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The purpose of this study was to measure forest workers' exposure to the herbicide glyphosate during silvicultural clearing work done with brush saws equipped with pressurized herbicide sprayers. Both the exposed (study) group and the nonexposed (control) group contained five persons who were medically examined before and after their 1-week working period (including laboratory tests) for possible health effects. In addition, exposure to glyphosate was measured in the study group from samples taken from the workers' breathing zone and from urine samples collected during the afternoons of the workweek. The laboratory tests and urinary glyphosate analyses were repeated for the exposed group 3 weeks later, when the men had entirely stopped their work with the herbicide. Exposure to glyphosate through the workers' breathing zone was low. The highest value found was 15.7 micrograms/m3. In this study, a biological monitoring method was also developed to monitor the workers' exposure to glyphosate. Urine concentrations were under the gas chromatographic detection level of less than 0.1 ng/microL (less than 1.0 mumol/L). No major differences were noted, either in medical examinations or in the laboratory tests performed, between the exposed and control groups before and after the work period.

A study of sewage workers' exposure to airborne culturable bacteria and inhaled endotoxins was performed at nine waste-water treatment plants that treat mainly industrial effluents. Airborne endotoxins were collected on glass fiber filters and analyzed using a chromogenic limulus assay. Endotoxin concentrations measured in the immediate vicinity of the waste-water treatment process varied from 0.1 to 350 ng/m3. The eight-hour time weighted average concentrations of endotoxin to which workers were exposed exceeded the suggested exposure limit (30 ng/m3 endotoxin) at four of the plants. Air samples of culturable bacteria concentrations varied between 10 and 10(5) colony-forming units/m3. Of the particles carrying culturable bacteria, 88% had an aerodynamic diameter of less than 4.7 microns. The most common genera of airborne gram-negative bacteria were acinetobacter, citrobacter, enterobacter, klebsiella, and pseudomonas. High levels of exposure to bacteria and bacterial endotoxin usually were related to certain phases of the treatment process. The microbiological contamination of air was highest near the inlets where incoming wastewater entered the basins, in the sludge treatment area, and inside the biofilter tower. In these spaces it is necessary to control and reduce exposure to airborne bacteria and endotoxin at wastewater plants.

An hygienic survey for hydrogen sulfide, methyl mercaptan and its derivatives and sulfur dioxide in kraft mills and in sulfite mills revealed concentrations varying from 0 to 20 ppm hydrogen sulfide, 0 to 15 ppm methyl mercaptan and comparable amounts of dimethyl sulfide with dimethyl disulfide up to 1.5 ppm. The greatest emissions were detected at chip chutes and evaporation vacuum pumps. Batch operations yielded clearly higher sulfur dioxide concentrations (up to 20 ppm) as compared to a continuous ammonia-base digester. Furthermore, there was a strong correlation with the season in the sulfite mills where higher concentrations were found in the winter when natural ventilation was poorer. As to the health effects, the exposed workers complained of headaches and a decrease in concentration capacity more often than matched controls. The number of sick leaves was greater in the exposed workers than among the controls.

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The exposure of sprayers and plant handlers to mevinphos, a toxic organophosphate insecticide, was evaluated in eight flower-growing greenhouses. The purpose was to assess an appropriate re-entry interval for mevinphos after its application in greenhouses. Inhalational and dermal exposure was measured during two days after application by measuring mevinphos in the greenhouse air and on the foliage. Workers' dermal exposure was measured with patch and handwash samples. The method of application considerably affected the levels of mevinphos in greenhouse air and on the foliage. The occupational exposure was measured with patch and handwash samples. The method of application considerably affected the levels of mevinphos in greenhouse air and on the foliage. The occupational exposure limit for mevinphos in Finland (100 micrograms/m3) was exceeded during the use of nonthermal foggers. Usually, however, the concentration of mevinphos in the breathing zone of the workers was below 10 micrograms/m3 9-12 hr after application. Mevinphos disappeared rapidly from greenhouse air and from the foliage after application, with a half-life of 9.2 hr. These data provide evidence that the main route of exposure to mevinphos is dermal, a conclusion supported by the excellent correlation between dermal exposure and the amount of mevinphos on the foliage. The calculated re-entry interval for mevinphos was approximately 4.5 hr. However, that interval is likely to be too short in practice because the risk of dermal exposure is considerable for more than 10 hr after the application of mevinphos.

The effects of phenoxyacetic acid herbicides were investigated on the induction of chromosome aberrations in human peripheral lymphocyte cultures in vitro and in lymphocytes of exposed workers in vivo. Pure 2,4-dichlorophenoxyacetic acid (2,4-D; 0.125, 0.150, 0.200 and 0.350 mM) did not increase the number of aberrations, whereas the commercial 2,4-D formulation (0.125, 0.250, 0.500, 1.000 and 1.250 mM, with respect to phenoxyacetic acid concentration) significantly increased the number of chromosome aberrations in vitro (without exogenous metabolic activation). The phenoxy acid levels in the breathing zone of the workers varied between 0.3 and 0.4 mg/m3, and the concentrations of phenoxyacetic acids in the urine of the workers after exposure varied from 0.000 to 0.055 mmol/l. There were no increases in chromosome aberrations in peripheral lymphocytes of the exposed subjects.