quantitative analysis. We found positive associations between pollutants and Total Non-accidental mortality for PM₁₀ ((RR:1.0043-1.0036), p < 0.0001), NO₂ (RR:1.0222 (1.0111-1.0336), p < 0.0001), SO₂ (RR:1.0107 - (1.0073-1.0140), p < 0.0001), O₃ (RR: 1.0038 (1.0023-1.0053), p < 0.0001) and PM_2.5 (RR: 1.0048 (1.0037-1.0059), p < 0.0001) for every 10 μg/m³ increase. We found positive association between Long-term exposure to PM₁₀ and Total Non-accidental mortality (RR: 1.0430 (1.0278-1.0583), p < 0.0001) We also found statistically significant positive associations between pollutants and Cardiorespiratory and Cardiovascular morbidity. The positive associations persisted when analysed amongst sub-groups. However, the high heterogeneity amongst studies persisted even after performing sub-group analysis. The study has found statistically significant positive associations between short-term and long-term exposure to Ambient air pollution with various health-outcome combinations.

Acute health effects of bushfire smoke on mortality in Sydney, Australia

BACKGROUND

Bushfire smoke is a major ongoing environmental hazard in Australia. In the summer of 2019-2020 smoke from an extreme bushfire event exposed large populations to high concentrations of particulate matter (PM) pollution. In this study we aimed to estimate the effect of bushfire-related PM of less than 2.5 μm in diameter (PM_2.5) on the risk of mortality in Sydney, Australia from 2010 to 2020.

METHODS

We estimated concentrations of PM_2.5 for three subregions of Sydney from measurements at monitoring stations using inverse-distance weighting and cross-referenced extreme days (95th percentile or above) with satellite imagery to determine if bushfire smoke was present. We then used a seasonal and trend decomposition method to estimate the Non-bushfire PM_2.5 concentrations on those days. Daily PM_2.5 concentrations above the Non-bushfire concentrations on bushfire smoke days were deemed to be Bushfire PM_2.5. We used distributed-lag non-linear models to estimate the effect of Bushfire and Non-bushfire PM_2.5 on daily counts of mortality with sub-analyses by age. These models controlled for seasonal trends in mortality as well as daily temperature, day of week and public holidays.

RESULTS

Within the three subregions, between 110 and 134 days were identified as extreme bushfire smoke days within the subregions of Sydney. Bushfire-related PM_2.5 ranged from 6.3 to 115.4 µg/m³. A 0 to 10 µg/m³ increase in Bushfire PM_2.5 was associated with a 3.2% (95% CI 0.3, 6.2%) increase in risk of all-cause death, cumulatively, in the 3 days following exposure. These effects were present in those aged 65 years and over, while no effect was observed in people under 65 years.

CONCLUSION

Bushfire PM_2.5 exposure is associated with an increased risk of mortality, particularly in those over 65 years of age. This increase in risk was clearest at Bushfire PM_2.5 concentrations up to 30 µg/m³ above background (Non-bushfire), with possible plateauing at higher concentrations of Bushfire PM_2.5.

Health impact assessments of shipping and port-sourced air pollution on a global scale: A scoping literature review

BACKGROUND

Globalisation has led to international trade expand rapidly. Seaborne transport moves 80% of traded goods across the globe, producing around 3% of greenhouse gases and other hazardous pollutants, such as PM, NOx and SOx, known to be harmful to health.

METHODS

A scoping literature review was conducted reviewing peer-reviewed studies on health impact assessments (HIA) of global shipping and port-sourced air pollution. For review inclusion, studies had to (1) use a HIA methodology; (2) quantify the air pollution concentration attributable to at least one shipping or port activity scenario; (3) assess at least one health outcome (i.e. epidemiological measure or monetization); (4) quantify the attributable health burden of the respective scenario.

RESULTS

Thirty-two studies were included, studying predominantly European Sea shipping/ port-sourced emissions with health impacts for global or respective European populations. Also, Global, Asian, North American and Australian Sea shipping/ port-sourced emissions were studied, with attributable health impacts for global or respective populations. The health outcome predominantly studied was mortality (all-cause, cause-specific, loss in life expectancy, years of life lost (YLLs)), but also morbidity (disease cases, hospital admissions, years lived with disability (YLDs)), disability-adjusted life-years (DALYs), restricted activity days and work loss days. The highest air pollution concentrations were identified along major shipping routes and ports, and the strongest health impacts occurred among respective riparian populations. Globally, ∼265,000 premature deaths were projected for 2020 (∼0.5% of global mortality) attributable to global shipping-sourced emissions. Emission control scenarios studied were predominantly sulphur fuel content caps and NOx emission reduction scenarios, consisting of technological interventions, cleaner fuels or fuel switches, and were assessed as effective in reducing shipping-sourced emissions, and hence, health burdens.

CONCLUSIONS

Our review positions maritime transport an important source of air pollution and health risk factor, which needs more research and policy attention and rigorous emission control efforts, as shipping-sourced emissions are projected to increase with increases in global trade and shipping volumes.

Fine particulate matter and cardiorespiratory health in China: A systematic review and meta-analysis of epidemiological studies

This review aimed to systematically summarize the epidemiological literature on the cardiorespiratory effects of PM_2.5 published during the 13^th Five-Year Plan period (2016-2020) in China. Original articles published between January 1, 2016 and June 30, 2021 were searched in PubMed, Web of Science, the China National Knowledge Internet Database and Wanfang Database. Random- or fixed-effects models were used to pool effect estimates where appropriate. Of 8558 records identified, 145 met the full eligibility criteria. A 10 µg/m³ increase in short-term PM_2.5 exposure was significantly associated with increases of 0.70%, 0.86%, 0.38% and 0.96% in cardiovascular mortality, respiratory mortality, cardiovascular morbidity, and respiratory morbidity, respectively. The specific diseases with significant associations included stroke, ischemic heart disease, heart failure, arrhythmia, chronic obstructive pulmonary disease, pneumonia and allergic rhinitis. The pooled estimates per 10 µg/m³ increase in long-term PM_2.5 exposure were 15.1%, 11.9% and 21.0% increases in cardiovascular, stroke and lung cancer mortality, and 17.4%, 11.0% and 4.88% increases in cardiovascular, hypertension and lung cancer incidence respectively. Adverse changes in blood pressure, heart rate variability, systemic inflammation, blood lipids, lung function and airway inflammation were observed for either short-term or long-term PM_2.5 exposure, or both. Collectively, we summarized representative exposure-response relationships between short- and long-term PM_2.5 exposure and a wide range of cardiorespiratory outcomes applicable to China. The magnitudes of estimates were generally smaller in short-term associations and comparable in long-term associations compared with those in developed countries. Our findings are helpful for future standard revisions and policy formulation. There are still some notable gaps that merit further investigation in China.

Association between short-term exposure to ambient air pollution and biomarkers of coagulation: A systematic review and meta-analysis

Ambient air pollution is one of the major global risk factors for cardiovascular health, and coagulation changes have been proposed to mediate this risk. Plasminogen activator inhibitor-1 (PAI-1), von Willebrand factor (vWF), soluble P-selectin (sP-selectin) and tissue plasminogen activator (t-PA) are major coagulation biomarkers. However, there has been no systematic meta-analysis to summarize associations of ambient air pollution with these coagulation biomarkers. To assess the overall associations between ambient particulate matter (PM_2.5, PM₁₀), ozone (O₃), nitrogen dioxide (NO₂), carbon monoxide (CO) and major coagulation biomarkers including PAI-1, vWF, sP-selectin and t-PA based on the existing epidemiological research. We performed a systematic literature search of publications reporting the associations of ambient air pollutants (PM_2.5, PM₁₀, O₃, NO_2, and CO) with coagulation biomarkers (PAI-1, vWF, sP-selectin and t-PA) in PubMed, Web of Science, EMBASE, and Scopus databases as of April 5, 2022. Then, we performed a random-effect meta-analysis, which included 27 articles, and then identified the potential sources of heterogeneity. The pooled percent changes of coagulation biomarkers per 10 μg/m³ increase in short-term exposure to ambient PM_2.5 were 2.43% (95% CI: 0.59%, 4.29%) in PAI-1, 1.08% (95% CI: 0.21%, 1.96%) in vWF and 1.14% (95% CI: 0.59%, 1.68%) in sP-selectin, respectively. We also found significant associations of short-term exposure to ambient O₃ with PAI-1 (1.62%, 95% CI: 0.01%, 3.25%), sP-selectin (9.59%, 95% CI:2.78%, 16.86%) and t-PA (0.45%, 95% CI: 0.02%, 0.88%), respectively. Short-term exposures to ambient PM₁₀, NO₂ and CO were not significantly associated with changes in coagulation biomarkers. In conclusion, short-term exposures to PM_2.5 and O₃ are associated with significant increases in coagulation biomarkers, suggesting an activated coagulation state upon air pollution exposure.

Size-segregated particle number concentrations and outpatient-department visits for pediatric respiratory diseases in Shanghai, China

BACKGROUND

Few studies have simultaneously explored which size of particles has the greatest impact on the risk for pediatric asthma, bronchitis and upper respiratory tract infections (URTIs).

OBJECTIVES

To investigate the short-term association between size-segregated particle number concentrations (PNCs) and outpatient-department visits (ODVs) for major pediatric respiratory diseases.

METHODS

Daily counts of pediatric ODVs for asthma, bronchitis and URTIs were obtained from 66 hospitals in Shanghai, China, from 2016 to 2018. Pollutant effects were estimated using Poisson generalized additive models combined with polynomial distributed lag models. We also fitted co-pollutant cumulative effects models included six criteria air pollutants and conducted stratifying analyses by gender, age, season and geographic distances.

RESULTS

We identified a total of 430,103 patients with asthma, 1,547,013 patients with bronchitis, and 2,155,738 patients with URTIs from the hospitals. Effect estimates increased with decreasing particle size. Ultrafine particle (UFP) and PNCs of 0.10-0.40 µm particles (PNC_0.10-0.40) were associated with increased ODVs for asthma, bronchitis and URTIs at cumulative lags up to 3d. Associations tended to appear stable after adjusting for criteria air pollutants. At the cumulative lag 0-2d, each interquartile range increase in UFP was associated with increased ODVs due to asthma (relative risk 1.21, 95% CI: 1.07, 1.38), bronchitis (1.20, 95% CI: 1.07, 1.34) and URTI (1.17, 95% CI: 1.06, 1.30), whereas the associations for PNC_0.10-0.40 remained significant but attenuated in magnitude.

CONCLUSIONS

UFP may be a leading contributor to the adverse respiratory effects of particulate air pollution and the effects increased with decreasing particle size.

Short term exposure to air pollution and mortality in the US: a double negative control analysis

RATIONALE

Studies examining the association of short-term air pollution exposure and daily deaths have typically been limited to cities and used citywide average exposures, with few using causal models.

OBJECTIVES

To estimate the associations between short-term exposures to fine particulate matter (PM_2.5), ozone (O₃), and nitrogen dioxide (NO₂) and all-cause and cause-specific mortality in multiple US states using census tract or address exposure and including rural areas, using a double negative control analysis.

METHODS

We conducted a time-stratified case-crossover study examining the entire population of seven US states from 2000-2015, with over 3 million non-accidental deaths. Daily predictions of PM_2.5, O₃, and NO₂ at 1x1 km grid cells were linked to mortality based on census track or residential address. For each pollutant, we used conditional logistic regression to quantify the association between exposure and the relative risk of mortality conditioning on meteorological variables, other pollutants, and using double negative controls.

RESULTS

A 10 μg/m³ increase in PM_2.5 exposure at the moving average of lag 0-2 day was significantly associated with a 0.67% (95%CI: 0.34-1.01%) increase in all-cause mortality. 10 ppb increases in NO₂ or O₃ exposure at lag 0-2 day were marginally associated with and 0.19% (95%CI: -0.01-0.38%) and 0.20 (95% CI-0.01, 0.40), respectively. The adverse effects of PM_2.5 persisted when pollution levels were restricted to below the current global air pollution standards. Negative control models indicated little likelihood of omitted confounders for PM_2.5, and mixed results for the gases. PM_2.5 was also significantly associated with respiratory mortality and cardiovascular mortality.

CONCLUSIONS

Short-term exposure to PM_2.5 and possibly O₃ and NO₂ are associated with increased risks for all-cause mortality. Our findings delivered evidence that risks of death persisted at levels below currently permissible.

Differentiating the effects of air pollution on daily mortality counts and years of life lost in six Chinese megacities

BACKGROUND

Ambient air pollution has been widely associated with increased mortality and years of life lost (YLL) from various diseases. However, no study has assessed that the effects of air pollution on overall YLL were due to increased number of mortalities or average YLL per death.

METHODS

We first conducted a time-series study from 2013 to 2016, covering six Chinese megacities. Generalized additive models with a Gaussian link were utilized to estimate the associations of fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂) with daily overall YLL and average YLL per death from various causes, including non-accidental causes, cardiovascular diseases (CVD), respiratory diseases (RD), ischemic heart disease (IHD), chronic obstructive pulmonary diseases (COPD), stroke and acute myocardial infraction (AMI). The city-specific estimates were then pooled by random-effects meta-analysis.

RESULTS

A total of 1,586,741 deaths from non-accidental causes and 21,916,857 YLLs were recorded in the six cities, providing an average of 13.81 daily YLLs per death. Significant effects of PM_2.5 and NO₂ on daily overall YLL and daily mortality count were observed, but there were no significant effects on average YLL per death. At the pooled level, each 10 μg/m³ increase in PM_2.5 and NO₂ was associated with increased YLL and higher mortality due to non-accidental causes [PM_2.5: 5.45 years, 95% CI: 1.47, 9.42 and ERR (excess relative risk) = 0.25%, 95% CI: 0.14%, 0.35%; NO₂: 20.46 years, 95% CI: 10.77, 30.15 and ERR = 1.13%, 95% CI: 0.63%, 1.63%]. Consistent results and patterns were observed for other cause-specific diseases, including IHD, COPD, stroke and AMI.

CONCLUSIONS

Our study indicates observed associations between air pollution and YLL might be mainly induced by increasing mortality count, rather than increasing average life lost for each death. More relevant intervention should be performed to reduce the number of deaths due to air pollution.

Assessing the health estimation capacity of air pollution exposure prediction models

BACKGROUND

The era of big data has enabled sophisticated models to predict air pollution concentrations over space and time. Historically these models have been evaluated using overall metrics that measure how close predictions are to monitoring data. However, overall methods are not designed to distinguish error at timescales most relevant for epidemiologic studies, such as day-to-day errors that impact studies of short-term health associations.

METHODS

We introduce frequency band model performance, which quantifies health estimation capacity of air quality prediction models for time series studies of air pollution and health. Frequency band model performance uses a discrete Fourier transform to evaluate prediction models at timescales of interest. We simulated fine particulate matter (PM_2.5), with errors at timescales varying from acute to seasonal, and health time series data. To compare evaluation approaches, we use correlations and root mean squared error (RMSE). Additionally, we assess health estimation capacity through bias and RMSE in estimated health associations. We apply frequency band model performance to PM_2.5 predictions at 17 monitors in 8 US cities.

RESULTS

In simulations, frequency band model performance rates predictions better (lower RMSE, higher correlation) when there is no error at a particular timescale (e.g., acute) and worse when error is added to that timescale, compared to overall approaches. Further, frequency band model performance is more strongly associated (R² = 0.95) with health association bias compared to overall approaches (R² = 0.57). For PM_2.5 predictions in Salt Lake City, UT, frequency band model performance better identifies acute error that may impact estimated short-term health associations.

CONCLUSIONS

For epidemiologic studies, frequency band model performance provides an improvement over existing approaches because it evaluates models at the timescale of interest and is more strongly associated with bias in estimated health associations. Evaluating prediction models at timescales relevant for health studies is critical to determining whether model error will impact estimated health associations.

Time series analysis of short-term effects of particulate matter pollution on the circulatory system disease mortality risk in Lishui District, China

Epidemiological evidence has shown a significant association between short-term exposure to air pollution and mortality risk for circulatory system diseases (CSD). However, informative insights on the significance and magnitude of its relationship in the process of government interventions on abating air pollution are still lacking, particularly in a burgeoning Chinese city. In this study, we conducted a time series study in Lishui District, Nanjing, to examine the effect of ambient particulate matter (PM), e.g., PM_2.5 and PM₁₀, on daily death counts of CSD which included cardiovascular disease (CVD), cerebrovascular disease (CEVD), and arteriosclerotic heart disease (ASHD) mortality from January 1, 2015, to December 31, 2019. The results revealed that each 10 μg/m³ increase in PM_2.5 and PM₁₀ concentration at lag0 day was associated with an increase of 1.33% (95% confidence interval, 0.08%, 2.60%) and 1.12% (0.43%, 1.82%) in CSD mortality; 2.42% (0.44%, 4.43%) and 1.43% (0.32%, 2.55%) in CVD mortality; 1.20% (- 0.31%, 2.73%) and 1.21% (0.38%, 2.05%) in CEVD mortality; and 2.78% (0.00%, 5.62%) and 1.66% (0.14%, 3.21%) in ASHD mortality, respectively. For cumulative risk, the corresponding increase in daily mortality for the same change in PM_2.5 concentration at lag03 day was significantly associated with 1.94% (0.23%, 3.68%), 3.17% (0.58%, 5.84%), 2.38% (0.17%, 4.63%), and 4.92% (1.18%, 8.81%) for CSD, CVD, CEVD, and ASHD, respectively. The exposure-response curves were approximately nonlinear over the entire exposure range of the PM concentrations. We also analyzed the effect modifications by season (warm or cold), age group (0-64 years, 65-74 years, or ≥ 75 years), and sex (male or female). Although not statistically significant, stratified analysis showed greater vulnerability to PM exposure for cold season, population over 65 years of age, and female group.

Acute Effects of Particulate Matter on All-Cause Mortality in Urban, Rural, and Suburban Areas, Italy

Background: Short-term exposure to particulate matter (PM) has been related to mortality worldwide. Most evidence comes from studies conducted in major cities, while little is known on the effects of low concentrations of PM and in less urbanized areas. We aim to investigate the relationship between PM and all-cause mortality at national level in Italy. Methods: Daily numbers of all-cause mortality were collected for all 8092 municipalities of Italy, from 2006 to 2015. A satellite-based spatiotemporal model was developed to estimate daily PM₁₀ (inhalable particles) and PM_2.5 (fine particles) concentrations at 1-km resolution. Multivariate Poisson regression models were fit to estimate the association between daily PM and mortality at province level, and then, results were pooled with a random-effects meta-analysis. Associations were estimated by combination of age and sex and degree of urbanization of the municipalities. Flexible functions were estimated to explore the shape of the associations at low PM concentrations. Results: We analyzed 5,884,900 deaths (40% among subjects older than 85 years, 60% occurring outside the main urban areas). National daily mean (interquartile range) PM₁₀ and PM_2.5 concentrations were 23 (14) μg/m³ and 15 (11) μg/m³, respectively. Relative increases of mortality per 10 μg/m³ variation in lag 0–5 (average of last six days since death) PM₁₀ and PM_2.5 were 1.47% (95% Confidence Intervals (CI): 1.15%, 1.79%) and 1.96% (1.33%, 2.59%), respectively. Associations were highest among elderly and women for PM₁₀ only, similar between rural and urbanized areas, and were present even at low concentrations, e.g., below WHO guidelines. Conclusions: Air pollution was robustly associated with peaks in daily all-cause mortality in Italy, both in large cities and in less urbanized areas of Italy. Current WHO Air Quality Guidelines (2021) for PM₁₀ and PM_2.5 are not sufficient to protect public health.

Association between ozone exposure and prevalence of mumps: a time-series study in a Megacity of Southwest China

In the present study, we aim to evaluate the delayed and cumulative effect of ozone (O3) exposure on mumps in a megacity with high population density and high humidity. We took Chongqing, a megacity in Southwest China, as the research area and 2013-2017 as the research period. A total of 49,258 confirmed mumps cases were collected from 122 hospitals of Chongqing. We employed the distributed lag nonlinear models with quasi-Poisson link to investigate the relationship between prevalence of mumps and O3 exposure after adjusting for the effects of meteorological conditions. The results show that the effect of O3 exposure on mumps was mainly manifested in the lag of 0-7 days. The single-day ;lag effect was the most obvious on the 4th day, with the relative risk (RR) of mumps occurs of 1.006 (95% CI: 1.003-1.007) per 10 μg/m3 in the O3 exposure. The cumulative RR within 7 days was 1.025 (95% CI: 1.013-1.038). Our results suggest that O3 exposure can increase the risk of mumps infection, which fills the gap of relevant research in mountainous areas with high population density and high humidity.

Spatio-temporal variations in fine particulate matter and evaluation of associated health risk over Pakistan

Human health and the environment are adversely affected by fine particulate matter. By utilizing standard deviation ellipse and trend analyses, we studied the spatial patterns and temporal trends of PM_2.5 over Pakistan from 1998 to 2016. The outcomes of these analyses indicated that PM_2.5 concentrations were considerably amplified in Pakistan, particularly in the provinces of Punjab and Sindh. The areal extent of PM_2.5 concentrations below 15 μg/m³ declined constantly, and the area with PM_2.5 concentrations above 35 μg/m³ increased significantly. The highly affected cities were Lahore, Faisalabad, Multan, Southern Gujranwala, Dera Ghazi Khan, Bahawalpur, Sukkur, and Larkana. Overall, the northwest-southeast axis experienced more rapid variations in the spatial pattern of PM_2.5 than the northeast-southwest axis; similarly, the east-north axis also experienced faster changes in the spatial distribution of this crucial pollutant than the west-south axis. To support nationwide air pollution control, a two-tier level was recommended for allocated regions in Pakistan depending on their PM_2.5 concentrations. From 1998 to 2016, health risks expanded and increased in Pakistan, particularly in Lahore, Karachi, Multan, Gujranwala, Faisalabad, and Hyderabad; these are Pakistan's most populated cities. The outcomes of this study suggest that human health is continuously affected by PM_2.5 in Pakistan, and that a plan of action to combat air pollution is immediately needed. Integr Environ Assess Manag 2021;17:1243-1254. © 2021 SETAC.

Indoor Particulate Matter in Urban Households: Sources, Pathways, Characteristics, Health Effects, and Exposure Mitigation

Particulate matter (PM) is a complex mixture of solid particles and liquid droplets suspended in the air with varying size, shape, and chemical composition which intensifies significant concern due to severe health effects. Based on the well-established human health effects of outdoor PM, health-based standards for outdoor air have been promoted (e.g., the National Ambient Air Quality Standards formulated by the U.S.). Due to the exchange of indoor and outdoor air, the chemical composition of indoor particulate matter is related to the sources and components of outdoor PM. However, PM in the indoor environment has the potential to exceed outdoor PM levels. Indoor PM includes particles of outdoor origin that drift indoors and particles that originate from indoor activities, which include cooking, fireplaces, smoking, fuel combustion for heating, human activities, and burning incense. Indoor PM can be enriched with inorganic and organic contaminants, including toxic heavy metals and carcinogenic volatile organic compounds. As a potential health hazard, indoor exposure to PM has received increased attention in recent years because people spend most of their time indoors. In addition, as the quantity, quality, and scope of the research have expanded, it is necessary to conduct a systematic review of indoor PM. This review discusses the sources, pathways, characteristics, health effects, and exposure mitigation of indoor PM. Practical solutions and steps to reduce exposure to indoor PM are also discussed.

Associations between sources of particle number and mortality in four European cities

BACKGROUND

The evidence on the association between ultrafine (UFP) particles and mortality is still inconsistent. Moreover, health effects of specific UFP sources have not been explored. We assessed the impact of UFP sources on daily mortality in Barcelona, Helsinki, London, and Zurich.

METHODS

UFP sources were previously identified and quantified for the four cities: daily contributions of photonucleation, two traffic sources (fresh traffic and urban, with size mode around 30 nm and 70 nm, respectively), and secondary aerosols were obtained from data from an urban background station. Different periods were investigated in each city: Barcelona 2013-2016, Helsinki 2009-2016, London 2010-2016, and Zurich 2011-2014. The associations between total particle number concentrations (PNC) and UFP sources and daily (natural, cardiovascular [CVD], and respiratory) mortality were investigated using city-specific generalized linear models (GLM) with quasi-Poisson regression.

RESULTS

We found inconsistent results across cities, sources, and lags for associations with natural, CVD, and respiratory mortality. Increased risk was observed for total PNC and natural mortality in Helsinki (lag 2; 1.3% [0.07%, 2.5%]), CVD mortality in Barcelona (lag 1; 3.7% [0.17%, 7.4%]) and Zurich (lag 0; 3.8% [0.31%, 7.4%]), and respiratory mortality in London (lag 3; 2.6% [0.84%, 4.45%]) and Zurich (lag 1; 9.4% [1.0%, 17.9%]). A similar pattern of associations between health outcomes and total PNC was followed by the fresh traffic source, for which we also found the same associations and lags as for total PNC. The urban source (mostly aged traffic) was associated with respiratory mortality in Zurich (lag 1; 12.5% [1.7%, 24.2%]) and London (lag 3; 2.4% [0.90%, 4.0%]) while the secondary source was associated with respiratory mortality in Zurich (lag 1: 12.0% [0.63%, 24.5%]) and Helsinki (4.7% [0.11%, 9.5%]). Reduced risk for the photonucleation source was observed for respiratory mortality in Barcelona (lag 2, -8.6% [-14.5%, -2.4%]) and for CVD mortality in Helsinki, as this source is present only in clean atmospheres (lag 1, -1.48 [-2.75, -0.21]).

CONCLUSIONS

We found inconsistent results across cities, sources and lags for associations with natural, CVD, and respiratory mortality.

Increasing mortality caused by chronic obstructive pulmonary disease (COPD) in relation with exposure to ambient fine particulate matters: an analysis in Southeastern China

The objective of this study was to investigate the association between ambient particulate matters (PMs) and chronic obstructive pulmonary disease (COPD) mortality. generalized additive mixed model was employed to investigate the effects of ambient fine and coarse PMs on COPD mortality using 13,066 deaths from 2014 to 2016 among six cities in Zhejiang Province in Southeastern China. The daily average death count due to COPD was 3, varying from 1 to 7 among six cities. The daily 24-h mean concentrations were diverse among cities, from 29.7 to 56.8 μg/m³ for PM_2.5, 16.7 to 30.3 μg/m³ for PM_2.5-10, and 50.3 to 87.1 μg/m³ for PM₁₀, respectively. The analysis showed that daily exposure to PM_2.5 and PM₁₀ was associated with increased mortality due to COPD and that weak effects were observed between PM_2.5-10 and COPD mortality. Our results provided solid evidence that the fine particles in air pollution have stronger functions on adverse health effects other than coarser particles in Southeastern China, which may be considered as a potential clinic target in PM-associated COPD.

A 10-year assessment of ambient fine particles and related health endpoints in a large Mediterranean city

Fine particles i.e., with an aerodynamic diameter lower than 2.5 μm (PM_2.5) have potentially the most significant effects on human health compared to other air pollutants. The main objectives of this study were to i) investigate the temporal variations of ambient PM_2.5 in Marseille (Southern France), where air pollution is again a major public health issue, and ii) estimate their short-term health effects and annual trend (Mann-Kendall test) over a 10-year period from 2010 to 2019. In Marseille, the main sources of PM_2.5 could be related to road traffic, industrial complexes, and oil refineries surrounded the city. The number of premature deaths and hospital admissions attributable to ambient PM_2.5 exposure for non-accidental causes, cardiovascular and respiratory diseases were estimated by using in-situ air quality data, city-specific relative risk values and baseline incidence. Despite significant reduction of PM_2.5 (- 0.80 μg m^-3 year^-1), Marseille citizens were exposed to PM_2.5 levels exceeding the World Health Organization (WHO) Air Quality Guideline for human health protection (10 μg m^-3) during entire study period. Exposure to ambient PM_2.5 substantially contributed to mortality and hospital admissions: 871 deaths for non-accidental causes, 515 deaths for cardiovascular diseases, 47 deaths for respiratory diseases, as well as 1034 hospital admissions for cardiovascular diseases and 834 for respiratory diseases were reported between 2010 and 2019. Compliance with WHO annual limit values can result in substantial socio-economic benefits by preventing premature deaths and hospital admissions. For instance, based on the value of a statistical life and average cost of a hospital admission, the associated benefit for healthcare would have been €131 million in 2019. Between 2010 and 2019, the number of PM_2.5-related non-accidental deaths decreased by 1.15 per 10⁵ inhabitants annually. Compared to 2010-2019, the restrictive measures associated to COVID-19 pandemic led to a reduction in PM_2.5 of 11% in Marseille, with 2.6 PM_2.5-related deaths averted in 2020.

Association between ambient particulate matter exposure and metabolic syndrome risk: A systematic review and meta-analysis

Although the association between ambient particulate matter and metabolic syndrome (MetS) has been investigated, the effect of particulate matter (PM) on MetS is inconclusive. We conducted a systematic review and meta-analysis to study the association between long-term ambient PM exposure and MetS risk. The data from five databases were extracted to analyze the association between ambient PM exposure and MetS risk. A random-effects model was performed to estimate the overall risk effect. The present systematic review and meta-analysis illustrated that an increase of 5 μg/m³ in annual PM_2.5 or PM₁₀ concentration was associated with 14% or 9% increases of MetS risk, respectively (PM_2.5, RR = 1.14, 95%CI [1.03, 1.25]; PM₁₀, RR = 1.09, 95%CI [1.00, 1.19]). The population-attributable risk (PAR) was 12.28% for PM_2.5 exposure or 8.26% for PM₁₀ exposure, respectively. There was statistical association between PM_2.5 exposure and risk of MetS in male proportion ≥50%, Asia, related disease or medication non-adjustment subgroup as well as cohort study subgroups, respectively. The significant association between PM₁₀ exposure and risk of MetS was observed in male proportion ≥50% and calories intake adjustment subgroups, respectively. Sensitivity analyses showed the robustness of our results. No publication bias was detected. In conclusion, there was positive association between long-term PM exposure and MetS risk. 12.28% of MetS risk could be attributable to PM_2.5 exposure.

The Use of Public Data from Low-Cost Sensors for the Geospatial Analysis of Air Pollution from Solid Fuel Heating during the COVID-19 Pandemic Spring Period in Krakow, Poland

In this paper, we present a detailed analysis of the public data provided by low-cost sensors (LCS), which were used for spatial and temporal studies of air quality in Krakow. A PM (particulate matter) dataset was obtained in spring in 2021, during which a fairly strict lockdown was in force as a result of COVID-19. Therefore, we were able to separate the effect of solid fuel heating from other sources of background pollution, mainly caused by urban transport. Moreover, we analyzed the historical data of PM2.5 from 2010 to 2019 to show the effect of grassroots efforts and pro-clean-air legislation changes in Krakow. We designed a unique workflow with a time-spatial analysis of PM1, PM2.5, and PM10, and temperature data from Airly(c) sensors located in Krakow and its surroundings. Using geostatistical methods, we showed that Krakow's neighboring cities are the main sources of air pollution from solid fuel heating in the city. Additionally, we showed that the changes in the law in Krakow significantly reduced the PM concentration as compared to neighboring municipalities without a fossil fuel prohibition law. Moreover, our research demonstrates that informative campaigns and education are important initiating factors in order to bring about cleaner air in the future.

Respiratory Emergency Department Visits Associations with Exposures to PM2.5 Mass, Constituents, and Sources in Dhaka, Bangladesh Air Pollution

RATIONALE

To date, there is no published local epidemiological evidence documenting the respiratory health effects of source specific air pollution in South Asia, where PM2.5 composition is different from past studies. Differences include more biomass and residue crop-burning emissions, which may have differing health implications.

OBJECTIVES

We assessed PM2.5 associations with respiratory emergency department (ED) visits in a biomass-burning dominated high pollution region, and evaluated their variability by pollution source and composition.

METHODS

Time-series regression modeling was applied to daily ED visits from January 2014 through December 2017. Air pollutant effect sizes were estimated after addressing long-term trends and seasonality, day-of-week, holidays, relative humidity, ambient temperature, and the effect modification by season, age, and sex.

RESULTS

PM2.5 yielded a significant association with increased respiratory ED visits [0.84% (95% CI: 0.33%, 1.35%)] per 10 μg/m3 increase. The PM2.5 health effect size varied with season, the highest being during monsoon season, when fossil-fuel combustion sources dominated exposures. Results from a source-specific health effect analysis was also consistent with fossil-fuel PM2.5 having a larger effect size per 10 μg/m3 than PM2.5 from other sources [fossil-fuel PM2.5: 2.79% (0.33% to 5.31%), biomass-burning PM2.5: 1.27% (0% to 2.54%), and other-PM2.5: 0.95% (0.06% to 1.85%)]. Age-specific associations varied, with children and older adults being disproportionately affected by the air pollution, especially by the combustion-related particles.

CONCLUSIONS

This study provided novel and important evidence that respiratory health in Dhaka is significantly affected by particle air pollution, with a greater health impact by fossil-fuel combustion derived PM2.5.

Health effects of air pollution: a Southern European perspective

Objective

To summarize the main updated evidence about the health effects of air pollution, with a special focus on Southern Europe.

Data sources

Literature was obtained through PubMed Central and the official websites of European Agencies and Scientific Societies.

Study selection

Recent shreds of evidence about the health effects of air pollution coming from international reports and original research were collected and described in this review.

Results

Air pollution is an avoidable risk factor that causes a huge burden for society, in terms of death, health disorders, and huge socio-economic costs. The southern European countries face a more threatening problem because they experience the effects of both anthropogenic pollutants and natural dusts (particulate matter [PM]). The European Environment Agency reported the number of premature deaths in the 28 countries of the European Union attributable to air pollutant exposure in the year 2016: 374,000 for PM_2.5, 68,000 for nitrogen dioxide, and 14,000 for ozone. In Italy, time series and analytical epidemiological studies showed increased cardio-respiratory hospital admissions and mortality, as well as increased risk of respiratory diseases in people living in urban areas.

Conclusions

Based on abundant evidence, the World Health Organization, which hosts the Global Alliance against Chronic Respiratory Diseases (GARD), the scientific respiratory societies, and the patients’ associations, as well as others in the health sector, must increase their engagement in advocacy for clean air policies.

Effects of exposure to chemical components of fine particulate matter on mortality in Tokyo: A case-crossover study

Fine particulate matter (PM_2.5) is composed of a variety of chemical components, and the dependency of the health effects of total PM_2.5 on specific components is still under discussion. We hypothesised that specific PM_2.5 components are responsible for the health effects, and investigated the association between PM_2.5 components and mortality in 23 Tokyo wards. We obtained mortality data from the Ministry of Health, Labour and Welfare for the period from April 2013 to March 2017. At a monitoring site within the study area, we collected daily samples of PM_2.5 on a filter, and determined the daily mean concentrations of total carbon (organic carbon and elemental carbon) and ions such as nitrate and sulphate. A case-crossover design was employed, and a conditional logistic regression model was used to estimate the strength of the association. Over the study period, we identified 280,460 total non-accidental deaths, and the average daily mean concentration of total PM_2.5 was 16.0 (standard deviation = 8.9) μg/m³. We observed a positive association of total PM_2.5 with total, cardiovascular, and respiratory mortality. After adjustment for total PM_2.5 and its components associated with mortality in the single-component models, the percentage increase per interquartile range (2.3 μg/m³) increase in the average total carbon concentration of the case- and previous-day was 2.1% (95% confidence interval = 1.0 to 3.1%) for total mortality. Carbon elements were associated with respiratory but not cardiovascular mortality. Our results suggest that specific components of PM_2.5 account for its adverse health effects.

Air pollution and cardiovascular mortality in Nanjing, China: Evidence highlighting the roles of cumulative exposure and mortality displacement

BACKGROUND

Few studies have investigated cumulative effects and mortality displacement of short-term air pollution exposure on deaths; therefore, uncertainty remains regarding its public health significance.

METHODS

We obtained air pollution and daily cause-specific mortality data of Nanjing from January 2004 to December 2019, covering a period of 16 years. We performed a time-series analysis with single-day, 2-day moving average, and distributed lag models, respectively, to estimate the effects of PM_2.5, PM₁₀, NO_2, and SO₂ exposure on total cardiovascular disease, ischaemic heart disease (IHD), and cerebrovascular disease (CBVD) mortality. Distributed lag models were used to assess the roles of cumulative exposure and mortality displacement.

RESULTS

Cumulative effect estimates for 0-7 lag days were more considerable than estimates for single-day lags and 2-day moving average lag. The cumulative effect estimates for PM₁₀, NO₂ and SO₂ on total cardiovascular and CBVD mortality became essentially zero within 30 days, which suggested the existence of mortality displacement. But the cumulative effect estimates for PM_2.5 and SO₂ on IHD mortality remained elevated and statistically significant within 27 (2.11%; 95% CI: 0.12, 4.27%) and 22 (2.63%; 95% CI: 0.39, 4.91%) days, respectively, which suggested the absence of mortality displacement.

CONCLUSIONS

Our results indicated that risk assessment based on single-day or 2-day moving average exposure rather than cumulative exposure likely underestimate the adverse effects of air pollution. The cumulative PM_2.5 and SO₂ exposure for nearly a month may have adverse effects on IHD mortality.

Mortality Risk Associated with Short-Term Exposure to Particulate Matter in China: Estimating Error and Implication

Most previous studies used a specific size of particulate matter (PM_x) for dosimetry estimation when determining particulate matter (PM)-associated risk, which precluded the impact of other sizes of PM. Here, we used a multiple-path particle dosimetry model to determine the deposition of PM in human airways and further estimated the associated mortality risk in 205 cities in China. Results showed that the fractions of PM₁, PM_1-2.5, and coarse PM (PM_2.5-10) deposited in the tracheobronchial (TB) and pulmonary airways were estimated in ranges of 11.06-12.83, 19.9-26.37, and 5.35-9.81%, respectively. Each 10 μg/m³ increase in deposited PM was significantly associated with a nationwide increment of 1.12% (95% confidence interval, CI, 0.77-1.49%) for total nonaccidental mortality. Short-term exposure to PM during 2014-2017 resulted in a nationwide mortality of 98 826 cases/year, with contributions from PM₁, PM_1-2.5, coarse PM of 37.7, 43.1, and 19.2%, respectively. Our study demonstrated that the estimated mortality counts may be associated with the coefficient of variation of dosimetry estimations. In addition, we revealed the caution should be exercised when interpreting PM_x-associated risk and further reinforced the importance of size distribution in relevant research.

Factors affecting variability in gaseous and particle microenvironmental air pollutant concentrations in Hong Kong primary and secondary schools

School-age children are particularly susceptible to exposure to air pollutants. To quantify factors affecting children's exposure at school, indoor and outdoor microenvironmental air pollutant concentrations were measured at 32 selected primary and secondary schools in Hong Kong. Real-time PM₁₀ , PM_2.5 , NO_2, and O₃ concentrations were measured in 76 classrooms and 23 non-classrooms. Potential explanatory factors related to building characteristics, ventilation practice, and occupant activities were measured or recorded. Their relationship with indoor measured concentrations was examined using mixed linear regression models. Ten factors were significantly associated with indoor microenvironmental concentrations, together accounting for 74%, 61%, 46%, and 38% of variations observed for PM_2.5 , PM₁₀ , O_3, and NO₂ microenvironmental concentrations, respectively. Outdoor concentration is the single largest predictor for indoor concentrations. Infiltrated outdoor air pollution contributes to 90%, 70%, 75%, and 50% of PM_2.5 , PM₁₀ , O_3, and NO₂ microenvironmental concentrations, respectively, in classrooms during school hours. Interventions to reduce indoor microenvironmental concentrations can be prioritized in reducing ambient air pollution and infiltration of outdoor pollution. Infiltration factors derived from linear regression models provide useful information on outdoor infiltration and help address the gap in generalizable parameter values that can be used to predict school microenvironmental concentrations.

Coarse particles (PM2.5-10) and cause-specific hospitalizations in southwestern China: Association, attributable risk and economic costs

The short-term morbidity effects of the coarse particle (diameter in 2.5-10 μm, PM_2.5-10), as well as the corresponding morbidity burden and economic costs, remain understudied, especially in developing countries. This study aimed to examine the associations of PM_2.5-10 with cause-specific hospitalizations in a multi-city setting in southwestern China and assess the attributable risk and economic costs. City-specific associations were firstly estimated using generalized additive models with quasi-poisson distribution to handle over-dispersion, and then combined to obtain the regional average association. City-specific and pooled concentration-response (C-R) associations of PM_2.5-10 with cause-specific hospitalizations were also modeled. Subgroup analyses were performed by age, sex, season and region. The health and economic burden of hospitalizations for multiple outcomes due to PM_2.5-10 were further evaluated. A total of 4,407,601 non-accidental hospitalizations were collected from 678 hospitals. The estimates of percentage change in hospitalizations per 10 μg/m³ increase in PM_2.5-10 at lag01 was 0.68% (95%CI: 0.33%-1.03%) for non-accidental causes, 0.86% (95% CI: 0.36%-1.37%) for circulatory diseases, 1.52% (95% CI: 1.00%-2.05%) for respiratory diseases, 1.08% (95% CI: 0.47%-1.69%) for endocrine diseases, 0.66% (95% CI: 0.12%-1.21%) for nervous system diseases, and 0.84% (95% CI: 0.42%-1.25%) for genitourinary diseases, respectively. The C-R associations of PM_2.5-10 with cause-specific hospitalizations suggested some evidence of nonlinearity, except for endocrine diseases. Meanwhile, the adverse effects were modified by age and season. Overall, about 0.70% (95% CI: 0.35%-1.06%) of non-accidental hospitalizations and 0.78% (95% CI: 0.38%-1.17%) of total hospitalization expenses could be attributed to PM_2.5-10. The largest morbidity burden and economic costs were observed in respiratory diseases. Our findings indicate that PM_2.5-10 exposure may increase the risk of hospitalizations for multiple outcomes, and account for considerable morbidity and economic burden.

The effect of air-pollution and weather exposure on mortality and hospital admission and implications for further research: A systematic scoping review

BACKGROUND

Air-pollution and weather exposure beyond certain thresholds have serious effects on public health. Yet, there is lack of information on wider aspects including the role of some effect modifiers and the interaction between air-pollution and weather. This article aims at a comprehensive review and narrative summary of literature on the association of air-pollution and weather with mortality and hospital admissions; and to highlight literature gaps that require further research.

METHODS

We conducted a scoping literature review. The search on two databases (PubMed and Web-of-Science) from 2012 to 2020 using three conceptual categories of "environmental factors", "health outcomes", and "Geographical region" revealed a total of 951 records. The narrative synthesis included all original studies with time-series, cohort, or case cross-over design; with ambient air-pollution and/or weather exposure; and mortality and/or hospital admission outcomes.

RESULTS

The final review included 112 articles from which 70 involved mortality, 30 hospital admission, and 12 studies included both outcomes. Air-pollution was shown to act consistently as risk factor for all-causes, cardiovascular, respiratory, cerebrovascular and cancer mortality and hospital admissions. Hot and cold temperature was a risk factor for wide range of cardiovascular, respiratory, and psychiatric illness; yet, in few studies, the increase in temperature reduced the risk of hospital admissions for pulmonary embolism, angina pectoris, chest, and ischemic heart diseases. The role of effect modification in the included studies was investigated in terms of gender, age, and season but not in terms of ethnicity.

CONCLUSION

Air-pollution and weather exposure beyond certain thresholds affect human health negatively. Effect modification of important socio-demographics such as ethnicity and the interaction between air-pollution and weather is often missed in the literature. Our findings highlight the need of further research in the area of health behaviour and mortality in relation to air-pollution and weather, to guide effective environmental health precautionary measures planning.

Time-weighted average of fine particulate matter exposure and cause-specific mortality in China: a nationwide analysis

BACKGROUND

Most previous assessments of the hazardous effects attributable to fine particulate matter (PM_2·5) exposure have used ambient PM_2·5 as an exposure metric, resulting in substantial bias in effect estimates. We did a study to examine the association between cause-specific mortality and the time-weighted average of PM_2·5 exposure after accounting for indoor exposure in 267 cities in China.

METHODS

We did a nationwide study, using Laser Egg air quality monitors in 36 cities to obtain data for indoor PM_2·5 concentrations from 18 484 anonymised households between Nov 1, 2015 and July 2, 2018. We developed and validated a nationwide indoor PM_2·5 prediction model for a further 302 cities by retrieving raw records of hourly concentrations from residents' air sensors; the model was used to predict indoor PM_2·5 during 2013 to 2018. Daily ambient PM_2·5 concentration data were estimated by averaging hourly ambient PM_2·5 concentrations obtained from China's National Urban Air Quality Real-time Publishing Platform. Daily numbers of deaths from all non-accidental causes were obtained from 324 cities from the Disease Surveillance Point System of China between Jan 1, 2013, to Dec 31, 2017, and calculated for 267 cities that had an average daily mortality above three, and data for PM_2·5 concentrations and meteorological information for at least 1 year between 2013 and 2017. We used distributed lag non-linear models to estimate city-specific associations between cause-specific mortality and reconstructed PM_2·5 exposure by considering indoor PM_2·5 exposure. We combined the city-specific effect estimates at the national level using a random effects meta-analysis.

FINDINGS

13 972 records of daily indoor PM_2·5 concentrations for 36 cities, extracted from 47 459 183 raw records from the sensors were included for modelling indoor PM_2·5 levels. The nationwide indoor PM_2·5 concentration was 40 μg/m³ (SD 21) between 2013 and 2017, which was approximately 20% lower than the ambient PM_2·5 concentration of 50 μg/m³ (42). An increase of 10 μg/m³ in time-averaged PM_2·5 exposure concentrations was associated with increased daily mortality estimates of 0·44% (95% CI 0·33-0·54) for total non-accidental causes, 0·50% (0·37-0·63) for cardiovascular diseases, 0·46% (0·28-0·63) for coronary heart disease, 0·49% (0·32-0·66) for stroke, 0·59% (0·39-0·79) for respiratory diseases, and 0·69% (0·45-0·92) for chronic obstructive pulmonary disease, respectively. Compared with previous estimations based on ambient PM_2·5, our estimates approximately doubled the size of the effects related to PM_2·5.

INTERPRETATION

This nationwide study revealed a higher mortality risk attributed to time-averaged indoor and ambient PM_2·5 exposure compared with the risk associated with ambient PM_2·5 exposure alone, which indicates that caution should be exercised when using ambient PM_2·5 as a surrogate for PM_2·5 exposure.

FUNDING

National Natural Science Foundation of China (Youth Program) and the Fundamental Research Project of Beihang University.

Variability of air pollutants, and PM composition and sources at a regional background site in the Balearic Islands: Review of western Mediterranean phenomenology from a 3-year study

The present study discloses the results of a comprehensive 3-years campaign (2010-2012) of air pollution measurements over an regional island background area (Can Llompart-Balearic Islands, Spain), contextualized with other measurements in the western Mediterranean region. Gaseous pollutants and particulate matter fractions were measured in real time; and PM₁₀ and PM₁ daily samples were obtained regularly from which chemical analyses were performed. Furthermore, during three intensive observation periods, real-time concentrations of particle number, black carbon and ammonia were additionally measured. Our results display particular diurnal and seasonal patterns for certain pollutants such as O₃ and particle number concentration. Our study reveals that concentrations of air pollutants and aerosol chemical composition are rather similar all over the central and western Mediterranean basin. The most abundant chemical components in PM₁₀ were mineral dust, followed by organic matter, sea spray and SO₄^2-; in PM₁ organic matter and SO₄^2- dominated, with significant contribution of mineral dust. Furthermore, a source apportionment Positive Matrix Factorization analysis was conducted. Natural sources exert most of the impact on the coarse-mode fraction, while most of fine-mode aerosols are linked to anthropogenic sources coming from local, regional or long range transport emissions. Prevalence of Atlantic air masses in 2010 had a positive effect in air quality, lowering mineral dust, SO₄^2- and EC concentrations. On the contrary, the high incidence of African dust and regional recirculation situations during the 2012 warm season favoured an overall PM load increase governed by mineral dust, SO₄^2- and trace elements associated to dust aerosols. The continuous increase in tourists in the Balearic Islands, and in general all around the Mediterranean, is clearly changing air quality patterns: while urban air pollution has strongly decreased since 2010, such downward trend is less pronounced at the regional scale, thus related to crescent sources such as maritime and air transport.

Association of fine particulate matter exposure with acute noncardiovascular critical illnesses and in-hospital outcomes in patients receiving intensive cardiac care

Background

The effect of short-term exposure to fine particulate matter (PM_2.5) on the incidence of acute noncardiovascular critical illnesses (ANCIs) and clinical outcomes is unknown in patients with acute cardiovascular diseases.

Methods

We conducted a retrospective study in 2337 admissions to an intensive cardiac care unit (ICCU) from June 2016 to May 2017. We used the 2-day average PM_2.5 concentration before ICCU admission to estimate the individual exposure level, and patients were divided into 3 groups according to the concentration tertiles. Major ANCI was defined as the composite of acute respiratory failure, acute kidney injury, gastrointestinal hemorrhage, or sepsis. The primary endpoint was all-cause death or discharge against medical advice in extremely critical condition.

Results

During the 12-month study period, the annual median concentration of PM_2.5 in Chengdu, China was 48 μg/m³ (IQR, 33–77 μg/m³). More than 20% of admissions were complicated by major ANCI, and the primary endpoints occurred in 7.6% of patients during their hospitalization. The association of short-term PM_2.5 exposure levels with the incidence of acute respiratory failure (adjusted OR [odds ratio] =1.31, 95% CI [confidence interval]1.12–1.54) and acute kidney injury (adjusted OR = 1.20, 95% CI 1.02–1.41) showed a significant trend. Additionally, there were numerically more cases of sepsis (adjusted OR = 1.21, 95% CI 0.92–1.60) and gastrointestinal hemorrhage (adjusted OR = 1.29, 95% CI 0.94–1.77) in patients with higher exposure levels. After further multivariable adjustment, short-term PM_2.5 exposure levels were still significantly associated with incident major ANCI (adjusted OR = 1.32, 95% CI 1.12–1.56), as well as a higher incidence of the primary endpoint (adjusted OR = 1.52, 95% CI 1.09–2.12).

Conclusion

Short-term PM_2.5 exposure before ICCU admission was associated with an increased risk of incident major ANCI and worse in-hospital outcomes in patients receiving intensive cardiac care.

Fine particulate air pollution and adult hospital admissions in 200 Chinese cities: a time-series analysis

BACKGROUND

The association between short-term exposure to ambient fine particulate matter (PM2.5) and morbidity risk in developing countries is not fully understood. We conducted a nationwide time-series study to estimate the short-term effect of PM2.5 on hospital admissions in Chinese adults.

METHODS

Daily counts of hospital admissions for 2014-16 were obtained from the National Urban Employee Basic Medical Insurance database. We identified more than 58 million hospitalizations from 0.28 billion insured persons in 200 Chinese cities for subjects aged 18 years or older. Generalized additive models with quasi-Poisson regression were applied to examine city-specific associations of PM2.5 concentrations with hospital admissions. National-average estimates of the association were obtained from a random-effects meta-analysis. We also investigated potential effect modifiers, such as age, sex, temperature and relative humidity.

RESULTS

An increase of 10 μg/m3 in same-day PM2.5 concentrations was positively associated with a 0.19% (95% confidence interval: 0.07-0.30) increase in the daily number of hospital admissions at the national level. PM2.5 exposure remained positively associated with hospital admissions on days when the daily concentrations met the current Chinese Ambient Air Quality Standards (75 μg/m3). Estimates of admission varied across cities and increased in cities with lower PM2.5 concentrations (p = 0.044) or higher temperatures (p = 0.002) and relative humidity (p = 0.003). The elderly were more sensitive to PM2.5 exposure (p < 0.001).

CONCLUSIONS

Short-term exposure to PM2.5 was positively associated with adult hospital admissions in China, even at levels below current Chinese Ambient Air Quality Standards.

Exposure to ambient fine particulate matter is associated with changes in fasting glucose and lipid profiles: a nationwide cohort study

BACKGROUND

Ambient fine particulate matter is a rising concern for global public health. It was recently suggested that exposure to fine particulate matter may contribute to the development of diabetes and dyslipidaemia. This study aims to examine the potential associations of ambient particulate matter exposure with changes in fasting glucose and lipid profiles in Koreans.

METHOD

We used the data from the National Health Insurance Service-National Sample Cohort (NHIS-NSC), a nationwide database representative of the Korean population. A total of 85,869 individuals aged ≥20 years were included. Multiple regression analyses were conducted to assess the associations between exposure to particulate matter and changes in fasting glucose and lipid profiles at 2-year intervals after adjusting for confounders.

RESULTS

Significant associations were observed between an increase in interquartile range for particulate matter < 2.5 μm in diameter (PM_2.5) and elevated levels of fasting glucose and low-density lipoprotein cholesterol (p for trend = 0.015 and 0.010, respectively), while no association for particulate matter sized 2.5-10 μm in diameter (PM_10-2.5) was noted after adjusting for the other covariates. Sub-group analyses showed stronger associations in individuals who were older (≥60 years) or physically inactive.

CONCLUSIONS

Fine particulate matter exposure affects worsening fasting glucose and low-density lipoprotein cholesterol levels, with no evidence of an association for coarse particulate matter.