Environmental health perspectives
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Researchers from the National Institute for Occupational Safety and Health (NIOSH) conducted an extent-of-exposure study of the 1,3-butadiene monomer, polymer, and end-user industries to determine the size of the exposed workforce, evaluate control technologies and personal protective equipment programs, and assess occupational exposure to 1,3-butadiene. A new analytical method was developed for 1,3-butadiene that increased the sensitivity and selectivity of the previous NIOSH method. The new method is sensitive to 0.2 microgram per 1,3-butadiene sample. ⋯ The present American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value for 1,3-butadiene is 10 ppm. To reduce the potential for occupational exposure, it is recommended that quality control sampling be conducted using a closed loop system. Also all process pumps should be retrofitted with dual mechanical seals, magnetic gauges should be used in loading and unloading rail cars, and engineering controls should be designed for safely voiding quality control cylinders.
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Environ. Health Perspect. · Oct 1981
Pneumoconiosis in animals exposed to poly(vinyl chloride) dust.
Rats, guinea pigs and monkeys were exposed by inhalation (6 hr/day, 5 days/week) for up to 22 months to a 13 mg/m3 concentration of PVC dust. Autopsies on rats and guinea pigs were performed after 12 months of exposure and on monkeys after 22 months after 22 months of exposure. Lung function tests were performed on monkeys after 9, 14 and 22 months of exposure. ⋯ No fibrosis or significant cellular infiltrates were present in or near these cellular aggregates. No significant effects on pulmonary function could be demonstrated in the monkeys exposed to PVC. Under the conditions of this experiment, inhaled PVC produced a benign pneumoconiosis.
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Environ. Health Perspect. · Oct 1978
ReviewIs behavior or morphology a more sensitive indicator of central nervous system toxicity?
Both behavior and morphology can be altered by exposure of the CNS to toxic substances. The brain is an organ with considerable structural redundancy and this presumably accounts for some of the ability of the CNS to maintain normal function in the presence of some structural damage. Compensation for damage may also occur through a form of "learning" due to the biochemical and morphological plasticity of the CNS. ⋯ Compensatory changes such as these are likely to require days or weeks to develop. On the other hand, short-term, reversible effects of substances such as drugs are not likely to cause morphological changes at doses which affect behavior. The importance of appropriate quantitative data on both morphology and behavior in evaluation of the CNS toxicity of substances is evident.
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Environ. Health Perspect. · Dec 1977
Effects of subanesthetic concentrations of enflurane on rat pregnancy and early development.
Anesthetic pollutants in the operating room have been implicated in producing spontaneous abortion in exposed personnel and congenital malformations among their offspring. To test the effects of trace concentrations of enflurane on pregnancy, rats were exposed to two levels (10.7 and 63.7 ppm) of the anesthetic for 8 hr daily from days 1 to 19 of pregnancy. Litter sizes were not affected but birth weights of exposed offspring were slightly higher than controls. ⋯ Weights of the cross-fostered groups in the high dose experiment were decreased at day seven compared to controls. In the same experiment, exposed offspring housed with exposed mothers were heavier than controls on day 21 of lactation. The modest nature of these alterations suggests that enflurane has little or no gross effect on rat pregnancy and postnatal development.
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We have studied mortality patterns in a large cohort of rubber workers. We have examined workers exposed to curing fumes, processing dusts, and industrial talc and have begun to evaluate exposures of these workers in detail. Gastrointestinal (especially stomach) cancer appears in excess in processing workers. ⋯ The leukemia risk is probably related to solvents. Whether this is all explainable by past benzene exposure is unknown. Further studies are planned to refine our knowledge concerning these risks so that occupational disease in the rubber industry can be prevented.