(1987)52-55. Demolition of a steel railway bridge was carried out by nine workers using flame-torch cutting. The air in the breathing zone of the workers contained from 2 to 38 mg of lead /rn t, which is a very high level in comparison with the Dutch exposure limit of 0.15 mg/m ' (8-h time-weighted average). Without very effectiverespiratory protection these concentrations may result in acute lead poisoning. Upwind of the flametorch exposure the level was below the exposure limit, whereas downwind lead concentrations of up to ten times the exposure limit were observed. Although filtering facepieces were used by the workers, average blood lead concentrations of about 4.5 /lmolll were rapidly attained. Possibly under these work conditions this value represents a maximum concentration attainable in blood. After termination of the exposure, there was a fast decrease of lead in the blood. This finding indicates that lead was mainly present in rapidly exchangeable compartments like blood. No stable correlation between the concentration of lead in blood and the concentration of zinc protoporphyrin in blood was found.
The effect of chronic subcutaneous administration of lead acetate was studied in female rabbits. The low-dose group (15 animals) received three times a week 0.10-0.20 microgram/kg body weight and the high-dose group (15 animals) 0.80-1.20 micrograms/kg. The control group received the vehicle only. Concentrations of lead in blood in the low-dose group increased to ca. 400 micrograms/l after 70 days and in the high-dose group to ca. 900 micrograms/l after 110 days. After 7.5 months eight animals of each group were sacrificed. The remaining rabbits were kept for an additional 4 months without treatment. Blood lead concentrations decreased with a half-time of 60-70 days. During exposure the gain in body weight was lower in the high-dose group than in the control group and the low-dose group. The high-dose group developed slight anaemia and low MCV, MCH and MCHC, and basophilic stippling of erythrocytes. These effects disappeared during recovery. ALAD activity in erythrocytes was very low during exposure in both exposed groups and did not reach control values during recovery. During exposure the concentrations of ZPP and ALA-U increased, but only ALA-U returned to normal during recovery. No other effects of lead on the composition of the urine were observed.(ABSTRACT TRUNCATED AT 250 WORDS)
One thousand five hundred fifty urine samples and 1,295 blood samples, collected from 919 workers, were analyzed for cadmium (Cd). The workers were employed at 16 different types of workplaces. In about 7.5% of the samples, the concentration of Cd exceeded the biological limit values proposed by the Dutch Expert Committee for Occupational Standards. Levels higher than these values were measured in both urine samples and blood samples of workers involved in electrochemical plating, in production of Cd-stabilizers and enamels, and in soldering with silver-cadmium solder. Significantly higher concentrations of beta 2-microglobulin (MG) were found in urine samples with CdU greater than 10 micrograms/g creatinine. Cd levels in urine increased with age.
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