Urinary and faecal mutagenicity in car mechanics exposed to diesel exhaust and in unexposed office workers.

Abstract The occurrence of mutagens in the urine and faeces of a group of car mechanics (n = 8) exposed to high concentrations of diesel exhaust in their working place and of a group of office workers (n = 9) not exposed to diesel exhaust during working hours was compared. The aim of the study was to investigate whether the specific diesel exposure and/or other, more lifestyle-related, factors such as diet had any influence on the mutagenicity of excreta. Faeces were collected and pooled for a consecutive period of 48 h, urine was collected in the same period, but in 4 separate portions representing the urine produced during the day and at night on the 2 collection days. Information about food intake was collected by a 2-day dietary record method. Smoking habits and medicinal drug use were recorded as well. Air particulates were collected in and outside the garage during working hours. The mutagenicity of extracts of air particulates (methanol extracts), urine (XAD-2 and XAD-7 extracts) and faeces (acetone, ether and ether-NaOH extracts) was examined in the Ames test. The results did not suggest that exposure to diesel exhaust mutagens enhanced the incidence and/or degree of either faecal or urinary mutagenicity. Urine of 2 mechanics appeared to contain rather high levels of XAD-7 mutagens, but in view of the uneven distribution over the different collection periods any relationship with the exposure to diesel exhaust mutagens seems improbable. Degree and frequency of faecal mutagenicity was higher in office workers than in mechanics. The pattern of faecal mutagenicity was characteristic of that of faecapentaenes. Statistical analysis did not reveal any consistent relationships between urinary and faecal mutagenicity and the various dietary variables.