[Polar neutral organic compounds in urban aerosols. 1. Chemical characterization and mutagenic effect in relation to various sources].

Abstract

Airborne particulate matter was collected by high volume samplers at two sampling stations in Berlin (West) between March 1983 and February 1984 (immissions). The stations were choosen so that two main-sources of urban air pollution could be considered (automobile) traffic and private fuel combustion (domesticfuel). Also in February and March 1983 particles were collected from private coal firing (emissions). The collected particles were fractionated into the following particle sizes (immissions, during October 1983-February 1984): greater than 7.2 microns, 7.2-1.5 microns and less than 1.5 micron (aerodynamic diameter). The etherextractable organic matter of the particles (= EEOM) was determined and the organic matter was then separated into acidic, basic, and neutral fractions. The neutral fraction was further separated into aliphatic compounds (= AlP), polycyclic aromatic hydrocarbons (= PAH), and polar neutral compounds (= POCN) by thin layer chromatography. The mutagenic activity of all organic fractions was determined by using the mammalian microsome bioassay by Ames and was compared with the activity of a whole polar organic extract (including POCN, acidic and basic fraction), a whole neutral extract, and a whole ethersoluble organic extract. Also in February 1984 the nitroreductase specific mutagenicity on immission-stations was determined using nitroreductase deficient strains. Some compounds of the POCN-fraction, and of PAH (in comparison) were identified by gas chromatography. The following results were obtained: The neutral fraction of the organic matter amounted to 70-90% of the EEOM (not depending from particle size, immissions and emissions). The separation of the neutral compounds into AlP, PAH and POCN showed a higher amount of AlP at the collecting station which includes mainly automobile traffic. Some cancer and/or mutagenic suspect compounds were identified by the chromatographic analysis of POCN and PAH. A higher amount of several nitrogroups-containing POCN was found at the collecting station which includes mainly private combustion whereas at the station including mainly automobile traffic 1-nitropyrene was the main compound. The POCN-fraction showed the mostly highest mutagenic activity in the Ames bioassay, mainly for lung penetrating particles (less than 1.5 micron diameter). The whole organic extract (EEOM) showed a lower mutagenic activity than the POCN-fraction. Using nitroreductase deficient strains, at the collecting station which includes mainly private fuel combustion a higher reduction of mutagenicity was shown than at the automobile-traffic including measurement station.