http://www.sltrib.com/news/5501880-155/utah-physicians-group-alarmed-by-studies

“The first of the studies, published last month in the New England Journal of Medicine, links chronic exposure to low levels of pollution with increased odds of premature death. . . A second study, published earlier this month in the International Journal of Environmental Research and Public Health, ties ozone exposure to pregnancy loss. When pregnant women are exposed to ozone shortly before delivery, they were between 13 percent and 22 percent more likely to experience stillbirth, according to the study. . . That analysis also estimated that 8,000 infants are stillborn every year the U.S. due to ozone pollution.”