Associations between personal exposure to air pollutants and lung function tests and cardiovascular indices among children with asthma living near an industrial complex and petroleum refineries.

OBJECTIVE: The acute cardiorespiratory effects of air quality among children living in areas with considerable heavy industry have not been well investigated. We conducted a panel study of children with asthma living in proximity to an industrial complex housing two refineries in Montreal, Quebec, in order to assess associations between their personal daily exposure to air pollutants and changes in pulmonary function and selected indicators of cardiovascular health. METHODS: Seventy-two children with asthma age 7-12 years in 2009-2010 participated in this panel study for a period of 10 consecutive days. They carried a small backpack for personal monitoring of sulphur dioxide (SO2), benzene, fine particles (PM2.5), nitrogen dioxide (NO2) and polycyclic aromatic hydrocarbons (PAHs) and underwent daily spirometry and cardiovascular testing (blood pressure, pulse rate and oxygen saturation). To estimate these associations, we used mixed regression models, adjusting for within-subject serial correlation, and for the effects of a number of personal and environmental variables (e.g., medication use, ethnicity, temperature). RESULTS: Children with asthma involved in the study had relatively good pulmonary function test results (mean FEV1 compared to standard values: 89.8%, mean FVC: 97.6%, mean FEF25-75: 76.3%). Median diastolic, systolic blood pressures and oxygen saturation were 60/94 mmHg and 99%, respectively. Median personal concentrations of pollutants were NO2, 5.5 ppb; benzene, 2.1 µg/m(3); PM2.5, 5.7 µg/m(3); and total PAH, 130 µg/m(3). Most personal concentrations of SO2 were below the level of detection. No consistent associations were observed between cardio-pulmonary indices and personal exposure to PM2.5, NO2 and benzene, although there was a suggestion for a small decrease in respiratory function with total concentrations of PAHs (e.g., adjusted association with FVC: -9.9 ml per interquartile range 95%CI: -23.4, 3.7). CONCLUSIONS: This study suggests that at low daily average levels of exposure to industrial emissions, effects on pulmonary and cardiovascular functions in children with asthma may be difficult to detect over 10 consecutive days.

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.

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.