(1/673) A comparison of the reproductive physiology of largemouth bass, Micropterus salmoides, collected from the Escambia and Blackwater Rivers in Florida.
Largemouth bass (LMB), Micropterus salmoides, were taken from the Escambia River (contaminated site) and the Blackwater River (reference site) near Pensacola, Florida. The Escambia River collection occurred downstream of the effluent from two identified point sources of pollution. These point sources included a coal-fired electric power plant and a chemical company. Conversely, the Blackwater River's headwaters and most of its length flow within a state park. Although there is some development on the lower part of the Blackwater River, fish were collected in the more pristine upper regions. Fish were captured by electroshocking and were maintained in aerated coolers. Physical measurements were obtained, blood was taken, and liver and gonads were removed. LMB plasma was assayed for the concentration of 17ss-estradiol (E2) and testosterone using validated radioimmunoassays. The presence of vitellogenin was determined by gel electrophoresis (SDS-PAGE) and Western blotting using a monoclonal antibody validated for largemouth bass vitellogenin. No differences in plasma concentrations of E2 or testosterone were observed in females from the two sites. Similarly, males exhibited no difference in plasma E2. However, plasma testosterone was lower in the males from the contaminated site, as compared to the reference site. Vitellogenic males occurred only at the contaminated site. Additionally, liver mass was proportionately higher in males from the contaminated site, as compared to males from the reference site. These data suggest that reproductive steroid levels may have been altered by increased hepatic enzyme activity, and the presence of vitellogenic males indicates that an exogenous source of estrogen was present in the Escambia River. (+info)
(2/673) Persistent respiratory effects in survivors of the Bhopal disaster.
OBJECTIVE: To examine the role of exposure to the 1984 Bhopal gas leak in the development of persistent obstructive airways disease. DESIGN: Cross sectional survey. SETTING: Bhopal, India. SUBJECTS: Random sample of 454 adults stratified by distance of residence from the Union Carbide plant. MAIN OUTCOME MEASURES: Self reported respiratory symptoms; indices of lung function measured by simple spirometry and adjusted for age, sex, and height according to Indian derived regression equations. RESULTS: Respiratory symptoms were significantly more common and lung function (percentage predicted forced expiratory volume in one second (FEV1), forced vital capacity (FVC), forced expiratory flow between 25% and 75% of vital capacity (FEF25-75), and FEV1/FEV ratio) was reduced among those reporting exposure to the gas leak. The frequency of symptoms fell as exposure decreased (as estimated by distance lived from the plant), and lung function measurements displayed similar trends. These findings were not wholly accounted for by confounding by smoking or literacy, a measure of socioeconomic status. Lung function measurements were consistently lower in those reporting symptoms. CONCLUSION: Our results suggest that persistent small airways obstruction among survivors of the 1984 disaster may be attributed to gas exposure. (+info)
(3/673) Measurement of some potentially hazardous materials in the atmosphere of rubber factories.
Two separate topics of work are outlined: methods for the measurement of chlorinated monomers in PVC and polychloroprene, and also methods for the measurement of these materials in factory air. Typical results which have been obtained in supplies of raw materials, in finished products, and in the working atmosphere at manufacturing operations are given. The second topic concerns the measurement of benzo[a]pyrene in the atmosphere of a tire manufacturing plant. This material is present in trace quantities in the mineral oils and carbon blacks used by the industry. The atmospheric concentrations present at various processes in this plant were measured on a daily basis over a period of two years, and the results obtained compared with results taken concurrently from an outside air station. It is shown that no significant quantities of benzo[a]pyrene are produced by tire manufacturing operations. (+info)
(4/673) Chronic diseases in the rubber industry.
An overview is presented of epidemiologic studies of chronic diseases in the rubber industry. Analyses of the mortality experience during the period 1964-1972 of workers age 40-64 and retirees age 65-84 of two large rubber and tire manufacturing companies consistently disclosed excesses of deaths attributed to leukemia and lymphosarcoma, and for cancers of the stomach, large intestine, and prostate. The relation of site-specific malignancies to work histories and grouped occupational titles as surrogate measures of work-related exposures to possible carcinogens is described. There was no evidence of company-wide, sizable, consistent excess for the other major chronic diseases causes of death. Although a total cohort deficit in the mortality rate for lung cancer was found, there was a history of increased frequency of exposure to certain work areas among lung cancer decedents. Morbidity studies, including analysis of disability retirements, and ad hoc questionnaire and health testing surveys, disclosed excesses of chronic pulmonary diseases. There was evidence of an interactive effect in the association of work and smoking histories with pulmonary disability retirement. (+info)
(5/673) Mortality and cancer morbidity in a group of Swedish VCM and PCV production workers.
The cohort of workers employed in a Swedish vinyl chloride/poly(vinyl chloride) plant since its start in the early 1940's has been followed for mortality and cancer morbidity patterns. Only 21 of the 771 persons could not be traced. Difficulties in establishing exposure levels at different work areas in the past makes an evaluation of dose-effect relationships impossible. A four- to fivefold excess of pancreas/liver tumors was found, including two cases later classified as angiosarcomas of the liver. The number of brain tumors and suicide do not deviate significantly from expected. Cardiovascular and cerebrovascular diseases, on the other hand, differ significantly from the expected. The discrepancies between previous reports on VCM/PVC workers and this report are discussed. The possible etiology of the cardiovascular deaths is also discussed. (+info)
(6/673) Clinical studies of styrene workers: initial findings.
Styrene monomer is a high volume chemical used chiefly in production of polystyrene. A clinical survey of 493 production workers was undertaken at the oldest and largest monomer production, polymerization, and extrusion facility in the U.S. Relative exposure durations and levels were obtained from occupational histories. Significant differences between the high and low exposure groups were found with regard to history of acute prenarcotic symptoms, acute lower respiratory symptoms, prevalence of FEV 1/FV less than 75 per cent, and elevated GCTP. Other liver function tests, chest x-ray, FVC less than 80 per cent, and hematological parameters showed no distinct pattern. A concomitant mortality study has been mounted and is in progress. (+info)
(7/673) Malignant tumors of the liver and lungs in an area with a PVC industry.
The incidence of malignant tumors of the lung and bronchus and of cytologically confirmed primary malignant tumor of the liver was analyzed for a 4-yr period in a city with several factories, including a PVC industry. Prior to the study two cases of angio-sarcoma of the liver were diagnosed in workers employed in PVC production. The total incidence of analyzed tumors was only slightly higher than predicted. The tumors of the liver recorded did not show any dependence on place of work or residence. During the period of observation, malignant tumors of the bronchus (lung) were not recorded in the PVC industry. Their rate in the area in which the PVC industry is situated was approximately the same as that for the entire city area. The study does not indicate that the occurrence of malignant tumors other than angiosarcoma is associated with exposure to vinyl chloride. (+info)
(8/673) Health hazards in the production and processing of some fibers, resins, and plastics in Bulgaria.
Results of the toxicological studies of working conditions, general and professional morbidity, and complex examinations carried out on workers engaged in the production of polyamides, polyacrylonitrile fibers, polyester fibers and poly (vinyl chloride) resin, urea-formaldehyde glue, glass fibre materials and polyurethane resins are given. An extremely high occupational hazard for workers in the production of poly (vinyl chloride) resin and porous materials from polyurethane resins and urea-formaldehyde glue has been established. Cases of vinyl chloride disease, poisoning from formaldehyde, isocyanates, and styrene were noted. Prophylactic measures were taken in Bulgaria to lessen the occupational hazard in the productions as set forth included limitation of the work day to 6 hr, free food, additional bonus and leave, and annual physical examinations of workers. (+info)