Daily children's hospital admissions for asthma, air pollution and meteorological conditions in Montreal, Canada

Epidemiological studies have shown significant increases in the prevalence and incidence of childhood asthma and many studies in a range of geographical locations have indicated relationships between numbers of cases, air quality and meteorological conditions. This study is based on daily admissions of acute asthmatic patients at the Montreal Children’s Hospital from 1990 to 1998. Additional information on the gender and age of each child is also included. Air quality data is available on an hourly basis for three stations in the Montreal area operated by the Montreal Urban Community which measure sulphur dioxide, carbon monoxide, ozone, particulate matter, coefficient of haze, nitric oxide and nitrogen dioxide. Hourly data for temperature, humidity, precipitation and wind speed are taken from Dorval International Airport, eight kilometers west of the city center. Preliminary results, concentrating on 1997, indicate twice as many male as female admissions, more admissions in winter than in summer, and greater explanatory power if the meteorological and pollution variables are lagged by one or two days. Significant relationships are found between admissions and maximum daily values of temperature, ozone, carbon monoxide, nitric oxide and relative humidity