Urban air pollution and chronic obstructive pulmonary disease-related emergency department visits

Air pollution as an early determinant of COPD

COPD is a progressive and debilitating disease often diagnosed after 50 years of age, but more recent evidence suggests that its onset could originate very early on in life. In this context, exposure to air pollution appears to be a potential contributor. Although the potential role of air pollution as an early determinant of COPD is emerging, knowledge gaps still remain, including an accurate qualification of air pollutants (number of pollutants quantified and exact composition) or the "one exposure-one disease" concept, which might limit the current understanding. To fill these gaps, improvements in the field are needed, such as the use of atmosphere simulation chambers able to realistically reproduce the complexity of air pollution, consideration of the exposome, as well as improving exchanges between paediatricians and adult lung specialists to take advantage of reciprocal expertise. This review should lead to a better understanding of the current knowledge on air pollution as an early determinant of COPD, as well as identify the existing knowledge gaps and opportunities to fill them. Hopefully, this will lead to better prevention strategies to scale down the development of COPD in future generations.

Air Pollution Exposure as a Relevant Risk Factor for Chronic Obstructive Pulmonary Disease Exacerbations in Male and Female Patients

Chronic obstructive pulmonary disease (COPD) is a multifactorial lung inflammatory disease that affects 174 million people worldwide, with a recently reported increased incidence in female patients. Patients with COPD are especially vulnerable to the detrimental effects of environmental exposures, especially from air particulate and gaseous pollutants; exposure to air pollution severely influences COPD outcomes, resulting in acute exacerbations, hospitalisations, and death. Here, a literature review of the recent work addressing air pollution-induced acute exacerbations of COPD (AECOPD) was conducted in order to determine whether sex was considered as a biological variable in these studies, and whether air pollution exposure affected patients with COPD in a sex-specific manner. It was found that, while the majority of studies enrolled both male and female patients, only a few reported results were disaggregated by sex. Most studies had a higher enrolment of male patients, only four compared AECOPD outcomes between sexes, and only one study identified sex differences in AECOPD, with females displaying higher rates. Overall, this analysis of the literature confirmed that air pollution exposure is a trigger for AECOPD hospitalisations and revealed a significant gap in the knowledge of sex-specific effects of air pollutants on COPD outcomes, highlighting the need for more studies to consider sex as a biological variable.

Assessing a Fossil Fuels Externality with a New Neural Networks and Image Optimization Algorithm: The Case of Atmospheric Pollutants as Cofounders to COVID-19 Lethality

This paper demonstrates how the combustion of fossil fuels for transport purpose might cause health implications. Based on an original case study [i.e. the Hubei province in China, the epicentre of the coronavirus disease-2019 (COVID-19) pandemic], we collected data on atmospheric pollutants (PM_2.5, PM₁₀ and CO₂) and economic growth (GDP), along with daily series on COVID-19 indicators (cases, resuscitations and deaths). Then, we adopted an innovative Machine Learning approach, applying a new image Neural Networks model to investigate the causal relationships among economic, atmospheric and COVID-19 indicators. Empirical findings emphasise that any change in economic activity is found to substantially affect the dynamic levels of PM_2.5, PM₁₀ and CO₂ which, in turn, generates significant variations in the spread of the COVID-19 epidemic and its associated lethality. As a robustness check, the conduction of an optimisation algorithm further corroborates previous results.

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

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

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

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

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

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

Particulate Matter and Cardiovascular Risk in Adults with Chronic Obstructive Pulmonary Disease

Rationale: People with chronic obstructive pulmonary disease (COPD) have an increased risk of cardiovascular disease and may be more susceptible to air pollution exposure. However, no study has examined the association between long-term fine particulate matter exposure (≤2.5 μm in aerodynamic diameter) and risk of cardiovascular events in this potentially vulnerable population. Objectives: To estimate the association between long-term fine particulate matter and risk of cardiovascular events among adults with COPD. Methods: This retrospective cohort study included 169,714 adults with COPD who were members of the Kaiser Permanente Northern California health plan during 2007-2016. Electronic health record data were linked to 1 km modeled particulate matter ≤2.5 μm in aerodynamic diameter exposure estimates. We fit Cox proportional hazard models, adjusting for age, sex, race/ethnicity, calendar year, smoking, body mass index, comorbidities, medications, and socioeconomic status. In low exposure analyses, we examined effects below the current regulation limit (12 μg/m³). Measurements and Main Results: Among adults with COPD, a 10-μg/m³ increase in 1-year mean fine particulate matter exposure was associated with an elevated risk of cardiovascular mortality (hazard ratio, 1.10; 95% confidence interval [CI], 1.01-1.20). Effects were stronger in low exposure analyses (hazard ratio, 1.88; 95% CI, 1.56-2.27). Fine particulate matter exposure was not associated with acute myocardial infarction or stroke in overall analyses. Conclusions: Long-term fine particulate matter exposure was associated with an increased risk of cardiovascular mortality among adults with COPD. Current regulations may not sufficiently protect those with COPD.

Environmental air pollution: respiratory effects

Environmental air pollution is a major risk factor for morbidity and mortality worldwide. Environmental air pollution has a direct impact on human health, being responsible for an increase in the incidence of and number of deaths due to cardiopulmonary, neoplastic, and metabolic diseases; it also contributes to global warming and the consequent climate change associated with extreme events and environmental imbalances. In this review, we present articles that show the impact that exposure to different sources and types of air pollutants has on the respiratory system; we present the acute effects-such as increases in symptoms and in the number of emergency room visits, hospitalizations, and deaths-and the chronic effects-such as increases in the incidence of asthma, COPD, and lung cancer, as well as a rapid decline in lung function. The effects of air pollution in more susceptible populations and the effects associated with physical exercise in polluted environments are also presented and discussed. Finally, we present the major studies on the subject conducted in Brazil. Health care and disease prevention services should be aware of this important risk factor in order to counsel more susceptible individuals about protective measures that can facilitate their treatment, as well as promoting the adoption of environmental measures that contribute to the reduction of such emissions.

Effects of short-term exposure to ambient airborne pollutants on COPD-related mortality among the elderly residents of Chengdu city in Southwest China

Background

Chronic obstructive pulmonary disease (COPD) has become a severe global burden in terms of both health and the economy. Few studies, however, have thoroughly assessed the influence of air pollution on COPD-related mortality among elderly people in developing areas in the hinterland of southwestern China. This study is the first to examine the association between short-term exposure to ambient airborne pollutants and COPD-related mortality among elderly people in the central Sichuan Basin of southwestern China.

Methods

Data on COPD-related mortality among elderly people aged 60 and older were obtained from the Population Death Information Registration and Management System (PDIRMS). Data on airborne pollutants comprised of particulate matter < 2.5 μm in aerodynamic diameter (PM_2.5), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), and ozone (O₃) were derived from 23 municipal environmental monitoring sites. Data on weather conditions, including daily mean temperature and relative humidity, were obtained from the Chengdu Meteorological Bureau. All data were collected from January 1, 2015, to December 31, 2018. A quasi-Poisson general additive model (GAM) was utilized to assess the effects of short-term exposure to airborne pollutants on COPD-related mortality among elderly people.

Results

A total of 61,058 COPD-related deaths of people aged 60 and older were obtained. Controlling the influences of daily temperature and relative humidity, interquartile range (IQR) concentration increases of PM_2.5 (43 μg/m³), SO₂ (8 μg/m³), NO₂ (18 μg/m³), CO (0.4 mg/m³), and O₃ (78 μg/m³) were associated with 2.7% (95% CI 1.0–4.4%), 4.3% (95% CI 2.1–6.4%), 3.6% (95% CI 1.7–5.6%), 2.7% (95% CI 0.6–4.8%), and 7.4% (95% CI 3.6–11.3%) increases in COPD-related mortality in people aged 60 and older, respectively. The exposure-response curves between each pollutant and the log-relative risk of COPD-related mortality exhibited linear relationships. Statistically significant differences in the associations between pollutants and COPD-related mortality were not observed among sociodemographic factors including age, gender, and marital status. The effects of O₃ remained steady after adjusting for PM_2.5, SO₂, NO₂, and CO each time in the two-pollutant models.

Conclusions

Increased concentrations of ambient airborne pollutants composed of PM_2.5, SO₂, NO₂, O₃, and CO were significantly and positively associated with COPD-related mortality in the central Sichuan Basin, which is located in the hinterland of southwestern China. The adverse effects of O₃ were stable, a finding that should receive more attention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12199-020-00925-x.

The relationship between air pollution and COVID-19-related deaths: An application to three French cities

Being heavily dependent to oil products (mainly gasoline and diesel), the French transport sector is the main emitter of Particulate Matter (PMs) whose critical levels induce harmful health effects for urban inhabitants. We selected three major French cities (Paris, Lyon, and Marseille) to investigate the relationship between the Coronavirus Disease 19 (COVID-19) outbreak and air pollution. Using Artificial Neural Networks (ANNs) experiments, we have determined the concentration of PM_2.5 and PM₁₀ linked to COVID-19-related deaths. Our focus is on the potential effects of Particulate Matter (PM) in spreading the epidemic. The underlying hypothesis is that a pre-determined particulate concentration can foster COVID-19 and make the respiratory system more susceptible to this infection. The empirical strategy used an innovative Machine Learning (ML) methodology. In particular, through the so-called cutting technique in ANNs, we found new threshold levels of PM_2.5 and PM₁₀ connected to COVID-19: 17.4 µg/m³ (PM_2.5) and 29.6 µg/m³ (PM₁₀) for Paris; 15.6 µg/m³ (PM_2.5) and 20.6 µg/m³ (PM₁₀) for Lyon; 14.3 µg/m³ (PM_2.5) and 22.04 µg/m³ (PM₁₀) for Marseille. Interestingly, all the threshold values identified by the ANNs are higher than the limits imposed by the European Parliament. Finally, a Causal Direction from Dependency (D2C) algorithm is applied to check the consistency of our findings.

The Respiratory Risks of Ambient/Outdoor Air Pollution

Globally, exposure to ambient air pollutants is responsible for premature mortality and is implicated in the development and exacerbation of several acute and chronic lung disease across all ages. In this article, we discuss the source apportionment of ambient pollutants and the respiratory health effects in humans. We specifically discuss the evidence supporting ambient pollution in the development of asthma and chronic obstructive pulmonary disease and acute exacerbations of each condition. Practical advice is given to health care providers in how to promote a healthy environment and advise patients with chronic conditions to avoid unsafe air quality.

Association between African Dust Transport and Acute Exacerbations of COPD in Miami

Background: Air pollution is increasingly recognized as a risk factor for acute exacerbation of chronic obstructive pulmonary disease (COPD). Changing climate and weather patterns can modify the levels and types of air pollutants. For example, dust outbreaks increase particulate air pollution. Objective: This paper examines the effect of Saharan dust storms on the concentration of coarse particulate matter in Miami, and its association with the risk of acute exacerbation of COPD (AECOPD). Methods: In this prospective cohort study, 296 COPD patients (with 313 events) were followed between 2013 and 2016. We used Light Detection and Ranging (LIDAR) and satellite-based Aerosol Optical Depth (AOD) to identify dust events and quantify particulate matter (PM) exposure, respectively. Exacerbation events were modeled with respect to location- and time-lagged dust and PM exposures, using multivariate logistic regressions. Measurements and main results: Dust duration and intensity increased yearly during the study period. During dust events, AOD increased by 51% and particulate matter ≤2.5 µm in aerodynamic diameter (PM_2.5) increased by 25%. Adjusting for confounders, ambient temperature and local PM_2.5 exposure, one-day lagged dust exposure was associated with 4.9 times higher odds of two or more (2+ hereto after) AECOPD events (odds ratio = 4.9; 95% CI = 1.8–13.4; p < 0.001). Ambient temperature exposure also showed a significant association with 2+ and 3+ AECOPD events. The risk of AECOPD lasted up to 15 days after dust exposure, declining from 10× higher on day 0 to 20% higher on day 15. Conclusions: Saharan dust outbreaks observed in Miami elevate the concentration of PM and increase the risk of AECOPD in COPD patients with recurring exacerbations.

Ambient air pollution and its influence on human health and welfare: an overview

Human health is closely related to his environment. The influence of exposure to air pollutants on human health and well-being has been an interesting subject and gained much volume of research over the last 50 years. In general, polluted air is considered one of the major factors leading to many diseases such as cardiovascular and respiratory disease and lung cancer for the people. Besides, air pollution adversely affects the animals and deteriorates the plant environment. The overarching objective of this review is to explore the previous researches regarding the causes and sources of air pollution, how to control it and its detrimental effects on human health. The definition of air pollution and its sources were introduced extensively. Major air pollutants and their noxious effects were detailed. Detrimental impacts of air pollution on human health and well-being were also presented.

Relationship between air pollution and hospitalizations for congestive heart failure in elderly people in the city of São Paulo

To evaluate the effects of air pollutants on hospitalizations of elderly people for congestive heart failure (CHF) in the city of São Paulo, stratified by sex, exploring lag structures, from 2000 to 2013. Ecological time series study using information on hospitalization of elderly patients for CHF (ICD-10th: I50) obtained from DATASUS for the city of São Paulo. Information on O₃, PM₁₀, NO₂, SO₂, CO, temperature and humidity was obtained from CETESB. Descriptive analyses, Pearson correlation, and generalized linear Poisson regression model were applied to estimate the effects of pollutants. The interquartile variations of O₃ (52.45 μg/m³), PM₁₀ (24.28 μg/m³), NO₂ (7.63 μg/m³), SO₂ (50.22 μg/m³), and CO (1.28 ppm) were associated with increased hospitalizations for CHF. Air pollutants continue to be a factor that contributes to the increase in the number of hospitalizations due to CHF.

Au W, Zhao W, Xia ZL. A Systematic Review and Meta-Analysis of Short-Term Ambient Ozone Exposure and COPD Hospitalizations

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death globally and ozone exposure is a main cause of its disease burden. However, studies on COPD hospitalizations from short-term ambient level ozone exposure have not generated consensus results. To address the knowledge gap, comprehensive and systematic searches in several databases were conducted using specific keywords for publications up to February 14, 2020. Random-effect models were used to derive overall excess risk estimates between short-term ambient-level ozone exposure and COPD hospitalizations. The influence analyses were used to test the robustness of the results. Both meta-regression and subgroup analyses were used to explore the sources of heterogeneity and potential modifying factors. Based on the results from 26 eligible studies, the random-effect model analyses show that a 10 µg/m³ increase in maximum 8-h ozone concentration was associated with 0.84% (95% CI: 0.09%, 1.59%) higher COPD hospitalizations. The estimates were higher for warm season and multiple-day lag but lower for old populations. Results from subgroup analyses also indicate a multiple-day lag trend and bigger significant health effects during longer day intervals. Although characteristics of individual studies added modest heterogeneity to the overall estimates, the results remained robust during further analyses and exhibited no evidence of publication bias. Our systematic review and meta-analysis indicate that short-term ambient level ozone exposure was associated with increased risk of COPD hospitalizations. The significant association with multiple-day lag trend indicates that a multiple-day exposure metric should be considered for establishing ambient ozone quality and exposure standards for improvement of population health. Future investigations and meta-analysis studies should include clinical studies as well as more careful lag selection protocol.

Associations of Ambient Air Pollutant Concentrations With Respiratory Symptoms and Perceived Health Status in Japanese Adults With and Without Chronic Respiratory Diseases: A Panel Study

Objectives

In recent years, transboundary air pollution from mainland East Asia has led to growing concerns about air pollution in Japan. Air pollution is reportedly associated with the exacerbation of respiratory diseases. In this study, we assessed the effects of air pollution on respiratory symptoms and the health status of participants with and without chronic respiratory diseases.

Methods

Participants (n=2753) with and without chronic respiratory diseases who visited healthcare facilities in Japan during February from 2010 to 2015 filled out a self-report questionnaire regarding their symptoms and perceived health status. Participants were followed up during April-May and June-July.

Results

Oxidant concentrations were associated with respiratory symptoms, overall health, and quality of life (QoL). Suspended particulate matter (SPM) and particulate matter <2.5 μm levels were associated with physical fitness; SPM was also associated with QoL. Recent experience of an Asian sand dust event had a significant effect on allergic symptoms, change in health, and QoL.

Conclusions

Respiratory symptoms were more strongly affected by oxidants than by other pollutants. Significant associations of air pollutants were found with a comprehensive range of items related to perceived health status, including overall health and QoL. Although the effects of air pollutants on respiratory symptoms and health status were more apparent among patients with respiratory diseases, the adverse effects of air pollutants were significant even among participants without such conditions.

Associations between short-term exposure to gaseous pollutants and pulmonary heart disease-related mortality among elderly people in Chengdu, China

BACKGROUND

Pulmonary heart disease (PHD) has become a global burden, especially in low- and middle-income countries. However, very few studies have assessed the influence of air pollution on PHD. This is the first study to explore the association between gaseous pollutants and PHD-related mortality in the central Sichuan Basin of southwestern China.

METHODS

Data on PHD-related mortality among elderly people (aged 60 and older) from 2013 to 2017 were collected from the Population Death Information Registration and Management System (PDIRMS). Data on air pollutants were collected from all 24 Municipal Environmental Monitoring Sites in Chengdu, and data on daily temperature, relative humidity, and atmospheric pressure were collected from the Chengdu Municipal Meteorological Bureau. An epidemiological design of time-stratified case-crossover was conducted to assess the association between short-term exposure to ambient gaseous pollutants and PHD-related mortality among elderly people.

RESULTS

About 54,920 PHD-related deaths among people aged 60 and older were reported. After controlling for daily temperature, relative humidity, and atmospheric pressure, an IQR concentration increase in levels of sulfur dioxide (SO₂) (13 μg/m³), nitrogen dioxide (NO₂) (17 μg/m³), and ozone (O₃) (74 μg/m³) was associated with 7.8, 6.2, and 5.5% increases in PHD-related mortality in people aged 60 and older, respectively. People over age 70 might have even higher susceptibility to PHD-related mortality associated with SO₂, NO₂, and O₃. Females and individuals with alternative marital statuses (widowed, divorced, or never married) had twice and more than twice the PHD-related mortality risk associated with SO₂ and NO₂ than males and married individuals, respectively.

CONCLUSIONS

Increased concentrations of ambient SO₂, NO₂, and O₃ were significantly and positively associated with PHD-related mortality in Chengdu, China. Sociodemographic factors - including gender, age, and marital status - may modify the acute health effects of gaseous pollutants.

Ambient carbon monoxide and increased risk of daily hospital outpatient visits for respiratory diseases in Dongguan, China

BACKGROUND

The toxicity of high-concentration carbon monoxide (CO) on human health has previously been documented. However, the epidemiological evidence on the association between acute exposure to ambient CO and respiratory diseases is relatively lacking and controversial.

OBJECTIVES

To examine the short-term association between ambient CO and hospital outpatient visits for respiratory diseases in Dongguan, China.

METHODS

The number of daily hospital outpatient visits for respiratory diseases, and air pollution and meteorological data were collected from January 2013 to August 2017. A generalized additive model with a quasi-Poisson link was used to estimate the association between ambient CO concentration and the total number of hospital outpatient visits for all respiratory diseases and those for asthma, bronchiectasis, chronic obstructive pulmonary disease (COPD) and pneumonia. We further analyzed the effect of ambient CO by gender and age.

RESULTS

Over the study period, a 24-h mean concentration of ambient CO of 0.88 mg/m³ (below the limit for CO in China) and a total of 89,484 hospital outpatient visits for respiratory diseases were recorded. Ambient CO was found to increase the risk for asthma, bronchiectasis, pneumonia and the total number of respiratory diseases. The per interquartile range (IQR) increase in ambient CO at lag₀₃ day corresponded to a 5.62% (95% confidence interval (CI): 3.24%, 8.05%), 8.86% (95% CI: 4.89%, 12.98%), 6.67% (95% CI: 0.87%, 12.81%) and 7.20% (95% CI: 2.35%, 12.29%) increased risk in outpatient visits for all respiratory diseases, asthma, bronchiectasis and pneumonia, respectively. Each association was partially weakened after adjusting for co-pollutants. The effect of ambient CO on respiratory diseases appeared to be greater for females and the elderly.

CONCLUSIONS

Short-term exposure to ambient CO was associated with increased risk of outpatient visits for respiratory diseases. Our analysis may help to understand the health effects of low-levels of CO and provide evidence for the creation of air quality standards.

The impact of ambient particulate matter on hospital outpatient visits for respiratory and circulatory system disease in an urban Chinese population

There are limited evidence on the association between short-term exposure to ambient particulate matter (PM) and overall hospital outpatient visits for respiratory system disease (RESD) and cardio-cerebrovascular system disease (CCD) in high-polluted countries like China. Though previous epidemiological studies of RESD and CCD generally applied a linear relationship of the acute PM effects, it is unclear whether this linear exposure-response relationship holds in high pollution area. In this study, a time-series study during 2013 through 2016 was conducted to investigate 245,442 and 430,486 hospital visits for RESD and CCD respectively from Nanjing city, China. A combination of logistic generalized additive model (GAM) was used to evaluate the exposure-response associations. The results disclosed that a 10 μg/m³ increase in PM_2.5 and PM₁₀ concentration on the current day of exposure (lag 0) was associated with 0.36% (95% CI: -0.02%-0.73%) and 0.33% (0.07%-0.60%) increase in RESD; and 0.42% (0.00%-0.85%) and 0.37% (0.08%-0.67%) increase in CCD. The exposure-response association was approximately linear within 0-150 μg/m³ of PM concentration and non-linear across the full range of exposures. The effects of PM on RESD and CCD were sensitive to additional adjustment for co-pollutants, indicating the health effects of air pollution mixture in Nanjing city. There was no evidence of potential effect modification of RESD and CCD by season (cold and warm), age (5-64, 65-74, ≧75 years) and sex (male and female) groups. Though not statistically significant, the estimated risks in warm season were higher than those in cold season, suggesting potential synergistic effects of ambient PM pollution and temperature on triggering RESD and CCD.

A comprehensive evaluation of the association between ambient air pollution and adverse health outcomes of major organ systems: a systematic review with a worldwide approach

Ambient air pollution is nowadays one of the most crucial contributors to deteriorating health status worldwide. The components of air pollution include PM_2.5 and PM₁₀, NO₂, SO₂, CO, O₃, and organic compounds. They are attributed to several health outcomes, for instance, cardiovascular diseases (CVD), respiratory diseases, birth outcomes, neurologic diseases, and psychiatric diseases. The objective of this study is to evaluate the association between different ambient air pollutants and the above-mentioned health outcomes. In this systematic review, a total of 76 articles was ultimately selected from 2653 articles, through multiple screening steps by the aid of a set of exclusion criteria as non-English articles, indoor air pollution assessment, work-related, occupational and home-attributed pollution, animal studies, tobacco smoking effects, letters to editors, commentaries, animal experiments, reviews, case reports and case series, out of 19,862 published articles through a systematic search in PubMed, Web of Science, and Scopus. Then, the associations between air pollution and different health outcomes were measured as relative risks and odds ratios. The association between air pollutants, PM_2.5 and PM₁₀, NO₂, SO₂, CO, O₃, and VOC with major organ systems health was investigated through the gathered studies. Relative risks and/or odds ratios attributed to each air pollutant/outcome were ultimately reported. In this study, a thorough and comprehensive discussion of all aspects of the contribution of ambient air pollutants in health outcomes was proposed. To our knowledge up to now, there is no such comprehensive outlook on this issue. Growing concerns in concert with air pollution-induced health risks impose a great danger on the life of billions of people worldwide. Should we propose ideas and schemes to reduce ambient air pollutant, there will be dramatic reductions in the prevalence and occurrence of health-threatening conditions.

Spatial patterns and effects of air pollution and meteorological factors on hospitalization for chronic lung diseases in Beijing, China

Chronic obstructive pulmonary disease (COPD), lung cancer (LC) and tuberculosis (TB) are common chronic lung diseases that generate a large disease burden and significant health care resource use in China. The aim of this study was to quantify spatial patterns and effects of air pollution and meteorological factors on hospitalization of COPD, LC and TB in Beijing. Daily counts of hospitalization for 2010 were obtained from the Beijing Urban Employees Basic Medical Insurance (UEBMI) system. Bayesian hierarchical Poisson regression models were applied to identify spatial patterns of hospitalization for COPD, LC and TB at the district level and explore associations with inhalable particulate matter (aerodynamic diameter <10 μm, PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), mean temperature and relative humidity. There were 18,882, 14,295 and 2,940 counts of hospitalizations for COPD, LC and TB respectively, in Beijing in 2010. Clusters of high relative risk were in different locations for the three diseases. The effect of relative humidity on COPD hospitalization was most significant with a relative risk (RR) of 1.070 (95%CI: 1.054, 1.086) per one percent increase. For lung cancer hospitalization, exposure to ambient SO₂ was associated with a RR of 1.034 (95%CI: 1.011, 1.058) per μg m^-3 increase. For tuberculosis, the effect of mean temperature was significant with a RR of 1.107 (95%CI: 1.038, 1.180) per °C increase. Risk factors and spatial patterns were different for hospitalization of non-infectious and infectious chronic lung disease in Beijing. Even over a short time period (one year), associations were apparent with air pollution and meteorological factors.

Cardiorespiratory health effects of gaseous ambient air pollution exposure in low and middle income countries: a systematic review and meta-analysis

BACKGROUND

Lack of research on the effects of gaseous pollutants (nitrogen oxides [NO_x], sulfur dioxide [SO₂], carbon monoxide [CO] and ozone [O₃]) in the ambient environment on health outcomes from within low and middle income countries (LMICs) is leading to reliance on results from studies performed within high income countries (HICs). This systematic review and meta-analysis examines the cardiorespiratory health effects of gaseous pollutants in LMICs exclusively.

METHODS

Systematic searching was carried out and estimates pooled by pollutant, lag and outcome, and presented as excess relative risk per 10 μg/m³ (NO_x, SO₂, O₃) or 1 ppm (CO) increase pollutant. Sub-group analysis was performed examining estimates by specific outcomes, city and co-pollutant adjustment.

RESULTS

Sixty studies met the inclusion criteria, most (44) from the East Asia and Pacific region. A 10 μg/m³ increase in same day NOx was associated with 0.92% (95% CI: 0.44, 1.39), and 0.70% (0.01, 1.40) increases in cardiovascular and respiratory mortality respectively, same day NO_x was not associated with morbidity. Same day sulfur dioxide was associated with 0.73% (0.04, 1.42) and 0.50% (0.01, 1.00) increases in respiratory morbidity and in cardiovascular mortality respectively.

CONCLUSIONS

Acute exposure to gaseous ambient air pollution (AAP) is associated with increases in morbidity and mortality in LMICs, with greatest associations observed for cardiorespiratory mortality.

Association of ambient pollution with inhaler use among patients with COPD: a panel study

BACKGROUND

Studies have linked ambient air pollution to chronic obstructive pulmonary disease (COPD) healthcare encounters. However, the association between air quality and rescue medication use is unknown.

OBJECTIVES

We assessed the role of air pollution exposure for increased short-acting beta-2-agonist (SABA) use in patients with COPD through use of remote monitoring technology.

METHODS

Participants received a portable electronic inhaler sensor to record the date, time and location for SABA use over a 3-month period. Ambient air pollution data and meteorological data were collected from a centrally located federal monitoring station. Mixed-effects Poisson regression was used to examine the association of daily inhaler use with pollutant levels. Four criteria pollutants (PM_2.5, PM₁₀, O₃ and NO₂), two particulate matter species (elemental carbon (EC) and organic carbon), estimated coarse fraction of PM₁₀ (PM_10-2.5) and four multipollutant air quality measures were each examined separately, adjusting for covariates that passed a false discovery rate (FDR) screening.

RESULTS

We enrolled 35 patients with COPD (94.3% male and mean age: 66.5±8.5) with a mean forced expiratory volume in 1 s (FEV₁) % predicted of 44.9+17.2. Participants had a median of 92 observation days (range 52-109). Participants' average SABA inhaler use ranged from 0.4 to 13.1 puffs/day (median 2.8). Controlling for supplemental oxygen use, long-acting anticholinergic use, modified Medical Research Council Dyspnoea Scale and influenza season, an IQR increase in PM₁₀ concentration (8.0 µg/m³) was associated with a 6.6% increase in daily puffs (95% CI 3.5% to 9.9%; FDR <0.001). NO₂ and EC concentration were also significantly associated with inhaler use (3.9% and 2.9% per IQR increase, respectively).

CONCLUSIONS

Exposure to increased ambient air pollution were associated with a significant increase in SABA use for patients with COPD residing in a low-pollution area.

Progesterone attenuates airway remodeling and glucocorticoid resistance in a murine model of exposing to ozone

Airway remodeling is a vital component of chronic obstructive pulmonary disease (COPD). Despite the broad anti-inflammation effects of glucocorticoids, they exhibit relatively little therapeutic benefit in COPD, indicating the accelerating demands of new agents for COPD. We aim to explore the effect of progesterone on airway remodeling in a murine modeling of exposing to ozone and to further examine the potential effect of progesterone on glucocorticoid insensitivity. C57/BL6 mice were exposed to ozone for 12 times over 6 weeks, and were administered with progesterone alone or combined with budesonide (BUD) after each exposure until the 10th week. The peribronchial collagen deposition was measured. The protein levels of MMP8 and MMP9 in bronchoalveolar lavage fluid (BALF) and lungs were assessed. Western blot analysis was used to detect the levels of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), a-smooth muscle actin (α-SMA), glycogen synthase kinase-3β (GSK-3β). The expression of VEGF and histone deacetylase 2 (HDAC2) in the lung were determined by Immunohistochemical analyses. We observe that progesterone attenuates the peribronchial collagen deposition, as well as the expression of MMP8, MMP9, HIF-1α, VEGF, α-SMA, and GSK-3β in BALF or lung tissues. Progesterone or BUD monotherapy has no effect on HDAC2 production. Progesterone combines with BUD induce dramatically enhanced effects. Thus, these results demonstrate novel roles of progesterone for the pathogenesis and airway remodeling in COPD. Progesterone plus BUD administration exerts more significant inhibition on airway remodeling with dose-independent. Additionally, progesterone may, to some extent, improve the glucocorticoid insensitivity.

Patterns and management of chronic obstructive pulmonary disease in urban and rural China: a community-based survey of 25 000 adults across 10 regions

Introduction

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide, with COPD deaths in China accounting for one-third of all such deaths. However, there is limited available evidence on the management of COPD in China.

Methods

A random sample of 25 011 participants in the China Kadoorie Biobank, aged 38–87 years, from 10 regions in China was surveyed in 2013–2014. Data were collected using interviewer-administered questionnaires on the diagnosis (‘doctor-diagnosed’ or ‘symptoms-based’) and management of COPD (including use of medication and other healthcare resources), awareness of diagnosis and severity of symptoms in COPD cases.

Results

Overall, 6.3% of the study population were identified as COPD cases (doctor-diagnosed cases: 4.8% and symptom-based cases: 2.4%). The proportion having COPD was higher in men than in women (7.9% vs 5.3%) and varied by about threefold (3.7%–10.0%) across the 10 regions. Among those with COPD, 54% sought medical advice during the last 12 months, but <10% reported having received treatment for COPD. The rates of hospitalisation for COPD, use of oxygen therapy at home and influenza or pneumococcal vaccinations in the previous year were 15%, 3% and 4%, respectively. Of those with COPD, half had moderate or severe respiratory symptoms, and over 80% had limited understanding of their disease and need for treatment.

Conclusion

Despite a high prevalence of COPD in China and its substantial impact on activities of daily living, knowledge about COPD and its management were limited.

A review of the experimental evidence on the toxicokinetics of carbon monoxide: the potential role of pathophysiology among susceptible groups

BACKGROUND

Acute high level carbon monoxide (CO) exposure can cause immediate cardio-respiratory arrest in anyone, but the effects of lower level exposures in susceptible persons are less well known. The percentage of CO-bound hemoglobin in blood (carboxyhemoglobin; COHb) is a marker of exposure and potential health outcomes. Indoor air quality guidelines developed by the World Health Organization and Health Canada, among others, are set so that CO exposure does not lead to COHb levels above 2.0%, a target based on experimental evidence on toxicodynamic relationships between COHb and cardiac performance among persons with cardiovascular disease (CVD). The guidelines do not consider the role of pathophysiological influences on toxicokinetic relationships. Physiological deficits that contribute to increased CO uptake, decreased CO elimination, and increased COHb formation can alter relationships between CO exposures and resulting COHb levels, and consequently, the severity of outcomes. Following three fatalities attributed to CO in a long-term care facility (LTCF), we queried whether pathologies other than CVD could alter CO-COHb relationships. Our primary objective was to inform susceptibility-specific modeling that accounts for physiological deficits that may alter CO-COHb relationships, ultimately to better inform CO management in LTCFs.

METHODS

We reviewed experimental studies investigating relationships between CO, COHb, and outcomes related to health or physiological outcomes among healthy persons, persons with CVD, and six additional physiologically susceptible groups considered relevant to LTCF residents: persons with chronic obstructive pulmonary disease (COPD), anemia, cerebrovascular disease (CBD), heart failure, multiple co-morbidities, and persons of older age (≥ 60 years).

RESULTS

We identified 54 studies published since 1946. Six studies investigated toxicokinetics among healthy persons, and the remaining investigated toxicodynamics, mainly among healthy persons and persons with CVD. We identified one study each of CO dynamics in persons with COPD, anemia and persons of older age, and no studies of persons with CBD, heart failure, or multiple co-morbidities. Considerable heterogeneity existed for exposure scenarios and outcomes investigated.

CONCLUSIONS

Limited experimental human evidence on the effects of physiological deficits relevant to CO kinetics exists to support indoor air CO guidelines. Both experimentation and modeling are needed to assess how physiological deficits influence the CO-COHb relationship, particularly at sub-acute exposures relevant to indoor environments. Such evidence would better inform indoor air quality guidelines and CO management in indoor settings where susceptible groups are housed.

Psychopathological Symptoms under Smog: The Role of Emotion Regulation

Over the past decade, major cities in China have suffered from severe air pollution, which is also known as smog. Despite lay considerations that smog might pose risks for psychopathology, it remains unknown whether it is only linked to affective psychopathology or to a broader range of symptomologies. Moreover, whether individual differences in emotion regulation, a transdiagnostic risk factor for psychopathology, would influence the magnitude of pollution-induced symptoms is not well understood. Using a longitudinal design, the current study measured trait emotion regulation and psychopathological symptoms in a sample of university students at Time 1 (without smog, N = 120) and then reassessed for psychopathology at Time 2 (after acute exposure to smog for 1 week, N = 102). The results showed that participants had higher levels of positive symptom distress, obsessive-compulsive symptoms, interpersonal sensitivity, depression, and psychoticism at Time 2. Moreover, reappraisal is negatively associated with smog-induced elevations in psychopathological symptoms only when participants rely heavily on suppression. We discuss the implications of this investigation for both intervention efforts and future work on the contextual factors surrounding the deployment of emotion regulation strategies.

Climate Change and Respiratory Infections

The rate of global warming has accelerated over the past 50 years. Increasing surface temperature is melting glaciers and raising the sea level. More flooding, droughts, hurricanes, and heat waves are being reported. Accelerated changes in climate are already affecting human health, in part by altering the epidemiology of climate-sensitive pathogens. In particular, climate change may alter the incidence and severity of respiratory infections by affecting vectors and host immune responses. Certain respiratory infections, such as avian influenza and coccidioidomycosis, are occurring in locations previously unaffected, apparently because of global warming. Young children and older adults appear to be particularly vulnerable to rapid fluctuations in ambient temperature. For example, an increase in the incidence in childhood pneumonia in Australia has been associated with sharp temperature drops from one day to the next. Extreme weather events, such as heat waves, floods, major storms, drought, and wildfires, are also believed to change the incidence of respiratory infections. An outbreak of aspergillosis among Japanese survivors of the 2011 tsunami is one such well-documented example. Changes in temperature, precipitation, relative humidity, and air pollution influence viral activity and transmission. For example, in early 2000, an outbreak of Hantavirus respiratory disease was linked to a local increase in the rodent population, which in turn was attributed to a two- to threefold increase in rainfall before the outbreak. Climate-sensitive respiratory pathogens present challenges to respiratory health that may be far greater in the foreseeable future.

Influence of Gaseous Pollutants on COPD Exacerbations in Patients with Cardiovascular Comorbidities

Exacerbations of chronic obstructive pulmonary disease (COPD) are a serious public health issue. Ambient pollution and meteorological factors are considered among precipitating factors. There are few data concerning the impact of ambient pollutants other than particulates on COPD exacerbations. Among gaseous pollutants four main groups of substances are primarily monitored: nitrogen oxides (NOx), sulphur dioxide (SO₂), carbon monoxide (CO), and ozone (O₃). In this study, 12,889 hospitalizations in the years 2006-2014 due to exacerbations of COPD in patients having a co-existing cardiovascular pathology were retrospectively analyzed. Cardiovascular disease was ruled out as the underlying reason of hospitalization. Data concerning the then accompanying gaseous pollutants and weather conditions were collected. The findings were that the impact of SO₂ content was significantly associated with the relative risk (RR) of COPD exacerbation when the exposure took place at least 30 days or longer before hospital admission (RR 1.04-1.05; p < 0.05). In contrast, risk of COPD exacerbation rose when a shortening of the time lag between exposure to NOx and hospital admission was considered (RR 1.02-1.04; p < 0.05). O₃ exposure was associated with a lower risk irrespective of the length of exposure/exacerbation lag (RR 0.77-0.90; p < 0.05). There were insignificant associations observed for CO. In conclusion, the study demonstrates a salient influence of a co-existing cardiovascular malady on the appearance of COPD-related respiratory exacerbations when the pollutant SO₂ and NOx contents rose. In contrast, higher O₃ content was associated with a lower risk of COPD exacerbation.

Cardiorespiratory health effects of particulate ambient air pollution exposure in low-income and middle-income countries: a systematic review and meta-analysis

BACKGROUND

Most prospective studies on the health effects of particulate ambient air pollution exposure have focused on high-income countries, which have much lower pollutant concentrations than low-income and middle-income countries (LMICs) and different sources of pollution. We aimed to investigate the cardiorespiratory health effects of particulate ambient air pollution exposure in LMICs exclusively.

METHODS

For this systematic review and meta-analysis, we searched PubMed, Web of Science, Embase, LILACS, Global Health, and Proquest for studies published between database inception and Nov 28, 2016, investigating the cardiorespiratory health effects of particulate ambient air pollution exposure in LMICs. Data were extracted from published studies by one author, and then checked and verified by all authors independently. We pooled estimates by pollutant type (particulate matter with a diameter of <2·5 μm [PM_2·5] or 2·5-10 μm [PM₁₀]), lag, and outcome, and presented them as excess relative risk per 10 μg/m³ increase in particulate ambient air pollution. We used a random-effects model to derive overall excess risk. The study protocol is registered with PROSPERO, number CRD42016051733.

FINDINGS

Of 1553 studies identified, 91 met the full eligibility criteria. Only four long-term exposure studies from China were identified and not included in the meta-analysis. A 10 μg/m³ increase in same-day PM_2·5 was associated with a 0·47% (95% CI 0·34-0·61) increase in cardiovascular mortality and a 0·57% (0·28-0·86) increase in respiratory mortality. A 10 μg/m³ increase in same-day PM₁₀ was associated with a 0·27% (0·11-0·44) increase in cardiovascular mortality and a 0·56% (0·24-0·87) increase in respiratory mortality.

INTERPRETATION

Short-term exposure to particulate ambient air pollution is associated with increases in cardiorespiratory morbidity and mortality in LMIC's, with apparent regional-specific variations.

FUNDING

None.

Global Associations between Air Pollutants and Chronic Obstructive Pulmonary Disease Hospitalizations. A Systematic Review

RATIONALE

Exacerbations are key events in chronic obstructive pulmonary disease (COPD), affecting lung function decline and quality of life. The effect of exposure to different air pollutants on COPD exacerbations is not clear.

OBJECTIVES

To carry out a systematic review, examining associations between air pollutants and hospital admissions for COPD exacerbations.

METHODS

MEDLINE, Embase, BIOSIS, Science Citation Index, and the Air Pollution Epidemiology Database were searched for publications published between 1980 and September 2015. Inclusion criteria were focused on studies presenting solely a COPD outcome defined by hospital admissions and a measure of gaseous air pollutants and particle fractions. The association between each pollutant and COPD admissions was investigated in metaanalyses using random effects models. Analyses were stratified by geographical clusters for investigation of the consistency of the evidence worldwide.

MEASUREMENTS AND MAIN RESULTS

Forty-six studies were included, and results for all the pollutants under investigation showed marginal positive associations; however, the number of included studies was small, the studies had high heterogeneity, and there was evidence of small-study bias. Geographical clustering of the effects of pollution on COPD hospital admissions was evident and reduced heterogeneity significantly.

CONCLUSIONS

The most consistent association was between a 1-mg/m³ increase in carbon monoxide level and COPD-related admissions (odds ratio, 1.02; 95% confidence interval, 1.01-1.03). The heterogeneity was moderate, and there was a consistent positive association in both Europe and North America, although levels were clearly below World Health Organization guideline values. There is mixed evidence on the effects of environmental pollution on COPD exacerbations. Limitations of previous studies included the low spatiotemporal resolution of pollutants, inadequate control for confounding factors, and the use of aggregated health data that ignored personal characteristics. The need for more targeted exposure estimates in a large number of geographical locations is evident.

Progression from Asthma to Chronic Obstructive Pulmonary Disease. Is Air Pollution a Risk Factor?

RATIONALE

Individuals with asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS), have more rapid decline in lung function, more frequent exacerbations, and poorer quality of life than those with asthma or COPD alone. Air pollution exposure is a known risk factor for asthma and COPD; however, its role in ACOS is not as well understood.

OBJECTIVES

To determine if individuals with asthma exposed to higher levels of air pollution have an increased risk of ACOS.

METHODS

Individuals who resided in Ontario, Canada, aged 18 years or older in 1996 with incident asthma between 1996 and 2009 who participated in the Canadian Community Health Survey were identified and followed until 2014 to determine the development of ACOS. Data on exposures to fine particulate matter (PM2.5) and ozone (O3) were obtained from fixed monitoring sites. Associations between air pollutants and ACOS were evaluated using Cox regression models.

MEASUREMENTS AND MAIN RESULTS

Of the 6,040 adults with incident asthma who completed the Canadian Community Health Survey, 630 were identified as ACOS cases. Compared with those without ACOS, the ACOS population had later onset of asthma, higher proportion of mortality, and more frequent emergency department visits before COPD diagnosis. The adjusted hazard ratios of ACOS and cumulative exposures to PM2.5 (per 10 μg/m(3)) and O3 (per 10 ppb) were 2.78 (95% confidence interval, 1.62-4.78) and 1.31 (95% confidence interval, 0.71-2.39), respectively.

CONCLUSIONS

Individuals exposed to higher levels of air pollution had nearly threefold greater odds of developing ACOS. Minimizing exposure to high levels of air pollution may decrease the risk of ACOS.

Urban air pollution and meteorological factors affect emergency department visits of elderly patients with chronic obstructive pulmonary disease in Taiwan

Both air pollution and meteorological factors in metropolitan areas increased emergency department (ED) visits from people with chronic obstructive pulmonary disease (COPD). Few studies investigated the associations between air pollution, meteorological factors, and COPD-related health disorders in Asian countries. This study aimed to investigate the relationship between the environmental factors and COPD-associated ED visits of susceptible elderly population in the largest Taiwanese metropolitan area (Taipei area, including Taipei city and New Taipei city) between 2000 and 2013. Data of air pollutant concentrations (PM₁₀, PM_2.5, O₃, SO₂, NO₂ and CO), meteorological factors (daily temperature, relative humidity and air pressure), and daily COPD-associated ED visits were collected from Taiwan Environmental Protection Administration air monitoring stations, Central Weather Bureau stations, and the Taiwan National Health Insurance database in Taipei area. We used a case-crossover study design and conditional logistic regression models with odds ratios (ORs), and 95% confidence intervals (CIs) for evaluating the associations between the environmental factors and COPD-associated ED visits. Analyses showed that PM_2.5, O₃, and SO₂ had significantly greater lag effects (the lag was 4 days for PM_2.5, and 5 days for O₃ and SO₂) on COPD-associated ED visits of the elderly population (65-79 years old). In warmer days, a significantly greater effect on elderly COPD-associated ED visits was estimated for PM_2.5 with coexistence of O₃. Additionally, either O₃ or SO₂ combined with other air pollutants increased the risk of elderly COPD-associated ED visits in the days of high relative humidity and air pressure difference, respectively. This study showed that joint effect of urban air pollution and meteorological factors contributed to the COPD-associated ED visits of the susceptible elderly population in the largest metropolitan area in Taiwan. Government authorities should review existing air pollution policies, and strengthen health education propaganda to ensure the health of the susceptible elderly population.

Assessment of Air Pollutant Concentrations Near Major Roads in Residential, Commercial and Industrial Areas in Ibadan City, Nigeria

BACKGROUND

Urbanization, energy consumption, intensification of road traffic and rapid population growth pose significant challenges to ambient air quality. Therefore, regular monitoring of current air quality is essential.

OBJECTIVES

The study investigated the concentration of sulfur dioxide (SO₂), oxides of nitrogen (NOx), ozone (O₃), ammonia (NH₃) and carbon monoxide (CO) in ten different sites to investigate possible anthropogenic sources within Ibadan, Nigeria.

METHODS

Air samples were collected into specific absorbing solutions twice daily in the morning and afternoon for four weeks. The resulting solutions were analyzed following specific colorimetric techniques according to standard methods of analysis.

RESULTS

Average concentrations varied among the sampling areas. All were above background levels obtained at the control site. Overall concentrations were found to be 30±19 μg/m³ (SO₂), 63±16 μg/m³ (NOx), 31±18 μg/m³ (O₃), 463±180 μg/m³ (NH₃) and 0.59±0.21 ppm (CO). These concentrations were present at the study areas at 15, 31, 17, 5 and 3 times the background concentrations for SO₂, NOx, O₃, NH₃ and CO, respectively.

CONCLUSIONS

In spite of the short duration of sampling, the data can guide future long term monitoring of air quality in Nigeria. The level of SO₂ exceeded World Health Organization limits within this short duration. This is an indication of the need for long term air quality monitoring with a sustainable plan for air pollution management.

Seven-day cumulative effects of air pollutants increase respiratory ER visits up to threefold

OBJECTIVE

Children are especially vulnerable to respiratory injury induced by exposure to air pollutants. In the present study, we investigate periods of up to 7 days, and evaluate the lagged effects of exposure to air pollutants on the daily number of children and adolescents visiting the emergency room (ER) for the treatment of lower respiratory obstructive diseases (LROD), in the city of São Paulo, Brazil.

METHODS

Daily records of LROD-related ER visits by children and adolescents under the age of 19, from January 2000 to December 2007 (2,922 days) were included in the study. Time-series regression models (generalized linear Poisson) were used to control for short- and long-term trends, as well as for temperature and relative humidity. Third-degree polynomial lag models were used to estimate both lag structures and the cumulative effects of air pollutants. Effects of air pollutants were expressed as the percentage increase in LROD-related ER visits.

RESULTS

We observed an acute effect at the same day of exposure to air pollutants; however, the cumulative effects of air pollutants on the number of LROD-related ER visits was almost threefold greater than the one observed at the same day of exposure to PM₁₀ , SO₂ , and NO₂ mainly in children aged 5 years and under. The 7-day cumulative effect of SO₂ reached 11.0% (95% CI: 5.0-16.7) increase in visits. Conclusion and Relevance: This study highlights the effects of intermediate-term exposure to air pollutants on LROD in children. Pediatr Pulmonol. 2017;52:205-212. © 2016 Wiley Periodicals, Inc.

Diesel exhaust alters the response of cultured primary bronchial epithelial cells from patients with chronic obstructive pulmonary disease (COPD) to non-typeable Haemophilus influenzae

BACKGROUND

Exacerbations constitute a major cause of morbidity and mortality in patients suffering from chronic obstructive pulmonary disease (COPD). Both bacterial infections, such as those with non-typeable Haemophilus influenzae (NTHi), and exposures to diesel engine emissions are known to contribute to exacerbations in COPD patients. However, the effect of diesel exhaust (DE) exposure on the epithelial response to microbial stimulation is incompletely understood, and possible differences in the response to DE of epithelial cells from COPD patients and controls have not been studied.

METHODS

Primary bronchial epithelial cells (PBEC) were obtained from age-matched COPD patients (n = 7) and controls (n = 5). PBEC were cultured at the air-liquid interface (ALI) to achieve mucociliary differentiation. ALI-PBECs were apically exposed for 1 h to a stream of freshly generated whole DE or air. Exposure was followed by 3 h incubation in presence or absence of UV-inactivated NTHi before analysis of epithelial gene expression.

RESULTS

DE alone induced an increase in markers of oxidative stress (HMOX1, 50-100-fold) and of the integrated stress response (CHOP, 1.5-2-fold and GADD34, 1.5-fold) in cells from both COPD patients and controls. Exposure of COPD cultures to DE followed by NTHi caused an additive increase in GADD34 expression (up to 3-fold). Importantly, DE caused an inhibition of the NTHi-induced expression of the antimicrobial peptide S100A7, and of the chaperone protein HSP5A/BiP.

CONCLUSIONS

Our findings show that DE exposure of differentiated primary airway epithelial cells causes activation of the gene expression of HMOX1 and markers of integrated stress response to a similar extent in cells from COPD donors and controls. Furthermore, DE further increased the NTHi-induced expression of GADD34, indicating a possible enhancement of the integrated stress response. DE reduced the NTHi-induced expression of S100A7. These data suggest that DE exposure may cause adverse health effects in part by decreasing host defense against infection and by modulating stress responses.

Major air pollutants and risk of COPD exacerbations: a systematic review and meta-analysis

Background

Short-term exposure to major air pollutants (O₃, CO, NO₂, SO₂, PM₁₀, and PM_2.5) has been associated with respiratory risk. However, evidence on the risk of chronic obstructive pulmonary disease (COPD) exacerbations is still limited. The present study aimed at evaluating the associations between short-term exposure to major air pollutants and the risk of COPD exacerbations.

Methods

After a systematic search up until March 30, 2016, in both English and Chinese electronic databases such as PubMed, EMBASE, and CNKI, the pooled relative risks and 95% confidence intervals were estimated by using the random-effects model. In addition, the population-attributable fractions (PAFs) were also calculated, and a subgroup analysis was conducted. Heterogeneity was assessed by I².

Results

In total, 59 studies were included. In the single-pollutant model, the risks of COPD were calculated by each 10 μg/m³ increase in pollutant concentrations, with the exception of CO (100 μg/m³). There was a significant association between short-term exposure and COPD exacerbation risk for all the gaseous and particulate pollutants. The associations were strongest at lag0 and lag3 for gaseous and particulate air pollutants, respectively. The subgroup analysis not only further confirmed the overall adverse effects but also reduced the heterogeneities obviously. When 100% exposure was assumed, PAFs ranged from 0.60% to 4.31%, depending on the pollutants. The adverse health effects of SO₂ and NO₂ exposure were more significant in low-/middle-income countries than in high-income countries: SO₂, relative risk: 1.012 (95% confidence interval: 1.001, 1.023); and NO₂, relative risk: 1.019 (95% confidence interval: 1.014, 1.024).

Conclusion

Short-term exposure to air pollutants increases the burden of risk of COPD acute exacerbations significantly. Controlling ambient air pollution would provide benefits to COPD patients.

Pulmonary Function and Incidence of Selected Respiratory Diseases Depending on the Exposure to Ambient PM10

It is essential in pulmonary disease research to take into account traffic-related air pollutant exposure among urban inhabitants. In our study, 4985 people were examined for spirometric parameters in the presented research which was conducted in the years 2008–2012. The research group was divided into urban and rural residents. Traffic density, traffic structure and velocity, as well as concentrations of selected air pollutants (CO, NO₂ and PM₁₀) were measured at selected areas. Among people who live in the city, lower percentages of predicted values of spirometric parameters were noticed in comparison to residents of rural areas. Taking into account that the difference in the five-year mean concentration of PM₁₀ in the considered city and rural areas was over 17 μg/m³, each increase of PM₁₀ by 10 μg/m³ is associated with the decline in FEV₁ (forced expiratory volume during the first second of expiration) by 1.68%. These findings demonstrate that traffic-related air pollutants may have a significant influence on the decline of pulmonary function and the growing rate of respiratory diseases.

Outdoor Air Pollution and COPD-Related Emergency Department Visits, Hospital Admissions, and Mortality: A Meta-Analysis

A systematic literature review was performed to identify all peer-reviewed literature quantifying the association between short-term exposures of particulate matter <2.5 microns (PM_2.5), nitrogen dioxide (NO₂), and sulfur dioxide (SO₂) and COPD-related emergency department (ED) visits, hospital admissions (HA), and mortality. These results were then pooled for each pollutant through meta-analyses with a random effects model. Subgroup meta-analyses were explored to study the effects of selected lag/averaging times and health outcomes. A total of 37 studies satisfied our inclusion criteria, contributing to a total of approximately 1,115,000 COPD-related acute events (950,000 HAs, 80,000 EDs, and 130,000 deaths) to our meta-estimates. An increase in PM_2.5 of 10 ug/m³ was associated with a 2.5% (95% CI: 1.6-3.4%) increased risk of COPD-related ED and HA, an increase of 10 ug/m³ in NO₂ was associated with a 4.2% (2.5-6.0%) increase, and an increase of 10 ug/m³ in SO₂ was associated with a 2.1% (0.7-3.5%) increase. The strength of these pooled effect estimates, however, varied depending on the selected lag/averaging time between exposure and outcome. Similar pooled effects were estimated for each pollutant and COPD-related mortality. These results suggest an ongoing threat to the health of COPD patients from both outdoor particulates and gaseous pollutants. Ambient outdoor concentrations of PM_2.5, NO₂, and SO₂ were significantly and positively associated with both COPD-related morbidity and mortality.

Direct cost saving potential in medication costs due to a reduction in outdoor air pollution for the Brussels Capital Region

INTRODUCTION

The adverse health effects of exposure to air pollution have been well-established and include mortality, hospital admissions, emergency department visits, etc, but also less severe outcomes such as medication use and purchase. The economic impact, an additional motivator for policy, has been studied primarily for the more severe outcomes.

METHODS

Purchase data of reimbursed medications typically prescribed for asthma and chronic obstructive pulmonary disease, were obtained through the mandatory Belgian health insurance system. A time series analyses approach was used to model daily sales on daily air pollution concentrations (NO2, PM10 and PM2.5) for residents of the Brussels Capital Region as a whole. In addition, a higher geographical resolution of both sales and pollutant concentrations allowed for a multi-sector approach. Annual savings were estimated for the scenario of a 10% reduction in each of the pollutants.

RESULTS

Medication purchase was significantly associated with NO2 concentrations, leading to an annual cost saving potential of € 107,845 [95%CI: € 71,483-€ 143,823] in R03 sales (WHO classification for drugs of obstructive airway diseases). Saving potentials of PM10 and PM2.5 were not significant. Estimates were not sensitive to the geographical resolution, however, higher precision can be obtained with higher resolution data, subject to the condition that the number of sales is sufficiently large.

A Time-Stratified Case-Crossover Study of Ambient Ozone Exposure and Emergency Department Visits for Specific Respiratory Diagnoses in California (2005-2008)

BACKGROUND

Studies have explored ozone's connection to asthma and total respiratory emergency department visits (EDVs) but have neglected other specific respiratory diagnoses despite hypotheses relating ozone to respiratory infections and allergic responses.

OBJECTIVE

We examined relationships between ozone and EDVs for respiratory visits, including specifically acute respiratory infections (ARI), asthma, pneumonia, chronic obstructive pulmonary disease (COPD), and upper respiratory tract inflammation (URTI).

METHODS

We conducted a multi-site time-stratified case-crossover study of ozone exposures for approximately 3.7 million respiratory EDVs from 2005 through 2008 among California residents living within 20 km of an ozone monitor. Conditional logistic regression was used to estimate associations by climate zone. Random effects meta-analysis was then applied to estimate pooled excess risks (ER). Effect modification by season, distance from the monitor and individual demographic characteristics (i.e., age, race/ethnicity, sex, and payment method), and confounding by other gaseous air pollutants were also investigated. Meta-regression was utilized to explore how climate zone-level meteorological, demographic, and regional differences influenced estimates.

RESULTS

We observed ozone-associated increases in all respiratory, asthma, and ARI visits, which were slightly larger in the warm season [asthma ER per 10-ppb increase in mean of same and previous 3 days ozone exposure (lag03) = 2.7%, 95% CI: 1.5, 3.9; ARI ERlag03 = 1.4%, 95% CI: 0.8, 1.9]. EDVs for pneumonia, COPD, and URTI were also significantly associated with ozone exposure over the whole year, but typically more consistently so during the warm season.

CONCLUSIONS

Short-term ozone exposures among California residents living near an ozone monitor were positively associated with EDVs for asthma, ARI, pneumonia, COPD, and URTI from 2005 through 2008. Those associations were typically larger and more consistent during the warm season. Our findings suggest that these outcomes should be considered when evaluating the potential health benefits of reducing ozone concentrations.

CITATION

Malig BJ, Pearson DL, Chang YB, Broadwin R, Basu R, Green RS, Ostro B. 2016. A time-stratified case-crossover study of ambient ozone exposure and emergency department visits for specific respiratory diagnoses in California (2005-2008). Environ Health Perspect 124:745-753; http://dx.doi.org/10.1289/ehp.1409495.

Exacerbations of Chronic Obstructive Pulmonary Disease (COPD): An Ecological Study in the Basque Country, Spain (2000-2011)

Chronic obstructive pulmonary disease (COPD) is a prevalent condition in adults aged ≥40 years characterized by progressive airflow limitation associated with chronic inflammatory response to noxious particles in the airways and lungs. Smoking, genetics, air pollution, nutrition and other factors may influence COPD development. Most hospitalizations and deaths for COPD are caused by its acute exacerbations, which greatly affect the health and quality of life of COPD patients and pose a high burden on health services. The aims of this project were to identify trends, geographic patterns and risk factors for COPD exacerbations, as revealed by hospitalizations and deaths, in the Basque Country, Spain, over a period of 12 years (2000-2011). Hospitalization and mortality rates for COPD were 262 and 18 per 100,000 population, respectively, with clusters around the biggest cities. Hospital mortality was 7.4%. Most hospitalized patients were male (77.4%) and accounted for 72.1% of hospital mortality. Hospitalizations decreased during the study period, except for 50-64 year-old women, peaking significantly. Using a multivariate modeling approach it was shown that hospitalizations were positively correlated with increased atmospheric concentrations of NO₂, CO, PM₁₀, and SO₂, and increased influenza incidence, but were negatively associated with increased temperatures and atmospheric O₃ concentration. COPD exacerbations decreased in the Basque Country during 2000-2011, but not among 50-64-year-old women, reflecting the high smoking prevalence among Spanish women during the 1970-1990s. The main metropolitan areas were those with the highest risk for COPD exacerbations, calling attention to the role of heavy car traffic. Influenza virus, cold temperatures, and increased atmospheric NO₂, CO, PM₁₀, and SO₂ (but decreased O₃) concentrations were identified as potential contributors to the burden of COPD exacerbations in the community. These findings are important for both the understanding of the disease process and in providing potential targets for COPD-reducing initiatives and new avenues for research.

Impact of air quality guidelines on COPD sufferers

Background

COPD is one of the leading causes of morbidity and mortality in both high- and low-income countries and a major public health burden worldwide. While cigarette smoking remains the main cause of COPD, outdoor and indoor air pollution are important risk factors to its etiology. Although studies over the last 30 years helped reduce the values, it is not very clear if the current air quality guidelines are adequately protective for COPD sufferers.

Objective

This systematic review was to summarize the up-to-date literature on the impact of air pollution on the COPD sufferers.

Methods

PubMed and Google Scholar were utilized to search for articles related to our study’s focus. Search terms included “COPD exacerbation”, “air pollution”, “air quality guidelines”, “air quality standards”, “COPD morbidity and mortality”, “chronic bronchitis”, and “air pollution control” separately and in combination. We focused on articles from 1990 to 2015. We also used articles prior to 1990 if they contained relevant information. We focused on articles written in English or with an English abstract. We also used the articles in the reference lists of the identified articles.

Results

Both short-term and long-term exposures to outdoor air pollution around the world are associated with the mortality and morbidity of COPD sufferers even at levels below the current air quality guidelines. Biomass cooking in low-income countries was clearly associated with COPD morbidity in adult nonsmoking females.

Conclusion

There is a need to continue to improve the air quality guidelines. A range of intervention measures could be selected at different levels based on countries’ socioeconomic conditions to reduce the air pollution exposure and COPD burden.

The Influence of Asian Dust, Haze, Mist, and Fog on Hospital Visits for Airway Diseases

Background

Asian dust is known to have harmful effects on the respiratory system. Respiratory conditions are also influenced by environmental conditions regardless of the presence of pollutants. The same pollutant can have different effects on the airway when the air is dry compared with when it is humid. We investigated hospital visits for chronic obstructive pulmonary disease (COPD) and asthma in relation to the environmental conditions.

Methods

We conducted a retrospective study using the Korean National Health Insurance Service claims database of patients who visited hospitals in Chuncheon between January 2006 and April 2012. Asian dust, haze, mist, and fog days were determined using reports from the Korea Meteorological Administration. Hospital visits for asthma or COPD on the index days were compared with the comparison days. We used two-way case-crossover techniques with one to two matching.

Results

The mean hospital visits for asthma and COPD were 59.37 ± 34.01 and 10.04 ± 6.18 per day, respectively. Hospital visits for asthma significantly increased at lag0 and lag1 for Asian dust (relative risk [RR], 1.10; 95% confidence interval [CI], 1.01-1.19; p<0.05) and haze (RR, 1.13; 95% CI, 1.06-1.22; p<0.05), but were significantly lower on misty (RR, 0.89; 95% CI, 0.80-0.99; p<0.05) and foggy (RR, 0.89; 95% CI, 0.84-0.93; p<0.05) days than on control days. The hospital visits for COPD also significantly increased on days with Asian dust (RR, 1.29; 95% CI, 1.05-1.59; p<0.05), and were significantly lower at lag4 for foggy days, compared with days without fog (RR, 0.85; 95% CI, 0.75-0.97; p<0.05).

Conclusion

Asian dust showed an association with airway diseases and had effects for several days after the exposure. In contrast to Asian dust, mist and fog, which occur in humid air conditions, showed the opposite effects on airway diseases, after adjusting to the pollutants. It would require more research to investigate the effects of various air conditions on airway diseases.

Occupational and environmental risk factors for chronic rhinosinusitis: a systematic review

BACKGROUND

Chronic rhinosinusitis (CRS) is a prevalent and disabling paranasal sinus disease, with a likely multifactorial etiology potentially including hazardous occupational and environmental exposures. We completed a systematic review of the occupational and environmental literature to evaluate the quality of evidence of the role that hazardous exposures might play in CRS.

METHODS

We searched PubMed for studies of CRS and following exposure categories: occupation, employment, work, industry, air pollution, agriculture, farming, environment, chemicals, roadways, disaster, and traffic. We abstracted information from the final set of articles across 6 primary domains: study design; population; exposures evaluated; exposure assessment; CRS definition; and results.

RESULTS

We identified 41 articles from 1080 manuscripts: 37 occupational risk papers, 1 environmental risk paper, and 3 papers studying both categories of exposures. None of the 41 studies used a CRS definition consistent with current diagnostic guidelines. Exposure assessment was generally dependent on self-report or binary measurements of exposure based on industry of employment. Only grain, dairy, and swine operations among farmers were evaluated by more than 1 study using a common approach to defining CRS, but employment in these settings was not consistently associated with CRS. The multiple other exposures did not meet quality standards for reporting associations or were not evaluated by more than 1 study.

CONCLUSION

The current state of the literature allows us to make very few conclusions about the role of hazardous occupational or environmental exposures in CRS, leaving a critical knowledge gap regarding potentially modifiable risk factors for disease onset and progression.

Novel aspects of pathogenesis and regeneration mechanisms in COPD

Chronic obstructive pulmonary disease (COPD), a major cause of death and morbidity worldwide, is characterized by expiratory airflow limitation that is not fully reversible, deregulated chronic inflammation, and emphysematous destruction of the lungs. Despite the fact that COPD is a steadily growing global healthcare problem, the conventional therapies remain palliative, and regenerative approaches for disease management are not available yet. We aim to provide an overview of key reviews, experimental, and clinical studies addressing lung emphysema development and repair mechanisms published in the past decade. Novel aspects discussed herein include integral revision of the literature focused on lung microflora changes in COPD, autoimmune component of the disease, and environmental risk factors other than cigarette smoke. The time span of studies on COPD, including emphysema, chronic bronchitis, and asthmatic bronchitis, covers almost 200 years, and several crucial mechanisms of COPD pathogenesis are described and studied. However, we still lack the holistic understanding of COPD development and the exact picture of the time-course and interplay of the events during stable, exacerbated, corticosteroid-treated COPD states, and transitions in-between. Several generally recognized mechanisms will be discussed shortly herein, ie, unregulated inflammation, proteolysis/antiproteolysis imbalance, and destroyed repair mechanisms, while novel topics such as deviated microbiota, air pollutants-related damage, and autoimmune process within the lung tissue will be discussed more extensively. Considerable influx of new data from the clinic, in vivo and in vitro studies stimulate to search for novel concise explanation and holistic understanding of COPD nowadays.

Epidemiologia de desfechos na saúde humana relacionados à poluição atmosférica no Brasil: uma revisão sistemática

ResumoO presente artigo revisa e discute aspectos da situação da pesquisa epidemiológica relacionados aos desfechos de saúde decorrentes da poluição atmosférica. Foi realizada uma revisão sistemática de estudos que avaliou os efeitos de poluentes do ar na saúde humana. A qualidade metodológica dos trabalhos também foi avaliada. A revisão identificou 432 estudos que abordaram a temática, dos quais 56 atendem aos critérios de inclusão previamente estabelecidos. Além de evidenciarem um cenário de pesquisa epidemiológica pautado na relação causa-efeito, os resultados apontam para a necessidade de revisão de parâmetros ambientais e expõem desafios e contribuições à pesquisa epidemiológica em saúde ambiental.