A larger pool of ozone-forming carbon compounds in urban atmospheres

Volatile organic compounds play a central role in the processes that generate both urban photochemical smog and tropospheric ozone. For successful and accurate prediction of these pollution episodes, identification of the dominant reactive species within the volatile organic carbon pool is needed. At present, lack of resolution inherent in single-column chromatographic analysis limits such a detailed chemical characterization of the complex urban atmosphere. Here we present an improved method of peak deconvolution from double-column (orthogonal) gas chromatography. This has enabled us to isolate and classify more than 500 chemical species of volatile organic compounds in urban air, including over 100 multi-substituted monoaromatic and volatile oxygenated hydrocarbons. We suggest that previous assessments of reactive carbon species may therefore have underestimated the contribution made by volatile organic compounds to urban pollution, particularly for compounds with more than six carbon atoms. Incorporating these species in predictive models should greatly improve our understanding of photochemical ozone yields and the formation of harmful secondary organic aerosols.     

A possible chemical basis for the higher mutagenicity of marijuana smoke as compared to tobacco smoke

Summary The results of comparative analyses of polynuclear aromatic hydrocarbons in marijuana and tobacco smoke indicate a considerably higher content of potential carcinogens in the former. A model experiment involving ⁹-tetrahydrocannabinol suggests that the pyrolysis products of cannabinoids are major contributors to the polynuclear aromatic hydrocarbons.We thank Dr.John Benner and Ms.Carolyn Keene of the University of Kentucky for help with the smoking experiments. This work was supported by Grant No. R01-DA-00507-01 from the National Institute of Mental Health.     

A possible chemical basis for the higher mutagenicity of marijuana smoke as compared to tobacco smoke.

The results of comparative anslyses of polynuclear aromatic hydrocarbons in marijuana and tobacco smoke indicate a considerably higher content of potential carcinogens in the former. A model experiment involving delta9-tetrahydrocannabinol suggests that the pyrolysis products of cannabinoids are major contributors to the polynuclear aromatic hydrocarbons.