Showing papers in "Journal of Occupational and Environmental Medicine in 1980"

Quantitative risk assessment.

Abstract: This paper presents a brief survey of current methodology available for quantitative risk assessment of environmental carcinogens. Four current models for low-dose extrapolation are reviewed. Current problems and controversies and possible options in doing quantitative risk assessments based on chronic animal studies are discussed.

Assessment of renal function of workers exposed to inorganic lead, calcium or mercury vapor.

Abstract: The renal function of workers occupationally exposed to cadmium (n = 148), to mercury vapor (n = 63) or to inorganic lead (n = 25) has been compared with that of workers with no occupational exposure to heavy metals (n = 88). A moderate exposure to lead (Pb-B < 62 microgram/100 ml) does not seem to alter renal function. Excessive exposure to cadmium increases the urinary excretion of both low- and high-molecular-weight proteins and of tubular enzymes. These changes are mainly observed in workers excreting more than 10 microgram Cd/g creatinine or with Cd-B above 1 microgram Cd/100 ml whole blood. Occupational exposure to mercury vapor induces glomerular dysfunction as evidenced by an increased urinary excretion of high-molecular-weight proteins and a slightly increased prevalence of higher beta 2-microglobulin concentration in plasma without concomitant change in urinary beta 2-microglobulin concentration. beta-galactosidase activity in blood and in urine is also increased. The likelihood of these findings is greater in workers with Hg-B and Hg-U exceeding 3 microgram/100 ml whole blood and 50 microgram/g creatinine, respectively. The hypothesis is put forward that the glomerular dysfunction induced by cadmium and mercury might result from an autoimmune mechanism.

Isometric strength testing as a means of controlling medical incidents on strenuous jobs.

Abstract: This investigation was performed to determine if isometric strength tests can be used to select workers for strenuous jobs and to reduce occupational injuries which are caused by a mismatch between worker strength and job strength requirements. Twenty jobs in a tire and rubber plant were studied biomechanically to identify critical strength-demanding tasks. Four strength tests were designed to simulate these tasks, and performance criteria were established for passing the tests. New applicants were administered the tests during their preplacement examinations to determine if they possessed sufficient strength to qualify for the jobs. The medical incidence rate of employees who were selected using the strength tests was approximately one-third that of employees selected using traditional medical criteria. It was concluded that isometric strength tests can be used to reduce occupational injuries and should be considered for implementation in industries with strenuous jobs.

The mortality experience of workers exposed to tetrachlorodibenzodioxin in a trichlorophenol process accident.

Abstract: A standardized mortality analysis was conducted on workers exposed to tetrachlorodibenzodioxin in a trichlorophenol process accident at the Monsanto Company plant in Nitro, West Virginia. One hundred and twenty-one workers who developed chloracne resulting from this accident on March 8, 1949, were selected for study. Follow-up of this group was 100% complete. The standardized mortality ratio for all causes of death was shown to be 0.69, with 32 deaths observed and 46.41 expected. For the categories of malignant neoplasms and circulatory diseases, the standardized mortality ratios were 1.00 and 0.68, respectively. Because of the small size of the cohort and the relatively small number of deaths observed, the results of this study cannot be considered conclusive. However, it is important that no apparent excess in total mortality or in deaths from malignant neoplasms or diseases of the circulatory system was observed in a group of workers with a high peak exposure to tetrachlorodibenzodioxin who were followed over a period of nearly 30 years. The results of this study will be incorporated with those of a larger study which will include plant workers exposed in the course of 2,4,5-trichlorophenoxyacetic acid production during the period 1948 to 1969.

An occupation and exposure linkage system for the study of occupational carcinogenesis.

Abstract: Studies of the adverse effects of occupational exposures are most informative when jobs can be classified according to the specific chemical or physical agents involved. However, information sufficiently detailed to permit this is not often available. In such instances a study usually will be based on subjects classified according to industry or task, effectively ignoring the specific agents to which exposure occurred. Such crude classification tends to reduce or obscure associations between specific exposures and disease. In response to this problem, the authors have developed an occupation and exposure linkage system with particular reference to carcinogenesis. Occupations were classified by industry and by task within the industry. Lists of suspect carcinogens were developed and each suspect carcinogen was linked to industries and tasks in which it has been used. These links make it possible to place in the same exposure category all study subjects whose employment history suggests contact with a particular agent. Epidemiologic analysis then can be based on chemical and physical exposures, rather than on industries or tasks. The linkage system enhances the value of information on occupation obtained from death certificates, cancer registries, medical records, and questionnaires.

The use of meditation--relaxation techniques for the management of stress in a working population.

Abstract: The efficacy of meditation-relaxation techniques has been widely researched in the laboratory, but their effectiveness for management of stress in organizational settings is still relatively unexplored. The present study compared relaxation and control conditions as part of a program of stress-reduction in industry. A total of 154 New York Telephone employees self-selected for stress learned one of three techniques--clinically standardized meditation (CSM), respiratory one method meditation (ROM) or progressive relaxation (PMR)--or served as waiting list controls. At 5.5 months, the treatment groups showed clinical improvement in self-reported symptoms of stress, but only the meditation groups (not the PMR group) showed significantly more symptom reduction than the controls. The meditation groups had a 78% compliance rate at 5.5 months with treatment effect seen whether subjects practiced their techniques frequently or occasionally. The safe and inexpensive semi-automated meditation training has considerable value for stress-management programs in organizational settings.

Fatality due to acute systemic fluoride poisoning following a hydrofluoric acid skin burn.

Abstract: Reports indicate that death due to hydrofluoric acid exposure is usually the result of inhalation of vapor causing pulmonary edema and fluoride poisoning. Absorption via the skin route of fluoride ion sufficient to cause serious systemic problems and even death has rarely been reported. A fatality resulting from a severe facial burn, which produced acute systemic fluoride poisoning with profound hypocalcemia and hypomagnesemia, is presented. The importance of proper personal protective equipment as well as the immediate initiation of first aid and appropriate medical measures, including the monitoring and replacement of serum calcium and magnesium, are emphasized.

Mortality among workers employed in petroleum refining and petrochemical plants.

Abstract: The cause-specific mortality experience of 3,105 members of the Oil, Chemical and Atomic Workers International Union was examined to determine if there were unusual patterns of fatal disease that may be indicative of hazardous agents in the work environment. Deaths among active Union members that were reported by locals in Texas between 1947 and 1977 were identified through membership records, and proportionate mortality was analyzed in several broad industrial categories. PMRs for cancers of the liver and biliary passages, pancreas, lung and skin were elevated among refinery and petrochemical plant workers; however risks did not increase with length of membership. Increased relative frequencies of stomach cancer, cancer of the brain, leukemia and multiple myeloma were confined to white males in the same category who had been Union members for 10 or more years. Excess deaths from stomach cancer and brain cancer were found among white male members employed at one specific oil refinery and petrochemical plant. Observed numbers of deaths from cancer of the stomach were greater than expected among whites and nonwhites, and an elevated PMR for lung cancer among nonwhites was found at an additional plant. Findings suggest that workers in this industry may be at increased riskmore » of certain cancers and indicate areas for further investigation.« less

Epidemiologic study of workers exposed to acrylonitrile.

Abstract: This retrospective cohort study of 1,345 male employees with potential for exposure to acrylonitrile analyzes cancer incidence and mortality from 1956 to 1976. Expected numbers based on company and national rates have been computed on person-years. The analyses consider calendar time, payroll classification, occupation, duration of exposure, severity of exposure, and latency. Overall, 25 cases of cancer occurred, with 20.5 expected based on company rates. Of these, eight were respiratory cancer cases, with 4.4 expected. Excesses were found primarily during the 1970-76 time period among wage roll employees who had worked during plant start-up. A trend toward increased risks was seen with increased duration and severity of exposure. Twenty cancer deaths were found, with 17.4 expected according to company rates. Since many cancer cases were recently diagnosed and are living, it may be premature to evaluate mortality statistics. These findings, coupled with results from tests in laboratory animals, raise the serious suspicion that acrylonitrile may be a human carcinogen.

Cancer mortality among workers exposed to zinc chromate paints.

Abstract: To evaluate the carcinogenicity of chromium compounds among user industries, the proportionate mortality experience of spray painters exposed to zinc chromate primer paints and electroplaters exposed to chromic acid in the aircraft maintenance industry was examined. Compared to the mortality patterns of U.S. white males, no excess of cancer was found in the 48 deaths among electroplaters. Analysis of the 202 deaths among spray painters revealed a significant excess of cancer, primarily of the respiratory tract. The relative increase of respiratory cancer showed a positive gradient with the length of estimated exposure time, and was confined to painters whose interval from first employment to death was at least 20 years. The findings consistent with occupational exposure to chromium compounds, previously shown to be carcinogenic in manufacturing processes, but the effect of other paint constituents, tobacco smoking, or methodologic limitations could not be discounted.

The association between parental occupation and childhood malignancy.

Abstract: A case control study was conducted to test Fabia and Thuy's observation that there was an excess of fathers in hydrocarbon-related occupations among children who died of childhood cancer compared to their controls. The study comprised 692 children who were born and died in Massachusetts for the years 1947-1957, and 1963-1967 and a control group of 1,384. No significant association was found between the four major groups of childhood cancer and the three hydrocarbon-related occupations: (1) mechanics and gas station attendants; (2) machinists; and (3) painters, cleaners, and dyers. However, there were two significant associations: (a) paternal employment as a paper or pulp mill worker was associated with tumors of the brain and other parts of the nervous system (relative odds of 2.8); and (b) paternal employment as a mechanic or machinist was associated with tumors of the urinary tract (relative odds of 2.5). Without strong supporting evidence from other studies, the authors are reluctant to conclude that these associations are causal. A weak association between childhood leukemia-lymphoma are parents' ages was observed.

A mortality analysis of employees engaged in the manufacture of 2,4,5-trichlorophenoxyacetic acid.

Abstract: There have been few published reports regarding surveillance of individuals occupationally exposed to 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). The present study examined the mortality experience of 204 persons exposed to 2,4,5-T during its manufacture from 1950 to 1971. Length of employment in job assignments within the 2,4,5-T process area ranged from less than one year to a maximum of approximately ten years. Efforts to minimize 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) contamination of the product resulted in nondetectable concentrations using a method of detection developed in 1966 that was sensitive to 1 part per million. Within the scope of this mortality survey, no adverse effects were observed with respect to occupational exposure to 2,4,5-T or its feedstock, 2,4,5-trichlorophenol.

Mortality experience of employees exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

Abstract: This study describes the mortality experience of a cohort of 61 males involved in a 1964 chloracne incident. Presumably as a result of skin absorption of the process contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or dioxin), 49 of these trichlorophenol production workers developed the skin condition. Within the limitations posed by cohort size and length of follow-up, TCDD does not appear to have adversely affected mortality experience. Overall, four deaths occurred and 7.8 were expected. Of these, one death was due to cardiovascular disease (3.8 expected) and three deaths were attributed to cancer (1.6 expected). None of the findings were statistically significant at alpha = 0.05. Further follow-up is contemplated.

Localized fatigue in accounting-machine operators.

Abstract: In order to study health problems related to keyboard operation, subjective symptoms of female accounting-machine operators were compared with those of sales-women in a department store. In addition the relationships between symptoms and length of service in accounting-machine operation, and between arm-hand symptoms and the motion of the right and left arms and hands were analyzed. The results lead to the following assumption of causal relations: (1) Tiredness, pain, stiffness, cramps, tremor and numbness in the right hand are important symptoms among accounting-machine operators and are related to repeated use of the right arm and hand in tapping the keyboard. (2) Tiredness, pain and stiffness in the left hand are also work-related symptoms of the operators and are related to the motion of the left hand in turning over coupons (3) Stiffness and pain in the area of the lumbar spine, stiffness in the cervical spine, and pain in the left side of the neck are related to the sitting posture with the neck bent forward and to the left. (4) Eyestrain and painful eyes are more frequent in the operators than in the sales-women. These symptoms are most probably related to visual tasks in accounting-machine operation. This pattern of stiffness, pain and other symptoms seems to be chronic and to develop into a kind of disease in some operators. The observations here conform closely to the picture of the occupational cervicobrachial disorder in Japan. From the standpoint of clinical medicine, it is difficult to combine the various work-related symptoms of the operators into a single disease. But from the standpoint of industrial medicine, it appears to be possible to group the symptoms into a specific pattern of occupational chronic (or clinical) fatigue produced by a specific pattern of work loads, i.e., the combination of repetitive, stereotyped upper limb exertion, static posture, and mental and visual stress.

Occupational symptoms among compost workers.

Abstract: Exposure to gram-negative bacteria and the presence of subjective symptoms among workers were investigated at an experimental compost plant. Four of the 11 workers reported nausea, headache, and diarrhea, an incidence greater than that reported by workers in a drinking water plant. The number of airborne gram-negative bacteria was high where household garbage was agitated by the technical equipment. The findings are similar to those in studies on workers in sewage treatment plants.

A case-control study of prostate cancer within a cohort of rubber and tire workers.

Abstract: A matched case-control study was conducted to test the hypothesis that prostate cancer is associated with employment in the compounding area of a rubber and tire manufacturing plant. A search of death certificates from the years 1964 to 1975 led to the identification of 88 cases of prostate cancer. These were individually matched with 258 controls on the factors of age, race, and date of entry into the plant. To eliminate possible confounding by sociodemographic differences, several variables were assessed but none differed significantly between cases and controls. The batch preparation work area showed statistically significant (p < 0.025) risk ratios over three exposure periods -- more than one month, more than 24 months, and more than 60 months. The service to batch preparation and shipping and receiving work areas showed significant risks for blacks. The data were used to assess a latent period or etilogic fraction for prostate cancer for those employed in batch preparation. Twenty-nine years was estimated to be the latent period while the period of greatest risk occurred during the years 1940 to 1947.

A cohort study on workers exposed to trichloroethylene.

Abstract: The mortality of 2,117 workers exposed to trichloroethylene sometime between 1963 and 1976 was studied. Their names were collected from the files of one biochemical laboratory performing urinary trichloroacetic acid determinations and from the Occupational Disease Register of Finland. Both the total mortality (SMR 69) and the cancer mortality (SMR 77) were lower than expected. Because of the young age structure and the brief follow-up time the results should be interpreted with caution. They suggest, however, that given as short a latency period as 6 to 13 years, trichloroethylene is not a strong human carcinogen. The present material provides a cohort with defined exposure for further follow-up.

Diesel exhaust - an occupational carcinogen?

Abstract: The existence of polycyclic aromatic hydrocarbons (PAH) in the particulate phase of diesel engine exhaust has raised concern about a carcinogenic effect in workers exposed to exhaust from diesel engines. Some of the PAH are carcinogenic following inhalation by experimental animals and are associated with excess cancer mortality in some occupational exposures. Studies of occupational exposure to diesel exhaust show concentrations of PAH are above ambient levels but below the very high levels in occupations with demonstrated excess cancer mortality. A critical review of the epidemiologic evidence on the carcinogenicity of workplace exposure to diesel engine exhaust is suggestive of a carcinogenic effect but the existing data are sparse and contradictory. Further epidemiologic studies of this question are needed.

Epidemiological assessment of occupationally related, chemically induced sperm count suppression

Abstract: Occupationally related, chemically induced sperm count suppression is a recently recognized problem, first brought to light in connection with the manufacture and formulation of dibromochloropropane (DBCP). The authors studied sperm count data from four occupational cohorts - two exposed to DBCP and two exposed to epichlorohydrin (ECH). In both DBCP cohorts there was a significant difference (alpha = 0.05) between sperm count distribution functions of the exposed group and of the non-exposed group. A much higher percentage of exposed men was oligospermic and the median sperm count for each exposed group was substantially lower than that for the respective non-exposed group. In the ECH cohorts there was no significant difference between sperm count data for the exposed group and for the non-exposed group. The authors concluded that exposure to DBCP, but not to ECH, was positively associated with detectable sperm count suppression. It is suggested that the key to identifying and assessing occupationally related sperm count suppression lies in the proper classification and interpretation of group sperm count data.

DBCP and testicular effects in chemical workers: an epidemiological survey in Midland, Michigan.

Abstract: The agriculturally important nematocide 1,2-dibromo-3-chloropropane (DBCP) has been implicated as a cause of human male sterility. A survey at the Michigan Division of The Dow Chemical Company included measurements of semen samples, testicular size, and serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone in 232 chemical workers with past potential exposures to DBCP and in 97 nonexposed comparison employees. Potentially exposed groups showed significantly higher, although not abnormal, mean levels of FSH and LH. In the subgroup with the highest potential exposure ending subsequent to 1972, greater duration of exposure correlated with lower sperm count, higher FSH level, and smaller testicular volume. Mean values for this latter time-divided subgroup were not abnormal. The findings are consistent with a testicular effect of DBCP and also with reversibility of that effect over time.

A method for monitoring the fertility of workers. 1. Method and pilot studies.

Abstract: A method has been developed for monitoring male and female industrial workers and other persons exposed to environmental agents which may impair fertility. The essential feature of the method is its ability to distinguish the potential effects of occupational exposure from a multitude of other factors known to affect fertility. Information is collected primarily through use of a questionnaire which take less than three minutes to complete and can be administered to persons of either sex. The advantages and limitations of the method are considered in the context of pilot studies at two small chemical plants and of a review of attempts to assess occupational effects of fertility from interviews of health records.

Cause-specific mortality among newspaper web pressmen.

Abstract: A mortality study of 1,361 newspaper web pressmen who were members of the Los Angeles Pressmen's Union for at least one year -- between 1949 and 1965 -- was conducted. Vital status as of December 31, 1978, was determined for 1,261 (91%), and death certificates were obtained for 344 of the 354 decedents. Using a modified life-table technique, cause-specific mortality among the pressmen was compared to that in the United States white male population. Overall mortality was similar to that expected. Analysis of the cancer mortality by site showed no significant differences between observed and expected except for leukemia (7 observed vs. 2.8 expected) and kidney cancer (5 observed vs. 1.6 expected). A significant excess of deaths due to cirrhosis of the liver (17 observed vs. 8.3 expected) was also observed.

Long-term effects of welding fumes upon respiratory symptoms and pulmonary function.

Abstract: To evaluate the long-term influence of welding fumes and of cigarette smoke on the function of the bronchopulmonary system a comparative study of spirometric measurements in 209 welders and 109 non-welder controls was performed in a shipyard. The two groups were matched for age, height, smoking habits, residence and social class. Fifty-one percent of the welders had one or more of the respiratory symptoms, while only 26% of the controls had any of the symptoms. Chronic bronchitis was found to be confined to welders who smoked or had smoked. The welders appeared to show significantly increased impairment of lung function and, with advancing years, a deterioration in lung function greater than that of the controls, but, in general, they did not show serious pulmonary insufficiency.

Subclinical effects of chronic increased lead absorption--a prospective study. III. Neurologic findings at follow-up examination.

Abstract: Neurologic examination, nerve conduction testing and electro-oculographic testing have been performed at a baseline examination and a follow-up examination in a group of lead workers with blood lead levels predominantly between 60 and 80 micrograms/dl and in a group of control workers. A statistically significant decreased saccade accuracy measurement in the lead workers compared to the controls was found at both examinations. No other simple test or pattern of findings differentiated between the lead workers and the controls, and the biological significance of the lower saccade accuracy is not clear. Nerve conduction measurements do not appear to be a satisfactory method of detecting subclinical neurologic effects of lead exposure.

Mortality among automobile assembly workers. I. Spray painters

Abstract: The primary objective of this study was to determine whether there was an increased mortality, especially with respect to cancer of the lung, among spray painters in the automobile manufacturing industry The study was carried out at ten assembly plants from five participating companies and utilized both proportionate mortality ratio (PMR) and case-control analyses Among workers with spray-painting experience, there were no statistically significant PMRs for lung cancer, either for all companies combined or for any company individually In addition, the case-control analyses did not demonstrate a statistically significant excess risk for lung cancer mortality, adjusting for length of employment and duration in spray painting The case-control analysis was large enough to detect approximately a two-fold increase if, in fact, an increase that large actually existed

Mortality among workers in the metal polishing and plating industry, 1951-1969.

Abstract: The numbers of deaths by cause among 1,292 white male metal polishers and platers identified from obituary listings in the Journal of the Metal Polishers, Buffers, Platers, and Allied Workers International Union were compared to an expected distribution based on the white male population of Illinois and the U.S. The proportions of deaths due to cancers of the esophagus and the liver were high, particularly among those over 65 and those listed as metal polishers or platers on the death certificate. The PCMRs for these two tumors were also moderately elevated. Despite methodologic limitations, these findings, along with the known use in this industry of chromium and nickel, strong acid and alkaline solutions, and the solvents trichloroethylene and tetrachloroethylene, suggest that metal polishers and platers may be subject to exposures capable of inducing cancer.

A mortality survey of employees engaged in the development or manufacture of styrene-based products.

Abstract: The authors examined the mortality experience of employees whose work assignments involved development or production of styrene-based products. To investigate potential relationships between mortality and work exposure in the diverse chemical operations under study, a multiple agent approach to exposure categorization was adopted. Mortality was less than that of the corresponding U.S. white male population and was consistent with that of an industrial comparison group. Although deaths due to malignant neoplasms were fewer than expected for the total cohort, an increase in lymphatic leukemia was observed among a subgroup of employees who had exposure to polymer extrusion fumes, solvents, and colorants. However, no relationship was found with duration or intensity of exposures experiences by these employees, and the etiology of the lymphatic leukemias was not established. The approach used to characterize exposure in this study may have application in other epidemiologic investigations involving complex work environments.

Type A coronary-prone behavior and stress in senior female managers and administrators.

Abstract: This article describes a study of relationships between Type A coronary-prone behavior patterns, as measured by the Bortner and Rosenman scale, and stress levels, coping ability and psychological stress-related symptoms of a group of 148 senior female managers and administrators. The results indicate that the majority of the sample were categorized as Type A individuals, and that Type A behavior was related to age. A relationship was found between Type A behavior and subjects perceiving themselves as having higher stress levels compared to the female and male peers with whom they worked. Type A individuals perceived that their "ability to cope with stress" was worse compared to that of their female peers and female superiors, but saw themselves as better "copers" compared to their female subordinates. Type A individuals did not see themselves as a source of stress to their subordinates. A relationship was also found between Type A behavior and symptoms of anxiety, frustration and irritation. Results are compared to those of previous relevant research, and the implications of the findings are discussed.

Absence of airway hyperreactivity to methacholine in a worker sensitized to toluene diisocyanate (TDI).

Abstract: A worker with occupational asthma due to toluene diisocyanate (TDI) was studied. Detailed immunologic studies, including those for p-tolyl isocyanate IgE antibodies and the presence of leukocyte inhibition factor for isocyanate antigen, were negative. Clinically, the subject noted more pronounced symptoms beginning on Monday morning, followed by weekend off work, and lessening of her symptoms over the working week. Methacholine challenges were negative when performed on three separate occasions, including the time when maximum symptoms were present, and again six months later, before and after bronchial challenge testing. A dose-related response to TDI was observed on bronchial provocation testing using nonirritating concentrations of TDI of 0.0165 and 0.030 ppm. This case provides evidence that the response of the airway to TDI may not always be accompanied by hyperreactivity to methacholine. Screening programs utilizing methacholine challenges may not always identify sensitized workers, since a negative methacholine challenge test does not exclude TDI sensitization.

Recovery of testicular function among DBCP workers.

Abstract: Twenty-one men with DBCP-related sperm count suppression were re-examined one year after termination of exposure in July 1977. When examined initially, 12 of these men were azoospermic and nine oligospermic. By October 1978 the sperm count of eight of the nine oligospermic men had improved considerably, six having recovered to a normospermic state. None of the 12 azoospermic men had improved by August 1978. Eleven of the 12 men exposed for more than four years were azoospermic. Serum follicle-stimulating hormone (FSH) for these 11 men increased significantly between assessments. Four children were born to the wives of the nine oligospermic men; three of the children were normal and one had several defects. The significance of this observation cannot be interpreted in terms of DBCP exposure, since this study was not designed to examine pregnancy outcome.