The effect of weather and air pollution on the prevalence of headaches

ABSTRACT

Background: Some epidemiological studies have indicated that weather and air pollution can cause adverse health conditions and that these effects can exhibit regional variation. The prevalence of headache is so high and it is a common cause of morbidity. Therefore, this study evaluated whether weather and air pollution were associated with the prevalence of headaches. Methods: A symmetric bidirectional case-crossover design was applied, using conditional logistic regression models to determine the association between headaches and weather and air pollution. From January 2006 to August 2007, a total of 245 patients with headaches were recruited. Headache subtypes were classifi ed as migraine, tension-type headaches, and others. Meteorological data (average temperature and relative humidity) and values related to air pollutants (CO, NO2 , O3 , SO2 , and particulate matter with an aerodynamic diameter of less than 10 μm) were obtained. Results: Higher average temperatures were associated with the total number of headaches (hazard ratio 1.124-1.130; P<0.001). With regard to headache subtype, O3 seems to provoke headaches, especially those related to tension and those listed as other headache varieties. Conversely, other pollutants, especially CO and SO2 , showed the opposite association. Conclusions: These fi ndings indicated that temperature and some air pollutants are able to affect headaches, suggesting that weather and air pollution levels seem to have an effect on the risk of headache.