Ambient air pollution, weather and daily emergency department visits for headache.

Background: Headache is a common condition, and a common complaint leading patients to emergency departments (ED). There have been a number of studies of the effect of environmental factors on headache, such as weather and air pollutants.

Methods: This retrospective cohort study included data on daily ED visits with a chief complaint of headache in Soroka University Medical Center (SUMC) during 2002-2012. Data on weather and air pollutants were obtained from monitor station in Be'er-Sheva. To estimate the short-term effects of air pollution and temperature on number of daily headache ED visits, we applied generalized linear mixed models (GLMM).

Results: A total of 22,021 ED visits were included in the analysis. An increase in 5℃ in temperature was associated with an increase in ED visits, relative risk (RR) = 1.042, (95% CI 1.009; 1.076). RR for headache was associated with an increase in 10 units of nitrogen dioxide (NO2), RR = 1.110 (95% CI 1.057; 1.167), with a higher effect for older patients.

Discussion: The current findings give evidence of an association between air pollution, weather and ED visits for headache, especially for NO2. Short-term increases in air pollution exposure may trigger headache by increasing pulmonary and systemic inflammation, increasing blood coagulability or altering endothelial function.