Lung cancer mortality and fibre exposures among North Carolina asbestos textile workers.

OBJECTIVE: To describe mortality among workers exposed to chrysotile asbestos and evaluate the relationship between lung cancer and asbestos fibre exposure. METHODS: Workers employed for at least 1 day between 1 January 1950 and 31 December 1973 in any of four plants in North Carolina, USA that produced asbestos textile products were enumerated. Vital status was ascertained through 31 December 2003. Historical exposures to asbestos fibres were estimated from work histories and 3578 industrial hygiene measurements taken in 1935-1986. Mortality of the cohort was compared with that of the national population via standardised mortality ratios (SMRs). Exposure-response relationships for lung cancer were examined within the cohort using Poisson regression to compute adjusted mortality rate ratios. RESULTS: Follow-up of 5770 workers included in the cohort resulted in 181 640 person-years of observation, with 2583 deaths from all causes and 277 from lung cancer. Mortality from all causes, all cancers and lung cancer was significant higher than expected, with SMRs of 1.47 for all causes, 1.41 for all cancer and 1.96 (95% CI 1.73 to 2.20) for lung cancer. SMRs for pleural cancer, mesothelioma and pneumoconiosis were also elevated. The risk of lung cancer and asbestosis increased with cumulative fibre exposure (RR 1.102 per 100 fibre-year/ml, 95% CI 1.044 to 1.164, and RR 1.249 per 100 fibre-year/ml, 95% CI 1.186 to 1.316, respectively, for total career exposure). CONCLUSIONS: This study provides further evidence that exposure to chrysotile asbestos in textile manufacturing is associated with increased risk of lung cancer, asbestosis cancer of the pleura and mesothelioma.

Homicide on the job: workplace and community determinants.

Homicide is the second leading cause of death on the job for workers in the United States. To identify workplace-level predictors of homicide risk, a case-control study of worker killings in North Carolina in 1994-1998 was conducted. Workplaces were the units of analysis: case workplaces (n = 105) were those where a worker was killed during the study period, while controls (n = 210) were a density sample of North Carolina workplaces, matched on time and industry sector. Potential risk and protective factors were assessed in telephone interviews with workplace managers. Associations were measured by the exposure odds ratio and 95% confidence interval, estimated via conditional logistic regression. Characteristics associated with notably higher risk included being at the current location for 2 years or less (odds ratio (OR) = 5.3, 95% confidence interval (CI): 2.2, 12.6), having only one worker (OR = 2.9, 95% CI: 1.2, 7.2), and having night (OR = 4.9, 95% CI: 2.7, 8.8) or Saturday (OR = 4.2, 95% CI: 1.9, 9.2) hours. Workplaces with only male employees (OR = 3.1, 95% CI: 1.5, 6.5) or with African-American or Asian employees were also more likely to experience a killing. While few of the preceding risk factors are directly modifiable through workplace interventions, it is important to identify them before developing or evaluating preventive measures.

Killed on the clock: a population-based study of workplace homicide, 1977-1991.

BACKGROUND: This paper describes the epidemiology of workplace homicides in North Carolina, with emphasis on the circumstances. METHODS: Workplace homicide victims were identified by and data were abstracted from the North Carolina medical examiner system. RESULTS: Workplace homicide rates are highest for men, older and self-employed workers, minorities and specific occupations, especially taxi drivers. Robberies, mostly in retail settings, accounted for half of the cases, while 20% were known to involve disputes, the contexts of which differed by sex. Women were most likely to be killed by estranged partners. CONCLUSIONS: Preventive strategies need to address the specific contexts in which workplace homicide occurs, such as retail and taxi robberies, and law enforcement officers interacting with suspects. A workplace response to domestic violence is also needed. Other areas for future research and intervention include environmental modifications, employee screening and training, and identifying more inclusive occupational data sources.

Fatal occupational injuries in a southern state.

Fatal occupational injuries were studied using data from medical examiners' reports in North Carolina for the years 1977-1991. Cases were defined as deaths due to accidents or homicide at the workplace, and populations at risk were estimated from the 1980 and 1990 US Censuses. Mortality rate ratios and proportionate mortality ratios were used as measures of association, and the population attributable risk percentage was used as an indicator of the burden of injury. Standard weights for direct age-adjustment of rates were obtained from the total state workforce. There were 2,524 eligible deaths-83 percent from unintentional traumatic injuries, 14 percent from homicide, and the remainder from other causes. This report focuses on unintentional trauma deaths, which were strongly associated with the wood production, fishing, and transportation industries. Elderly, African-American, and self-employed workers had higher fatality rates than members of other groups. Among male workers, motor vehicle crashes were the principal cause of death on the job, followed by falling objects, machinery, and falls. The industries contributing the largest proportions of these deaths were construction, trucking, agriculture, and logging (population attributable risk percentages were 16.8%, 8.8%, 7.9%, and 6.9%, respectively). The fatality patterns of female workers were different: Numbers of deaths from homicide and unintentional trauma were equal, and 27% of the latter deaths occurred in one catastrophic fire. Decentralized and rural industries were the most hazardous, but many deaths were outside the current jurisdiction of occupational safety and health agencies. These patterns suggest that greater scrutiny of such industries, through both research and intervention, is warranted.

Fatal agricultural injuries in North Carolina by race and occupation, 1977-1991.

Medical examiner reports and death certificates were reviewed for all fatal agricultural injuries (n = 228) that occurred on-the-job in North Carolina between 1977 and 1991. Data were collected on the decedents' age, gender, race, data and time of injury, means of injury, and occupation. Annual workforce estimates were derived from the 1980 and 1990 US Census of the Population. Overall, 54% of the fatal injuries were due to tractors. Farmers who suffered fatal injuries tended to be older (median age = 56 years) and Caucasian (87%), while farm workers who died on the job were younger (median age = 35 years) and more often African-American (60%). The crude mortality rate for farmers was 38 per 100,000 worker-years; the crude rate for farm laborers was 16 per 100,000 worker-years. Age-adjusted fatal injury rates were 2.5 times higher among African-American farmers than among Caucasian farmers; furthermore, between 1977 and 1991 the rate of fatal injury among African-American farmers increased an estimated 14.7% per year. African-American farmers in North Carolina have experienced rising rates of fatal injuries at a time when employment in the industry is declining due to consolidation of farm ownership and foreclosures of African-American owned farms. In order to address the growing racial disparity in farm fatalities, efforts need to be made to improve the conditions under which African-American farmers are working.

Mortality of workers at a nuclear materials production plant at Oak Ridge, Tennessee, 1947-1990.

The Y-12 plant at Oak Ridge, Tennessee, produced nuclear materials for the U.S. government's nuclear weapons program beginning in 1943. Workers at Y-12 were exposed to low dose, internal, alpha radiation and external, penetrating radiation, as well as to beryllium, mercury, solvents, and other industrial agents. This paper presents updated results from a long-term mortality study of workers at Y-12 between 1947 and 1974, with follow-up of white men through 1990 and data reported for the first time for women and men of other races. Vital status was determined through searches of the National Death Index and other records, and the workers' mortality was compared to the national population's using standardized mortality ratios (SMRs). Total mortality was low for all Y-12 workers and total cancer mortality was as expected. Among the 6,591 white men, there were 20% more lung cancer deaths than expected (95% confidence interval [CI] 1.04-1.38). Death rates from brain cancer and several lymphopoietic system cancers were also elevated among white men, with SMRs of 1.28 and 1.46. Mortality from cancer of the pancreas, prostate, and kidney was similarly elevated. There was evidence of excess breast cancer among the 1,073 female workers (SMR 1.21, 95% CI 0.60-2.17). Lung cancer mortality among these workers warrants continued surveillance because of the link between internal alpha radiation exposure and this disease, but other agents, notably beryllium, also merit considerations as potential causes of lung cancer. Other cancers and agents should also be investigated as part of a comprehensive study of the health consequences of the production of nuclear weapons.

Radiation, work experience, and cause specific mortality among workers at an energy research laboratory.

A retrospective cohort mortality study was conducted among 8375 white male employees who had worked at the Oak Ridge National Laboratory for at least one month between 1943 and 1972. This plant has been the site of energy related research, including uranium and plutonium reactor technology and radioisotope production. Radiation doses, primarily from gamma rays, were generally low; the median cumulative exposure for workers was 0.16 rems. Historical follow up was conducted for the years 1943-77 and ascertainment of vital status was achieved for 92.3% of the cohort. Standardised mortality ratios (SMRs) were computed to contrast the subjects' cause specific mortality experience with that of the United States white male population. The observed number of 966 deaths from all causes was 73% of the number expected. Mortality deficits were also seen for arteriosclerotic heart disease (SMR = 0.75; 344 observed) and all cancers (SMR = 0.78; 194 observed). These results are indicative of the healthy worker effect and the favourable influence on health of the cohort's relatively high socioeconomic status. Non-statistically significant raised SMRs were seen for all leukaemias (SMR = 1.49, 16 observed), cancer of the prostate (SMR = 1.16, 14 observed), and Hodgkin's disease (SMR = 1.10, 5 observed). Internal comparisons of mortality (standardised rate ratios, SRRs) were made between subgroups of the cohort according to radiation dose level and duration of employment in various job categories. No consistent gradients of cause specific mortality were detected for radiation exposure. Leukaemia mortality was highest among workers with greater than or equal to 10 years employment in engineering (SRR = 2.40) and maintenance (SRR = 3.12) jobs. The association of leukaemia with employment in engineering was unexpected; maintenance jobs entail potential exposures to radiation and to a wide range of organic chemicals; metals, and other substances.

Physician opnions on the use of antibiotics in respiratory infections.

To investigate the feasibility of establishing standards of care based on a broad consensus, a questionnaire concerning the management of signs and symptoms of common respiratory infections in infants was given to a national sample of pediatric infectious disease specialists, general pediatricians, and family physicians. There was significant disagreement (p less than .01) among the three groups of physicians in 15 of the 18 clinical situations concerning the appropriateness of prescribing antibiotics. Whenever there was disagreement, the family physician group was most inclined and the infectious disease group least inclined to favor antibiotics therapy. More than 75% of each group favored antibiotics in the same situation in only three instances. These results suggest that it may be difficult to set widely accepted standards for the evaluation of medical care where there are such differences of opinion.

Influence of training and experience on selecting criteria to evaluate medical care.

To determine whether training and experience affect the selection of process criteria for evaluating medical care, three groups of physicians (family physicians, general pediatricians, and pediatricians specializing in infectious disease) were sent a questionnaire asking their opinions about various clinical actions in 125 clinical situations concerning respiratory infections in infants. Five hundred and twenty-four (54 per cent) physicians returned completed questionnaires. The three groups agreed in 93 (74 per cent) situations, especially about history taking, physical examination, and follow-up observation. Disagreements occurred most often regarding antibiotic use. Of the three groups, the family physicians selected the most extensive list of recommended actions including the greatest number of indications for antibiotics. The general pediatricians selected the fewest situations requiring history taking, physical examination and diagnostic tests. The infectious-disease pediatricians felt the greatest necessity to record history and physical-examination items but were the most restrictive in recommending antibiotics and other drugs.