Air pollution, aeroallergens and cardiorespiratory emergency department visits in Saint John, Canada

Existing studies of the association between air pollution, aeroallergens and emergency department (ED) visits have generally examined the effects of a few pollutants or aeroallergens on individual conditions such as asthma or chronic obstructive pulmonary disease. In this study, we considered a wide variety of respiratory and cardiac conditions and an extensive set of pollutants and aeroallergens, and utilized prospectively collected information on possible effect modifiers which would not normally be available from purely administrative data. The association between air pollution, aeroallergens and cardiorespiratory ED visits (n = 19,821) was examined for the period 1992 to 1996 using generalized additive models. ED visit, air pollution and aeroallergen time series were prefiltered using LOESS smoothers to minimize temporal confounding, and a parsimonious model was constructed to control for confounding by weather and day of week. Multipollutant and multi-aeroallergen models were constructed using stepwise procedures and sensitivity analyses were conducted by season, diagnosis, and selected individual characteristics or effect modifiers. In single-pollutant models, positive effects of all pollutants but NO2 and COH were observed on asthma visits, and positive effects on all respiratory diagnosis groups were observed for O3, SO2, PM10, PM2.5, and SO4(2-). Among cardiac conditions, only dysrhythmia visits were positively associated with all measures of particulate matter. In the final year-round multipollutant models, a 20.9% increase in cardiac ED visits was attributed to the combination of O3 (16.0%, 95% CI 2.8-30.9) and SO2 (4.9%, 95%CI 1.7-8.2) at the mean concentration of each pollutant. In the final multipollutant model for respiratory visits, O3 accounted for 3.9% of visits (95% CI 0.8-7.2), and SO2 for 3.7% (95% CI 1.5-6.0), whereas a weak, negative association was observed with NO2. In multi-aeroallergen models of warm season asthma ED visits, Ascomycetes, Alternaria and small round fungal spores accounted for 4.5% (95% CI 1.8-7.4), 4.7% (95% CI 1.0-8.6) and 3.0% (95% CI 0.8-5.1), respectively, of visits at their mean concentrations, and these effects were not sensitive to adjustment for air pollution effects. In conclusion, we observed a significant influence of the air pollution mix on cardiac and respiratory ED visits. Although in single-pollutant models, positive associations were noted between ED visits and some measures of particulate matter, in multipollutant models, pollutant gases, particularly ozone, exhibited more consistent effects. Aeroallergens were also significantly associated with warm season asthma ED visits.     

Association between ozone and emergency department visits: an ecological study

The objective of this study was to examine the association between the levels of ozone concentration and emergency department (ED) visits for respiratory and cardiovascular conditions in Maryland in the United States by considering temporal and spatial characteristics, including socioeconomic status (SES), as a covariate. This study used multiple large datasets derived from government agencies for data of ozone, weather, census, and ED visits to represent Maryland in the summer of 2002. Block kriging was used to estimate the daily ozone and weather factors by ZIP code-day level. Results from a negative binomial regression showed that a 10-ppb increment of the 8-hr ozone level as a three-day average was associated with increased respiratory ED visits by 2.4%, after adjusting for weather factors, SES, and day of the week. For cardiovascular ED visits, an increment of 10 ppb of the 8-hr ozone level as a five-day average increased by 3.5%.     

Ambient ozone and emergency department visits for cellulitis

Objectives were to assess and estimate an association between exposure to ground-level ozone and emergency department (ED) visits for cellulitis. All ED visits for cellulitis in Edmonton, Canada, in the period April 1992-March 2002 (N = 69,547) were examined. Case-crossover design was applied to estimate odds ratio (OR, and 95% confidence interval) per one interquartile range (IQR) increase in ozone concentration (IQR = 14.0 ppb). Delay of ED visit relating to exposure was probed using 0- to 5-day exposure lags. For all patients in the all months (January-December) and lags 0 to 2 days, OR = 1.05 (1.02, 1.07). For male patients during the cold months (October-March): OR = 1.05 (1.02, 1.09) for lags 0 and 2 and OR = 1.06 (1.02, 1.10) for lag 3. For female patients in the warm months (April-September): OR = 1.12 (1.06, 1.18) for lags 1 and 2. Cellulitis developing on uncovered (more exposed) skin was analyzed separately, observed effects being stronger. Cellulitis may be associated with exposure to ambient ground level ozone; the exposure may facilitate cellulitis infection and aggravate acute symptoms.     

臭氧暴露与儿童哮喘就诊人数相关性的Meta分析

目的 系统性评价臭氧暴露对儿童哮喘就诊人数的影响。方法 计算机检索中国知网、万方数据库、维普中文期刊数据库、Pubmed、Embase、Cochrane 等数据库,以哮喘、臭氧、空气污染物、asthma、bronchial asthma、wheeze、respiratory tract allergy、ozone、O3、gaseous pollutants为检索词,检索从建库至2020年8月26日公开发表的文献,依据纳入标准和排除标准进行文献筛选。最终纳入文献使用Revman 5.4进行meta分析。结果 最终纳入文献14篇,meta分析结果显示,环境臭氧每上升10 μg/m3,哮喘儿童就诊人数平均增加1.33%。亚组分析结果显示哮喘儿童因臭氧暴露入院人数与急诊就诊人数基本一致,但急诊就诊受臭氧浓度影响更大。根据研究类型分析显示两种研究方法均支持儿童哮喘就诊人数与臭氧浓度呈正相关。结论 环境臭氧浓度上升可导致儿童哮喘就诊人数增加,且因臭氧暴露导致的急诊就诊人数高于入院就诊人数,降低环境臭氧浓度可有效减轻哮喘疾病负担。     

Associations between outdoor air pollution and emergency department visits for stroke in Edmonton, Canada

Inconsistent results have been obtained from studies that have examined the relationship between air pollution and hospital visits for stroke. We undertook a time-stratified case-crossover study to evaluate associations between outdoor air pollution and emergency department visits for stroke among the elderly according to stroke type, season, and sex. Analyses are based on a total of 12,422 stroke visits among those 65 years of age and older in Edmonton, Canada between April 1, 1992 and March 31, 2002. Daily air pollution levels for SO₂, NO₂, PM_2.5, PM₁₀, CO and O₃ were estimated using data from fixed-site monitoring stations. Particulate matter data were only available from 1998 onwards. Conditional logistic regression was used to estimate the odds ratios (ORs) and their 95% confidence intervals in relation to an increase in the interquartile range (IQR) of each pollutant. ORs were adjusted for the effects of temperature and relative humidity. We found no association between outdoor measures of air pollution and all stroke visits. In contrast, elevated risks were observed between levels of air pollution and acute ischemic stroke between April and September. During this season, the ORs associated with an increase in the IQR of the 3-day average for CO and NO₂ were 1.32 (95% CI = 1.09–1.60) and 1.26 (95% CI = 1.09–1.46), respectively. CO exposures in the same season, lagged 1 day, were associated with an increased risk of hemorrhagic stroke with ORs was 1.20 (95% CI = 1.00–1.43). Our results suggest it is possible that vehicular traffic, which produces increased levels of NO₂ and CO, contributes to an increased incidence of emergency department visits for stroke.     

An association between fine particles and asthma emergency department visits for children in Seattle.

Asthma is the most common chronic illness of childhood and its prevalence is increasing, causing much concern for identification of risk factors such as air pollution. We previously conducted a study showing a relationship between asthma visits in all persons < 65 years of age to emergency departments (EDs) and air pollution in Seattle, Washington. In that study the most frequent zip codes of the visits were in the inner city. The Seattle-King County Department of Public Health (Seattle, WA) subsequently published a report which showed that the hospitalization rate for children in the inner city was over 600/100,000, whereas it was < 100/100,000 for children living in the suburbs. Therefore, we conducted the present study to evaluate whether asthma visits to hospital emergency departments in the inner city of Seattle were associated with outdoor air pollution levels. ED visits to six hospitals for asthma and daily air pollution data were obtained for 15 months during 1995 and 1996. The association between air pollution and childhood ED visits for asthma from the inner city area with high asthma hospitalization rates were compared with those from lower hospital utilization areas. Daily ED counts were regressed against fine particulate matter (PM), carbon monoxide (CO), sulfur dioxide, and nitrogen dioxide using a semiparametric Poisson regression model. Significant associations were found between ED visits for asthma in children and fine PM and CO. A change of 11 microg/m3 in fine PM was associated with a relative rate of 1.15 [95% confidence interval (CI), 1.08-1.23]. There was no stronger association between ED visits for asthma and air pollution in the higher hospital utilization area than in the lower utilization area. These findings were seen when estimated PM2.5 concentrations were below the newly adopted annual National Ambient Air Quality Standard of 15 microg/m3.     

Association between hospital emergency visits for asthma and air pollution in Valencia,Spain

OBJECTIVE: To assess the short term effect of concentrations of black smoke, sulphur dioxide (SO2), nitrogen dioxide (NO2) and ozone (O3) in ambient air on emergency room visits for asthma in the city of Valencia, Spain during the period 1994-5. METHODS: Ecological study with time series data and application of Poisson regression. Associations between number of daily emergency visits in a city''s hospital and concentrations of air pollutants were analysed taking into account potential confounding factors by the standardised protocol of the air pollution and health: a European approach (APHEA) project. RESULTS: Mean (range) daily number of emergency room visits for asthma was 1 (0-5). Concentrations of all pollutants studied remained within current air quality standards. The association between an increase of 10 micrograms/m3 in ambient air pollution and asthma, measured as a relative risk (RR) of emergency visits, was significant for NO2 24 hour mean (lag 0, RR 1.076, 95% confidence interval (95% CI) 1.020 to 1.134), NO2 hour maximum (lag 0, RR 1.037, 95% CI 1.008 to 1.066), and O3 hour maximum (lag 1, RR 1.063, CI 95% 1.014 to 1.114). The association was not significant for SO2 or for black smoke during the period analysed. The effects were not significantly different for the time of year, cold months (November to April), or warm months (May to October). CONCLUSIONS: Current concentrations of ambient air pollution in Valencia are significantly associated with emergency room visits for asthma. This association is high and more consistent for NO2 and O3 than for particulate matter and SO2 (classic pollutants).       

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.     

Pesticide spraying for West Nile virus control and emergency department asthma visits in New York City, 2000

Pyrethroid pesticides were applied via ground spraying to residential neighborhoods in New York City during July-September 2000 to control mosquito vectors of West Nile virus (WNV). Case reports link pyrethroid exposure to asthma exacerbations, but population-level effects on asthma from large-scale mosquito control programs have not been assessed. We conducted this analysis to determine whether widespread urban pyrethroid pesticide use was associated with increased rates of emergency department (ED) visits for asthma. We recorded the dates and locations of pyrethroid spraying during the 2000 WNV season in New York City and tabulated all ED visits for asthma to public hospitals from October 1999 through November 2000 by date and ZIP code of patients' residences. The association between pesticide application and asthma-related emergency visits was evaluated across date and ZIP code, adjusting for season, day of week, and daily temperature, precipitation, particulate, and ozone levels. There were 62,827 ED visits for asthma during the 14-month study period, across 162 ZIP codes. The number of asthma visits was similar in the 3-day periods before and after spraying (510 vs. 501, p = 0.78). In multivariate analyses, daily rates of asthma visits were not associated with pesticide spraying (rate ratio = 0.92; 95% confidence interval, 0.80-1.07). Secondary analyses among children and for chronic obstructive pulmonary disease yielded similar null results. This analysis shows that spraying pyrethroids for WNV control in New York City was not followed by population-level increases in public hospital ED visit rates for asthma.     

Associations between grass and weed pollen and emergency department visits for asthma among children in Montreal

CONTEXT AND OBJECTIVE: Asthma among children is a major public health problem worldwide. There are increasing number of studies suggesting a possible association between allergenic pollen and exacerbations of asthma. In the context of global climate change, a number of future climate and air pollution scenarios predict increases in concentrations of pollen, an extension of the pollen season, and an increase in the allergenicity of pollen. The goal of the present study is to evaluate the short-term effects of exposure to grass and weed pollen on emergency department visits and readmissions for asthma among children aged 0-9 years living in Montreal between April and October, 1994-2004. METHODOLOGY AND RESULTS: Time-series analyses were carried out using parametric log-linear overdispersed Poisson models that were adjusted for temporal variations, daily weather conditions (temperature, atmospheric pressure), and gaseous air pollutants (ozone and nitrogen dioxide). We have found positive associations between emergency department visits and concentrations of grass pollen 3 days after exposure. The effect of grass pollen was higher on emergency department readmissions as compared to initial visits. Weak negative associations were found between weed pollen (including ragweed pollen) and emergency department visits 2 days after exposure. CONCLUSION: The data indicate that among children, emergency department visits increased with increasing concentrations of grass pollen.     

Outdoor air pollution and emergency department visits for asthma among children and adults: A case-crossover study in northern Alberta,Canada

Background  

Recent studies have observed positive associations between outdoor air pollution and emergency department (ED) visits for asthma. However, few have examined the possible confounding influence of aeroallergens, or reported findings among very young children.     

Associations between atmospheric concentrations of spores and emergency department visits for asthma among children living in Montreal

The authors carried out a time-series study to determine whether short-term increases in the concentrations of spores were associated with emergency department visits from asthma among children 0 to 9 years of age in Montreal, 1994-2004. Concentrations of spores were obtained from one sampling monitor. The authors used parametric Poisson models to model the association between daily admissions to emergency rooms for asthma and ambient exposures to a variety of spores, adjusting for secular trends, changes in weather, and chemical pollutants. For first admissions and exposures to Basidiomycetes, the authors found positive associations at all lags but the concurrent day. For Deuteromycetes and Cladosporium, risks were positive starting at lag 3 days and diminished at lag 6 days. There was little evidence of associations for readmissions, except for Basidiomycetes. The results indicate that Basidiomycetes and Cladosporium spores may be implicated in the exacerbation of asthma among children, most notably in the case of first-time visits to emergency departments, and that the effects appear to be delayed by several days.     

Association between continuity of care and emergency department visits and hospitalization in senior adults with asthma-COPD overlap

Objective

To investigate associations between continuity of care (COC) and emergency department (ED) visits and hospitalization for chronic obstructive pulmonary disease (COPD) or asthma among elderly adults with asthma-COPD overlap (ACO).

Air pollution and emergency department visits for asthma among Ohio Medicaid recipients, 1991-1996

We examined the effects of nitrogen dioxide (NO(2)), ozone (O(3)), particulate matter of <10 microm aerodynamic diameter (PM(10)), and sulfur dioxide (SO(2)) on asthmatics ages 5-34 years enrolled in Medicaid in Cincinnati, Cleveland, and Columbus, OH (N=5416). Our study period was for the summer months, June-August, from July 1, 1991 to June 30, 1996. We preformed Poisson regression analyses for the number of daily emergency department (ED) visits for asthma in each city and on the aggregate data controlling for time trends and minimum temperature. We found a 12% increased likelihood of an asthma ED visit per 50 microg/m(3) increase in PM(10) in Cleveland [95% confidence interval (CI)=0-27%] and a 35% increase per 50 microg/m(3) increase in SO(2) in Cincinnati (95% CI=9-21%). When data were analyzed for all three cities combined, the risk of an ED visit increased for all pollutant increases and specifically by 12% (95% CI=1-23%) per 50 microg/m(3) increase in SO(2). Attributable risk estimates show a five times greater impact on Cleveland over Cincinnati or Columbus. Between 1991 and 1996, air pollutants in Cincinnati, Cleveland, and Columbus increased ED visits for asthmatics enrolled in Medicaid.