REPORT FROM THE ACTRIMS-ECTRIMS – BOSTON, MA, SEPTEMBER 10-13, 2014 – Few studies have examined the potential impact of ambient air quality and airborne particulates on multiple sclerosis. A decade ago, a study in Finland suggested that the frequency of MS relapses was higher with increasing levels of inhaled particulates (Oikonen et al. Neuroepidemiology 2003;22:95-99).