Exposure to n-nitrosodimethylamine in a leather tannery

Abstract N -Nitrosodimethylamine (NDMA) was detected in the atmosphere of a leather tannery at levels of up to 47 μg/m 3 . As far as we know this is the highest occupational exposure to this potent animal carcinogen yet discovered. NDMA was detected in all the air samples taken at different sites in the tannery on three visits in 1978. The highest level was in the re-tanning, colouring and fat-liquoring area. The average atmospheric level of NDMA on the first and second visits was 19 μg/m 3 . The levels were considerably reduced on the third visit, when the tannery had been thoroughly cleaned, and ranged from 0·1 to 3·4 μg/m 3 . Small amounts of NDMA were also found in process and waste water. The tannery examined uses basic processes that are standard within the industry; therefore, NDMA may also contaminate the atmosphere of other tanneries. Exposure of tannery workers to NDMA suggests an area for epidemiological studies, as well as for further analytical work, which could contribute to a knowledge of the possible carcinogenic effects of NDMA in man.