Air Pollution and Emergency Department Visits for Mental Disorders among Youth.

Although exposure to ambient air pollution has been linked to mental health problems, little is known about its potential effects on youth. This study investigates the association between short-term exposure to air pollutants and emergency department (ED) visits for mental health disorders. The National Ambulatory Care Reporting System database was used to retrieve ED visits for young individuals aged 8-24 years in Toronto, Canada. Daily average concentrations of nitrogen dioxide (NO2), fine particulate matter (PM2.5), and daily maximum 8 h ozone (O3) were calculated using measurement data from seven fixed stations. A case-crossover (CC) design was implemented to estimate the associations between ED visits and air pollution concentrations. Mental health ED visits were identified using International Classification of Diseases 10th Revision (ICD-10) codes, with seven categories considered. Models incorporating air pollutants and ambient temperature (with lags of 0-5 days) using a time-stratified CC technique were applied. Multivariable regression was performed by sex, three age groups, and seven types of mental health disorders to calculate relative risk (RR). The RRs were reported for one interquartile range (IQR) change in the air pollutant concentrations. Between April 2004 and December 2015 (4292 days), there were 83,985 ED visits for mental-health related problems in the target population. Several exposures to air pollutants were shown to have associations with ED visits for mental health including same day exposure to fine particulate matter (IQR = 6.03 µg/m3, RR = 1.01 (95% confidence interval: 1.00-1.02), RR = 1.02 (1.00-1.03)) for all and female-only patients, respectively. One-day lagged exposure was also associated with ED visits for PM2.5 (RR = 1.02 (1.01-1.03)), for nitrogen dioxide (IQR = 9.1 ppb, RR = 1.02 (1.00-1.04)), and ozone (IQR = 16.0 ppb, RR = 1.06 (1.01-1.10)) for males. In this study, urban air pollution concentration-mainly fine particulate matter and nitrogen dioxide-is associated with an increased risk for ED visits for adolescents and young adults with diagnosed mental health disorders.

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 (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.

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.

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 pollutant's 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.

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.

Factorization methods applied to characterize the sources of volatile organic compounds in Montreal, Quebec.

OBJECTIVES: The study objective was to assemble emission characteristics of the sources of the ambient volatile organic compounds (VOCs) and to elaborate methods of organizing them into the sources' chemical profiles. MATERIAL AND METHODS: The UNMIX--sensor modeling method from the U.S. Environment Protection Agency (EPA)--was used to process the VOC concentration data acquired over the years 2000-2009 for 175 VOC species in 4 air quality monitoring stations in Montreal, Quebec. RESULTS: The method enabled to assess VOC emissions from the typically distributed sources existing in urban environment and VOC occurrences characterizing the local, or point-like, sources. The distributed sources were inextricably associated with hydrocarbons from exhaust, heavier hydrocarbons from contaminated urban soil, fugitive evaporations of gasoline and liquefied petroleum gases (LPG), leakage from the industrial and commercial use of solvents, and the inert, ozone depleting gases permeating urban atmosphere. The sources' profiles were charted involving 60-120 VOC species per source. Spatial distribution of the sources was examined. CONCLUSIONS: The UNMIX application and the source profiling methods, by building robust chemical profiles of VOC sources, provided information that can be used to assign the measured VOC emissions to physical sources. This, in turn, provides means of assessing the impact of environmental policies, on one hand, and of industrial activities on the other hand on VOC air pollution.

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 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.

Emergency department visits for asthma in relation to the Air Quality Health Index: a case-crossover study in Windsor, Canada.

OBJECTIVES: In this study, associations of short-term changes in ambient air pollution with emergency department (ED) visits for asthma were examined in hospitals in the area of Windsor, Ontario. Ambient air pollution quality was represented by the Air Quality Health Index(AQHI), calculated using a formula that combines the concentrations and the relative health impacts of three ambient air pollutants: ozone , nitrogen dioxide and fine particulate matter. METHODS: Data on ED visits were retrieved from the National Ambulatory Care Reporting System. Only patients two years of age and older were considered. A time-stratified case-crossover design was applied to 6,697 ED visits for asthma for the period of April 2004 to December 2010. Odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) for ED visits associated with increased (by one unit) levels of AQHI were calculated by applying conditional logistic regression. RESULTS: Positive and statistically significant results were observed between AQHI levels and ED visits for asthma. For all patients the largest value, OR=1.17 (CI: 1.09, 1.26), was obtained for exposures lagged by 9 days in the warm season (April-September). Effects among children 2 to 14 years of age were observed for same-day exposure (lag 0), with an OR=1.11(CI: 1.01, 1.21). CONCLUSION: Exposure to ambient air pollution in Windsor increases the risk of ED visits for asthma. When the adverse effects of air pollutants are increased, patient visits to the ED depend on the patient's age.

Ambient ozone and emergency department visits due to lower respiratory condition.

OBJECTIVES: Ambient 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 METHODS: Data 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. RESULTS: Overall, 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). CONCLUSIONS: These findings support the hypothesis concerning positive associations between ozone and the ED visits due to LRD.