To the genotoxicity of stack gas condensates of Bavarian waste incineration plants - III. Emission monitoring with a simple UDS assay using the humanlung cell lines NCl-H 322 and 358

For the validation of the genotoxicity testing on stack gas condensates fro m waste incineration plants using bacterial short time tests (15), a modifi ed UDS assay with the lung cell lines NCI-H 322 and 358 was developed. The UDS assay is more sensitive than the SOS chromotest and discriminates bette r between the negative or weakly positive and the clearly positive samples. It has a high sensitivity and specificity and also accuracy, is practicabl e in a comparatively simple, speedy and reasonably priced manner and is the refore appropriate for an emission monitoring similar to simple bacterial s hort time tests. Especially in strongly concentrated crude and clean gas condensates, maxima l induction factors were seen in the range of strong UDS inducers. From 55 samples on 16 incineration plants tested in the years 1992 to 1995, in 48 w e found weak to strong UDS inductions in at least one of the two test cell lines. From three plants examined continuously in this period only two emit ted stack gases with constantly low genotoxicity at the end of sampling. 5 clean gas condensates, that were taken in random samples from 3 other plant s in the period 1994 to 1995, proved to be non-genotoxic in the UDS assay. However, one of these plants emitted stack gases with high cytotoxicity,whi ch might have masked UDS-inducing single substances. It is not possible to make a statement on the human toxicological relevance. However, a clearly p ositive development towards more harmless stack gas condensates was establi shed. A definite correlation could not be shown between the chemical analysis of the detected cancerogenic organic single substances of the samples and the detected UDS inductions. Further investigations for finding strong UDS indu cers from the substance spectrum of municipal stack gas emissions are neces sary.