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Biomedical subjects

G G Bond

Publications and source records attributed to G G Bond.

At least 19 recordsLinked to original sources

General mortality and respiratory cancer among a cohort of male chemical workers in California.

Cohort mortality and nested case-control studies were conducted involving 2,901 men employed 1 year or more between 1940 and 1986 at any of four California facilities of a major chemical company. Employees experienced fewer deaths from each of the major causes than were expected based on U.S., California, and local county mortality rates. Respiratory cancer was significantly elevated in one socioeconomic category comprised of operators (SMR = 157, 95% CI = 109-220). The 34 cases who died from respiratory cancer and 136 matched controls, all of whom were operators, were included in a nested case-control study. Departments in which subjects had worked were grouped into 13 work assignment or product categories by an industrial hygienist without knowledge of case-control status. Smoking habits and other occupational exposures were ascertained by telephone interview from subjects or surrogate-responders. As expected, current cigarette smoking was strongly related to respiratory cancer. After adjustment for smoking, cases were significantly more likely than controls to have ever worked in one of the 13 work areas (supervision, services, and business support). However, no dose-response relationship was evident with duration of employment in this work area and the departments involved were associated with plant security and not chemical production. Results were similar when a 15-year latency period was assumed. These findings suggest that the excess of respiratory cancer mortality among operators was most likely due to differences in cigarette smoking or other factors not ascertained, rather than to a specific occupational exposure.

Adult

The health belief model and adolescents with insulin-dependent diabetes mellitus.

We tested the predictive utility of the health belief model (HBM) for adherence with a complex, ongoing medical regimen in the context of a chronically ill youthful population (56 adolescent outpatients with insulin-dependent diabetes mellitus; mean age = 14 years). A three-construct model of health beliefs was tested: Threat (perceived susceptibility combined with severity), Benefits-Costs, and Cues to seek treatment. Multiple indicators of compliance were used, and metabolic control was measured by glycosylated hemoglobin. The Benefits-Costs and Cues constructs were related to compliance in the theoretically expected positive direction. Threat interacted with Benefits-Costs in the prediction of compliance and with Cues in the prediction of metabolic control. The greatest compliance was achieved with low perceived Threat and high perceived Benefits-Costs. Poor metabolic control was associated with high Threat and Cues. As age increased, adherence to the exercise, injection, and frequency components of the regimen decreased.

Adaptation, Psychological

Prevalence of back pain and joint problems in a manufacturing company.

To estimate prevalence of back pain and joint problems in employees of a chemical manufacturing company, a questionnaire was administered during medical surveillance examinations between 1987 and 1989. Among 5903 employees completing the questionnaire 35.4% reported back or joint pain during the past year. Back pain lasting 30 days or more occurred in 5.3% of employees, while joint pain and/or swelling occurred in 19.3% of employees. A physician visit was involved for 10.5% and 11.1% of employees reporting back pain and joint problems respectively. A trend of increasing prevalence with increasing age was significant (P less than .001) for all musculoskeletal outcomes. Unadjusted prevalence of back pain and joint problems was significantly higher among men and among whites. After adjusting for age, race, and occupation using logistic regression, the difference in prevalence for the two sexes was diminished or reversed. Similarly, differences in race were diminished when other variables were controlled. Differences in prevalence by occupation were attenuated after adjustment for age, gender, and race. Back pain tended to be reported more frequently for managers, back pain and joint problems for technicians, and back pain requiring physician visit for craftsmen. Self-reported back pain and joint problems during the previous year vary more by age and occupation and less by gender and race in this employed population.

Adult

Preliminary evaluation of an employer-sponsored mammography screening program.

Recognizing the importance of early detection of breast cancer, the Dow Chemical Company initiated a breast cancer awareness program in 1988. Evaluation of operational aspects of mammography screening component revealed that about half (53%) of 1186 eligible women in the evaluation cohort took part, although participation was three times higher for active than for retired employees. Eleven per cent of participants were considered to have "positive" screens, ie, had roentgenogram films with suspicious areas, and at least 82% of these women had follow-up medical services within 1 year of screening, as determined by a review of group insurance claims records. Two women with positive mammograms were subsequently diagnosed and treated for breast cancer within 2 months of screening. None of the women with negative mammograms developed breast cancer in the subsequent year. The suitability of group insurance data resources for responding to health care delivery questions is discussed.

Adult

Mortality among workers engaged in the development or manufacture of styrene-based products--an update.

Mortality was updated another 11 years through 1986 for a previously studied cohort of 2904 male chemical workers who were potentially exposed to styrene and related materials for a year or more between 1937 and 1971. Substantial deficits in mortality from all causes and total cancer were observed in the cohort when it was compared with white males in the United States, and also other chemical workers who were unexposed to styrene-based products. Mortality from leukemia was slightly less than expected during the updated period, in contrast to an excess of lymphatic leukemia observed in the original period. Yet small elevations in risk of other types of lymphatic cancer, particularly multiple myeloma, persisted. The risk of these cancers did not increase with estimated intensity or duration of styrene exposure. The findings are discussed in context with those of studies of similarly exposed workers in related industries.

Cause of Death

A 5-year evaluation of a smoking cessation incentive program for chemical employees.

BACKGROUND: This 5-year study of the Dow Chemical Texas Operations 1984-1985 Smoking Cessation Incentive Program (SCIP) evaluated the smoking habits of 1,097 participants and 1,174 nonparticipants. RESULTS: We observed, via questionnaire and saliva cotinine data, that participants were 2.3 times more likely to be long-term (greater than or equal to 5 years) nonusers of tobacco than nonparticipants (10.2% vs 4.4%, P less than or equal to 0.01). However, smoking cessation rates for 3-4 years, 1-2 years, and less than 1 year were similar for participants who remained smokers at the conclusion of SCIP and nonparticipants. Age and the interaction between the management job category and having quit smoking for at least 30 days sometime prior to the worksite program were important predictors of smoking cessation among participants. Thirty-six percent of the participants who were considered exsmokers of 6 months duration at the conclusion of the program in 1985 remained long-term quitters 5 years later. Stress and enjoyment of smoking were the two most important reasons provided by participants for recidivism. CONCLUSIONS: The results of this 5-year evaluation demonstrate the heterogeneity of employee participation and success with a worksite smoking cessation program.

Absenteeism

Ethical issues relating to the conduct and interpretation of epidemiologic research in private industry.

This paper identifies the parties to which epidemiologists are obligated and explores the areas in which potential conflicts of obligations can occur. It is concluded that all epidemiologists, regardless of the organizational context in which they operate, share similar obligations to their subjects, society, their employer or funding agency, and their colleagues. The fundamental principals inherent to an epidemiologist's obligation to protect the public health is to identify real health problems and promote their resolution. It is in everyone's interest, including private industry, to respect those principals, and an industry supported epidemiology program can be an effective means for accomplishing that. These programs can be innovatively designed to protect those fundamental principles and thereby avoid conflicts of interest. This is illustrated with some examples from the epidemiology program operated at The Dow Chemical Company.

Chemical Industry

A comparison of cause-specific mortality among participants and nonparticipants in a work-site medical surveillance program.

Nonparticipants in general population health surveys have been found to be less healthy than participants, but data on nonparticipants in work-site health surveys have been more scarce. We compared cause-specific mortality among 11,156 male employees of The Dow Chemical Company who participated in at least one work-site health examination between 1967 and 1978 with 6915 employees who did not participate. The nonparticipants experienced higher mortality rates for nearly every cause of death examined but particularly from smoking and alcohol-abuse related diseases. This was especially true during the first 5 years of follow-up, suggesting that some employees do not participate because they are already ill. These findings have important implications for the use of examination data for both primary and secondary disease prevention purposes, and these are discussed.

Adult

Weight of the evidence on the human carcinogenicity of 2,4-D.

The phenoxy herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is widely used to control the growth of weeds and broadleaf plants. We convened a panel of 13 scientists to weigh the evidence on the human carcinogenicity of 2,4-D. The panel based its findings on a review of the toxicological and epidemiological literature on 2,4-D and related phenoxy herbicides. The toxicological data do not provide a strong basis for predicting that 2,4-D is a human carcinogen. Although a cause-effect relationship is far from being established, the epidemiological evidence for an association between exposure to 2,4-D and non-Hodgkin's lymphoma is suggestive and requires further investigation. There is little evidence of an association between use of 2,4-D and soft-tissue sarcoma or Hodgkin's disease, and no evidence of an association between 2,4-D use and any other form of cancer. Scientists on the panel were asked to categorize 2,4-D as a "known," "probable," "possible," or "unlikely" carcinogen or as a noncarcinogen in humans. The predominant opinion among the panel members was that the weight of the evidence indicates that it is possible that exposure to 2,4-D can cause cancer in humans, although not all of the panelists believed the possibility was equally likely: one thought the possibility was strong, leaning toward probable, and five thought the possibility was remote, leaning toward unlikely. Two panelists believed it unlikely that 2,4-D can cause cancer in humans.

2,4-Dichlorophenoxyacetic Acid

Lung cancer and hydrogen chloride exposure: results from a nested case-control study of chemical workers.

There are few epidemiologic data available to address the question of potential carcinogenic effects of hydrogen chloride (HCl) exposure on humans. An opportunity arose to augment a nominal HCl exposure classification that had been done earlier for a nested case-control study of lung cancer among a cohort of chemical manufacturing employees. Working from first-hand knowledge of the relevant chemical processes and limited HCl monitoring data, a certified industrial hygienist estimated average exposures for each of the job assignments of 308 lung cancer cases and 616 comparison workers. The risk of lung cancer was then analyzed in relation to several measures of HCl exposure, including duration, a cumulative exposure score, highest average exposure, and latency. None showed evidence of an association between HCl exposure and lung cancer. This is consistent with the limited rodent bioassay data, which also failed to find a tumorigenic response from HCl. Thus, even at high level occupational exposures (up to 3000 micrograms/m3 for several years) there is no evidence that HCl is a human carcinogen.

Adult

Occupation and industry on death certificates of long-term chemical workers: concordance with work history records.

This study evaluated the concordance between occupation and industry listed on death certificates with actual work history information for a group (n = 5,882) of long-term (10 years or more) workers at a chemical company. Match rates were calculated as the percent of death certificate occupation and company entries that were confirmed by work history data using 3-digit 1980 U.S. Census Bureau group codes. The concordance rate for industry differed by employment status at death: employed, 94.9%; inactive, 30.8%; and retired, 91.1%. Concordance on occupation was analyzed for employed (n = 467) and retired (n = 932) subjects who had computerized work histories (randomly done prior to the study) and who had matched on the company on the death certificate. Concordance ranged from 0 to 50% for the first job, to 50 to 70% for the last job, longest job, and longest job in the last 10 years of company employment. The most consistent predictor of concordance was job duration. Misclassification was reviewed by occupational category. Results from this and other investigations lead to the inevitable conclusion that usual occupation data from death certificates are grossly inadequate for studies of occupational risks.

Aged

Liver and biliary tract cancer among chemical workers.

A recent cohort mortality study of male, hourly wage employees of a large Michigan chemical production and research facility had found a greater than expected number of deaths coded to liver and biliary tract cancer. In response, an additional investigation was then undertaken of the 44 liver and biliary tract cancer deaths observed between 1940 and 1982. A random sample (N = 1,888) of subjects was selected from the total cohort (N = 21,437) to serve as referents. Company work history records were used to classify cases and referents by work area assignment and potential for exposure to 11 selected chemical agents which have been shown to produce cancer of the liver or biliary passages in experimental animals. Statistically significant associations in both positive and negative directions were found for several work areas within the facility. A suggestive association was found for vinyl chloride monomer, based on five cases with presumed exposure.

Biliary Tract Neoplasms

Determinants of spermatogenesis recovery among workers exposed to 1,2-dibromo-3-chloropropane.

The purpose of this study was to investigate the determinants of spermatogenesis recovery among 30 azoospermic and 17 oligospermic workers who had a maximum of 18 months of exposure to 1,2-dibromo-3-chloropropane during 1976 to 1977. A maximum of 11 years of follow-up data were examined. Of the 26 azoospermic subjects who voluntarily participated in follow-up, 19 (73.0%) showed evidence of spermatogenesis recovery. Thirteen azoospermic subjects recovered to normospermic levels; however, their mean most recent sperm count (44.4 million/mL) was significantly lower (P less than .01) than the mean (88.8 million/mL) of the 17 oligospermic subjects who recovered to normospermic levels. The lack of spermatogenesis recovery was definitively shown to be job (drumming and canning) and, possibly, age related. Duration of exposure and the initial 1977 categorization of exposure (high, moderate, and low) were not predictive of recovery. Testicular atrophy was observed with azoospermia, and the testicles subsequently increased in size among those azoospermic subjects who returned to normospermic levels. The follicle-stimulating hormone level in 1977 was significantly associated with azoospermia as well as the likelihood of return to normospermia among the azoospermic subjects.

Adult

Mortality comparisons of chemical workers hired before, during, and after World War II (1941-1945).

Cause-specific mortality was evaluated by period of hire for 37,682 male chemical workers in order to test the hypothesis that employees hired during World War II (1941-1945) were at increased risk for selected causes of death. One recent study of refinery workers reported that those hired during the war years had experienced greater mortality from external causes (accidents, homicides, and suicides), alcoholism, and cancers of several sites relative to employees hired before or after the war. In the present study, employees were divided into three period-of-hire subcohorts: prior to 1941, 1941-1945 (World War II), and 1946 and after. Comparison of observed mortality among these subcohorts through 1982 was made with expected levels based on age- and calendar year-specific U.S. white male rats. Neither hourly nor salaried employees hired during the war showed evidence of higher mortality from homicide, suicide, alcoholism, or any of the selected cancer types suggested from the refinery study. Hourly, but not salaried, war years new hires experienced excessive mortality from only those accidents involving motor vehicles. Possible reasons for the discrepant findings between this and the earlier study of refinery workers are discussed, with methodological differences being dismissed.

Cause of Death

Phenoxy herbicides and cancer: insufficient epidemiologic evidence for a causal relationship.

The question as to whether or not any or all of the phenoxy herbicides are carcinogenic to humans continues to be evaluated. We review the evidence available from the retrospective cohort and case-control epidemiology studies. Graphs of the individual probability densities for the odds ratios from the eight case-control studies of soft-tissue sarcoma, Hodgkin's disease, or non-Hodgkin's lymphoma demonstrate gross inconsistencies which are not likely to be attributable to chance. Early studies, conducted in Sweden, had indicated strong associations, but subsequent work from New Zealand and the United States has failed to substantiate those findings. The reasons for the discordant results may relate more to methodologic problems in the earlier studies than to qualitative or quantitative differences in the exposures of the underlying populations. The retrospective cohort studies offer the advantage of having focused on occupational groups believed to have had the highest exposures, although they have been criticized as being individually too small to assess the risks of the rarer forms of cancer. Consideration of the combined cohort studies of workers exposed to the phenoxy herbicides per se provides little or no evidence of carcinogenicity. Thus, the total weight of evidence currently available does not support a conclusion that the phenoxy herbicides present a carcinogenic hazard to humans.

2,4,5-Trichlorophenoxyacetic Acid