In a retrospective cohort study, 265 female workers exposed to CS2 and 291 non-exposed female workers, as well as 530 pregnancies were investigated focusing on the status of menstruation and the term and outcome of pregnancy. The average CS2 concentration to which the workers had been exposed for the 15 years prior to the study was 1.7-14.8 mg/m3. The result showed that exposed female workers had a higher incidence rate of menstrual disturbance than the non-exposed women (35.9% vs. 18.2%, RR=2.0, p<0.01), and an exposure-response relationship between the CS2 level and the incidence rate of menstrual disturbance was reveal-ed. No significant difference was found between the exposed and non-exposed groups in terms of rates of toxemia, emesis gravidarum, spontaneous abortion, stillbirth, premature and overdue delivery, or congenital malformation. 'The birth weights for the two groups were similar. The possible effect of confounding factors was controlled during both the survey and data analysis. These results show that exposure to CS2 at around 10 mg/m3 might affect the function of the female re-productive system.
Oral administration of O, O, S-Trimethyl phosphorothioate (TMP), a known impurity present in technical grade malathion and other organophosphorus insecticides, causes a striking weight loss associated with hypophagia and cachexia in rats. Although it is known that treatment with TMP produces lung injury, the actual mechanism of delayed toxicity remains unknown. To determine the effect of TMP treatment on amino acid metabolism, we have investigated the amino acid pattern in plasma and in urine after treatment with TMP, using an Automatic Amino acid Analyzer. The concentrations of 41 amino acids were determined simultaneously. Together with treated (N=6) and control animals (N=6), we also used a pair-fed (N=3) group. Animals were dosed with TMP at 20 mg/kg in corn oil (approximately one third of the LD50) and sacrificed 72 hr after the treatment. During this period, the animals were put into metabolic cages and their urine was collected every 24 hrs. The amount of ethanolamine excreted in the urine of the treated animals increased as a function of time after treatment. Between 48 and 72 hr, the amount excreted (4311 ± 1160 nmoles : M ± SD) was 3 to 4 times higher than that in either the controls (1008±889 nmoles) or the pair-fed animals (1437 ± 300 nmoles). In plasma, the concentrations of ethanolamine and phenylalanine were higher in the TMP treated animals than in either the control or pair-fed animals. In contrast, the concentrations of valine, methionine and asparagine in the treated animals were similar to those in the control animals but higher than in the pair-fed animals. Clinical chemistry data, serum GOT, GPT, and urinary N-acetyl-β-D-glucosaminidase, were within normal ranges. These find-ings strongly indicate that amino acid utilization is impaired in delayed toxicity.
An adsorption sampling method for airborne silane was developed using active carbon made from synthetic thermosetting resin beads, and an ac-companying procedure to determine silane concentration was established. The resin active carbon had very low silicon contamination (0.31-3.14 μg Si/g), and its ca-pacity for adsorbing silane was improved by impregnating sodium hydroxide up to 20 wt.% of the carbon. This sodium hydroxide-impregnated-active carbon (200 mg) had the capacity to adsorb 5 ppm of silane in 6l of air drawn at the rate of 200 m//min, without breakthrough. To quantify the silane, the adsorbed silane was desorbed into 4 ml of water at 80°C with more than 90% efficiency, and the final solution of silicate ions in the sodium hydroxide solution was analyzed by graphite furnace AAS with a pyrocoated graphite tube. From the results, adsorp-tion sampling tubes were formed by packing 200 mg and 100 mg of the resin active carbon impregnated with sodium hydroxide as two separate beds in a polyethylene tube of 4 mm inside diameter. The lower limit of slilane determination by this method was less than 1 ppm in 1l of air.