NEW YORK (Reuters Health) - High outdoor levels of nitrogen dioxide apparently raise the risk of sudden infant death syndrome (SIDS), according to California-based researchers.
Dr. H. Klonoff-Cohen, from the University of California San Diego at La Jolla, and colleagues linked air pollutant data obtained from the California Air Resources Board with occurrences of SIDS.
The study, in the Archives of Disease in Childhood, involved 169 infants born between 1988 and 1992 who died suddenly and 169 matched "controls" who were born during the same period.
The incidence of SIDS cases went up and down with average carbon monoxide and nitrogen dioxide levels, but only the latter was significant from a statistical standpoint.
High levels of nitrogen dioxide more than doubled the risk of SIDS, even after accounting for tobacco smoke exposure.
This is the first study to implicate high outdoor levels of nitrogen dioxide as a risk factor for SIDS, the researchers comment. However, they add that it did not allow for seasonal variation of respiratory infections, which should be included in future investigations.
SOURCE: Archives of Disease in Childhood, July 2005.