Children whose mothers were exposed to high levels of ultrafine particulate pollution while they were in utero were more likely to develop asthma, new research has found. The study, published in the American Journal of Respiratory and Critical Care Medicine, followed about 375 mostly Black and Latina women in the Boston metro area, and found 18% of their children developed asthma as preschoolers, more than double the nationwide 7% average. Many of the women studied were more likely to live near busy roads, where levels of particulate matter 0.1 microns in diameter, are higher. Particulates pollution 2.5 microns wide (PM2.5) is regulated by EPA, but the extremely fine pollution tracked in study is not. (E&E $)