Stronger associations between daily mortality and fine particulate air pollution in summer than in winter: evidence from a heavily polluted region in western Europe.
J Epidemiol Community Health
; 61(2): 146-9, 2007 Feb.
Article
in En
| MEDLINE
| ID: mdl-17234874
ABSTRACT
BACKGROUND:
Numerous studies have shown a strong association between daily mortality and small particulate with a diameter of <10 microm (PM10) air pollution, but the effects of season have not always been well characterised.AIM:
To study the shape of the association between short-term mortality and PM10 across seasons and quintiles of outdoor temperature. DESIGN, SETTING ANDPARTICIPANTS:
Daily data on mortality (n = 354 357), outdoor temperature and PM10 in Flanders, Belgium, from January 1997 to December 2003, were analysed across warm versus cold periods of the year (April-September v October-March), with seasons and quintiles of outdoor temperature as possible effect modifiers.RESULTS:
There was a significant (p<0.001) interaction between PM10 and period of the year in relation to mortality. To allow for non-linearity, daily mean PM10 concentrations were categorised into quartiles. Season-specific PM10 quartiles showed a strong and steep linear association between mortality and PM10 in summer and a less linear association in spring and autumn, whereas in winter the association was less strong and mortality was only increased in the highest PM10 quartile. The effect sizes expressed as the percentage increase in mortality on days in the highest season-specific PM(10) quartile versus the lowest season-specific PM10 quartile were 7.8% (95% CI 6.1 to 9.6) in summer, 6.3% (4.7 to 7.8) in spring, 2.2% (0.58 to 3.8) in autumn and 1.4% (0.06 to 2.9) in winter. An analysis by quintiles of temperature confirmed these effect sizes.CONCLUSION:
The short-term effect of particulate air pollution on mortality strongly depends on outdoor temperature, even in a temperate climate.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Respiration Disorders
/
Seasons
/
Environmental Monitoring
/
Air Pollutants
/
Air Pollution
/
Particulate Matter
Type of study:
Diagnostic_studies
/
Etiology_studies
/
Risk_factors_studies
Limits:
Humans
Country/Region as subject:
Europa
Language:
En
Journal:
J Epidemiol Community Health
Year:
2007
Type:
Article
Affiliation country:
Belgium