Investigation of a testicular cancer cluster using a case-control approach.

A case-control methodology was developed and utilized to investigate a reported cluster of testicular cancer among leather workers in New York. Eighteen cases of testicular cancer, including the three index cases, diagnosed from 1974 to 1986 among residents of two counties with substantial leather tanning and finishing establishments made up the case group. Controls (n = 259) consisted of men of similar age who had been diagnosed with cancers of all other sites during the same time period. Reports of usual occupation for cases and controls, obtained from cancer registry reports and death certificates, indicated that cases were much more likely to be leather workers (28%) than controls (7%). After adjustment for age, the relative risk estimate for occupation and testicular cancer was 7.2 (95% Cl: 1.9-27.7). The association was further supported by occupational histories showing similar work environments within the leather industry for five out of six cases known to have been leather workers. Case-control analysis of a reported cluster does not provide independent confirmation of an association between occupational factors and testicular cancer. The methodology, however, can provide a timely way to evaluate the significance of occupational cancer clusters.

Epidemiologic design for field studies: occupational neurotoxicity.

Assessing the neurotoxicity effects of occupational exposures has become increasingly sophisticated in the past decade with the application of neurophysiological and neurobehavioral research techniques to occupational disease problems. With a good epidemiologic study design and the careful application of these techniques, occupational field studies of neurotoxic effects are possible. Three examples from recent health hazard evaluations of the National Institute for Occupational Safety and Health (NIOSH) illustrate some of the problems in performing these studies and methods to overcome these problems.

Reproductive hazards in the workplace. Development of epidemiologic research.

Application of the techniques of epidemiology and clinical toxicology has accelerated study of the reproductive effects of toxic chemical and physical exposures in the workplace. Three examples of work in progress are included in the present communication. The first concerns 1,2-dibromo-3-chloropropane, a known cause of male sterility, which continues to be used as a nematocide in Hawaii. Occupational exposures of Hawaiian agricultural workers to airborne 1,2-dibromo-3-chloropropane are mainly in the range of parts per billion. A prospective study of pineapple field workers has been undertaken to evaluate sperm counts and morphology before, during, and after 1,2-dibromo-3-chloropropane application. To date, no sperm count depression is evident at this level of exposure. The second example involves a cluster of seven spontaneous abortions in female office workers exposed to video display terminals. The cluster has been analyzed with the use of fetal life tables. Excess incidence was confirmed (p = 0.0045), but no etiology was determined. The findings may have been due to chance. The third example pertains to male chemical workers manufacturing diaminostilbene, an optical brightener, and the workers' reported sexual impotence. Impotence was confirmed in 7 of 29 workers by questionnaire and suggested for another 7. Serum testosterone analyses found depressed values (less than 300 mg/ml) in 8 of 28 exposed workers. The luteinizing hormone and follicular stimulating hormone levels were generally normal.

Assessing the health effects of potential exposure to PCBs, dioxins, and furans from electrical transformer fires: the Binghamton State Office Building medical surveillance program.

A medical surveillance program has been established for 482 persons who were potentially exposed to polychlorinated biphenyls (PCBs), dibenzo-p-dioxins, and dibenzofurans from an electrical transformer fire in a Binghamton, NY office building in 1981. Blood samples were analyzed for serum concentrations of PCBs and for biochemical and hematologic parameters at the time of the fire and 9 to 12 mo later. Firefighters and individuals who were in the building for 25 hr or more were also asked about post-fire symptomatology and examined after 1 yr for disorders of the skin, eyes, liver, and neurologic system. The results indicated that reported exposure was positively related to mean serum PCB levels (p = .004). The means and individual values, however, were within the range reported by other studies of persons with no unusual exposures. Significant correlations were observed between serum PCB concentrations and levels of liver enzymes and lipids, but mean levels of these biochemical parameters were not associated with reported exposure after adjustment for relevant covariables. Approximately one-half of those examined had skin lesions, but no cases of chloracne were detected, and there was no clinical evidence of any other exposure-related systemic disorder. The data suggest that exposure to contaminants from the building did not result in substantial absorption or cause any major short-term health effects.

Health effects three years after potential exposure to the toxic contaminants of an electrical transformer fire.

A medical surveillance program has been established for 482 persons who were potentially exposed to polychlorinated biphenyls (PCBs), dibenzo-p-dioxins, and dibenzofurans from an electrical transformer fire in a Binghamton, NY office building in 1981. Vital Record and Cancer Registry data, medical records, and mail questionnaires were used to assess mortality, symptomatology, cancer incidence, and reproductive events through 1984. The numbers of deaths, cancers, fetal deaths, and infants with low birth weight or congenital malformations were similar to those expected on the basis of age- and sex-specific rates for upstate New York and other comparison populations. Two suicides were observed compared with 0.31 expected, but the difference was not statistically significant. After adjustment for possible confounders, persons with the greatest degree of potential exposure were significantly more likely than those with less exposure to report unexplained weight loss (relative risk [RR] = 12.80), muscle pain (RR = 5.07), frequent coughing (RR = 4.14), skin color changes (RR = 3.49), and nervousness or sleep problems (RR = 3.19). The possibility of recall bias and the intervening effects of stress, however, weaken the conclusion that toxic chemicals caused the symptomatology. Exposure-related systemic disorders, e.g., chloracne or peripheral neuropathy, were not diagnosed by personal physicians; however, some persons refused to release their medical records because of ongoing litigation. The findings are consistent with those of our earlier assessment.

Breast cancer risk and residence near industry or traffic in Nassau and Suffolk Counties, Long Island, New York.

A case-control interview study was used to evaluate the relationship between breast cancer risk and residential proximity to industrial facilities and traffic for pre- and postmenopausal women in Nassau and Suffolk Counties on Long Island, New York. A geographic information system was used to assign industry and traffic counts to 1-km2 grid cells (5-kM2 grid cells for traffic) and to assign potential exposure values to study subjects, based on 20-y residential histories. A significantly elevated risk of breast cancer was observed among postmenopausal subjects who were ever potentially exposed to chemical facilities (Nassau County adjusted odds ratio [OR] = 1.61, 95% confidence interval [95% CI] = 1.06-2.43; Suffolk County adjusted OR = 1.58, 95% CI = 0.71-3.51. This elevated risk, however, was not observed among premenopausal subjects. Risk increased for post-menopausal subjects as number of chemical facilities increased from one (adjusted OR = 1.45, 95% CI = 0.93-2.25) to two or more (adjusted OR = 3.47, 95% CI = 1.06-11.38). Crude and adjusted ORs for high traffic density were elevated among Nassau--but not Suffolk--county subjects and were not significant statistically.

Occupational health for firefighters.

Occupational health and safety programs for firefighters have received increasing attention over the last several years, due to the growing recognition of potential long-term health risks for firefighters. These workers not only face severe physical and psychological demands, but also risks of chronic or delayed adverse job-related health consequences. Firefighters are routinely exposed to a large number of toxic substances (e.g., carbon monoxide, benzene, particulate, asbestos, polynuclear aromatic compounds, hydrogen chloride, and cyanide) as well as physical hazards such as heat and noise. Their emergency medical response duties also put them at risk of exposure to infectious agents. Firefighters are at increased risk of cardiovascular disease, pulmonary disease, cancer, and noise-induced hearing loss. Occupational medical care for firefighters needs to monitor for these long-term health risks.

Cardiovascular disease among firefighters.

The author reviews the literature of the past 20 years on heart disease among firefighters, covering the specific aspects of firefighting that may be related to potential cardiovascular disease. The author then outlines steps that can be taken to reduce the risks of developing cardiovascular disease.

Medical surveillance for hazardous waste workers.

The efforts to clean up hazardous waste disposal sites have led to an increasing number of workers involved in these activities. Industrial hygiene surveys have demonstrated that these workers are potentially exposed to low levels of multiple contaminants during the work day and to high levels of some contaminants for very short time periods. Personal protective equipment and work practices are important components in protecting workers from these exposures. Medical monitoring for these workers is problematic. While monitoring for the potential health effects of these multiple exposures may be useful, any attempt to monitor for possible health effects of all potential exposures could lead to a long array of medical tests. The utility and effectiveness of this approach is doubtful. Screening for a worker's physical ability to conduct hazardous waste cleanup jobs while he wearing protective equipment is also important and may cause difficulties due to our limited knowledge in this area. These issues will be discussed in the context of various programs designed to monitor these workers.

OSHA standard for medical surveillance of hazardous waste workers.

The increasing amount of work involving hazardous waste sites and the heavy involvement of the federal and state governments in this work have led to the gradual development of guidelines and standards providing for occupational safety and health programs for these sites. On March 6, 1989, the Occupational Safety and Health Administration published its final rule governing occupational safety and health matters at hazardous waste sites and emergency operations. This rule is currently scheduled to take effect on March 6, 1990. This chapter will briefly describe this regulation, particularly its medical surveillance requirements.

Future needs: research, education, and service.

Sections on research, education, and service summarize efforts that are needed to control the workplace transmission of TB and measures that can be taken while research is being carried out. Topics include ways to identify infectious patients, techniques for measuring the airborne concentration of TB, and the need for surveillance programs.

Lead poisoning in construction.

Ways to prevent lead poisoning and regulations intended to eliminate exposures to lead are the topics here. Lead registries and other studies are described that were designed to evaluate the extent of the problem and to address the lack of routine blood-lead monitoring in the industry.

Methylene chloride exposure and birthweight in Monroe County, New York.

This study examined the relationship between birthweight and exposure to emissions of methylene chloride (DCM) from manufacturing processes of the Eastman Kodak Company at Kodak Park in Rochester, Monroe County, New York. County census tracts were categorized as exposed to high, moderate, low or no DCM based on the Kodak Air Monitoring Program (KAMP) model, a theoretical dispersion model of DCM developed by Eastman Kodak Company. Birthweight and information on variables known to influence birthweight were obtained from 91,302 birth certificates of white singleton births to Monroe County residents from 1976 to 1987. No significant adverse effects of exposure to DCM on birthweight were found. Adjusted birthweight in high exposure census tracts was 18.7 g less than in areas with no exposure (95% confidence interval for the difference between high and no exposure - 51.6, 14.2 g). Problems inherent in the method of estimation of exposure, which may decrease power or bias the results, are discussed. Better methods to estimate exposure to emissions from multiple industrial point sources are needed.

Investigation of a fatal heatstroke.

On June 30, 1981, a young, apparently healthy, obese white male suffered a fatal heatstroke. This was the beginning of summer in southern Ohio, when mid-day temperatures can reach into the 30s degrees C (90s degrees F) and the humidity can climb above 70%. The predisposition of the individual in terms of acclimatization, physical size and dietary intake, along with strong motivation to perform well on a job requiring a heavy workload in a hot environment, pushed him beyond his physiologic capacity. Of those people who attended him, only professional rescue personnel recognized the illness and properly treated the man. The death may have prevented by acclimatization and training as to the hazards, recognition and treatment of heat illness.

Control of tuberculosis in the workplace: engineering controls.

In this review of engineering controls that can be used to check the spread of tuberculosis in health care settings, the authors address types of ventilation and supplements to ventilation such as HEPA filtration and ultraviolet germicidal irradiation. They also specifically cover engineering controls for use during medical procedures that pose an increased risk for transmission of TB.