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The exposure of paving workers to polycyclic aromatic hydrocarbons (PAH) during stone mastic asphalt (SMA) paving and remixing was evaluated. The effects on the workers' PAH exposure were also evaluated during the use of an industrial by-product, coal fly ash (CFA), instead of limestone as the filler in the SMA. The PAH exposure was measured by personal air sampling and by analysing the levels of urinary naphthols, phenanthrols and 1-hydroxypyrene (1-OHP) in the workers' pre- and post-shift urine samples. The respiratory PAH exposure of the paving workers (geometric mean (GM) 5.7 μg m−3) was about ten-fold that of the traffic controllers (GM 0.43 μg m−3). The levels of PAH metabolites were significantly higher (p < 0.05) in the post-shift urine samples than in the pre-shift urine samples, and the levels of metabolites in the post-shift urine of paving workers were significantly higher than in that of the controls (p < 0.01). Urinary 1-naphthol correlated well with the airborne concentrations of the two- to three-ring PAHs (r = 0.544, p = 0.003) and naphthalene (r = 0.655, p < 0.001), when non-smoking paving workers were tested. A good correlation was observed between urinary 1-OHP and the airborne concentrations of the four- to six-ring PAHs (r = 0.524, p = 0.003) as well as total PAHs (r = 0.575, p = 0.001). The concentrations of 1-OHP and phenanthrols in the urine of the pavers were significantly higher (p < 0.01) during remixing than during SMA paving. The CFA in the asphalt had no effect on the airborne PAH exposure or on the concentrations of the PAH metabolites in the paving workers' urine.

Blood samples from 34 workers at a pulp and paper mill and from 14 control persons were analysed for 2,3,7,8-substituted PCDDs and PCDFs. There were no statistically significant differences in total lipid-adjusted PCDD/PCDF concentrations, expressed as toxic equivalents, in blood plasma between the potentially exposed bleaching plant or paper mill workers and the controls. The mean level was 61 pg/g I-TEQ in bleaching plant workers, 60 pg/g I-TEQ in paper mill workers and 49 I-TEQ pg/g in controls. Regarding the concentrations of individual isomers, however, there was an indication that the blood plasma concentrations might be affected by the living and working environment.

The concentrations of airborne 2,3,7,8-substituted polychlorinated dibenzo- p -dioxins and dibenzofurans measured at a pulp and paper mill ranged from 0.04 to 1.9 pg/m 3 . The paper mill used softwood and hardwood pulp which was bleached with solely chlorine dioxinde in the first chlorination stage. The chlorinated furans dominated in all samples, while very few dioxins were detected. No 2,3,7,8-tetrachlorodibenzo- p -dioxin was detected. The highest concentration was measured for 1,2,3,4,6,7,8-heptachlorodibenzofuran, which was present in all samples. The toxic equivalent concentrations varied between 0.002 and 0.2 pg/m 3 using the international toxic equivalency factors. The congener profile of a paper dust sample was similar to that of the corresponding air samples.

A procedure for air sampling and analysis of polychlorinated phenols was developed and used for field measurements at two pulp-bleaching plants. The sampler consisted of an XAD-2 resin tube with a glass fibre prefliter. The filter and the resin were separately eluted with toluene, followed by acetylation of the chlorophenols with a mixture (5:2) of acetic acid anhydride and pyridine and determination by capillary gas chromatography using electron-capture and mass-selective detection. The sampler was tested in the μg/m 3 range for desorption and collection efficiency. The collection efficiency of the sampling device was not affected by humidity (40–80%) or sampling rate (200–750 ml/min) for the tested compounds. Stability tests at +20, +4 and −20°C showed no degradation of the chlorophenols studied during 4 weeks. The detection limit was below the μg/m 3 range for 180-1 air samples.

A softwood and hardwood kraft pulp mill, utilizing chlorine-containing bleaching agents, was monitored for 40 organohalogen compounds in the workplace air. Low levels of chloroform, carbon tetrachloride, tetrachloroethene, 1,1,1-trichloroethane, 1,4-dichlorobenzene, methanesulphonyl chloride, 2,5-dichlorothiophene and pentachlorophenol were detected. The workplace air at the bleaching plant was found to be slightly genotoxic in an on-site bacterial mutagenicity test.

Worker exposure to polychlorinated biphenyls (PCBs) in renovation of prefabricated houses was assessed by biological monitoring of 24 PCB congeners including the 10 most abundant PCBs in elastic polysulphide sealants. Serum samples from 22 exposed and 21 non-exposed men were analysed using gas chromatography-mass spectrometry with negative chemical ionization. Total PCB concentration of 24 PCB congeners in workers' serum varied between 0.6 and 17.8 microg/l (mean 3.9 microg/l, median 1.9 microg/l). The Finnish upper reference limit for occupationally non-exposed persons (3 microg/l) was exceeded in the serum samples of 10 workers. Concentrations for non-exposed persons were 0.3-3.0 microg/l (mean 1.7 microg/l, median 1.5 microg/l). The concentration for the sum of the 10 most abundant PCB congeners in elastic polysulphide sealants in serum samples taken in autumn after the renovation season was 2-10 times higher than in samples from the same workers (n=5) taken in the previous spring. The concentrations of PCB congeners PCB 28, 52, 77, 101, 138, 153 and 180 in hygienic samples taken from the breathing zone of the workers were low, ranging from not detected to 3.1 microg/m3. The concentrations of PCB 28 and 52 in sera were positively correlated with the concentrations in air samples taken from the breathing zone of six workers (r=0.70 and 0.80).

A sensitive and selective method for the determination of 24 polychlorinated biphenyls (PCBs) by gas chromatography-mass spectrometry with negative chemical ionization (GC-MS-NCI) was applied for the recent needs of occupational exposure in waste incineration. The three most abundant ions were used in determining compounds with at least five chlorine atoms in the PCB molecule. Selecting ions Cl(35) and Cl(37) for di-, tri-, and tetrachlorinated PCBs resulted in reliable quantification of these compounds. The detection limits for the 24 individual compounds varied from 0.01 to 0.08 microg/l. The recovery of the method was 113+/-16%. Stability tests showed no degradation of the compounds studied during 6 weeks. The sum of 24 PCB compounds measured from the sera of workers in a disposal plant was 1.9-10.9 microg/l, and 0.3-3.0 microg/l for controls, respectively. The mean proportion of the low chlorinated PCB compounds (with four or less chlorine atoms) was 20% for workers in the disposal plant and 14% for the controls.