Long-term exposure to air pollution increases risk of recurrent headache in kids

Migraines, characterized by recurrent headaches, are among the most common childhood headaches. Furthermore, childhood migraine may persist into adulthood. The influence of environmental factors on the attacks of migraine/recurrent headaches leads to extensive debate over the past decades. Indeed, environmental factors, such as air pollutants and weather, may produce neurogenic inflammation and trigger migraine/recurrent headaches onset. To date, several studies have suggested an association between some outdoor air pollutants and frequency, severity, or medical consultation rates for headaches. Although studies have suggested environmental factors to be triggers of headache, the contribution of long-term air pollution exposure to recurrent headaches is poorly understood especially in children. Therefore, researchers of China Medical University, Taiwan conducted a nationwide cohort study to investigate associations between levels of ambient air pollutants and risks of recurrent headaches in children in Taiwan from 2000 to 2012.

Researchers used data from the Taiwan National Health Insurance Research Database (NHIRD) and linked them to the Taiwan Air Quality Monitoring Database (TAQMD). They identified 218,008 children aged less than 18 and evaluated them from 1 January 2000, and then followed until they were diagnosed by a physician for ≥3 times with recurrent headaches or until 31 December 2012. They categorized the annual average concentration of each air pollutant (fine particulate matter, total hydrocarbon, methane, sulfur dioxide, and nitrogen dioxide) into quartiles (Q1–Q4).