Ambient air pollution and emergency department visits for asthma in Erie County, New York 2007-2012

Short-term exposure to fine particulate matter and asthma exacerbation: a large population-based case-crossover study in Southern Thailand

BACKGROUND

Asthma exacerbations remain a significant global health issue despite advances in management. Fine particulate matter (PM2.5, particles ≤ 2.5 μm in diameter) is a known trigger for asthma exacerbations. However, studies on the acute effects of PM2.5, particularly in regions with relatively low pollution levels, are limited. This study examined the time-lagged association between daily PM2.5 exposure and asthma exacerbations in Songkhla province, southern Thailand, where PM2.5 concentrations frequently approach the World Health Organization's (WHO) Global Air Quality Guidelines. Approximately 41% of days during the study period had PM2.5 concentrations below the 2021 Guideline level of 15 µg/m³. Additionally, the province is periodically affected by seasonal transboundary haze from forest fires.

METHODS

A case-crossover study was conducted using daily PM2.5 and meteorological data from January 2010 to December 2023, alongside health records of asthma patients from Songklanagarind Hospital. District-level daily PM2.5 concentrations were estimated through inverse distance weighted interpolation. Conditional logistic regression, incorporating time-lagged models and cubic splines, was applied.

RESULTS

The study included 11,848 case days and 39,810 control days, with a mean daily PM2.5 concentration of 18.2 µg/m³. PM2.5 concentrations > 50 µg/m³ were significantly associated with asthma exacerbations at multiple time lags (lag0, lag2, and lag01 to lag03), with odds ratios ranging from 1.41 to 1.64, compared to the lowest concentration group (PM2.5 0-15 µg/m³). Temperature showed no significant effect, while relative humidity was positively associated with asthma exacerbations at lag3, lag06, and lag07. Subgroup analyses revealed associations between PM2.5 exposure and asthma exacerbations at early lags for both males and females. Additionally, children aged 6-11 years and 12-17 years exhibited greater susceptibility to asthma exacerbations, particularly at PM2.5 concentrations of 15-25 µg/m³.

CONCLUSION

This study underscores the short-term effects of PM2.5 on asthma exacerbations, particularly during high-pollution episodes of transboundary haze in regions that generally experience low levels of air pollution. These findings emphasize the importance of achieving the WHO air quality targets to mitigate the health impacts from PM2.5.

Study on the impact of air pollutants on childhood asthma in Nanjing based on a distributed lag non-linear model

Background

Asthma, a chronic respiratory disease, is a significant public health concern globally. Air pollution has been identified as one of the key risk factors exacerbating respiratory conditions, particularly in children. Previous studies have shown a correlation between air pollution levels and asthma visits. However, the impact of air pollutants on childhood asthma visits stratified by gender, age and season remains a topic of interest, and further investigation is necessary to comprehend this complex relationship.

Objective

This study aimed to explore the association between air pollution and childhood asthma visits in Nanjing from 2013 to 2021. It focused on the effects of various pollutants, including PM2.5, PM10, NO2, SO2, CO, and O3, and examined variations in impact based on demographic characteristics (gender and age) and seasonal changes.

Methods

Data on childhood asthma visits and concentrations of air pollutants were collected and analyzed. The lag effects of pollutants on asthma visits were assessed, and the impacts were stratified by gender, age group (0-5 years, 6-11 years, and over 11 years), and season. Statistical methods were used to identify significant correlations and the timing of maximum effects of pollutants.

Results

A positive correlation was found between childhood asthma visits and concentrations of AQI, PM2.5, PM10, SO2, NO2, and CO, with the strongest effects typically occurring on lag day 1. The study revealed that PM2.5 and PM10 had a more pronounced impact on females, and children aged 0-5 years were the most affected age group. Seasonal analysis showed that PM2.5 and SO2 had the greatest impact in spring, while PM10 and NO2 were most significant in winter. Notably, SO2 showed no significant impact on childhood over 11 years old or during summer, and the negative correlation between CO concentrations and childhood asthma visits in the summer, while in other seasons, the correlation was positive.

Conclusion

The findings indicate a substantial effect of air pollutants, particularly PM2.5 and SO2, on childhood asthma, emphasizing the need for targeted pollution control measures. Variations in impact based on gender, age, and season suggest the importance of tailored interventions to protect vulnerable populations, especially young children in urban and industrial areas.

Establishment of a mouse model of allergic asthma sensitized and triggered with PM2.5

To establish a mouse model of asthma sensitized and challenged with PM2.5 extract, 48 female BALB/c mice were included in this analysis. They were divided into six groups: normal control, ovalbumin (OVA) control, three PM2.5 dose groups, and a PM2.5+OVA combined group. Mice received intraperitoneal injections of PBS, OVA, PM2.5, or OVA+PM2.5 every 7 days for three weeks, followed by a one-week intranasal challenge. Airway responsiveness to acetylcholine was measured 24 hours post-challenge. Lung and nasal tissues were analyzed for histopathology, and bronchoalveolar lavage fluid (BALF) was assessed for inflammatory cells and cytokines. Compared to controls, PM2.5 and PM2.5+OVA groups showed increased airway hyperresponsiveness, pathological changes, elevated serum IgE, and altered cytokine levels (higher IL-4, IL-13; lower IFN-γ). In conclusion, PM2.5 extract can successfully establish a mouse model of allergic asthma.

Relationship between air quality and asthma-related emergency hospital admissions in Mexico City 2017-2019

BACKGROUND

Previous studies found exposure to air pollution leads to exacerbations of asthma in paediatric and adult patients and increases asthma-related emergency hospital admissions (AREHA).

METHODS

AREHAs and levels of air pollutants (PM10, PM2.5 and NO2) were obtained from Mexico City for the period 2017-2019. A time-series approach was used to explore the relationship between air pollutants and AREHA. Relative risks of AREHA were estimated using a negative binomial regression in young children (less than 5 years) and adults (greater than 18 years).

RESULTS

There was a positive association between AREHA and PM10, PM2.5 and NO2 in adults, which remained after mutual adjustment for these pollutants. The relative risk (RR) of admission in adults increased by 3% (95% CI 1% to 4%) for a 10 µg/m3 increase in PM10, 1% (0.03% to 3%) for a 5 µg/m3 increase in PM2.5 and by 1% (0.06% to 2%) for a 5 µg/m3 increase in NO2. In contrast, in young children, AREHAs were negatively associated with PM10 after adjustment for NO2 (RR 0.97 (0.95 to 0.99) for a 10 µg/m3 and with NO2 after adjustment for PM10 and PM2.5 (RR 0.98 (0.96 to 0.99) and 0.97 (0.96 to 0.99), respectively, for a 5 µg/m3 increase in NO2). AREHAs in children were not associated with PM2.5 after adjustment for NO2.

CONCLUSIONS

Ambient air pollution, within the previous week, was associated with emergency hospital admissions for asthma to public hospitals in adults in Mexico City. The relationship in children was less consistent. Further work is needed to explore why differences between adults and children exist to inform appropriate interventions to benefit public health.

Modelling variations of emergency attendances using data on community mobility, climate and air pollution

Air pollution is associated with morbidity and mortality worldwide. We investigated the impact of improved air quality during the economic lockdown during the SARS-Cov2 pandemic on emergency room (ER) admissions in Germany. Weekly aggregated clinical data from 33 hospitals were collected in 2019 and 2020. Hourly concentrations of nitrogen and sulfur dioxide (NO2, SO2), carbon and nitrogen monoxide (CO, NO), ozone (O3) and particulate matter (PM10, PM2.5) measured by ground stations and meteorological data (ERA5) were selected from a 30 km radius around the corresponding ED. Mobility was assessed using aggregated cell phone data. A linear stepwise multiple regression model was used to predict ER admissions. The average weekly emergency numbers vary from 200 to over 1600 cases (total n = 2,216,217). The mean maximum decrease in caseload was 5 standard deviations. With the enforcement of the shutdown in March, the mobility index dropped by almost 40%. Of all air pollutants, NO2 has the strongest correlation with ER visits when averaged across all departments. Using a linear stepwise multiple regression model, 63% of the variation in ER visits is explained by the mobility index, but still 6% of the variation is explained by air quality and climate change.

The Impact of Climate Change on Asthma and Allergic-Immunologic Disease

PURPOSE OF REVIEW

This review discusses climate change-related impacts on asthma and allergic-immunologic disease, relevant US public health efforts, and healthcare professional resources.

RECENT FINDINGS

Climate change can impact people with asthma and allergic-immunologic disease through various pathways, including increased exposure to asthma triggers (e.g., aeroallergens, ground-level ozone). Climate change-related disasters (e.g., wildfires, floods) disrupting healthcare access can complicate management of any allergic-immunologic disease. Climate change disproportionately affects some communities, which can exacerbate disparities in climate-sensitive diseases like asthma. Public health efforts include implementing a national strategic framework to help communities track, prevent, and respond to climate change-related health threats. Healthcare professionals can use resources or tools to help patients with asthma and allergic-immunologic disease prevent climate change-related health impacts. Climate change can affect people with asthma and allergic-immunologic disease and exacerbate health disparities. Resources and tools are available to help prevent climate change-related health impacts at the community and individual level.

Acute Effects of Ambient Air Pollution on Asthma Emergency Department Visits in Ten U.S. States

BACKGROUND

Previous studies of short-term ambient air pollution exposure and asthma morbidity in the United States have been limited to a small number of cities and/or pollutants and with limited consideration of effects across ages.

OBJECTIVES

To estimate acute age group-specific effects of fine and coarse particulate matter (PM), major PM components, and gaseous pollutants on emergency department (ED) visits for asthma during 2005-2014 across the United States.

METHODS

We acquired ED visit and air quality data in regions surrounding 53 speciation sites in 10 states. We used quasi-Poisson log-linear time-series models with unconstrained distributed exposure lags to estimate site-specific acute effects of air pollution on asthma ED visits overall and by age group (1-4, 5-17, 18-49, 50-64, and 65 + y), controlling for meteorology, time trends, and influenza activity. We then used a Bayesian hierarchical model to estimate pooled associations from site-specific associations.

RESULTS

Our analysis included 3.19  million asthma ED visits. We observed positive associations for multiday cumulative exposure to all air pollutants examined [e.g., 8-d exposure to PM 2.5 : rate ratio of 1.016 with 95% credible interval (CI) of (1.008, 1.025) per 6.3 - μ g / m 3 increase, PM 10 - 2.5 : 1.014 (95% CI: 1.007, 1.020) per 9.6 - μ g / m 3 increase, organic carbon: 1.016 (95% CI: 1.009, 1.024) per 2.8 - μ g / m 3 increase, and ozone: 1.008 (95% CI: 0.995, 1.022) per 0.02 -ppm increase]. PM 2.5 and ozone showed stronger effects at shorter lags, whereas associations of traffic-related pollutants (e.g., elemental carbon and oxides of nitrogen) were generally stronger at longer lags. Most pollutants had more pronounced effects on children (< 18 y old) than adults; PM 2.5 had strong effects on both children and the elderly (> 64 y old); and ozone had stronger effects on adults than children.

CONCLUSIONS

We reported positive associations between short-term air pollution exposure and increased rates of asthma ED visits. We found that air pollution exposure posed a higher risk for children and older populations. https://doi.org/10.1289/EHP11661.

Association of ambient carbon monoxide exposure with hospitalization risk for respiratory diseases: A time series study in Ganzhou, China

Background

Ambient carbon monoxide (CO) exposure is associated with increased mortality and hospitalization risk for total respiratory diseases. However, evidence on the risk of hospitalization for specific respiratory diseases from ambient CO exposure is limited.

Methods

Data on daily hospitalizations for respiratory diseases, air pollutants, and meteorological factors from January 2016 to December 2020 were collected in Ganzhou, China. A generalized additive model with the quasi-Poisson link and lag structures was used to estimate the associations between ambient CO concentration and hospitalizations of total respiratory diseases, asthma, chronic obstructive pulmonary disease (COPD), upper respiratory tract infection (URTI), lower respiratory tract infection (LRTI), and influenza-pneumonia. Possible confounding co-pollutants and effect modification by gender, age, and season were considered.

Results

A total of 72,430 hospitalized cases of respiratory diseases were recorded. Significant positive exposure-response relationships were observed between ambient CO exposure and hospitalization risk from respiratory diseases. For each 1 mg/m³ increase in CO concentration (lag0-2), hospitalizations for total respiratory diseases, asthma, COPD, LRTI, and influenza-pneumonia increased by 13.56 (95% CI: 6.76%, 20.79%), 17.74 (95% CI: 1.34%, 36.8%), 12.45 (95% CI: 2.91%, 22.87%), 41.25 (95% CI: 18.19%, 68.81%), and 13.5% (95% CI: 3.41%, 24.56%), respectively. In addition, the associations of ambient CO with hospitalizations for total respiratory diseases and influenza-pneumonia were stronger during the warm season, while women were more susceptible to ambient CO exposure-associated hospitalizations for asthma and LRTI (all P < 0.05).

Conclusion

In brief, significant positive exposure-response relationships were found between ambient CO exposure and hospitalization risk for total respiratory diseases, asthma, COPD, LRTI, and influenza-pneumonia. Effect modification by season and gender was found in ambient CO exposure-associated respiratory hospitalizations.

Short-term exposure to ozone and asthma exacerbation in adults: A longitudinal study in China

Background

The relationships between short-term ozone exposure and the acute exacerbations of asthma in adults have not been fully studied. Existing studies commonly ignored the effects of ozone on mild or early asthma exacerbations.

Objective

To investigate the associations between short-term ozone exposure and asthma exacerbations in Chinese adults.

Methods

We administered health management for adult asthma patients through the Respiratory Home Platform and required them to monitor their lung function every morning and evening by themselves. Finally, a total of 4,467 patients in 18 Chinese cities were included in the current analyses, with 79,217 pairs of lung function records. The maximum daily 8-h average ozone concentrations were collected from fixed-site air quality monitoring stations. We calculated diurnal peak expiratory flow (PEF) variation using morning and evening measurements of PEF and then defined different severity of asthma exacerbations with diurnal PEF variations >10, 15, and 20%, respectively. A binomial distributed generalized additive mixture model combined with distribution non-linear models was applied to examine the association of ozone with asthma exacerbations. We further conducted stratified analyses by sex, age, season of lung function tests, and region.

Measurements and results

We found that short-term ozone exposure was independently associated with an elevated risk of asthma exacerbations defined by lung function and the effects could last for about 2 days. At lag 0-2 days, each 10 μg/m3 increment in ozone concentration was associated with odds ratios of 1.010 [95% confidence interval (CI): 1.003, 1.017], 1.014 (95% CI: 1.005, 1.023), and 1.017 (95% CI: 1.006, 1.028) for asthma exacerbations that were defined by diurnal PEF variation over 10, 15, and 20%, respectively. The associations remained significant after adjusting for other pollutants, and became unstable when using 24-h average ozone concentration. We also found that the associations were relatively stronger in males, those aged 45 years and older, and in the warm season.

Conclusions

Our results suggest that short-term ozone exposure can increase the risk of asthma exacerbations, even in the early stage of exacerbation. Male and older asthma patients may be more vulnerable to ozone air pollution, especially in the warm season.

Nitrogen dioxide, an EPA parameter, may forecast the incidence of asthma exacerbations across urban areas: An observational study

RATIONALE

Efforts to reduce nitrogen dioxide (NO₂ ) have the potential to reduce the morbidity and mortality related to asthma in children. We analyze the associations of pediatric hospital admission rates for asthma with Environmental Protection Agency (EPA) NO₂  parameters at the patient zip code level.

METHODS

We identified zip codes that had EPA monitors which monitored NO₂  levels located in states with high asthma burden. We used the Healthcare Cost and Utilization Project (HCUP) State Inpatient Database (SID) to identify patients who were <17 years of age with diagnosis codes for asthma. We compared NO₂  levels at the zip code level with the number of patients hospitalized for asthma from the HCUP SID database.

RESULTS

Data from zip codes in Buffalo, Detroit, Phoenix, and Tucson from 2009 to 2011 demonstrated that the monthly mean NO₂  levels predicted pediatric asthma hospital admission rates in six monitored zip codes in these four cities with time series modeling (Buffalo zip code 14206, p = 0.0089; Detroit zip code 48205, p = 0.0179; Phoenix zip code 85006, p = 0.0433; Phoenix zip code 85009, p = 0.0007; Phoenix zip code 85015, p = 0.0036; Tucson zip code 85711, p = 0.0004).

CONCLUSION

Pediatric admissions to the hospital for asthma exacerbations mirror the cyclic and seasonal pattern of NO₂  levels in the cities of Detroit, Buffalo, Phoenix, and Tucson. While traffic density may be higher in cities with periodicity of NO₂  and asthma exacerbations, other factors could be contributing to high NO₂  levels.

Review of Ground-Level Ozone Impact in Respiratory Health Deterioration for the Past Two Decades

Background: Ground-level ozone has been gaining notoriety with increasing evidence of its nefarious effects on health, especially respiratory diseases. Where do we stand on the solidity of this data and is there room for improvement? Objectives: Evaluate this evidence for incongruities or heterogeneity in this field of research. How is the exposure assessment conducted, where does Portugal stand in this field, and what can be improved? Health deterioration concerning asthma, chronic obstructive pulmonary disease (COPD), and acute respiratory distress syndrome (ARDS) are analysed. Methods: A review of 1735 studies was conducted through PubMed and Google Scholar engines for the past two decades. We identified 59 eligible studies and included an array of variables, including O3 measurements, number of air-quality monitoring stations used, relative risks, odds ratios, hazard ratios, number of hospital admissions, visits, or mortality, and size of population dataset used. Results: Approximately 83% of data in this review presents significant correlations of ozone with asthma, COPD, and ARDS. Studies that report negative or not significant associations mention a lack of data or topographic differences as the main issue with these divergent results. Studies consistently report summer as a period of particular concern. Portuguese data in this field is lacking. Conclusions: This research field is growing in interest and there is evidence that ozone plays a non-negligible role in health deterioration. The few Portuguese studies in this field seem aligned with the literature reviewed but more research is needed. Suggested improvements are more and better data through denser air-quality networks to accurately depict personal exposure to ozone. Homogenization of the exposure assessment concerning averaging times of ozone to daily maximum 8 h averages whenever possible. Risk increments based on 10 ppb instead of interquartile ranges. Lastly, contrary to some studies in this review, the topographic effect on concentrations and health deterioration should not be underestimated and seasonality should always be checked.

Generating Data Visualizations of Longitudinal Cohort Ambient Air Pollution Exposure: Report-Back Intervention Development in Participatory Action Research

A civic engagement and data science design was used to develop a report-back intervention to address stakeholder concerns related to air emissions surrounding a coke oven factory near Buffalo, NY. This factory had historically emitted high levels of benzene pollution and ceased operation in October 2018 because of violations of the US Clean Air Act and US Resource Conservation and Recovery Act. Using publicly available air pollution and weather data, descriptive time series and wind-rose data visualizations were developed using open-source software as part of a two-page report-back brief. Data from two air toxics monitoring sites in this direction suggest that industrial sources were likely the major contributor to the benzene in the air at these locations prior to May 2018, after which traffic emissions became the likely major contributor. Wind-rose visualizations demonstrated that the wind typically blew toward the northeast, which was qualitatively consistent with locations of stakeholder concerns. With the factory closed, collective efforts subsequently shifted to address traffic emission air pollution sources, factory site cleanup, and ground and water pollution mitigation. Because this intervention utilized open-source software and publicly available data, it can serve as a blueprint for future data-driven nursing interventions and community-led environmental justice efforts.

Outdoor air pollution and the risk of asthma exacerbations in single lag0 and lag1 exposure patterns: a systematic review and meta-analysis

Objective: To synthesize evidence regarding the relationship between outdoor air pollution and risk of asthma exacerbations in single lag0 and lag1 exposure patterns.Methods: We performed a systematic literature search using PubMed, Embase, Cochrane Library, Web of Science, ClinicalTrials, China National Knowledge Internet, Chinese BioMedical, and Wanfang databases. Articles published until August 1, 2020 and the reference lists of the relevant articles were reviewed. Two authors independently evaluated the eligible articles and performed structured extraction of the relevant information. Pooled relative risks (RRs) and 95% confidence intervals (CIs) of lag0 and lag1 exposure patterns were estimated using random-effect models.Results: Eighty-four studies met the eligibility criteria and provided sufficient information for meta-analysis. Outdoor air pollutants were associated with increased risk of asthma exacerbations in both single lag0 and lag1 exposure patterns [lag0: RR (95% CI) (pollutants), 1.057(1.011, 1.103) (air quality index, AQI), 1.007 (1.005, 1.010) (particulate matter of diameter ≤ 2.5 μm, PM_2.5), 1.009 (1.005, 1.012) (particulate matter of diameter, PM₁₀), 1.010 (1.006, 1.014) (NO₂), 1.030 (1.011, 1.048) (CO), 1.005 (1.002, 1.009) (O₃); lag1:1.064(1.022, 1.106) (AQI), 1.005 (1.002, 1.008) (PM_2.5), 1.007 (1.004, 1.011) (PM₁₀), 1.008 (1.004, 1.012) (NO₂), 1.025 (1.007, 1.042) (CO), 1.010 (1.006, 1.013) (O₃)], except SO₂ [lag0: RR (95% CI), 1.004 (1.000, 1.007); lag1: RR (95% CI), 1.003 (0.999, 1.006)]. Subgroup analyses revealed stronger effects in children and asthma exacerbations associated with other events (including symptoms, lung function changes, and medication use).Conclusion: Outdoor air pollution increases the asthma exacerbation risk in single lag0 and lag1 exposure patterns.Trial registration: PROSPERO, CRD42020204097. https://www.crd.york.ac.uk/.Supplemental data for this article is available online at https://doi.org/10.1080/02770903.2021.2008429 .

Pricing air pollution: evidence from short-term exposure to air pollution on hospitalization of acute bronchitis and chronic obstructive pulmonary disease in southwestern China

Existing evidence suggests that ambient air pollution has serious adverse effects on respiratory diseases, yet there is little direct evidence from China regarding corresponding economic losses. Here we quantified air pollution-related acute health effects and related economic losses of the most common two respiratory diseases in southwestern China, acute bronchitis and chronic obstructive pulmonary disease (COPD). We applied a distributed lag non-linear model to analyse the relationship between ambient air pollutants and hospital admissions of acute bronchitis and COPD, then applied the cost of illness method to explore the attributing economic burden. During the study period, 528 334 and 99 419 hospital admissions of acute bronchitis and COPD, respectively, were recorded. As a result, during the study period the total hospitalization economic losses attributable to air pollution were 486.40 and 254.74 million yuan for acute bronchitis and COPD, respectively, accounting for 0.015% of local gross domestic product. Our research provides intuitive evidence on the health and economic impacts of short-term exposure to air pollution, which is a key basis for the formulation of environmental policies.

The association between asthma emergency department visits and satellite-derived PM2.5 in Lima, Peru

BACKGROUND

Asthma affects millions of people worldwide. Lima, Peru is one of the most polluted cities in the Americas but has insufficient ground PM2.5 (particulate matter that are 2.5 μm or less in diameter) measurements to conduct epidemiologic studies regarding air pollution. PM2.5 estimates from a satellite-driven model have recently been made, enabling a study between asthma and PM2.5.

OBJECTIVE

We conducted a daily time-series analysis to determine the association between asthma emergency department (ED) visits and estimated ambient PM2.5 levels in Lima, Peru from 2010 to 2016.

METHODS

We used Poisson generalized linear models to regress aggregated counts of asthma on district-level population weighted PM2.5. Indicator variables for hospitals, districts, and day of week were included to account for spatial and temporal autocorrelation while assessing same day, previous day, day before previous and average across all 3-day exposures. We also included temperature and humidity to account for meteorology and used dichotomous percent poverty and gender variables to assess effect modification.

RESULTS

There were 103,974 cases of asthma ED visits during the study period across 39 districts in Lima. We found a 3.7% (95% CI: 1.7%-5.8%) increase in ED visits for every interquartile range (IQR, 6.02 μg/m3) increase in PM2.5 same day exposure with no age stratification. For the 0-18 years age group, we found a 4.5% (95% CI: 2.2%-6.8%) increase in ED visits for every IQR increase in PM2.5 same day exposure. For the 19-64 years age group, we found a 6.0% (95% CI: 1.0%-11.0%) increase in ED visits for every IQR in average 3-day exposure. For the 65 years and up age group, we found a 16.0% (95% CI: 7.0%-24.0%) decrease in ED visits for every IQR increase in PM2.5 average 3-day exposure, although the number of visits in this age group was low (4,488). We found no effect modification by SES or gender.

DISCUSSION

Results from this study provide additional literature on use of satellite-driven exposure estimates in time-series analyses and evidence for the association between PM2.5 and asthma in a low- and middle-income (LMIC) country.

Short-term effects of air pollution on daily asthma-related emergency department visits in an industrial city

BACKGROUND

Epidemiological studies from Europe and North America have provided evidence that exposure to air pollution can aggravate symptoms in asthmatic patients.

METHODS

Daily number of AEDv, air pollution levels (PM10, PM2.5, SO2, NO2 and CO) and meteorological variables was obtained from Jubail Industrial City, Saudi Arabia, for the period of 2007-11. Data were analyzed using a time-series approach. Relative risks (RRs) were estimated using Poisson regression.

RESULTS

The associations between AEDv and PM10, PM2.5, SO2 and NO2 remained positive and statistically significant after mutual adjustment in the multi-pollutant model.The RR of AEDv increased by 5.4, 4.4, 3.4 and 2.2% per an inter-quartile range increase in SO2 (2.0 ppb), PM2.5 (36 μg/m3), NO2 (7.6 ppb) and PM10 (140 μg/m3), respectively. No significant associations between AEDv and CO were found.

CONCLUSIONS

Current levels of ambient air pollution are associated with AEDv in this industrial setting in the Middle East. Greater awareness of environmental health protection and the implementation of effective measures to improve the quality of air in such settings would be beneficial to public health.

Nitrogen dioxide and asthma emergency department visits in California, USA during cold season (November to February) of 2005 to 2015: A time-stratified case-crossover analysis

Nitrogen dioxide (NO₂) is responsible for aggravating respiratory diseases, particularly asthma. The aim of this study is to investigate the association between NO₂ exposure and asthma emergency department (ED) visits during the cold season (November-February) in five populated locations (Sacramento, San Francisco, Fresno, Los Angeles, and San Diego) of California from 2005 to 2015 (1320 Days). Conditional logistic regression models were used to obtain the odds ratio (OR) and 95% confidence interval (CI) associated with a 5 ppb increase in NO₂ concentration for the 19,735 ED visits identified. An increase in NO₂ exposure increased the odds of having asthma ED visits for the studied population. The potential effect modification by sex (female and male), race (White, Black, Hispanic, and Asian), and age (2-5, 6-18, 19-40, 41-64, and ≥65) was explored. A 5 ppb increase in the concentration of NO₂ during lag 0-30 was associated with a 56% increase in the odds of having an asthma ED visit (OR = 1.560, CI: 1.428-1.703). Sex was not found to be a modifier. Asthma ED visits among all the races/ethnicities (except Asians) were associated with NO₂ exposure. Whites had the highest OR 75% (OR = 1.750, CI: 1.417-2.160) at lag 0-30 in response to NO₂ exposure. The association between NO₂ exposure and asthma ED visits was positive among all age groups except for 19 to 40 years old; the OR was higher among 2 to 18 year old (at lag 0-30: age group 2-5 (OR = 1.699, CI: 1.399-2.062), and age group 6-18 (OR = 1.568, CI 1.348-1.825)). For stratification by location, San Diego and Fresno were found to have the highest OR, compared to the other studied locations.

Differential time-lag effects of ambient PM2.5 and PM2.5-bound PAHs on asthma emergency department visits

Epidemiological studies have suggested the effects of ambient fine particles (PM_2.5) on asthma, but the effects of specific components of PM_2.5 on asthma remain to be explored. Here, we studied the effect of PM_2.5-bound polycyclic aromatic hydrocarbons (PAHs) on asthma acute exacerbation. The data on daily counts of emergency room visits (ERVs) were obtained from Wan Fang Medical Center, Taipei, Taiwan, from 2012 to 2015. The daily concentrations of PM_2.5 and pollutant gases were obtained from a local air quality monitoring station. The levels of PM_2.5-bound PAH were estimated by an established grid-scale model. Relative risks for ERVs as the increase in the level of ambient pollutants were calculated by using a generalized additive model of Poisson regression. In the present study, we observed statistically significant positive associations between PM_2.5 and asthma ERVs for all age groups. PM_2.5-bound PAH was also associated with asthma ERVs for all age groups. In the adult subgroup analysis, there was a significant association between PM_2.5-bound PAH and asthma ERVs at lags 1 and 2 (RR 1.289, 95% CI 1.050-1.582 and RR 1.242, 95% CI 1.039-1.485). The impacts of air pollution on the risk of pediatric asthma ERV were found to be significant for PM_2.5 at lag day 0 (RR 1.310, 95% CI 1.069-1.606). Moreover, pediatric asthma ERVs were significantly associated with the levels of PM_2.5-bound PAH at lag 1 and 2 days (RR 1.576, 95% CI 1.371-1.810 and RR 1.426, 95% CI 1.265-1.607). The study provides evidence that PM_2.5-bound PAHs were associated with an increased risk of asthma attacks. Our data further suggested that traffic exhaust is a primary source of PM_2.5-bound PAHs.

Association between air pollutants and outpatient and emergency hospital visits for childhood asthma in Shenyang city of China

Effects of air pollution on asthma vary in different study areas, and long-term time series research on the effects of air pollution on asthma outpatients and emergency hospital visits has not been conducted in Northeast China. We assessed the impact of air pollutants on the risk of asthma outpatients and emergency hospital visits in Shenyang, China. A distributed lag non-linear model with a Poisson regression was used to assess the short-term effects of air pollutants on asthma outpatient and emergency hospital visits between January 1, 2013 and December 31, 2017. Confounding factors were adjusted using natural cubic splines. Ozone (O₃), carbon monoxide (CO), and suspended particulates < 10 μm in aerodynamic diameter (PM₁₀) were positively associated with the number of asthma hospital visits. The largest cumulative effects of O₃, CO, and PM₁₀ on hospital visits were on lag day 2 (RR = 1.163, 95% CI 1.051-1.287) for 0-5-year-old childhood asthma, on lag day 3 (RR = 1.386, 95% CI 1.136-1.69) for asthma in winter, and on lag day 10 (RR = 1.148, 95% CI 0.942-1.399) for female asthma, respectively. The cumulative effect of air pollution represented by the air quality index (AQI) was largest on lag day 10 for 0-5-year-old childhood asthma with an increase of 28.6% (95% CI 6.5-55.4) hospital visits every IQR increment of the AQI. CO, O₃, and PM₁₀ were the main air pollutants in Shenyang city. Children with bronchitis asthma were more vulnerable to air pollution during the cold season.

The Impact of Chronic Ambient Exposure to PM2.5 and Ozone on Asthma Prevalence and COPD Mortality Rates in the Southeastern United States

Respiratory diseases affect millions of people across the United States annually. Two of the most common respiratory diseases are chronic obstructive pulmonary disease (COPD) and asthma. Mortality rates due to COPD have increased by an estimated 30% between 1980 and 2014, with significant variances among geographic regions. Both acute and chronic ambient exposures to fine particulate matter (PM_2.5) and ozone have been associated with exacerbations of respiratory diseases in numerous studies, and exposure to air pollutants are considered as the largest health risk factor globally. This study adds to the current literature by reporting the results of a time series analysis of the impact of PM_2.5 and ozone on prevalence rates of asthma and mortality rates for COPD at regional and county levels across the southeastern United States for the years 2005-2014. While general reductions in levels of PM_2.5 and ozone were demonstrated across all years, a distributed lag model showed continued strong associations between PM_2.5 and prevalence of asthma and mortality due to COPD, even at relatively small increases in ambient exposure (<1 μg/m³) across the southeastern United States. The results of the study support the need for additional research that considers factors such as patient demographics, medical histories, and health disparities in combination with ambient exposures to known pollutants.

Short-term impacts of ambient fine particulate matter on emergency department visits: Comparative analysis of three exposure metrics

BACKGROUND

Research argued that daily excessive concentration hours (DECH) could be more informative through accounting for within-day variations, when assessing population-level exposure to ambient fine particle (PM_2.5). However, few studies have comparatively investigated PM_2.5-associated risks using DECH and two common metrics of daily mean and hourly peak concentration.

METHODS

We collected daily records of all-cause emergency department visits (EDVs) and hourly data on air pollutants and meteorological factors from Shenzhen, China, 2015-2018. According to guidelines proposed by the World Health Organization, DECH was calculated by summing up daily concentrations exceeding 25 μg/m³. Based on time-stratified case-crossover design, we adopted conditional logistic regression models to assess short-term attributable risks of EDVs associated with PM_2.5 using three exposure metrics.

RESULTS

DECH and daily average of PM_2.5 strongly elevated risks of EDVs, while less evident associations were observed using hourly peak metric. Estimated excess relative risks at lag 0 day were 0.56% (95% confidence interval [CI]: 0.21 to 0.91), 0.69% (95% CI: 0.25 to 1.13) and 0.37% (95% CI: 0.02 to 0.76), respectively, associated with an interquartile range increase in DECH (420.2 μg/m³), 24-h average (24.9 μg/m³) and hourly peak concentration (38 μg/m³). More emergency visits could be attributed to DECH than daily mean PM_2.5, with attributable fractions of 2.02% (95% CI: 1.42 to 2.61) and 1.09% (95% CI: 0.69 to 1.49), respectively.

CONCLUSIONS

This study added evidence for increased risk of EDVs associated with exposure to ambient PM_2.5. DECH was a potential alternative exposure metric for PM_2.5 assessment, which may have implications for future revision of air quality standards.

Applying the NIEHS translational research framework (NIEHS-TRF) to map clinical environmental health research trajectories

Background:

There is a need for comprehensive planning tools and exemplars for clinical environmental health research programs. The National Institute of Environmental Health Sciences Translational Research Framework (NIEHS-TRF), as a comprehensive research activity mapping framework, promises to fill this gap in program planning and communication tools.

Objective:

The objective is a proof of concept demonstration to apply the NIEHS-TRF as a research project and career trajectory cartography framework.

Methods:

We utilized case series examples to apply the NIEHS-TRF as a project/career cartography framework. After a tailored research mission statement is clarified, the four step process in the NIEHS-TRF application includes 1) identifying research categories and activities (depicted visually by rings/nodes) that link to research program deliverables, 2) within each category (visual ring), linking specific works and program outcomes to activities (visual nodes), 3) coherently depicting visually as an overall map, and 4) developing recommended improvements for the NIEHS-TRF for research program cartography utility.

Results:

Successful mapping of a research project plan in a training grant application, a summary of an individual trajectory of research, and a community-initiated project was completed with mapping visualizations. The exercise facilitated purposeful planning and communication to describe common translational goals, progress, and targeted need for interdisciplinary collaboration.

Discussion:

Utilizing the NIEHS-TRF as a mapping tool for research program planning enabled unique insights into strengths, gaps, collaboration opportunities, and applications for environmental health nursing. This research project, career, and community-initiated research program trajectory mapping communication tool promises to accelerate impact and advancement through purposeful and clear planning for ongoing research activities along the translational continuum.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Methyl-bromide and asthma emergency department visits in California, USA from 2005 to 2011

Objective: Urban monitors of Methyl bromide (MBr), not typically near application sites, are used to investigate the impact of ambient concentrations on asthma Emergency Department (ED) visits.Methods: 4262 ED visits from August to February of 2005 to 2011 in Central and Southern California were selected from California's Office of Statewide Health Planning and Development (OSHPD). A bidirectional-symmetric case-crossover study design using conditional logistic regression model was used to obtain the odds ratio (OR) and 95% confidence interval associated with a 0.01 ppb (interquartile range) increase in MBr.Results: The population sample was comprised of 46.0% male and 53.9% females. Ethnic groups included 32.0% Non-Hispanic White, 23.5% Non-Hispanic Black, and 44.4% Hispanic. Age distribution was between 2 and 5 years old (11.6%), 6 and 18 years old (23.5%), 19 and 40 years old (29.3%), 41 and 64 years old (24.1%), and 65 or older (6.9%). There was a positive association between MBr and asthma ED visits among Non-Hispanic Blacks [OR: 1.065 (95% confidence intervals: 1.019, 1.108)] and Hispanics [OR: 1.107 (95% confidence intervals: 1.043, 1.173)], while Non-Hispanic Whites did not have an association with asthma ED visits. Positive association between MBr and asthma ED visits was found only among 6 to 18 [OR: 1.071 (95% confidence intervals: 1.016, 1.125)] years old.Conclusion: An increase in MBr concentration was found to be associated with an increase of the odds of having asthma ED visits in California among 6 to 18 years old and disproportionately affects Non-Hispanic Blacks and Hispanics over Non-Hispanic Whites.

Toward an Improved Air Pollution Warning System in Quebec

The nature of pollutants involved in smog episodes can vary significantly in various cities and contexts and will impact local populations differently due to actual exposure and pre-existing sensitivities for cardiovascular or respiratory diseases. While regulated standards and guidance remain important, it is relevant for cities to have local warning systems related to air pollution. The present paper proposes indicators and thresholds for an air pollution warning system in the metropolitan areas of Montreal and Quebec City (Canada). It takes into account past and current local health impacts to launch its public health warnings for short-term episodes. This warning system considers fine particulate matter (PM_2.5) as well as the combined oxidant capacity of ozone and nitrogen dioxide (O_x) as environmental exposures. The methodology used to determine indicators and thresholds consists in identifying extreme excess mortality episodes in the data and then choosing the indicators and thresholds to optimize the detection of these episodes. The thresholds found for the summer were 31 μg/m³ for PM_2.5 and 43 ppb for O_x in Montreal, and 32 μg/m³ and 23 ppb in Quebec City. In winter, thresholds found were 25 μg/m³ and 26 ppb in Montreal, and 33 μg/m³ and 21 ppb in Quebec City. These results are in line with different guidelines existing concerning air quality, but more adapted to the cities examined. In addition, a sensitivity analysis is conducted which suggests that O_x is more determinant than PM_2.5 in detecting excess mortality episodes.

Long-term impacts of prenatal and infant exposure to fine particulate matter on wheezing and asthma: A systematic review and meta-analysis

This systematic review aimed to summarize epidemiologic evidence regarding long-term effects of prenatal and infant particulate matter with an aerodynamic diameter less than 2.5 µm (PM_2.5) exposure on wheezing and asthma.

Methods

Epidemiologic data investigating the associations between ambient PM_2.5 exposures during prenatal or the first 2 years of life and wheezing or asthma throughout life were extracted from five databases. All included studies were assessed according to the Critical Appraisal Skills Programme checklists. We performed meta-analyses if ≥2 studies estimated the effects of continuous PM_2.5.

Results

Nine of 18 eligible studies were suitable for meta-analyses. For prenatal PM_2.5 exposure and asthma by 10 years of age (n = 4), the overall risk estimate per 10-unit increase (95% confidence interval) was 1.12 (1.00, 1.26). Although meta-analysis of prenatal exposure and wheezing by 4 years of age (n = 5) was not possible due to inconsistent exposure and outcome assessments, four studies found strong positive associations with wheeze by 2 years of age. The overall risk of developing asthma (n = 5) and wheezing (n = 3) by 8 years of age for infant PM_2.5 exposure was 1.14 (0.96, 1.35) and 1.49 (0.99, 2.26), respectively. One large high-quality study reporting risk differences not suitable for meta-analysis demonstrated significant associations between prenatal or infant PM_2.5 exposure and childhood asthma. High heterogeneity was present among studies of prenatal exposures and asthma, whereas studies of other associations showed low heterogeneity. There was insufficient evidence about susceptible subgroups.

Conclusions

The limited and inconsistent evidence is suggestive of an association between early life PM_2.5 exposure and wheezing/asthma. Large standardized studies are needed to explore the associations and identify vulnerable populations.

The association between 1,3-dichloropropene and asthma emergency department visits in California, USA from 2005 to 2011: a bidirectional-symmetric case crossover study

Objective: The ever-increasing rate of pesticide use in California farmlands is of great concern due to its potential toxicity on human health. In this study, the association between short term exposure to 1,3-dichloropropene (1,3-D) and asthma emergency department (ED) visits in central and southern California from 2005 to 2011 is investigated.Methods: 3878 ED visits were identified from 2005 to 2011 (1064 days). Conditional logistic regression models were used to obtain the odds ratio (OR) associated with 0.01 ppb increase in 1,3-D. Potential effect modification by sex, race/ethnicity (Non-Hispanic White, Non-Hispanic Black, or Hispanic), and age (2-5, 6-18, 19-40, 41-64 or ≥ 65) are investigated.Results: It was found that a 0.01 ppb increase in 1,3-D at the event day is associated with 13.5% [OR = 1.135, 95% CI: 1.123, 1.149] increase in the odds of having asthma ED visits in central and southern California during October to February of 2005 to 2011. Race had a positive association between 1,3-D and asthma ED visits among Non-Hispanic Black [OR= 1.095 95% CI: 1.035, 1.155] and Hispanic [OR= 1.121 95% CI: 1.064, 1.179]; while Non-Hispanic Whites had no association. Positive association for age was found between 1,3-D and asthma ED visits among patients 2 to 5 [OR= 1.065 95% CI: 1.020, 1.133], 6 to 18 [OR= 1.142 95% CI: 1.086, 1.196], and 19 to 40 [OR= 1.023 95% CI: 1.015, 1.073] years old.Conclusion: These findings suggest a 0.01 ppb increase in 1,3-D concentration increases the odds of having asthma ED visits.

Nursing Practice and Particulate Matter Exposure

: Environmental factors underlie more than one-fifth of deaths and disability worldwide. Globally, both indoor and outdoor particulate matter pollution are leading risk factors for reduced quality of life and death. Nurses are in a key position to assess particulate matter exposure and to intervene, providing population, community, family, and individual risk reduction and care. This article presents a case study describing one patient's experiences with asthma and multiple comorbidities, an overview of particulate matter exposure and health, and management strategies for practice.

Ambient air pollution and the hospital outpatient visits for eczema and dermatitis in Beijing: a time-stratified case-crossover analysis

BACKGROUND

Eczema and dermatitis are a group of common skin conditions with multiple risk factors. Evidence of the effects of air pollutants on eczema and dermatitis remains limited. This study aimed to investigate the effects of short-term exposure to air pollution on eczema and dermatitis in Beijing.

METHODS

A time-stratified case-crossover design was used to assess the associations between short-term changes in air pollution and the hospital outpatient visits for eczema and dermatitis in Beijing.

RESULTS

A total of 157 595 outpatient visits for eczema and dermatitis were recorded from April 1, 2012 to April 30, 2014. All pollutants showed significant positive associations with the number of outpatient visits for eczema and dermatitis on lag 0 (the current day). Per IQR increase in PM2.5, PM10, NO2 and SO2 was associated with 3.81% (95% CI: 2.92-4.7%), 3.18% (95% CI: 2.39-3.97%), 5.43% (95% CI: 4.43-6.43%) and 5.57% (95% CI: 4.55-6.58%) increases in outpatient visits for eczema and dermatitis on lag 0. Associations of air pollutants with eczema and dermatitis outpatient visits varied with the seasons and were stronger among older people and females. Also, an association of consecutive days' high concentration pollution with increased outpatient visits was observed.

CONCLUSIONS

Exposure to air pollution increases the exacerbation of eczema and dermatitis and stronger positive associations between air pollutants and outpatient visits for eczema and dermatitis were found among the aged, females and when high concentration air pollution occurs continuously.

Socioeconomic determinants of pediatric asthma emergency department visits under regional economic development in western New York

Although the links between asthma in children and physical environmental factors have been well established, the role of community-level socioeconomic status remains inconclusive. Consequently, little attention has been paid to the dynamic changes in the associations between socioeconomic status and asthma outcomes due to structural changes in the community, such as an influx of financial resources. This study examined the relationship between community-level socioeconomic status indicators and asthma-related emergency department utilization for school-aged children in 2011 and 2015, assessing the early impact of a large-scale regional economic development project in western New York, United States. Our analyses controlled for other community-level health risk factors, such as environmental exposure, and spatial correlation of the emergency department usage data. Results indicated that both median household income and health insurance coverage were key socioeconomic predictors of the children's asthma-related emergency department utilization over the study period. We also found that the risk of emergency department utilization for asthma decreased significantly in the area in which regional economic development projects were completed during the initial stage of the project. Through a comparison study we demonstrated that the spatial correlation present in asthma-related ED utilization improved model fit and corrected biases in the estimates. Although our findings suggest that improving the socioeconomic status of communities contributes to a reduction in emergency department utilization for pediatric asthma, more empirical studies are warranted for evaluating the comprehensive effects of regional economic development on public health.

Ozone pollution and asthma emergency department visits in the Central Valley, California, USA, during June to September of 2015: a time-stratified case-crossover analysis

Objective: The San Joaquin Valley (SJV) exceeds the state and national standards for ozone (O₃). This study investigates whether short-term exposure to O₃ is associated with asthma emergency department (ED) visits. Methods: We identified 1,101 ED visits in June-September of 2015 in SJV, California, who lived within 15 km of active air monitors. Conditional logistic regression models were used to obtain the odds ratio (OR) and 95% confidence interval (CI) associated with an interquartile (IQR) increase in ozone. We explored the potential effect modification by sex (female and male), race (White, Black and Hispanic), age (2-5, 6-18, 19-40, 41-64 and > = 65) and county (Merced, Madera, Kings, Fresno and Kern). Results: An IQR range (18.1 ppb) increase in O₃ exposure three days before an asthma attack (lag 3) was associated with a 6.6% [OR: 1.066 (95% CI: 1.032, 1.082)] increase in the odds of having an asthma ED visit. The overall ORs differed across age groups and races/ethnicities, with strongest for children aged 6-18 years [OR: 1.219 (95% CI: 1.159, 1.280)], adults 19-40 years [OR: 1.102 (95% CI: 1.053, 1.154)] and Blacks [OR: 1.159 (95% CI: 1.088, 1.236)], respectively. O₃ exposure was not positively associated with asthma ED visits for Whites, while it was for other underrepresented groups. Fresno had the highest number of asthma ED visits and positive association among all five counties. Conclusion: We found that O₃ exposure is associated with asthma ED visits in the SJV.

Ambient air quality and spatio-temporal patterns of cardiovascular emergency department visits

BACKGROUND

Air pollutants have been associated with various adverse health effects, including increased rates of hospital admissions and emergency room visits. Although numerous time-series studies and case-crossover studies have estimated associations between day-to-day variation in pollutant levels and mortality/morbidity records, studies on geographic variations in emergency department use and the spatial effects in their associations with air pollution exposure are rare.

METHODS

We focused on the elderly who visited emergency room for cardiovascular related disease (CVD) in 2011. Using spatially and temporally resolved multi-pollutant exposures, we investigated the effect of short-term exposures to ambient air pollution on emergency department utilization. We developed two statistical models with and without spatial random effects within a hierarchical Bayesian framework to capture the spatial heterogeneity and spatial autocorrelation remaining in emergency department utilization.

RESULTS

Although the cardiovascular effect of spatially homogeneous pollutants, such as PM2.5 and ozone, was unchanged, we found the cardiovascular effect of NO[Formula: see text] was pronounced after accounting for the spatially correlated structure in emergency department utilization. We also identified areas with high ED utilization for CVD among the elderly and assessed the uncertainty associated with risk estimates.

CONCLUSIONS

We assessed the short-term effect of multi-pollutants on cardiovascular risk of the elderly and demonstrated the use of community multiscale air quality model-derived spatially and temporally resolved multi-pollutant exposures to an epidemiological study. Our results indicate that NO[Formula: see text] was significantly associated with the elevated ED utilization for CVD among the elderly.

Air pollution and emergency department visits for respiratory diseases: A multi-city case crossover study

Increasing evidence suggests that ambient air pollution is a major risk factor for both acute and chronic respiratory disease exacerbations and emergencies. The objective of this study was to determine the association between ambient air pollutants and emergency department (ED) visits for respiratory conditions in nine districts across the province of Ontario in Canada. Health, air pollutant (PM_2.5, NO₂, O₃, and SO₂), and meteorological data were retrieved from April 2004 to December 2011. Respiratory diseases were categorized as: chronic obstructive pulmonary disease (COPD, including bronchiectasis) and acute upper respiratory diseases. A case-crossover design was used to test the associations between ED visits and ambient air pollutants, stratified by sex and season. For COPD among males, positive results were observed for NO₂ with lags of 3-6 days, for PM_2.5 with lags 1-8, and for SO₂ with lags of 4-8 days. For COPD among females, positive results were observed for O₃ with lags 2-4 days, and for SO₂ among lags of 3-6 days. For upper respiratory disease emergencies among males, positive results were observed for NO₂ (lags 5-8 days), for O₃, (lags 0-6 days), PM_2.5 (all lags), and SO₂ (lag 8), and among females, positive results were observed for NO₂ for lag 8 days, for O₃, PM_2.5 among all lags. Our study provides evidence of the associations between short-term exposure to air pollution and increased risk of ED visits for upper and lower respiratory diseases in an environment where air pollutant concentrations are relatively low.