Termeh Kousha

Air Pollution and Emergency Department Visits for Hypertension in Edmonton and Calgary, Canada: A Case-Crossover Study

BACKGROUND Ambient air pollutant exposures have been associated with a wide variety of cardiovascular events; however, few studies have evaluated their impact upon acute emergency department (ED) visits for hypertension. METHODS The purpose of this study was to examine the associations between ED visits for hypertension and ambient air pollution concentrations among 6,532 patients during the period of January 2010 to December 2011 in Edmonton and Calgary, Alberta, Canada. The associations were evaluated using a case-crossover design. RESULTS Odds ratios and their 95% confidence interval have been calculated for 1 unit increase in their interquartile range for lags (the time between air pollutant measurement and exposure-response) 0-8 days. During the cold season, statistically significant positive results were observed for SO2 among lag days 4-6 and 8 for females and lag days 5 and 6 for males. Moreover, statistically significant positive results were observed for NO2 on lag day 7 for females and for PM2.5 on lag days 5 and 7, for females and lag day 6 for males. During the warm season, statistically significant positive results were observed for O3 on lag days 3 and 4 and for SO2 on lag days 2 and 8 for females. CONCLUSIONS These findings support the hypothesis that recent exposures to ambient levels of several air pollutants can be capable of elevating blood pressure to a clinically significant extent such that it leads to ED visits for hypertension.

Air Pollution and Emergency Department Visits for Depression: A Multicity Case-Crossover Study

Background The aim of this study was to investigate the associations between ambient air pollution and emergency department (ED) visits for depression. Methods Health data were retrieved from the National Ambulatory Care Reporting System. ED visits for depression were retrieved from the National Ambulatory Care Reporting System using the International Classification of Diseases (ICD-10), Tenth revision codes; ICD-10: F32 (mild depressive episode) and ICD-10: F33 (recurrent depressive disorder). A case-crossover design was employed for this study. Conditional logistic regression models were used to estimate odds ratios. Results For females, exposure to ozone was associated with increased risk of an ED visit for depression between 1 and 7 days after exposure, for males, between 1 and 5, and 8 days after exposure, with odds ratios ranging between 1.02 and 1.03. Conclusions These findings suggest that, as hypothesized, there is a positive association between exposure to air pollution and ED visits for depression.

The Air Quality Health Index and Emergency Department Visits for Otitis Media

PURPOSE The purpose of this study was to explore novel multipollutant exposure assessments using the Air Quality Health Index in relation to emergency department visits for otitis media (OM). DESIGN This study was a retrospective analysis using information from emergency department visits for OM, air pollution, and weather databases. METHODS For children 3 years of age or younger, there were 4,815 emergency department visits for OM over a 6-year period across hospitals in Windsor, Ontario, Canada. Both time-stratified case-crossover and nonlinear time series distributed lag analyses were applied to investigate the association between the Air Quality Health Index and visits for OM. FINDINGS Using case-crossover analysis, there was an increase in emergency department visits with OM diagnoses 6 to 7 days postexposure to increased ozone and 3 to 4 days after exposure to increased particulate matter. For every 1 unit increase in the Air Quality Health Index, discharge diagnosis of OM increased 5% to 6% three days postexposure. Effects were stronger using the nonlinear time series analysis. The overall risk for OM, in the first 15 days after an increase in the Air Quality Health Index, was 1.22 times the risk of OM on days following no increase in exposures. CONCLUSIONS These findings confirm that there is an association between the multipollutant Air Quality Health Index and emergency department visits for OM. The findings can be used to inform risk communication, patient education, and policy. CLINICAL RELEVANCE Clinicians can use the Air Quality Health Index as an education and advocacy tool to promote and protect the health of those at high risk for OM to reduce exposures.

Ambient ozone and emergency department visits due to lower respiratory condition

ObjectivesAmbient ozone (O3) exposure is associated with a variety of health conditions. The objective of this study was to examine the effect of increased daily concentrations of ozone on emergency department (ED) visits due to lower respiratory diseases (LRD), such as acute or chronic bronchitis, in Edmonton, Canada.Materials and MethodsData concerning 10 years (1992–2002) were obtained from 5 Edmonton hospital Emergency Departments. Odds ratios (ORs) for ED visits associated with the increased ozone levels were calculated employing a case-crossover technique with a time-stratified strategy to define controls. In the constructed conditional logistic regression models, adjustments were made for daily number of influenza ED visits and weather variables using natural splines. ORs and their 95% confidence intervals (95% CI) were reported in relation to an increase in the interquartile range (IQR = 17.9 ppb) of the ground-level ozone.ResultsOverall, 48 252 ED visits due to LRD were identified, of which 53% were made by males. The presentations peaked in December (12%) and February (11.7%) and were the lowest in August (5.6%). Positive and statistically significant results were obtained for acute bronchitis: for same day (OR = 1.09, 95% CI: 1.05–1.13, lag 0) and for lag 2, lag 3–7 and 9 days; for chronic bronchitis: for lag 6, 7, and lag 9 days (OR = 1.11, 95% CI: 1.05–1.18, lag 9). For all ED visits for LRD, lag 0, lag 1, and lag 3–9 days showed positive and statistically significant associations (OR = 1.06, 95% CI: 1.03–1.09, lag 0).ConclusionsThese findings support the hypothesis concerning positive associations between ozone and the ED visits due to LRD.

The Air Quality Health Index and Emergency Department Visits for Urticaria in Windsor, Canada

Ambient air pollution exposure has been associated with several health conditions, limited not only to respiratory and cardiovascular systems but also to cutaneous tissues. However, few epidemiological studies examined pollution exposure on skin problems. Basically, the common mechanism by which pollution may affect skin physiology is by induction of oxidative stress and inflammation. Urticaria is among the skin pathologies that have been associated with pollution. Based on the combined effects of three ambient air pollutants, ozone (O3), nitrogen dioxide (NO2), and fine particulate matter (PM) with a median aerodynamic diameter of less than 2.5 μm (PM 2.5), on mortality, the Air Quality Health Index (AQHI) in Canada was developed. The aim of this study was to examine the associations of short-term changes in AQHI with emergency department (ED) visits for urticaria in Windsor-area hospitals in Canada. Diagnosed ED visits were retrieved from the National Ambulatory Care Reporting System (NACRS). A time-stratified case-crossover design was applied to 2905 ED visits (males = 1215; females = 1690) for urticaria from April 2004 through December 2010. Odds ratios (OR) and their corresponding 95% confidence intervals (95%CI) for ED visits associated with increase by one unit of risk index were calculated employing conditional logistic regression. Positive and significant results were observed between AQHI levels and OR for ED visits for urticaria in Windsor for lags 2 and 3 days. A distributed lag nonlinear model technique was applied to daily counts of ED visits for lags 0 to 10 and significant results were obtained from lag 2 to lag 5 and for lag 9. These findings demonstrated associations between ambient air pollution and urticarial confirming that air pollution affects skin conditions.

Air pollution and emergency department visits for conjunctivitis: A case-crossover study.

OBJECTIVES The purpose of this study was to examine the associations between emergency department (ED) visits for conjunctivitis and ambient air pollution levels in urban regions across the province of Ontario, Canada. MATERIAL AND METHODS Information from the National Ambulatory Care Reporting System was used to create time-series records, for the period of April 2004 to December 2011, on emergency department visits of patients suffering from conjunctivitis. A total of 77 439 emergency department visits for conjunctivitis were analyzed. A time-stratified case-crossover design was applied, completed with meta-analysis in order to pool inter-city results. Odds ratio (OR) for an emergency department visit was calculated in different population strata per one-unit increase (one interquartile range - IQR increase in a pollutants daily level) while controlling for the impacts of temperature and relative humidity. RESULTS Statistically significant positive results were observed in the female population sample, for nitrogen dioxide (NO2) exposure lagged 5-8 days, with the highest result for the 7-day lag (OR = 1.035, 95% CI: 1.018-1.052) and for fine particulate matter with a median aerodynamic diameter of less than 2.5 μm (PM2.5), for lags 6 and 7 days, with the highest result for lag 7 (OR = 1.017, 95% CI: 1.003-1.031). In the male population sample, statistically significant positive results were observed for NO2; at lag 5 days (OR = 1.024, 95% CI: 1.004-1.045) and for ozone (O3), at lags 0-3 and 7 days, with the highest result for lag 0 (OR = 1.038, 95% CI: 1.012-1.056). Also for males, statistically significant results were observed in the case of PM2.5 exposure lagged by 5 days (OR = 1.003, 95% CI: 1.000-1.038) and sulfur dioxide (SO2) exposure lagged by 1 and 2 days (OR = 1.016, 95% CI: 1.000-1.031 and OR = 1.018, 95% CI: 1.002-1.033). CONCLUSIONS The findings of this study suggest that there are associations between levels of air pollution and ED visits for conjunctivitis, with different temporal trends and strength of association by age, sex, and season.

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

&NA; 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 (PM2.5, 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 PM2.5 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), PM2.5 (all lags), and SO2 (lag 8), and among females, positive results were observed for NO2 for lag 8 days, for O3, PM2.5 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. HighlightsExtensive research exists on the effects of ambient air pollution on respiratory diseases.Emergency department visits for respiratory diseases increase after days with higher concentrations of air pollution.Ambient pollution, even at low concentrations, appear to adversely affect the respiratory system.

Ambient air pollution and emergency department visits for skin conditions

Studies have reported associations between ambient air pollution exposure and occurrence of various skin diseases. In addition, a few epidemiological studies also indicated associations of air pollution exposure with cellulitis. The purpose of this multi-city study was to examine potential associations between emergency department (ED) visits for skin conditions and ambient air pollution concentrations. The study was conducted using the data for the period from April 2004 to December 2011 in nine cities across the province of Ontario, Canada. ED visits for skin conditions were retrieved from the National Ambulatory Care Reporting System using the International Classification of Diseases, ICD-10 codes: R20, R21, and for cellulitis L03, L25.9, and L50.9. For this study, a case-crossover design was applied. Conditional logistic regression was used to realize statistical models. Temperature and humidity in the form of natural splines were used as cofounders. Odds ratios and their 95% confidence interval have been calculated for one unit increases in the interquartile values of considered air pollutants. For cellulitis (N=252,799), significant positive results were observed for O3 for lags 1, 4 and 5 days among females. For males, statistically significant positive results were observed for PM2.5 for lags 3 to 6. For other skin conditions (N=201,571), significant positive results were also observed in females for PM2.5, for lags 2 to 8 days; for O3, for lags 0 to 2 days; and, for NO2 and SO2, for lags 6 to 8 days. For males, PM2.5 remained positive among all lags, and was statistically significant for lags 4 and 6 days. Our findings support the associations between air pollutants and ED visits for cellulitis and other skin conditions. Correspondence to: Dr. Mieczysław Szyszkowicz, Health Canada, 200 Eglantine Driveway, Ottawa, Ontario, Canada K1A 0K9, Tel: (613) 762-1830; Fax: (613) 941-3883; E-mail: mietek.szyszkowicz@hc-sc.gc.ca