Air pollution during New Year's fireworks and daily mortality in the Netherlands.

Short-term exposure to air pollution has been associated with cardiovascular and respiratory mortality and morbidity. Little is known about associations between air pollution caused by firework events and daily mortality. We investigated whether particulate matter from fireworks during New Year's celebrations was associated with daily mortality. We analyzed the celebrations of the years 1995-2012. PM concentrations increased dramatically during the firework events. Countrywide, the daily average PM concentrations from 27-30 December was 29 μg/m and increased during the first hour of the New Year by 277 μg/m. In the more densely populated areas of the Netherlands the increase was even steeper, 598 μg/m in the first hour of the New Year. No consistent associations were found using linear regression models between PM concentrations during the first six hours of 1 January and daily mortality in the general population. Yet, using a case-crossover analysis firework-days and PM concentrations were associated with daily mortality. Therefore, in light of the contradictory results obtained with the different statistical analyses, we recommend further epidemiological research on the health effects of exposure to firework emissions.