Formation and Fate of Toxic Chemicals in California's Atmosphere. Final Report July 10, 1984-November 22, 1985

摘要

An experimental program has been carried out utilizing environmental chambers with in situ long pathlength Fourier transform infrared spectroscopy, a flash photolysis-resonance fluorescence apparatus and combined gas chromatography-mass spectrometry (GC/MS) to investigate the atmospheric chemistry of trimethylphosphate, nitrobenzene, chlorobenzene, aniline, N,N-dimethylaniline, pyridine, 1,3,5-triazine, and methylethyl-, dimethyl- and trimethylamine, a series of chemical compounds closely related to toxic air contaminants in present use by industry and in agricultural operations. In addition, 1,2-dibromo-3-chloropropane (DBCP), until last year a widely-used soil fumigant and nematicide, was studied. The kinetic data obtained allowed atmospheric lifetimes to be calculated for the reaction of these chemicals with hydroxyl (OH) radicals and with ozone, and for certain of the N-containing agents with gaseous nitric acid (HNO3). In all cases, reaction with O3 was a minor atmospheric loss process. The atmospheric lifetimes of the 12 compounds against reaction with OH radicals (their major loss process under clean or moderately polluted conditions) ranged from 1 hr in the case of N,N-dimethylaniline and aniline to approximately 150 days for 1,3,5-triazine. The influence of the calculated lifetimes on the geographical distribution and impacts of these chemicals is discussed.