Mutagenic activity of non-volatile organic matter associated with suspended matter in urban air.

Extracts of atmospheric suspended matter showed a direct mutagenic effect in the Ames test. This effect was increased by metabolic activation. These extracts were separated into an aliphatic, an aromatic and a polar fraction. The aliphatic fraction had no effect, with or without activation; the aromatic fraction showed the greatest mutagenicity with and without activation; the polar fraction was also mutagenic, but its metabolic activation did not enhance the effect. The active compounds in this last fraction could be represented in a significant part by oxygenated derivatives of polycyclic aromatic hydrocarbons.

[Potentiometric determination of urinary thiocyanates (author's transl)]. / Dosage potentiométrique des thiocyanates urinaires.

A sensitive, reproductible and specific technique for the quantitative determination of urinary thiocyanates is proposed. Its analytical characteristics make it feasible for epidemiological surveys of populations potentially exposed to cyanides.

[Particulate distribution of heavy hydrocarbons associated with suspended particles in the air of Belgium]. / Répartition granulométrique des hydrocarbures lourds associés aux particules en suspension dans l'air de La Belgique.

In order to study in more detail the possibility of transporting aerosols produced by combustion over long distances, the distribution of heavy hydrocarbons (polycyclic and paraffinic) on atmospheric particles has been studied according to their diameter. For this purpose the Anderson cascade impactor has been used. The results show that the hypothesis, that hydrocarbon aerosols are transported over long distaces, is perfectly plausible and thus, that aromatic polycyclic hydrocarbons are more accurate and specific indicators than the total hydrocarbon matter.

[Estimation of atmospheric benzo(a)pyrene using fluorimetry coupled with liquid scintillation spectrometry (author's transl)]. / Dosage du benzo (a) pyrène atmosphérique à scintillation liquide

Methods for the rapid determination of benzo(a)pyrene rest mainly on the separation of the substance by thin-layer chromatography, followed by its spectrophotometric or fluorimetric estimation. Published papers seldom state the recovery results. It is shown here that, with the aid of radioactive benzo(a)pyrene tracer and liquid scintillation spectrometry, recovery becomes poorer and less reproducible as the sample decreases in size (to less than 1 mug benzo(a)pyrene). Coupling fluorimetry with liquid scintillation spectrometry provides an easy means of reducing this common source of error.