Influence of exposure differences on city-to-city heterogeneity in PM2.5-mortality associations in US cities

Prevalence and associated factors of impaired kidney functions among children and adolescents in India: insights from the Comprehensive National Nutrition Survey (CNNS) 2016-18

BACKGROUND

Chronic kidney disease (CKD) is a significant public health problem. The burden of CKD in children and adolescents in India is not well described. We used data from the recent Comprehensive National Nutrition Survey (CNNS) to estimate the prevalence of impaired kidney function (IKF) and its determinants in children and adolescents between the ages of 5 and 19.

METHODS

CNNS 2016-18 adopted a multi-stage sampling design using probability proportional to size sampling procedure after geographical stratification of urban and rural areas. Serum creatinine was tested once in 24,690 children and adolescents aged 5-19 years. The estimated glomerular filtration rate (eGFR) was derived using the revised Schwartz equation. The eGFR value below 60 ml/min/1.73 m2 is defined as IKF. Bivariate analysis was done to depict the weighted prevalence, and multivariable logistic regression examined the predictors of IKF.

RESULTS

The mean eGFR in the study population was 113.3 + 41.4 mL/min/1.73 m2. The overall prevalence of IKF was 4.9%. The prevalence in the 5-9, 10-14, and 15-19 year age groups was 5.6%, 3.4% and 5.2%, respectively. Regression analysis showed age, rural residence, non-reserved social caste, less educated mothers, Islam religion, children with severe stunting or being overweight/obese, and residence in Southern India to be predictors of IKF.

CONCLUSIONS

The prevalence of IKF among children and adolescents in India is high compared to available global estimates. In the absence of repeated eGFR-based estimates, these nationally representative estimates are intriguing and call for further assessment of socio-demographic disparities, genetics, and risk behaviours to have better clinical insights and public health preparedness.

Geographic information system-based determination of priority monitoring areas for hazardous air pollutants in an industrial city

Industrial cities are hotspots for many hazardous air pollutants (HAPs), which are detrimental to human health. We devised an identification method to determine priority HAP monitoring areas using a comprehensive approach involving monitoring, modeling, and demographics. The methodology to identify the priority HAP monitoring area consists of two parts: (1) mapping the spatial distribution of selected categories relevant to the target pollutant and (2) integrating the distribution maps of various categories and subsequent scoring. The identification method was applied in Ulsan, the largest industrial city in South Korea, to identify priority HAP monitoring areas. Four categories related to HAPs were used in the method: (1) concentrations of HAPs, (2) amount of HAP emissions, (3) the contribution of industrial activities, and (4) population density in the city. This method can be used to select priority HAP monitoring areas for intensive monitoring campaigns, cohort studies, and epidemiological studies.

Case-Control Study of Occupational Acute Myeloid Leukemia in the Republic of Korea

Background

We conducted a case-control study to identify high-risk occupations and exposure to occupational hazards for acute myeloid leukemia (AML).

Methods

When patients with AML admitted to the Department of Hematology in the study hospital for the first time are referred to the Department of Occupational and Environmental Medicine, data on occupation are collected by investigators to evaluate work-relatedness. Community-based controls were recruited through an online survey agency, and four controls per case were matched. Occupational information was estimated using structured questionnaires covering 27 specific occupations and 32 exposure agents. Conditional logistic regression analysis was performed by pairing cases and controls.

Results

In the analysis of the risk of AML according to occupational classification, a significant association was found in paint manufacturing or painting work (OR = 2.22, 95% CI: 1.03-4.81) and aircrew (OR = 6.00, 95% CI: 1.00-35.91) in males, and in pesticide industry (OR = 6.89, 95% CI: 1.69-28.07) and cokes and steel industry (OR = 2.00, 95% CI: 1.18-22.06) in ≥60 years old. Moreover, the risk of AML increased significantly as the cumulative exposure to thinners increased. In the analyses stratified by sex and age, the association between pesticide exposure and AML was significant in males (OR = 3.28, 95% CI: 1.10-9.77) and in ≥60 years old (OR = 6.22, 95% CI: 1.48-26.08).

Conclusion

This case-control study identified high-risk occupational groups in the Republic of Korea including paint manufacturers and painters, aircrew, and those who are occupationally exposed to pesticides or paint thinners.

The effects of surface vegetation coverage on the spatial distribution of PM2.5 in the central area of Nanchang City, China

The frequent occurrence of haze has caused widespread concern in China, and PM2.5 is thought to be the main cause. Previous research showed that PM2.5 was not only influenced by meteorological conditions but also by land cover especially surface vegetation. It was concluded that PM2.5 concentration is significantly influenced by surface vegetation, but spatially how and in what manner are still unanswered. Taking the central area of Nanchang City, China, as a case, this study firstly applied land use regression (LUR) model to simulate the distribution of PM2.5 in 2020. Then, the dichotomous model was used to determine vegetation coverage. A statistical regression model was used to analyze the influence of vegetation cover on PM2.5 and the scale effects. The results showed that (1) vegetation coverage and PM2.5 concentration were both significantly negatively correlated at the spatial scales selected for this study. (2) The effect of vegetation coverage on PM2.5 varied with season and the 500 m had the best correlation. (3) The non-linear regression model fits better than the linear model, and the effect of vegetation coverage on PM2.5 was complex. (4) The effect of vegetation coverage on PM2.5 concentration was different with PM2.5 concentration level. The higher the PM2.5 concentration, the more pronounced the effect of vegetation coverage on it. This study proposed the idea and method of coupling vegetation coverage with PM2.5 concentration at the regional scale from gradient landscape's point of view and provided some references for mitigating PM2.5 pollution through optimizing urban vegetation patterns.

An Overview of How the Built Environment Relates to Children's Health

PURPOSE OF REVIEW

Explore the varied pathways between the built environment and children's health. The review begins by describing how the built environment and transport infrastructure relate to conditions that lead to health outcomes. The review examines emissions, noise, and traffic dangers in relation to children's physical, mental, and social health.

RECENT FINDINGS

Evidence is increasing for walkable neighborhoods and health-related behavior such as physical activity. However, diverse land uses (often supporting walkability) were also found to increase traffic injuries. Cognitive impacts of motorways on children at schools were found. Finally, the relationships between social activities and built environment are beginning. The built environment's influence on various physical health outcomes is increasingly clear and is often through a transport pathway. However, the links with mental and social health are less developed, though recent findings show significant results. Having accessible child-relevant destinations is an important consideration for children's health.

The effect of ozone short-term exposure on flow-mediated dilation: Using data before and after COVID-19 lockdown in Shanghai

BACKGROUND

Short-term ambient ozone exposure has been shown to have an adverse impact on endothelial function, contributing to major cardiovascular diseases and premature death. However, only limited studies have focused on the impact of short-term ozone exposure on Flow-mediated Dilation (FMD), and their results have been inconsistent. The current study aims to explore the relationship between short-term ambient ozone exposure and FMD. In addition, the study aims to investigate how lockdown measures for COVID-19 may influence ozone concentration in the atmosphere.

METHODS

Participants were recruited from a hospital in Shanghai from December 2020 to August 2022. Individuals' ozone exposure was determined using residential addresses. A distributed lag nonlinear model was adopted to assess the exposure-response relationship between short-term ozone exposure and FMD. A comparison was made between ambient ozone concentration and FMD data collected before and after Shanghai's lockdown in 2022.

RESULTS

When ozone concentration was between 150 and 200 μg/m³, there was a significant reduction in FMD with a 2-day lag. Elderly individuals (age ≥ 65), females, non-drinkers, and non-smokers were found to be more susceptible to high concentrations of ozone exposure. The lockdown did elevate ambient ozone concentration compared to the same period previously.

INTERPRETATION

This study proposes that an ambient ozone concentration of 150-200 μg/m³ is harmful to endothelial function, and that a reduction in human activity during lockdown increased the concentration, which in turn reduced FMD. However, the underlying mechanism requires further research.

Mortality and morbidity assessment attributed to short- and long-term exposure to fine particles in ambient air of Agadir city, Morocco: The AirQ model approach

It is well established that respiratory mortality and morbidity are associated with high concentrations of fine particles such as PM2.5. The aim of this study was to evaluate the long- and short-term impacts of PM2.5 on the population of Agadir, Morocco, using AirQ 2.1.1 software. The mean PM2.5 values were obtained from data collected at three sites. Baseline incidence data were obtained from the literature, and relative risk (RR) values were referenced from the World Health Organization. This study quantified long-term total mortality (LT-TM), lung cancer mortality (LT-LC), morbidity from acute lower respiratory tract infections (LT-ALRI), and morbidity from chronic obstructive pulmonary disease (LT-COPD), as well as short-term total mortality (ST-TM). The attributable proportions (AP) of LT-TM and LT-LC were estimated to 14.19% and 18.42%, respectively. Their excess deaths were estimated to 279 and 11 persons, respectively, and their RRs to 1.16 (95% CI: 1.10-1.22) and 1.23 (95% CI: 1.12-1.37), respectively. Furthermore, the AP of LT-ALRI and LT-COPD were estimated to 14.36% and 15.68%, respectively, their excess deaths to 33 and 4, and their RRs to 1.17 (95% CI: 1.11-1.31) and 1.19 (95% CI: 1.00-1.02), respectively. In comparison, the AP of ST-TM was estimated to 1.27%, with a 25-person excess death rate. This study was conducted to inform decision-making and to promote local policies on ambient air quality.

Cyclists' exposure to air pollution, noise, and greenery: a population-level spatial analysis approach

Urban travel exposes people to a range of environmental qualities with significant health and wellbeing impacts. Nevertheless, the understanding of travel-related environmental exposure has remained limited. Here, we present a novel approach for population-level assessment of multiple environmental exposure for active travel. It enables analyses of (1) urban scale exposure variation, (2) alternative routes' potential to improve exposure levels per exposure type, and (3) by combining multiple exposures. We demonstrate the approach's feasibility by analysing cyclists' air pollution, noise, and greenery exposure in Helsinki, Finland. We apply an in-house developed route-planning and exposure assessment software and integrate to the analysis 3.1 million cycling trips from the local bike-sharing system. We show that especially noise exposure from cycling exceeds healthy thresholds, but that cyclists can influence their exposure by route choice. The proposed approach enables planners and individual citizens to identify (un)healthy travel environments from the exposure perspective, and to compare areas in respect to how well their environmental quality supports active travel. Transferable open tools and data further support the implementation of the approach in other cities.

Neighborhood infrastructure-related risk factors and non-communicable diseases: a systematic meta-review

BACKGROUND

With rapid urbanization, the urban environment, especially the neighborhood environment, has received increasing global attention. However, a comprehensive overview of the association between neighborhood risk factors and human health remains unclear due to the large number of neighborhood risk factor-human health outcome pairs.

METHOD

On the basis of a whole year of panel discussions, we first obtained a list of 5 neighborhood domains, containing 33 uniformly defined neighborhood risk factors. We only focused on neighborhood infrastructure-related risk factors with the potential for spatial interventions through urban design tools. Subsequently, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic meta-review of 17 infrastructure-related risk factors of the 33 neighborhood risk factors (e.g., green and blue spaces, proximity to major roads, and proximity to landfills) was conducted using four databases, Web of Science, PubMed, OVID, and Cochrane Library, from January 2000 to May 2021, and corresponding evidence for non-communicable diseases (NCDs) was synthesized. The review quality was assessed according to the A MeaSurement Tool to Assess Systematic Reviews (AMSTAR) standard.

RESULTS

Thirty-three moderate-and high-quality reviews were included in the analysis. Thirteen major NCD outcomes were found to be associated with neighborhood infrastructure-related risk factors. Green and blue spaces or walkability had protective effects on human health. In contrast, proximity to major roads, industry, and landfills posed serious threats to human health. Inconsistent results were obtained for four neighborhood risk factors: facilities for physical and leisure activities, accessibility to infrastructure providing unhealthy food, proximity to industry, and proximity to major roads.

CONCLUSIONS

This meta-review presents a comprehensive overview of the effects of neighborhood infrastructure-related risk factors on NCDs. Findings on the risk factors with strong evidence can help improve healthy city guidelines and promote urban sustainability. In addition, the unknown or uncertain association between many neighborhood risk factors and certain types of NCDs requires further research.

Effect modification of consecutive high concentration days on the association between fine particulate matter and mortality: a multi-city study in Korea

OBJECTIVES

Although there is substantial evidence for the short-term effect of fine particulate matter (PM2.5) on daily mortality, few epidemiological studies have explored the effect of prolonged continuous exposure to high concentrations of PM2.5. This study investigated how the magnitude of the mortality effect of PM2.5 exposure is modified by persistent exposure to high PM2.5 concentrations.

METHODS

We analyzed data on the daily mortality count, simulated daily PM2.5 level, mean daily temperature, and relative humidity level from 7 metropolitan cities from 2006 to 2019. Generalized additive models (GAMs) with quasi-Poisson distribution and random-effects meta-analyses were used to pool city-specific effects. To investigate the effect modification of continuous exposure to prolonged high concentrations, we applied categorical consecutive-day variables to the GAMs as effect modification terms for PM2.5.

RESULTS

The mortality risk increased by 0.33% (95% confidence interval [CI], 0.16 to 0.50), 0.47% (95% CI, -0.09 to 1.04), and 0.26% (95% CI, -0.08 to 0.60) for all-cause, respiratory, and cardiovascular diseases, respectively, with a 10 μg/m3 increase in PM2.5 concentration. The risk of all-cause mortality per 10 μg/m3 increase in PM2.5 on the first and fourth consecutive days significantly increased by 0.63% (95% CI, 0.20 to 1.06) and 0.36% (95% CI, 0.01 to 0.70), respectively.

CONCLUSIONS

We found increased risks of all-cause, respiratory, and cardiovascular mortality related to daily PM2.5 exposure on the day when exposure to high PM2.5 concentrations began and when exposure persisted for more than 4 days with concentrations of ≥35 μg/m3. Persistently high PM2.5 exposure had a stronger effect on seniors.

Improving the design stage of air pollution studies based on wind patterns

A growing literature in economics and epidemiology has exploited changes in wind patterns as a source of exogenous variation to better measure the acute health effects of air pollution. Since the distribution of wind components is not randomly distributed over time and related to other weather parameters, multivariate regression models are used to adjust for these confounding factors. However, this type of analysis relies on its ability to correctly adjust for all confounding factors and extrapolate to units without empirical counterfactuals. As an alternative to current practices and to gauge the extent of these issues, we propose to implement a causal inference pipeline to embed this type of observational study within an hypothetical randomized experiment. We illustrate this approach using daily data from Paris, France, over the 2008-2018 period. Using the Neyman-Rubin potential outcomes framework, we first define the treatment of interest as the effect of North-East winds on particulate matter concentrations compared to the effects of other wind directions. We then implement a matching algorithm to approximate a pairwise randomized experiment. It adjusts nonparametrically for observed confounders while avoiding model extrapolation by discarding treated days without similar control days. We find that the effective sample size for which treated and control units are comparable is surprisingly small. It is however reassuring that results on the matched sample are consistent with a standard regression analysis of the initial data. We finally carry out a quantitative bias analysis to check whether our results could be altered by an unmeasured confounder: estimated effects seem robust to a relatively large hidden bias. Our causal inference pipeline is a principled approach to improve the design of air pollution studies based on wind patterns.

The association between environmental cadmium exposure, blood pressure, and hypertension: a systematic review and meta-analysis

We performed a systematic and meta-analysis study to find the association between cadmium (Cd) exposure and blood pressure (BP)/hypertension (HTN) in exposed general populations. We searched main databases for literature published between year 2000 and April 15, 2021. Quality assessment was performed with the Joanna Briggs Institute (JBI) critical appraisal tools. Heterogeneity between studies was determined by I-squared (I²) statistic. The random effects model was used to determine the association between blood and urine Cd levels with hypertension. The overall standard differences in mean for Cd level in hypertensive and control groups were 3.34, 1.79, and 8.09 based on samples from blood, urine, and hair, respectively. The overall standard differences in mean for Cd level in the low and high exposure groups were - 0.795 and - 1.036 based on blood and urinary samples, respectively. Our findings indicate a positive relationship between blood and hair Cd levels and hypertension. We also found that hair is the optimal biological sample to find the relationship between Cd exposure and hypertension for both genders. However, more studies are needed to confirm these findings.

The world-wide waste web

Countries globally trade with tons of waste materials every year, some of which are highly hazardous. This trade admits a network representation of the world-wide waste web, with countries as vertices and flows as directed weighted edges. Here we investigate the main properties of this network by tracking 108 categories of wastes interchanged in the period 2001–2019. Although, most of the hazardous waste was traded between developed nations, a disproportionate asymmetry existed in the flow from developed to developing countries. Using a dynamical model, we simulate how waste stress propagates through the network and affects the countries. We identify 28 countries with low Environmental Performance Index that are at high risk of waste congestion. Therefore, they are at threat of improper handling and disposal of hazardous waste. We find evidence of pollution by heavy metals, by volatile organic compounds and/or by persistent organic pollutants, which are used as chemical fingerprints, due to the improper handling of waste in several of these countries.

The 2001–2019 web of international waste trade is investigated, allowing the identification of countries at threat of improper handling and disposal of waste. Chemical tracers are used to identify the environmental impact of waste in these countries.

Chronic kidney disease of unknown etiology in India: a comparative study with Mesoamerican and Sri Lankan nephropathy

Chronic kidney disease of unknown etiology [CKDu] is a condition characterized by decline in kidney function and is not associated with diabetic nephropathy or hypertensive nephropathy. In this review, we have done a detailed literature analysis on CKDu in India, and then had a comparison with that of Mesoamerica and Sri Lanka. In India, CKDu became the second most common type of CKD after diabetic nephropathy. Silica was seen in the groundwater of both India and Sri Lanka, whereas in Mesoamerica silica exposure through particulate matter was seen among CKDu communities. DDE is a common agrochemical seen in both India and Sri Lanka. The risk factors vary from region to region and it is important to categorize CKDu population based on the risk factors to avoid misinterpretation of the condition as non-CKDu category and to evade further complications. More studies have to be conducted to reveal the detailed pathophysiological mechanisms and its relation with irrational exploitation of environmental resources.

Reverse logistics research of municipal hazardous waste: a literature review

The reverse logistics of municipal hazardous waste (RLMHW) have received close attention from researchers and practitioners alike, given the essential impact of safe transportation and effective management of hazardous waste on public health and environmental sustainability. There are a great number of studies in the extant literature on RLMHW, with many and diverse research topics; however, a concise and complete overview of the research works already conducted in this particular area is conspicuous by its absence. This paper strives to fill the gap through the conduct of rigorous systematic literature review of RLMHW in the past three decades, and then establish a framework of studies on RLMHW. The main contributions of this study are as follows: (1) to identify the trend of journals publishing research papers on RLMHW; (2) to extract the main topics in studies on RLMHW; (3) to locate the most popular research areas of RLMHW; (4) to summarize the methods adopted in studies on RLMHW; (5) to identify research deficiencies in certain categories of RLMHW; and (6) to establish the future research directions of RLMHW. The main implications of the study are to offer a better understanding of RLMHW by systematic crystallization of archival data in a systematic chronological order across central issues. This study contributes to scholarly debate in this field by serving as a snapshot paper to document the development of the field and gives input to policymakers in process design and policy making in the domain of RLMHW.

Exploration of PM mass, source, and component-related factors that might explain heterogeneity in daily PM2.5-mortality associations across the United States

Multi-city epidemiologic studies examining short-term (daily) differences in fine particulate matter (PM_2.5) provide evidence of substantial spatial heterogeneity in city-specific mortality risk estimates across the United States. Because PM_2.5 is a mixture of particles, both directly emitted from sources or formed through atmospheric reactions, some of this heterogeneity may be due to regional variations in PM_2.5 toxicity. Using inverse variance weighted linear regression, we examined change in percent change in mortality in association with 24 "exposure" determinants representing three basic groupings based on potential explanations for differences in PM toxicity - size, source, and composition. Percent changes in mortality for the PM_2.5-mortality association for 313 core-based statistical areas and their metropolitan divisions over 1999-2005 were used as the outcome. Several determinants were identified as potential contributors to heterogeneity: all mass fraction determinants, vehicle miles traveled (VMT) for diesel total, VMT gas per capita, PM_2.5 ammonium, PM_2.5 nitrate, and PM_2.5 sulfate. In multivariable models, only daily correlation of PM_2.5 with PM₁₀ and long-term average PM_2.5 mass concentration were retained, explaining approximately 10% of total variability. The results of this analysis contribute to the growing body of literature specifically focusing on assessing the underlying basis of the observed spatial heterogeneity in PM_2.5-mortality effect estimates, continuing to demonstrate that this heterogeneity is multifactorial and not attributable to a single aspect of PM.

Air pollution impacts from COVID-19 pandemic control strategies in Malaysia

Mitigation measures and control strategies relating to novel coronavirus disease 2019 (COVID-19) have been widely applied in many countries in order to reduce the transmission of this pandemic disease. A Movement Control Order (MCO) was implemented in Malaysia starting from the March 18, 2020 as a pandemic control strategy which restricted all movement and daily outdoor activities. To investigate the impact of MCO, air pollutants: particulate matter with an aerodynamic diameter less than 10 μm (PM10), particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5), sulphur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3) and carbon monoxide (CO) in nine major cities in Malaysia were measured before and during the implementation of the MCO. The non-carcinogenic health risk assessments of the air pollutants are also determined using the United States Environmental Protection Agency (USEPA) Health Risk Assessment method. Overall, NO2 recorded an average percentage reduction of 40% with the highest reduction observed at Kota Kinabalu (62%). The largest reductions of PM10, PM2.5, SO2, O3 and CO were recorded at Kota Kinabalu (17%), Kuantan (9.5%), Alor Star (38%), Kota Bharu (15%), and Ipoh (27%) respectively. All cities had hazard quotient (HQ) values of <1 suggesting no non-carcinogenic health effects. The highest HQ was observed for PM2.5 during the MCO period (4.53E-02) in Kuala Lumpur. An average hazard index (HI) value of 1.44E-01 (before the MCO) and 1.40E-01 (during the MCO) showed higher human health risks before the MCO than during the MCO. This study gives confidence to regulatory bodies that the reduction of human activities significantly reduces air pollution and increases human health and so good air pollution control strategies can provide crucial impacts, especially in reducing air pollution and improving human health.

General and specified vulnerability to extreme temperatures among older adults

Extreme temperatures pose significant risks to human health and well-being. Older adults are particularly at risk and their susceptibility is a function of vulnerability to general daily life circumstances and to specified events or threats. For the first time, this paper develops a combined general and specified approach to understand the determinants of vulnerability. The findings show that most participants exhibit high levels of heat-related vulnerability, followed by cold-related vulnerability and lastly, general vulnerability. General vulnerability was shown to be primarily shaped by financial, physical and social assets. Whilst, specified vulnerability was found to be mainly shaped by human, physical and placed based assets. Such findings present opportunities to focus on the types of assets that contribute to reducing vulnerability. These findings also suggest that the role assets play in shaping vulnerability must be attended to if we are to fully understand and effectively implement strategies to reduce vulnerability.

A framework for estimating the US mortality burden of fine particulate matter exposure attributable to indoor and outdoor microenvironments

Exposure to fine particulate matter (PM_2.5) is associated with increased mortality. Although epidemiology studies typically use outdoor PM_2.5 concentrations as surrogates for exposure, the majority of PM_2.5 exposure in the US occurs in microenvironments other than outdoors. We develop a framework for estimating the total US mortality burden attributable to exposure to PM_2.5 of both indoor and outdoor origin in the primary non-smoking microenvironments in which people spend most of their time. The framework utilizes an exposure-response function combined with adjusted mortality effect estimates that account for underlying exposures to PM_2.5 of outdoor origin that likely occurred in the original epidemiology populations from which effect estimates are derived. We demonstrate the framework using several different scenarios to estimate the potential magnitude and bounds of the US mortality burden attributable to total PM_2.5 exposure across all non-smoking environments under a variety of assumptions. Our best estimates of the US mortality burden associated with total PM_2.5 exposure in the year 2012 range from ~230,000 to ~300,000 deaths. Indoor exposure to PM_2.5 of outdoor origin is typically the largest total exposure, accounting for ~40-60% of total mortality, followed by residential exposure to indoor PM_2.5 sources, which also drives the majority of variability in each scenario.

Oxidative Potential Versus Biological Effects: A Review on the Relevance of Cell-Free/Abiotic Assays as Predictors of Toxicity from Airborne Particulate Matter

Background and Objectives: The oxidative potential (OP) of particulate matter (PM) in cell-free/abiotic systems have been suggested as a possible measure of their biological reactivity and a relevant exposure metric for ambient air PM in epidemiological studies. The present review examined whether the OP of particles correlate with their biological effects, to determine the relevance of these cell-free assays as predictors of particle toxicity. Methods: PubMed, Google Scholar and Web of Science databases were searched to identify relevant studies published up to May 2019. The main inclusion criteria used for the selection of studies were that they should contain (1) multiple PM types or samples, (2) assessment of oxidative potential in cell-free systems and (3) assessment of biological effects in cells, animals or humans. Results: In total, 50 independent studies were identified assessing both OP and biological effects of ambient air PM or combustion particles such as diesel exhaust and wood smoke particles: 32 in vitro or in vivo studies exploring effects in cells or animals, and 18 clinical or epidemiological studies exploring effects in humans. Of these, 29 studies assessed the association between OP and biological effects by statistical analysis: 10 studies reported that at least one OP measure was statistically significantly associated with all endpoints examined, 12 studies reported that at least one OP measure was significantly associated with at least one effect outcome, while seven studies reported no significant correlation/association between any OP measures and any biological effects. The overall assessment revealed considerable variability in reported association between individual OP assays and specific outcomes, but evidence of positive association between intracellular ROS, oxidative damage and antioxidant response in vitro, and between OP assessed by the dithiothreitol (DDT) assay and asthma/wheeze in humans. There was little support for consistent association between OP and any other outcome assessed, either due to repeated lack of statistical association, variability in reported findings or limited numbers of available studies. Conclusions: Current assays for OP in cell-free/abiotic systems appear to have limited value in predicting PM toxicity. Clarifying the underlying causes may be important for further advancement in the field.

Comparison of Short-Term Associations between PM2.5 Components and Mortality across Six Major Cities in South Korea

Association between short-term exposure to fine particulate matter (PM_2.5) and mortality or morbidity varies geographically, and this variation could be due to different chemical composition affected by local sources. However, there have been only a few Asian studies possibly due to limited monitoring data. Using nationwide regulatory monitoring data of PM_2.5 chemical components in South Korea, we aimed to compare the associations between daily exposure to PM_2.5 components and mortality across six major cities. We obtained daily 24-h concentrations of PM_2.5 and 11 PM_2.5 components measured from 2013 to 2015 at single sites located in residential areas. We used death certificate data to compute the daily counts of nonaccidental, cardiovascular, and respiratory deaths. Using the generalized additive model, we estimated relative risks of daily mortality for an interquartile range increase in each pollutant concentration, while controlling for a longer-term time trend and meteorology. While elemental carbon was consistently associated with nonaccidental mortality across all cities, nickel and vanadium were strongly associated with respiratory or cardiovascular mortality in Busan and Ulsan, two large port cities. Our study shows that PM_2.5 components responsible for PM_2.5-associated mortality differed across cities depending on the dominant pollution sources, such as traffic and oil combustion.

Human exposure factors as potential determinants of the heterogeneity in city-specific associations between PM2.5 and mortality

Multi-city population-based epidemiological studies of short-term fine particulate matter (PM_2.5) exposures and mortality have observed heterogeneity in risk estimates between cities. Factors affecting exposures, such as pollutant infiltration, which are not captured by central-site monitoring data, can differ between communities potentially explaining some of this heterogeneity. This analysis evaluates exposure factors as potential determinants of the heterogeneity in 312 core-based statistical areas (CBSA)-specific associations between PM_2.5 and mortality using inverse variance weighted linear regression. Exposure factor variables were created based on data on housing characteristics, commuting patterns, heating fuel usage, and climatic factors from national surveys. When survey data were not available, air conditioning (AC) prevalence was predicted utilizing machine learning techniques. Across all CBSAs, there was a 0.95% (Interquartile range (IQR) of 2.25) increase in non-accidental mortality per 10 µg/m³ increase in PM_2.5 and significant heterogeneity between CBSAs. CBSAs with larger homes, more heating degree days, a higher percentage of home heating with oil had significantly (p < 0.05) higher health effect estimates, while cities with more gas heating had significantly lower health effect estimates. While univariate models did not explain much of heterogeneity in health effect estimates (R² < 1%), multivariate models began to explain some of the observed heterogeneity (R² = 13%).

Meteorological correlates and AirQ+ health risk assessment of ambient fine particulate matter in Tehran, Iran

There are few studies in the world that have been evaluated the mortality due to exposure to particulate matter smaller than 2.5 µm by AirQ+ software. Therefore, the study aimed to correlate between fine particulate matter (PM2.5) and meteorological variables and estimate all-cause annual mortality and mortality from cerebrovascular disease (stroke), ischemic heart disease (IHD), acute lower respiratory infection (ALRI), lung cancer (LC), chronic obstructive pulmonary disease (COPD) attributed to long-term exposure to ambient PM2.5 in Tehran from March 2017 to March 2018 using the WHO AirQ+ software. Data related to air quality, meteorological condition, population and the baseline incidence rates of health endpoints in Tehran were gathered from government agencies. The association between the PM2.5 concentrations and meteorological variables in the period of study were assessed by correlation analysis. The results of correlation analysis showed a weak positive correlation between PM2.5 concentrations and average monthly temperature (r = 0.42, P < 0.05) and average monthly humidity (r = 0.37, P < 0.05) in Tehran. The quantitative risk assessment related to all-cause annual mortality, the mortality of IHD, stroke, COPD, LC and ALRI were estimated 6710, 3797, 1145, 172, 135 and 27 cases, respectively. The results of regression association analysis between PM_2.5 and the number of recorded deaths was showed that with an increase of one microgram per cubic meter of PM_2.5, it is expected that about 27 cases will be added to air pollution mortality in Tehran.

Association between PM2.5 Exposure and All-Cause, Non-Accidental, Accidental, Different Respiratory Diseases, Sex and Age Mortality in Shenzhen, China

Background: China is at its most important stage of air pollution control. Research on the association between air pollutants and human health is very important and necessary. The purpose of this study was to evaluate the association between PM2.5 concentrations and residents' mortality and to compare the effect of PM2.5 on the different diseases, accidental deaths, sex or age of residents from high polluted areas with less polluted areas. Methods: The semi-parametric generalized additive model (GAM) with Poisson distribution of time series analysis was used. The excess risk (ER) of mortality with the incremental increase of 10 µg/m³ in PM2.5 concentration was calculated. Concentration-response relationship curves and autocorrelation between different lags of PM2.5 were also evaluated. Results: PM2.5 exposure was significantly associated with the mortality of residents. The strongest ERs per 10 µg/m³ increase in PM2.5 were 0.74% (95% CI: 0.11⁻1.38%) for all-cause, 0.67% (95% CI: 0.01⁻1.33%) for non-accidental, 1.81% (95% CI: 0.22⁻3.42%) for accidental, 3.04% (95% CI: 0.60⁻5.55%) for total respiratory disease, 6.38% (95% CI: 2.78⁻10.11%) for chronic lower respiratory disease (CLRD), 8.24% (95% CI: 3.53⁻13.17%) for chronic obstructive pulmonary disease (COPD), 1.04% (95% CI: 0.25⁻1.84%) for male and 1.32% (95% CI: 0.46⁻2.19%) for elderly. Furthermore, important information on the concentration-response relationship curves was provided. Conclusions: PM2.5 can increase the risk of residents' mortality, even in places with less air pollution and developed economy in China.

Early warning signals for critical transitions in cardiopulmonary health, related to air pollution in an urban Chinese population

Respiratory, and cardio-cerebrovascular health-related diseases significantly threaten human health and together with air pollution form a complex pathophysiological system. Other complex biological systems show that increased variance and autocorrelations in time series may act as valid early warning signals for critical transitions. On population level, we determined the likelihood that increased variance and autocorrelation of hospital visit on cardiopulmonary disease preceded critical transitions in population health by human-pollution interactions. We investigated long-term hospital visits from a hospital in Nanjing City, China during 2006-2016 for the most important cardiopulmonary diseases likely to be influenced by air pollution: cerebrovascular accident disease (CVAD), coronary artery disease (CAD), chronic obstructive pulmonary disease (COPD), lung cancer disease (LCD), and the grouped categories of respiratory system disease (RESD) and cardio-cerebrovascular system disease (CCD). The time series of standard deviations (SDs) and autocorrelation at-lag-1 (AR-1) were studied as potential Early-Warning Indicators (EWIs) of transitions in population health. Elevated SDs provided an early warning for critical transitions in visit for LCD and overall CCD and CVAD, for the period of 2012-2013, after which a real transition of increased visit occurred for these disease categories. Statistical testing showed that these SDs were significantly increased (p < 0.1). The long-term air pollution together with intermittent pollution episodes may have triggered critical transitions in population health for cardiopulmonary disease. It is recommended to consider significant increases in variability in time series of relevant system parameters, such as visit, as early warning signs for future transitions in populations' health states.

PM2.5 exposure significantly improves the exacerbation of A549 tumor-bearing CB17-SCID mice

Here we investigate the effects and potential mechanisms of PM2.5 on tumor development in a lung cancer mouse model. Tumor-bearing mice (n = 32) were established and randomized into two groups: the PM2.5 or NS exposure group. Compared with the NS exposure group, mice in the PM2.5 exposure group showed an increased number of tumor nodules, increased BAL fluid protein levels, and elevated expressions of MMP1, IL1β and VEGF. Measurement of angiogenesis from blood serum using an angiogenesis antibody array revealed increased levels of 12 angiogenesis factors in mice after PM2.5 exposure. We also isolated bacteria from the upper respiratory tract of the mice and found that the microecosystem of the upper respiratory tract of tumor-bearing mice was perturbed by PM2.5 exposure. Our findings further establish a key link between PM2.5 and lung cancer and further elucidation of these mechanisms may reveal potential treatment strategies for lung cancer.

Correction to: Lung cancer mortality of residents living near petrochemical industrial complexes: a meta-analysis

After publication of the article [1], it has been brought to our attention that the original version of this Article contained a typo in the 3rd paragraph of the section 'Review process and data extraction'. It concerns the equation published as "Var(lnRR) = Var(lnR1 + lnR0)". On the right part, the "+" within the parenthesis should be "-", as defined and derived from the left part. As a result, Var(lnRR) = Var(lnR1 + lnR0) should be revised to Var(lnRR) = Var(lnR1 - lnR0).

Air pollution and risk of hospitalization for epilepsy: the role of farm use of nitrogen fertilizers and emissions of the agricultural air pollutant, nitrous oxide

ABSTRACT The link between various air pollutants and hospitalization for epilepsy has come under scrutiny. We have proposed that exposure to air pollution and specifically the pervasive agricultural air pollutant and greenhouse gas, nitrous oxide (N2O), may provoke susceptibility to neurodevelopmental disorders. Evidence supports a role of N2O exposure in reducing epileptiform seizure activity, while withdrawal from the drug has been shown to induce seizure-like activity. Therefore, we show here that the statewide use of anthropogenic nitrogen fertilizers (the most recognized causal contributor to environmental N2O burden) is significantly negatively associated with hospitalization for epilepsy in all three pre-specified hospitalization categories, even after multiple pollutant comparison correction (p<.007), while the other identified pollutants were not consistently statistically significantly associated with hospitalization for epilepsy. We discuss potential neurological mechanisms underpinning this association between air pollutants associated with farm use of anthropogenic nitrogen fertilizers and hospitalization for epilepsy.

Association of ambient Particulate matter 2.5 with intensive care unit admission due to pneumonia: a distributed lag non-linear model

Air pollution in China has become a major environmental problem. There is a lack of evidence on the impact of haze (especially PM2.5) on intensive care unit admission due to pneumonia (ICUp). We hypothesized that PM2.5 was independently associated with ICUp and there was a non-linear time lag effect. All ICU admissions occurred from January 1, 2014 to December 31, 2016 in Sir Run-Run Shaw hospital were included in the study. The primary reasons for admission were categorized into pneumonia and non-pneumonia. Distributed lag non-linear model (DLNM) was built to account for the effect of air quality parameters in both value and temporal lag dimensions. There was a total of 7487 ICU admissions during the study period, including 391 admissions due to pneumonia. The DLNM showed that the relative risk (RR) of ICUp increased with PM2.5 concentrations. At a PM2.5 concentration of 200 mcg/m3, the RR increased from 1.06 (95% CI: 0.57-1.95) at day 0 to 1.40 (95% CI: 1.05-1.86) at day 3, and returned normal at day 6 (RR: 1.13; 95% CI: 0.83-1.55). The study showed that PM2.5 was independently associated with the risk of ICUp, and the maximum effect occurred at 3 to 4 days after exposure.

Selective ATP-Binding Cassette Subfamily C Gene Expression and Proinflammatory Mediators Released by BEAS-2B after PM2.5, Budesonide, and Cotreated Exposures

ATP-binding cassette subfamily C (ABCC) genes code for phase III metabolism proteins that translocate xenobiotic (e.g., particulate matter 2.5 (PM_2.5)) and drug metabolites outside the cells. IL-6 secretion is related with the activation of the ABCC transporters. This study assesses ABCC1–4 gene expression changes and proinflammatory cytokine (IL-6, IL-8) release in human bronchial epithelial cells (BEAS-2B) exposed to PM_2.5 organic extract, budesonide (BUD, used to control inflammation in asthmatic patients), and a cotreatment (Co-T: PM_2.5 and BUD). A real-time PCR assay shows that ABCC1 was upregulated in BEAS-2B exposed after 6 and 7 hr to PM_2.5 extract or BUD but downregulated after 6 hr of the Co-T. ABCC3 was downregulated after 6 hr of BUD and upregulated after 6 hr of the Co-T exposures. ABCC4 was upregulated after 5 hr of PM_2.5 extract, BUD, and the Co-T exposures. The cytokine assay revealed an increase in IL-6 release by BEAS-2B exposed after 5 hr to PM_2.5 extract, BUD, and the Co-T. At 7 hr, the Co-T decreases IL-6 release and IL-8 at 6 hr. In conclusion, the cotreatment showed an opposite effect on exposed BEAS-2B as compared with BUD. The results suggest an interference of the BUD therapeutic potential by PM_2.5.