Airplane emissions: a source of mutagenic nitrated polycyclic aromatic hydrocarbons.

Organic solvent extracts from airplane emission particulates are mutagenic for Salmonella typhimurium strain TA98. Using Salmonella tester strains deficient in enzymes required for the bioactivation of various nitroarenes, the mutagenicity present in these emissions was ascribed to the presence of nitrated polycyclic aromatic hydrocarbons. Based on the known aircraft particulate emission rates at U.S. airports, and using 1-nitropyrene (1-NP) and 1,8-dinitropyrene (1,8-DNP) as surrogates, it is calculated that at a minimum 7 kg 1-NP and 20 g, 1,8-DNP are emitted daily at a typical U.S. airport.

The relationship of supplemental iodine to neural tube defects in Rochester, New York, 1924-1932.

The geographic distribution of infants born with anencephaly and spina bifida in Rochester, New York, in 1924-1932, was examined to test the hypothesis that iodine supplemented water may have reduced the prevalence of these defects. During this period the region had a high prevalence of iodine deficiencies. Comparing the prevalence of neural tube defects in an area with iodine supplemented water to one without iodine supplementation, we found no significant difference in prevalence at birth of neural tube defects. Because the prevalence rates for these defects in children of foreign-born parents (except the Irish) was low, we reexamined the data, excluding these cases. There remained no differences in rates. Iodine supplemented water thus appears to have had no effect on the occurrence of neural tube defects.