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.

Design and conduct of occupational injury intervention studies: a review of evaluation strategies.

Occupational injuries continue to exact a great toll on American workers and their employers--the physical and financial costs are enormous. However, in the current political climate, few employers or regulatory agencies will implement injury prevention interventions without specific evidence of their effectiveness. This paper reviews the literature on the design, conduct, and evaluation of occupational injury interventions. Our review suggests that randomized controlled trials are rare and also notes that the quasi-experimental studies in the literature often use the weakest designs. We recommend a hierarchical approach to evaluating occupational injury interventions--beginning with qualitative studies, following up with simple quasi-experimental designs using historical controls, continuing with more elaborate quasi-experimental designs comparing different firms' experience, and, when necessary, implementing randomized controlled trials.

Stress among package truck drivers.

In 1992, a cross-sectional questionnaire study of package truck drivers in one company was conducted at four widely scattered sites throughout the US; 317 drivers participated, representing 82% of those eligible. The package truck drivers scored significantly above the US working population comparison norm on all summary and individual scales derived from the SCL 90-R, indicating a substantial increase in psychologic distress for this group. The Global Severity Index, the best single summary measure of psychological distress in the SCL 90-R, revealed a mean T score for the drivers of 64.20, 91st percentile of the normative population. The group perceived significantly more daily stressful events than the average working adult, and their sensitivity to these events was also increased. Role overload, a component of the Occupational Stress Inventory, was the most consistent factor associated with symptoms of psychological distress on multiple regression analysis. This study suggests that job stress is a psychological health hazard for these drivers.

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.

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.

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.

Health insurance and workers' compensation: the delivery of medical and rehabilitation services for construction workers.

The construction industry has one of the highest proportions of workers without health insurance. The authors review the two types of insurance systems that are generally used to cover the cost of health care for construction workers in the U.S.: health and welfare funds and workers' compensation. Recent developments in health care delivery in the U.S. are discussed, as are the more comprehensive occupational medicine services offered in France, Germany, The Netherlands, and Sweden.

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.

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.

New-onset asthma after exposure to the steam system additive 2-diethylaminoethanol. A descriptive study.

Through a leak in the steam heating system, the anticorrosive agent 2-diethylaminoethanol was released into the air of a large office building. Irritative symptoms were experienced by most of the 2500 employees, and 14 workers developed asthma within 3 months of exposure. This study was undertaken to review clinical characteristics of these asthmatics. Environmental exposure monitoring data and medical records were reviewed. Seven of 14 cases were defined as "confirmed" and 7 of 14 as "suspect," using the National Institute for Occupational Safety and Health surveillance case definition of occupational asthma. Spirometry was positive in 4 of 14 of the cases and peak flow testing in 10 of 14. Three cases were diagnosed on the basis of work-related symptoms and physical examination alone. The study suggests that acute exposure to the irritating steam additive 2-diethylaminoethanol was a contributing factor in the development of clinical asthma in this population.

Risk factors for developing eosinophilia myalgia syndrome among L-tryptophan users in New York.

Using a case-control study design, patients with eosinophilia myalgia syndrome (EMS) who had used L-tryptophan (LT) were compared with LT users who did not develop EMS. Of the 113 case patients and 95 controls who had used a retail brand that could be traced to a bulk LT producer, all (100%) case-patients and 69 (73%) controls used LT brands that were traced to Showa Denko K.K. (lower 95% CL = 10.0). Among the users of LT produced by Showa Denko K.K., the risk of EMS was greater for persons who used LT produced after December 1, 1988 (OR = 25.8, [95% CL = 7.1, 101.4]). The risk of developing EMS increased with increased dosage of LT, increased age, and use of LT as a sleeping aid. These epidemiologic data support the hypothesis that the etiologic agent in EMS is a contaminant introduced into LT products during production.

Risk of congenital malformations associated with proximity to hazardous waste sites.

Concern about environmental pollutants has increased; however, it remains unclear whether chronic exposures to toxic chemicals in the environment occur at doses sufficient to produce adverse health effects in humans. To date, community studies have not adequately addressed this question. In this study, the authors linked two existing data bases of the New York State Department of Health to evaluate the relation between congenital malformations and residential proximity to hazardous waste sites in New York State. A total of 9,313 newborns with congenital malformations and 17,802 healthy controls living in proximity to 590 hazardous waste sites in 1983 and 1984 were evaluated. After the authors controlled for several possible confounding factors, results indicated that maternal proximity to hazardous waste sites may carry a small additional risk of bearing children with congenital malformations (odds ratio (OR) = 1.12, 95% confidence interval (Cl) 1.06-1.18). Higher malformation rates were associated with both a higher exposure risk (no exposure risk: OR = 1.00; low exposure risk: OR = 1.09, 95% Cl 1.04-1.15; high exposure risk: OR = 1.63, 95% Cl 1.34-1.99) and documentation of off-site chemical leaks (not exposed: OR = 1.00; exposed, but no leaks at site: OR = 1.08, 95% Cl 1.02-1.15; exposed, and leaks found at site: OR = 1.17, 95% Cl 1.08-1.27). The increased rates detected may be important in terms of their public health implications. Further research is necessary to strengthen causal inferences regarding the teratogenicity, of waste site exposure.

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.

Bone cancer incidence rates in New York State: time trends and fluoridated drinking water.

BACKGROUND: Recent animal studies of the potential carcinogenicity of fluoride prompted an examination of bone cancer incidence rates. METHODS: Trends in the incidence of primary bone cancers, including the incidence of osteosarcomas were examined among residents of New York State, exclusive of New York City. Average annual osteosarcoma incidence rates in fluoridated and non-fluoridated areas were also compared. RESULTS: Among persons less than 30 years of age at diagnosis, bone cancer incidence among males demonstrated a significant increase since 1955, while incidence among females has remained unchanged. A significant decrease in bone cancer incidence rates since 1955 was observed among both males and females age 30 years and over at time of diagnosis. Osteosarcoma incidence rates have remained essentially unchanged since 1970, among both younger and older males and females. The average annual age adjusted incidence of osteosarcomas (1976-1987) in areas served by fluoridated water supplies was not found to differ from osteosarcoma incidence rates in non-fluoridated areas. CONCLUSIONS: These data do not support an association between fluoride in drinking water and the occurrence of cancer of the bone.

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.

Fluoride: benefits and risks of exposure.

This summarizes current knowledge of the benefits and risks of fluoride ingestion. The preponderance of evidence indicates that fluoride can reduce the incidence of dental caries and that fluoridation of drinking water can provide such protection. Due to the ubiquitous nature of exposures to fluoride sources other than drinking water, it is currently impossible to draw firm conclusions regarding the independent effect of fluoride in drinking water on caries prevalence using an ecologic study design. Moderate dental fluorosis occurs in 1 to 2% of the population exposed to fluoride at 1 mg/l in drinking water and in about 10% of the population at 2 mg/l; moderate/severe fluorosis occurs in variable percentages ranging up to 33% of the population exposed to fluoride at 2.4 to 4.1 mg/l in drinking water. The issue of whether moderate or severe dental fluorosis represents an adverse health effect is still controversial. There is no evidence of skeletal fluorosis among the general U.S. population exposed to drinking water fluoride concentrations lower than 4 mg/l. Radiographically detected osteosclerosis after chronic exposure to fluoride in drinking water at 8 mg/l was not associated with clinical symptoms. Reports of crippling skeletal fluorosis associated with low concentrations of fluoride in drinking water in tropical countries have been attributed to other dietary factors. The available data suggest that some individuals may experience hypersensitivity to fluoride-containing agents. Further studies on hypersensitivity are required. There is no evidence of increased incidence of renal disease or renal dysfunction in humans exposed to up to 8 mg fluoride per liter in drinking water. Structural changes in kidneys of experimental animals have been detected at doses exceeding 1 to 5 mg fluoride per kilogram per day. Based on four case reports, individuals with renal insufficiency who consume large volumes of naturally fluoridated water at 2 to 8 mg/l are possibly at increased risk of developing skeletal fluorosis. Studies on the effects of fluoride in individuals with renal insufficiency are needed. There is no evidence that chronic exposure to concentrations of fluoride reported to be greater than 2 mg/l in drinking water increases human cancer mortality or incidence. A study of lifetime exposure to fluoride on cancer incidence in rats and mice has been completed, but assessment for cancer has not been completed. There is no evidence that fluoride is genotoxic except in some in vitro assays at cytotoxic concentrations. There is no in vivo evidence that fluoride affects human cellular enzyme activities.(ABSTRACT TRUNCATED AT 400 WORDS)