气候变化领域集成服务门户

No study has evaluated the mutagenicity of atmospheres with a calculated air quality health index (AQHI). Thus, we generated in a UV-light-containing reaction chamber two simulated atmospheres (SAs) with similar AQHIs but different proportions of criteria pollutants and evaluated them for mutagenicity in three Salmonella strains at the air-agar interface. We continuously injected into the chamber gasoline, nitric oxide, and ammonium sulfate, as well as either alpha-pinene to produce SA-PM, which had a high concentration of particulate matter (PM): 119 ppb ozone (O-3), 321 ppb NO2, and 1007 mu g/m(3) PM2.5; or isoprene to produce SA-O-3, which had a high ozone (O-3) concentration: 415 ppb O-3, 633 ppb NO2, and 55 mu g/m(3)PM(2.5). Neither PM2.5 extracts, NO2, or O-3 alone, nor nonphoto-oxidized mixtures were mutagenic or cytotoxic. Both photo-oxidized atmospheres were largely direct-acting base substitution mutagens with similar mutagenic potencies in TA100 and TA104. The mutagenic potencies [(revertants/h)/(mgC/m(3))] of SA-PM (4.3 +/- 0.4) and SA-O-3 (9.5 +/- 1.3) in TA100 were significantly different (P < 0.0001), but the mutation spectra were not (P = 0.16), being similar to 54% C T and similar to 46% C -> A. Thus, the AQHI may have some predictive value for the mutagenicity of the gas phase of air.