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Biomedical subjects

J J Beaumont

Publications and source records attributed to J J Beaumont.

15 recordsLinked to original sources
PubMed1992

Adjustment for smoking, alcohol consumption, and socioeconomic status in the California Occupational Mortality Study.

This paper presents methods for adjusting for smoking, alcohol, and socioeconomic status in death certificate-based occupational mortality surveillance. The methods were applied in the California Occupational Mortality Study, a statewide study of rates based on 180,000 deaths and census estimates of occupations. For each occupation, levels of smoking, alcohol consumption, and socioeconomic status were estimated using National Health Interview Survey and U.S. Census data, and an empirical Bayes procedure was used to improve the stability of smoking and alcohol estimates for small occupations. Expected death rates for occupations were calculated by modeling rates as a function of age, smoking, alcohol, and socioeconomic status with Poisson regression. The effect of adjustment was usually moderate and in the expected direction, and the adjusted mortality ratios were generally closer to 1.0. Full data on agricultural occupations are presented for illustration.

Adolescent↗
PubMed1992

Disease determinants of sporadic salmonellosis in four northern California counties. A case-control study of older children and adults.

A population-based, case-control study of sporadic salmonellosis was conducted in 1988 and 1989 in four northern California counties. The study included 120 patients and 265 control subjects. Conditional logistic regression analysis (adjusted for age) revealed that patients were more likely to consume undercooked chicken prior to the onset of disease (odds ratio [OR], 23.57; 95% confidence interval [CI], 2.89 to 192.30). Elevated associations were also found with recent travel to foreign countries (OR, 9.69; 95% CI, 3.18 to 29.56), diabetes (OR, 6.29; 95% CI, 1.56 to 25.34), hormonal replacement therapy (principally conjugated estrogen) in older women (OR, 4.20; 95% CI, 1.82 to 9.71), and antibiotic therapy prior to illness (OR, 1.96; 95% CI, 0.86 to 4.37). The problems of studying self-selected cases that may lead to alternative explanations for these findings are also discussed.

Adolescent↗
PubMed1991

Power and detectable risk of seven tests for standardized mortality ratios.

Power and minimum detectable risk are calculated for seven one-sided tests of standardized mortality ratios with Poisson-distributed events. Each test contrasts the number of observed deaths (D) with the number expected (E). Three tests use exact Poisson probabilities: 1) the exact test, which computes a p value as the probability of equaling or exceeding the number of observed events; 2) the optimal randomized exact test which, although not used in practice, serves as a standard for the other statistics; and 3) the exact "mid-p" procedure, which counts only one-half the probability of the observed event. The remaining four tests use normal approximations to the Poisson ("Z statistics"): 4) Z = magnitude of D-E/square root of E; 5) the Z statistic corrected for continuity, Z = (magnitude of D-E)-0.5)/square root of E; 6) a statistic based on a square root transformation, Z = 2(square root of D-square root of E); and 7) a statistic created by Byar, which, when D is greater than E, is Z = square root of 9D[1-1/(9D)-3 square root of D/E]. Power differences among these procedures with one-sided alpha of 0.05, 0.025, and 0.01 are small as long as four or more events are expected. If fewer than four events are expected, the uncorrected Z has unacceptably high type I error. Simple approximations to the power and detectable risk of these tests are evaluated and prove satisfactory. Differences in minimum detectable risk, actual and approximated, are slight for E of 2.0 or more.

Humans↗
PubMed1991

An epidemiologic study of cancer and other causes of mortality in San Francisco firefighters.

To test the hypothesis that firefighter exposures may increase cancer risk, mortality rates were calculated for 3,066 San Francisco Fire Department firefighters employed between 1940 and 1970. Vital status was ascertained through 1982, and observed and expected rates, rate ratios (RR), and 95% confidence intervals (CI) were computed using United States death rates for comparison. The total number deceased (1,186) was less than expected and there were fewer cancer deaths than expected. However, there were significant excess numbers of deaths from esophageal cancer (12 observed, 6 expected), cirrhosis and other liver diseases (59 observed, 26 expected), and accidental falls (21 observed, 11 expected). There were 24 line-of-duty deaths, which were primarily due to vehicular injury, falls, and asphyxiation. Heart disease and respiratory disease deaths occurred significantly less often than expected. It was concluded that the increased risks of death from esophageal cancer and cirrhosis and other liver diseases may have been due to firefighter exposures, alcohol consumption, or interaction between alcohol and exposures. Because this was an older cohort and firefighter exposures have changed due to the increasing use of synthetic materials, it is recommended that the effects of modern-day exposures be further studied.

Accidental Falls↗
PubMed1989

Lung cancer mortality among nonsmoking uranium miners exposed to radon daughters.

Radon daughters, both in the workplace and in the household, are a continuing cause for concern because of the well-documented association between exposure to radon daughters and lung cancer. To estimate the risk of lung cancer mortality among nonsmokers exposed to varying levels of radon daughters, 516 white men who never smoked cigarettes, pipes, or cigars were selected from the US Public Health Service cohort of Colorado Plateau uranium miners and followed up from 1950 through 1984. Age-specific mortality rates for nonsmokers from a study of US veterans were used for comparison. Fourteen deaths from lung cancer were observed among the nonsmoking miners, while 1.1 deaths were expected, yielding a standardized mortality ratio of 12.7 with 95% confidence limits of 8.0 and 20.1. These results confirm that exposure to radon daughters in the absence of cigarette smoking is a potent carcinogen that should be strictly controlled.

Adult↗
PubMed1989

A computer program for analyses of vital statistics-based occupational mortality data.

Routinely collected vital statistics mortality data (death certificate data) on occupation and industry are useful for (1) generating hypotheses about potential occupational hazards and (2) identifying occupational mortality differentials possibly associated with socioeconomic and life-style factors. This paper presents a Fortran program that analyzes occupational mortality using vital statistics and census data. The user can form any desired grouping of age, race, occupation (or industry), and cause of death codes for analysis. The program also allows stratification on social class or other user-defined correlates of occupation such as smoking behavior. Furthermore, program output can be used for Poisson regression analysis of mortality rates.

California↗
PubMed1989

A computer program for incidence density sampling of controls in case-control studies nested within occupational cohort studies.

A nested case-control study is a case-control study performed with a cohort study. The nested case-control design is useful because the number of study subjects for whom risk factor information is needed is smaller than in the original cohort study. The approach is especially helpful when collection of data is expensive or time consuming, as when it is necessary to contact subjects or next of kin. Selection of controls in nested case-control studies is best performed with a method called "incidence density" sampling. An approach to incidence density sampling that yields a valid estimate of the rate ratio is sampling without replacement from noncases at the time of case occurrence. To implement this approach, a system of computer programs was written that randomly selects a user defined number of controls for each case. The case-control data produced by this program can be analyzed by conditional logistic regression.

Cohort Studies↗
PubMed1987

Mortality of chrome leather tannery workers and chemical exposures in tanneries.

A retrospective mortality analysis was conducted in a cohort of 9,365 individuals employed as of 1940 in two chrome leather tanneries in the United States and followed to the end of 1982. Vital status as of the closing date was determined for over 95% of the cohort. Potential hazardous workplace exposures varied with department and included nitrosamines, chromate pigments, benzidine-based direct dyestuffs, formaldehyde, leather dust, and aromatic organic solvents. Mortality from all causes combined was lower than expected for each tannery, the standardized mortality ratio being 81 for one and 93 for the other. Deaths from cancer of each site, including the lung, were also lower than expected compared to those of either the population of the United States or of local state rates. A significant excess of deaths was observed, however, due to accidental causes in one tannery and cirrhosis of the liver, suicide, and alcoholism in the other. These excesses did not appear to be causally associated with occupational exposures. The findings of this study are consistent with those of the only other mortality investigation of leather tannery employees.

Alcoholism↗
PubMed1987

Lung cancer mortality in workers exposed to sulfuric acid mist and other acid mists.

Mortality patterns were studied in 1,165 workers exposed to sulfuric acid mist and other acid mists (primarily hydrochloric acid mist) in steel-pickling operations. Standardized mortality ratio (SMR) analysis of the full "any acid exposure" cohort (n = 1,165), with the use of U.S. death rates as a standard, showed that lung cancer was significantly elevated, with a mortality ratio of 1.64 [95% confidence interval (CI) = 1.14-2.28, based on 35 observed deaths]. The lung cancer mortality ratio for workers exposed only to sulfuric acid (n = 722) was lower (SMR = 1.39), but further restriction to the time 20 years and more from first employment in a job with probable daily sulfuric acid exposure (approximately equal to 0.2 mg/m3) yielded a mortality ratio of 1.93 (95% CI = 1.10-3.13). An excess lung cancer risk was also seen in workers exposed to acids other than sulfuric acid (SMR = 2.24; 95% CI = 1.02-2.46). When comparison was made to other steel workers (rather than to the U.S. general population) to control for socioeconomic and life-style factors such as smoking, the largest lung cancer excess was again seen in workers exposed to acids other than sulfuric acid (SMR = 2.00; 95% CI = 1.06-3.78). Adjustment for potential differences in smoking habits showed that increased smoking was unlikely to have entirely explained the increased risk. Mortality from causes of death other than lung cancer was unremarkable, with the exception of significantly low rates for deaths due to digestive system diseases.

Adolescent↗
PubMed1986

A case-control study of leukemia at a naval nuclear shipyard.

A matched case-control study was conducted of 53 leukemia deaths and of 212 controls within a previously studied cohort of 24,545 on-shore workers employed between January 1, 1952 and August 15, 1977 at the Portsmouth (New Hampshire) Naval Shipyard. The study sought to ascertain a priori whether there was an association between leukemia deaths and occupational exposure to either ionizing radiation or organic solvents. To obtain information on individual exposures, radiation dose histories and detailed work histories by job and shop were evaluated for each subject. No statistically significant associations were found either between ionizing radiation or presumed solvent exposure and myelogenous or lymphatic leukemia. However, when specific job categories and shops were examined without benefit of a priori hypotheses, two occupations, electrician and welder, were found to be associated with leukemia. For electricians, the Mantel-Haenszel odds ratio (ORMH) was significantly elevated for all leukemias (ORMH = 3.00, 95% confidence interval (CI) = 1.29-6.98), particularly for lymphatic leukemia (ORMH = 6.00, 95% CI = 1.47-24.45). For welders, the odds ratio was not significantly elevated for all leukemias (ORMH = 2.25, 95% CI = 0.92-5.53), but was significantly elevated for myeloid leukemia (ORMH = 3.83, 95% CI = 1.28-11.46). These findings persisted when potential confounders were adjusted by means of a conditional logistic regression model.

Aged↗
PubMed1985

Mortality patterns among styrene-exposed boatbuilders.

In order to test the hypothesis that leukemia and lymphoma may be associated with exposure to styrene, cause-of-death patterns were studied at two reinforced plastic boatbuilding facilities. There were 5,021 workers who met the criterion of having worked at the two plants between 1959 and 1978. Based on industrial hygiene surveys conducted at the two plants, 2,060 individuals were determined to have worked in departments classified as having high exposure to styrene. There were 176 deaths observed among the total cohort, in comparison to 195.3 deaths expected (standardized mortality ratio [SMR] = 90). Among the high styrene exposure group, 47 deaths were observed in comparison to 41.5 deaths expected (SMR = 113). No leukemia or lymphoma deaths were observed in either the high exposure group or the total cohort. An excess of accidental deaths among the high exposure group (18 observed vs 12.4 expected) did not appear to be due to styrene's acute central nervous system effects, since none of the individuals were employed at the facilities at the time of their death. However, the possibility of a chronic effect could not be dismissed. While leukemia and lymphoma did not appear to be related to styrene exposure, the study had little statistical power to detect excesses of these diseases, due to the short length of observation and the young age of most cohort members. It was concluded that the cohort should provide increasingly useful information on chronic styrene toxicity as the population ages and the observation period increases.

Adolescent↗
PubMed1985

Notification and risk assessment for bladder cancer of a cohort exposed to aromatic amines. III. Mortality among workers exposed to aromatic amines in the last beta-naphthylamine manufacturing facility in the United States.

A retrospective cohort mortality study was conducted among workers employed at the last facility in the United States that manufactured beta-naphthylamine (BNA), a recognized human bladder carcinogen. This study was conducted in conjunction with a pilot project in which workers were notified of the health risks associated with exposures to carcinogenic amines. Cause-specific mortality for 1,312 male workers employed between 1940 and 1972, and followed through 1979, was compared with the mortality of the general population in the United States. Two deaths from bladder cancer were observed while 0.7 such deaths were expected. Due to the use of these potent carcinogenic amines, it had been anticipated that more bladder cancer deaths would be found in this population. The reasons for the small number of bladder cancer deaths could have been the low percentage of the work force exposed, an inadequate latency period, and/or the high survival rate for bladder cancer. In fact, a notification and medical screening project recently conducted in this same population found an additional 11 bladder cancer cases. This suggests that mortality may not always be an adequate indicator of disease risk.

2-Naphthylamine↗
PubMedDate not supplied

An investigation of mortality from cancer and other causes of death among workers employed at an east Texas chemical plant.

The cause-specific mortality of 2,510 males employed at an east Texas chemical plant was examined in a historical prospective study to evaluate a suspected increase in deaths from multiple myeloma and brain cancer. Potential exposures from chemicals, either used in manufacturing processes or produced during the study period 1952-1977, included the fuel additive tetraethyl lead, ethylene dibromide and dichloride, inorganic lead, and vinyl chloride monomer. Overall mortality for all workers (156 observed vs. 211.14 expected) and for workers first employed between 1952 and 1959 (131 observed vs. 167.33 expected) when tetraethyl lead was the single major product was lower than expected when compared to the United States general population. There were no significant increases in mortality from malignancies or other causes of death. The deficits may be due to the small number of total deaths, and the low power for detecting excess risk of mortality from multiple myeloma (Z1-beta = 27, alpha = .05), brain cancer (Z1-beta = 31, alpha = .05), or other rare causes of death; lack of complete workplace exposure data for production workers; and the absence of historical measurements on the extent of environmental exposure to tetraethyl lead and other chemicals.

Actuarial Analysis↗
PubMedDate not supplied

Epidemiologic and toxicologic evidence for chronic health effects and the underlying biologic mechanisms involved in sub-lethal exposures to acidic pollutants.

Since the 1880s, a disparate and extensive literature has evolved examining the biologic effects of acidification on cells. More recently, effects on the health of human and other species of acidic agents contained, for example, in pollutants have been suggested, particularly relating to long-term exposures. This paper provides a review of the epidemiologic and toxicologic evidence concerning health effects--particularly carcinogenicity--attributable to sub-lethal acid exposure. Underlying biologic mechanisms that explain adverse health outcomes include pH modulation of toxicity for a number of xenobiotics (including carcinogens, genotoxins, and teratogens), and low-pH-induced changes of cells involving, for example, alterations in mitotic and enzyme regulation. More focused research is recommended to test the relationship between long-term exposures to acidic agents (with a consequent lowered cellular pH) and various health effects.

Air Pollutants↗