Enzyme induction in rat lung and liver by condensates and fractions from main-stream and side-stream cigarette smoke

Aryl hydrocarbon hydroxylase (AHH) and dimethylnitrosamine demethylase (DMND) activities in pulmonary and hepatic tissues of male Sprague-Dawley rats were assayed following pretreatment with known inducers (benzo[a]pyrene, 3-methylcholanthrene, Aroclor 1254, phenobarbital) and with main-stream (MS) and side-stream (SS) cigarette smoke condensates and their related fractions. Biochemical assays by spectrophotofluorimetry (AHH activity) and spectrophotometry (DMND activity) and by a biological assay (Ames test) were performed to detect AHH and DMND induction. Ames test proved to be much less sensitive than the spectrophotofluorimetric analysis for AHH determination. Both main-stream and side-stream cigarette smoke condensates and some fractions, containing water-soluble bases, water-insoluble bases, and polycyclic aromatic hydrocarbons, were found to induce AHH activity in lung and liver, the lung being induced to the greatest extent. The highest levels of AHH inducibility were found for the SS-smoke condensate and related fractions. In particular, the insoluble bases fractions gave the highest induction. On the contrary, pulmonary DMND activity was not affected by pretreatment with the same materials, while hepatic DMND response was only minimally induced by Aroclor and phenobarbital treatment.

Environmental monitoring of mutagenic/carcinogenic hazards during road paving operations with bitumens

Environmental monitoring of mutagenic/carcinogenic hazards associated with occupational exposure to bitumen fumes was performed during road paving operations. Bitumen samples were collected and analysed for polycyclic aromatic hydrocarbons (PAH) content by HPLC and for mutagenicity by the Ames test. The exposure of sixteen road workers to bitumen fumes was studied. Time-weighted average values of bitumen fumes were determined by personal samplers. PAH concentration in the air and the mutagenicity of airborne particulates were also analysed. The results showed that bitumen samples contained low levels of total PAH (microgram/g) and were not mutagenic. Environmental monitoring showed a low level of exposure to bitumen fumes, which were found to contain only trace levels of PAH and not to be mutagenic. The authors suggest that these workers' exposure to mutagenic/carcinogenic agents is low.

Bone marrow transplantation in Brazil

The first program of bone marrow transplantation in Latin America was started 5 years ago at the Federal University Hospital, Curitiba, Paraná. The results of 62 patients who underwent bone marrow transplantation are presented and discussed.

Mutagenicity studies and D-glucaric acid determination in urine of workers exposed to mineral oils

Urine from workers of a cold-rolling steel plant exposed to mineral oils were tested for the mutagenic activity by the Salmonella/microsome assay, and for D-glucaric acid content as a measure of hepatic mixed-function oxidase activity. An occupationally unexposed group served as control. The biological monitoring phase followed an environmental phase carried out in the working environment that showed a substantially low mutagenic/carcinogenic risk for the exposed workers. Urine samples were collected before, during and after work. From the results it was observed that the urinary mutagenicity was detectable only with TA98 strain in the presence of enzymatic activation (+ S9 mix). Further addition of beta-glucuronidase did not give any enhanced mutagenic effects. There was a significant difference in urinary mutagenicity between the exposed and control workers. However, in both groups the highest mutagenicity data was found in smokers: both exposed smoking workers and smoking controls had significantly higher urine mutagenicity than the non-smoking exposed and control workers. The results suggested a synergistic effect of smoking with exposure to mineral oils: the mutagenicity of urine from exposed smokers was significantly higher than that of control smokers. There was no difference in urinary D-glucaric acid results between exposed and unexposed groups, however, smokers of both groups had a significant increase in D-glucaric acid excretion. The authors suggest that even for this workplace with its low mutagenic/carcinogenic risk, smoking could interact with the complex mixtures present in the environment, and thus modify urinary mutagenicity data.

Mutagenic/carcinogenic hazards in a cold-rolling steel plant exposed to mineral oils: environmental monitoring phase

A survey was carried out in a cold-rolling steel plant exposed to mineral oils to study the mutagenic/carcinogenic hazards, following a coupled environmental/biological monitoring. The present paper deals only with the environmental phase by determining polycyclic aromatic hydrocarbons (PAH) and applying a mutagenicity test (Ames test), and includes the following steps: (a) work process and environment study; (b) sampling and analysing mineral oils before and after use (PAH determination and mutagenicity analysis); (c) sampling and analysing oil mist (TWA determination, PAH determination and mutagenicity analysis). The results showed that: (1) both unused and used (recycled) mineral oils contained only trace amounts of PAH and were not mutagenic; (2) the TWA concentrations of oil mists were lower than the TLV (less than 5 mg/m3); (3) oil mists contained only trace amounts of PAH and were not mutagenic. The authors suggest that these results could be due to the moderate temperature of the oil during the work process and that there is a relationship between low PAH content and absence of mutagenicity in the oils and air samples.

Detection of mutagenic/carcinogenic compounds in unused and used motor oils

The discharge of used motor oils in the environment poses public health problems because of the mutagenic/carcinogenic compounds in them. Among these hazardous chemicals, polycyclic aromatic hydrocarbons (PAH) are of particular interest since the carcinogenic properties of some of them are known. The authors have applied the Salmonella/microsome test, coupled with two preparation methods of samples, to motor oils of different brands, both before and after use in car petrol engines. A PAH determination method was also studied. The results showed the unused motor oils to be nonmutagenic and to contain traces of PAH, while the used motor oils of the samples taken according to both preparation methods were highly mutagenic and contained a much higher quantity of mutagenic/carcinogenic PAH.

Mutagens in urine of carbon electrode workers

Following previous work carried out in an Italian factory producing carbon electrodes and evaluating the occupational mutagenic-carcinogenic hazards, the authors studied the presence of mutagen metabolites in the urine of workers in the same factory who were exposed to petroleum coke and pitch and in the urine of a control group of unexposed workers. The urine samples were concentrated by absorption on XAD-2 columns and were tested using the Salmonella/microsome assay (strain TA 98, TA 100, TA 1535, TA 1538) with and without the addition of beta-glucuronidase and metabolizing system. The collection of urine samples was carried out twice, with an interval of 2 months; "before working time", "after working time", and also during Sunday. The results showed that (1) urine samples collected "before" occupational exposure (upon waking) or on Sunday revealed no mutagenic activity in either worker groups and (2) that the urine samples collected after or during occupational exposure revealed high mutagenic activity in the exposed workers, with a statistically significant difference (P less than 0.05) between the mean of the revertants/plate values for exposed and unexposed workers. On the basis of the previous and the present research, the authors suggest that application of the Salmonella/microsome test to work environments could offer useful and suitable tool for evaluating the health hazards due to mutagenic/carcinogenic substances from occupational exposure.

Application of the Salmonella mutagenicity assay and determination of polycyclic aromatic hydrocarbons in workplaces exposed to petroleum pitch and petroleum coke

Workplaces of an Italian carbon electrode factory, exposed to petroleum pitch and petroleum coke, were studied using a coupled chemical and biological approach to evaluate occupational mutagenic/carcinogenic hazards. Analytical procedures for the determination of polycyclic aromatic hydrocarbons (PAH) and Salmonella/microsome mutagenicity tests (with TA98 and TA100 strains) were performed on both industrial ingredients (pitch and coke) and airborne particulate matter of the working environment, after fractionating by sequential Soxhlet extractions with four organic solvents of increasing polarity (benzene, chloroform, methanol and acetone). The results showed: (a) the presence of extraordinarily high PAH (carcinogenic and non-carcinogenic) contents in the benzene extracts of petroleum pitch (3.6 wt% of total PAH) and of airborne particulate samples (up to 0.35 wt% of total PAH), in correlation with very high indirect (after metabolic activation) mutagenic responses of benzene extracts with strain TA98; (b) very high indirect mutagenic responses in the other extracts of the airborne particulate samples (especially with strain TA98); (c) the production during the processing at high temperatures of directly acting mutagens (without metabolic activation) which were absent in the starting materials and their release in the air of workplaces. The comparison of chemical analytical and mutagenicity data has proved to be an interesting approach for better defining the relative health hazards due to occupational exposure to potentially mutagenic/carcinogenic petroleum products.