Short-term associations between outdoor air pollution and mortality in London 1992-4.

Abstract

Objectives-A previous study of the short term eVects of air pollution in London from April 1987 to March 1992 found associations between all cause mortality and black smoke and ozone, but no clear evidence of specificity for cardiorespiratory deaths. London data from 1992 to 1994 were analysed to examine the consistency of results over time and to include particles with a mean aerodynamic diameter of 10 µm (PM 10 ) and carbon monoxide. Methods-Poisson regression was used of daily mortality counts grouped by age and diagnosis, adjusting for trend, seasonality, calendar eVects, deaths from influenza, meteorology, and serial correlation. The pollutants examined were particles (PM 10 and black smoke), nitrogen dioxide, ozone, sulphur dioxide, and carbon monoxide with single and cumulative lags up to 3 days. Results-No significant associations were found between any pollutant and all cause mortality, but, with the exception of ozone, all estimates were positive. Each pollutant apart from ozone was significantly associated with respiratory mortality; PM 10 showed the largest eVect (4% increase in deaths of all ages for a 10th-90th percentile increment). The pollutants significantly associated with cardiovascular deaths were nitrogen dioxide, ozone, and black smoke but there was no evidence of an association with PM 10 . In two pollutant models of respiratory deaths, the eVect of black smoke, which in London indicates fine particles of diesel origin, was independent of that of PM 10 , but not vice versa. Conclusion-These results from a new data set confirm a previous report that there are associations between various air pollutants and daily mortality in London. This new study found greater specificity for associations with respiratory and cardiovascular deaths, and this increases the plausibility of a causal explanation. However, the eVects of ozone found in the earlier study were not replicated. The fraction of PM 10 which comprises black smoke accounted for much of the eVect of PM 10 . (Occup Environ Med 1999;56:237-244)

Effect of air pollution on daily mortality in Hong Kong.

“…These observations are consistent with those reported by Bremner et al (29) in London: the effects increased from lag-day 0 to a maximum at lag-day 1 for NO 2 , SO 2 , and PM 10 .…”

Comparison of different exposure settings in a case–crossover study on air pollution and daily mortality: counterintuitive results

“…For the other two age categories, ages 0-14 and 15-64 years, results were available from three studies conducted in London (Atkinson et al, 1999), West Midlands (Bremner et al, 1999) and Rome (Michelozzi et al, 2000) (Tables A4). Together these cities represent a population in excess of 10 million people. A meta-analysis of results from these three cities gave summary estimates of 1.010 (0.998, 1.021) and 1.008 (1.001, 1.015) per 10 µg/m 3 increases in PM 10 for respiratory admissions, ages 0-14 and 15-64 years respectively.…”

Air conditioning and source-specific particles as modifiers of the effect of PM(10) on hospital admissions for heart and lung disease.

“…An epidemiologic study in the Netherlands showed that exposure to diesel exhaust particles, measured as either truck traffic density or classroom black smoke concentrations, was significantly associated with reduced lung function and increased prevalence of chronic respiratory symptoms in school children (26,27). In addition, deaths from cardiovascular disease in European cities have been associated with ambient concentrations of black smoke, for which the major source is diesel-powered vehicles, with the effect estimates of black smoke being more stable than those for PM 10 (21,28).…”