Back to Search
Start Over
Molecular Compositions, Mutagenicity, and Mutation Spectra of Atmospheric Oxidation Products of Alkenes and Dienes Initiated by NOx + UV or Ozone: A Structure-Activity Analysis.
- Source :
-
Environmental science & technology [Environ Sci Technol] 2024 Oct 22; Vol. 58 (42), pp. 18846-18855. Date of Electronic Publication: 2024 Oct 07. - Publication Year :
- 2024
-
Abstract
- Photooxidation products resulting from volatile organic compounds (VOCs) reacting with sunlight are important contributors to gas-phase air pollution. We characterized the product-weighted mutagenic potencies (rev m <superscript>3</superscript> mgC <superscript>-1</superscript> h <superscript>-1</superscript> ) in Salmonella TA100 of atmospheres resulting from the hydroxyl radical (OH)-initiated photochemical oxidation of 11 C <subscript>4</subscript> or C <subscript>5</subscript> alkenes or dienes in the presence of nitric oxide (NO) and from the ozonolysis of four VOCs without NO (isoprene; 1,3-pentadiene; 1,4-pentadiene; and 1,3-butadiene). Irradiated atmospheres from precursors with a single C═C bond (3-methyl-1-butene, 2-methyl-1-butene, cis/trans -2-pentene, 2-methyl-2-butene, 1-butene, and 1-pentene) had low potencies (<5), whereas linear dienes with terminal C═C bonds had high potencies (50-65). Dienes with a branched structure (isoprene) or internal C═C bonds (1,3-pentadiene) had intermediate potencies (15-20). No VOCs were mutagenic without photochemical oxidation. VOCs+O <subscript>3</subscript> in the dark produced less mutagenic atmospheres than photochemistry in the presence of NO. Atmospheres induced primarily C to T and C to A mutations, the main base substitutions in nonsmoker lung cancer. Atmospheres from the photooxidation of isoprene and 1,3-pentadiene also induced GG to TT, the signature mutation of peroxyacetyl nitrate. Five molecular compositions identified by Chemical Ionization Mass Spectrometry (CIMS), most containing nitrogen, correlated ( r = 0.76-0.85) with the mutagenic potencies of irradiated atmospheres; most had a likely nitrate functional group. Assessment of the mutagenicity of emitted VOCs should consider VOC photooxidation products, especially dienes with terminal C═C bonds, as these products likely contribute to overall health effects from ambient air pollution.
Details
- Language :
- English
- ISSN :
- 1520-5851
- Volume :
- 58
- Issue :
- 42
- Database :
- MEDLINE
- Journal :
- Environmental science & technology
- Publication Type :
- Academic Journal
- Accession number :
- 39374177
- Full Text :
- https://doi.org/10.1021/acs.est.4c04603