Manganese concentrations were determined in the ferromanganese plant. In 300 stationary and individual samples manganese was determined by pulse polarography (sensitivity-0.007 mg/m3, precision-10%). The present manganese concentrations are lower than those from earlier studies. Over 50% workers are exposed to manganese concentrations slightly exceeding threshold limit values (TLVs) (0.09-0.43 mg/m3). The other workers are exposed to concentrations several times higher than the TLVs (0.82-1.91 mg/m3). At some workplaces lead concentrations were also determined. TLVs for lead were not surpassed. In result of the use of anodic mass in arc furnaces, the occurrence of polycyclic aromatic hydrocarbons (PAH) is thought possible. Recommendations related to monitoring and selection of workplaces with the same exposures for medical estimation were given. Possible risks for people living near the plant were pointed out.
Concentractions of aerosols, amount of polycyclic hydrocarbons, in terms of soluble in benzene fraction and benzo(a)pyrene concentration were determined in coking plant air. Air was sampled on the roofs of modern coke batteries and on old-type batteries prior to, and following, modernization and major reapir. Aerosols were determined by passing 10--100 m3 of air through a 26 X 18.5 cm filter. After a weight determination of aerosol content the filter was subjected to benzene extraction and aromatic polycyclic hydrocarbons were isolated from the extract, using thin-layer chromatography. Quantitative determination of these hydrocarbons was done using ultraviolet spectrophotometry. Results of determinations on work-posts in modern and old-type coke batteries prior to, and following, modernization were comapred. Average concentrations of aerosols in the air, amounts of polycyclic hydrocarbons soluble in benzene and concentration of benzo(a)pyrene determined on the roofs of old coke batteries before modernization were as follows: 11.26 mg/m3, 6.37 ug/m3 and 112.28 mg/m3, and after modernization: 0.88 mg/m3, 0.25 mg/m3 and 1.29 ug/m3, respectively. On the roofs of modern high chamber coke batteries average concentrations of aerosols, polycyclic hydrocarbons--benzo(a)pyrene amounts were: 4.21 mg/m3, 0.79 mg/m3 and 5.72 ug/m3, respectively. The results clearly demonstrate that work conditions in modernized coking plants are much better than those in old non-modernized coking plants.
Due to a number of cases of acute arsine poisonings in one of zinc metallurgic plants, the environmental concentrations of arsenic compounds were determined. In the technological process of zinc metallurgy, the highest arsine concentrations can occur: a) during zinc refining in the furnace, where, because of the full automatization process, the presence of workers is not necessary, b) during the refining furnace repair--because of the melting loss wetting. Levels of arsenic concentrations, just as cadmium and zinc concentrations, according to the valid hygienic standards, are very low at the shaft furnace and the agglomerating plant. The urinary arsenic concentrations in workers has not exceeded 100 micrograms/l and these results also testify to a small exposure. However, it is necessary to take into account the high lead concentrations at some work-posts, both due to the multiple exceeding of the hygienic standard, and the simultaneous occurrence of lead and arsenic, which create a potential possibility of forming more toxic compounds, e.g. lead arsenide. In view of the carcinogenic exposure, it is important to take into account the possibility of interaction between arsenic and polycyclic aromatic hydrocarbones which occur during coke dry degassing.
The dust was sampled using personal samplers and stationary aspirators. PAHs were determined by thin layer chromatography and spectrophotometry in the UV and Vis range. In the samples the concentrations of coal tar pitch volatiles (benzene extract) and phenanthrene, fluoranthene, pyrene, chrysene, tetraphene, benzo(a)pyrene, benzo(e)pyrene, perylene, 1,12 benzoperylene, indeno(1,2,3-cd) pyrene were determined. The qualitative analysis identified all these hydrocarbons but only fluoranthene, pyrene, chrysene, tetraphene and benzo(a)pyrene could be quantitatively determined. The benzene extract concentration exceeds the value of 0.2 mg/m3 in 50% of samples. Much higher results were obtained for tar-concrete (1.45-2.85 mg/m3) than for asphalt-concrete (0.14-0.71 mg/m3). Also the drivers are exposed to excess benzene extract concentrations (0.055-0.669 mg/m3). Laboratory workers were found to be exposed to high concentrations of PAH and several solvents.
concentrations of hydrogen fluoride and fluorides were determined near pots with a vertical pin Söderberg anodes and near the prototype pot with a prebaked anode. Samples were collected by the stationary method and with personal samplers (Casella) where the membrane filter was connected with the bubbler filled with 0.1 M NaOH. Hydrogen fluoride and fluorides were determined by colorimetric and potentiometric methods. Altogether 300 samples were determined. Fluorides concentrations near pots with Söderberg anodes ranged between 1.42-2.43 mg/m3 (P = 95), geometric mean being 1.86 mg/m3 (with stationary and personal samples). The range of hydrogen fluoride concentrations was 1.28-3.08 mg/m3 (P = 95), whereas geometric mean--1.99 mg/m3 (personal samples). Hydrogen fluoride concentrations in stationary samples were lower (geometric mean--1.47 mg/m3). Fluorides concentrations during the tests with the prototype pot (prebaked anode) were five times lower, as compared to fluorides concentrations near the traditional pots.
The biological response to lead, taking into account pulmonary ventilation values, has been checked in nonferrous metal plant workers. Except for lead rolling-mill workers, increased blood lead, decreased delta-aminolevulinic dehydratase activity in erythrocytes, and increased urinary excretion of lead, delta-aminolevulinic acid and coproporphyrin were found in the metallurgists. The intensity of the biological response to lead was dependent on pulmonary ventilation. A positive, statistically significant correlation was found between these indices. With extensive correlation studies, a lead dose was calculated that is probably absorbed in the respiratory tract during a6-hr shift. This dose ranges between 352 -- 1056 mu g in lead refiners exposed to identical airborne lead concentration (0.163 mg/Pb/m3), the degree of physical effort being different (pulmonary ventilation from 11.8 -- 35.8 1/min). The authors indicate a need for including -- to a greater extent than so far -- pulmonary ventilation measurements in lead exposure evaluation.
Working environment has been evaluated in two copper metallurgy plants by analysis of Cu and other metals (Pb, Cd, Zn) concentrations. At the Charge Preparation Department the greatest concentrations of Cu and Pb were found. Copper concentrations at Metallurgy Department (shaft furnace, converter and anodic furnace) oscillate between 0.1-0.5 mg/m3, and Pb 0.06-0.71 mg/m3. In order to accurately evaluate copper exposure at working places where copper fume may arise (Metallurgy Department) it is necessary to determine Cu concentrations in respirable dust. At other working places Cu, Pb and Zn concentrations were low. Cadmium appears in vestigial amounts. The quantitative analysis indicates that airborne copper at the Charge Preparation Department and at the shaft furnace appears as CuS, at converter as Cu2O, and at other working places as metal Cu.
Concentrations of cadmium at 9 selected workplaces were measured for 3 years. Cadmium was determined by squarewave polarography. Results ranged between 0.024 mg/m3--0.737 mg/m3 (mean concentrations). The highest concentrations occurred at cadmium electrodes production for strip plate batteries. The study of cadmium concentration along with medical examinations allowed to specify how far Vitamin C administration might affect the health status of cadmium--exposed workers.
92 cadmium accumulators operators had their blood and urine cadmium concentrations determined. At nine workstations, during three years, repeated CdO concentrations measurements were made in the air by a stationary method, and additionally, at two workstations, measurements by an individual sampler were taken. The investigation showed a good correlation between CdO airborne concentrations measurements made by a stationary method and those made by individual samplers only at those workstations where workers do not change their place during a working day. Cadmiumuria indicated a greater dependence on the degree of exposure than did the concentration of this metal in blood. The findings suggest that cadmium concentration in blood and urine after body stores saturation is a better informant of current exposure than of cadmium stored in the organism.
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