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Biomedical subjects

J B Cartmill

Publications and source records attributed to J B Cartmill.

16 recordsLinked to original sources
PubMed2001

Mortality in chemical workers potentially exposed to 2,4-dichlorophenoxyacetic acid (2,4-D) 1945-94: an update.

OBJECTIVE: To update and add to a previously identified cohort of employees potentially exposed to the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The putative association between 2,4-D and non-Hodgkin's lymphoma has been debated for more than a decade. METHODS: Cohort members were male employees of The Dow Chemical Company who manufactured or formulated 2,4-D any time from 1945 to the end of 1994. Their mortality experience was compared with national rates and with more than 40 000 other company employees who worked at the same location. RESULTS: 330 Deaths were observed among 1517 people compared with 365 expected (standardised mortality ratio (SMR)=0.90, 95% confidence interval (95% CI) 0.81 to 1.01). There were no significantly increased SMRs for any of the causes of death analyzed. When compared with the United States rates, the SMR for non-Hodgkin's lymphoma (NHL) was 1.00 (95% CI 0.21 to 2.92). The internal comparison with other Dow employees showed a non-significant relative risk of 2.63, (95% CI 0.85 to 8.33). Death was attributed to amyotrophic lateral sclerosis (ALS) for three cohort members. Compared with the other company employees, the relative risk was 3.45 (95% CI 1.10 to 11.11). The cases were employed in the manufacture or formulation of 2,4-D at different periods (1947-9, 1950-1, and 1968-86), and for varying durations of time (1.3, 1.8, and 12.5 years). CONCLUSION: There was no evidence of a causal association between exposure to 2,4-D and mortality due to all causes and total malignant neoplasms. No significant risk due to NHL was found. Although not an initial hypothesis, an increased relative risk of ALS was noted. This finding is unsupported by other animal and human studies.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1999

Mortality experience for Louisiana chemical workers.

A previous mortality study for Louisiana workers of The Dow Chemical Company identified greater than expected deaths due to leukemia and aleukemia and cancer of the brain and central nervous system. The current study updated the mortality experience through 1992. No new deaths due to leukemia and aleukemia and only one new death due to cancer of the brain and central nervous system were observed. No causes of death were statistically significantly elevated. The number of observed deaths was statistically significantly less than expected for a number of disease categories. Mortality rates were not shown to be higher among Louisiana chemical employees when compared to the United States, state, and regional populations.

Brain Neoplasms↗
PubMed1998

Update of the morbidity experience of employees potentially exposed to chlorpyrifos.

OBJECTIVES: Chlorpyrifos, an organophosphate ingredient of several important insecticides, has been manufactured at The Dow Chemical Company for 25 years. A previous morbidity study among employees of The Dow Chemical Company found no increased prevalence of illness or symptoms among employees potentially exposed to chlorpyrifos from 1977 to 1985 compared with matched controls. The purpose of the current study was to update the original study to 1994, thereby increasing the statistical power. METHODS: In the present study, 496 potentially exposed subjects were identified and matched for age, race, sex, pay, and year of hire to 911 control subjects. Morbidity data were abstracted from company medical records. RESULTS: The prevalence of peripheral neuropathy was not significantly increased among this group of employees potentially exposed to chlorpyrifos. Significantly increased prevalence odds ratios were identified for five diagnostic categories: diseases of the ear and mastoid process; acute respiratory infections; other diseases of the respiratory system; general symptoms, signs, and ill defined conditions; and symptoms, signs, and ill defined conditions involving the digestive system. There was a strong association of diagnosis with duration of observation period, indicating that the exposed workers were more likely than unexposed workers to have a diagnosis abstracted from the company medical records due to their longer mean period of follow up. Analyses by exposure classification and mean plasma cholinesterase activity did not show a dose response. CONCLUSIONS: These data do not support a cause and effect relation of the diagnoses mentioned and exposure to chlorpyrifos.

Adult↗
PubMed1997

Mortality from pancreatic and lymphopoietic cancer among workers in ethylene and propylene chlorohydrin production.

OBJECTIVES: A previous study reported a fivefold increase in mortality from pancreatic cancer and a threefold increase in lymphopoietic and haematopoietic cancer among 278 men who were assigned to a now dismantled Union Carbide chlorohydrin unit in the Kanawha Valley of West Virginia. There were also significant trends with duration of employment. The purpose of this study was to determine whether a comparable increased risk in mortality from pancreatic cancer and lymphopoietic and haematopoietic cancer occurred among male employees assigned to the Dow Chemical Company's ethylene and propylene chlorohydrin production processes. METHODS: The cohort consisted of 1361 male employees who worked at the company's Freeport, Texas, Plaquemine, Louisiana or Midland, Michigan plants. Subjects were considered to have had a minimum of 30 days of workplace experience in 1940-92, in the ethylene chlorohydrin and propylene chlorohydrin process areas. These process areas were located within the ethylene oxide and propylene oxide production plants. A total of 300 deaths was observed to 31 December 1992. RESULTS: The standardised mortality ratio (SMR) for all malignant neoplasms was 94 (95% CI 74 to 118). There was one pancreatic cancer death compared with 4.0 expected (SMR 25, 95% CI 1 to 140). There were 10 lymphopoietic and haematopoietic cancer deaths compared with 7.7 expected (SMR 129, 95% CI 62 to 238). Additional analyses, which examined location, production process, duration of employment, and a 25 year induction latency period, were not significant. CONCLUSIONS: The results provide some assurance that the Dow Chemical cohort, to date, has not experienced increased risks of pancreatic cancer and lymphopoietic and haematopoietic cancer as previously reported in a different cohort of chlorohydrin workers. Possible reasons are discussed for the inconsistent findings between the two cohorts.

Chlorohydrins↗
PubMed1997

A thirty-eight year comparison of cancer incidence and mortality among employees at a Connecticut chemical plant.

An important aspect of occupational mortality is the fact that death registration is complete and has good specificity and sensitivity for those cancers with poor survival. However, if available and complete, cancer incidence data are preferable. A unique opportunity presented itself at The Dow Chemical Company's Allyn's Point plant (Gales Ferry, Connecticut) to conduct a cancer incidence and mortality study since the plant began operation in 1951, several years after the establishment of the Connecticut Tumor Registry. All male employees (N = 666) with one or more years of service from 1951-1989 were eligible for the study. Altogether there were 47 primary incident cancers which represented 40 individuals. The Standardized Incidence Ratio (SIR) for all cancer was 124 (95% confidence interval [CI] 91-165). There were 23 deaths reported for all cancers (Standardized Mortality Ratio [SMR] 87, 95% CI 55-131). Only laryngeal cancer incidence was statistically significant (Standardized Incidence Ratio [SIR] 417, 95% CI 135-972). After review of the work history records, this association was found to be inconsistent with a common exposure hazard at the plant.

Adult↗
PubMed1996

Mortality in a cohort of pentachlorophenol manufacturing workers, 1940-1989.

Mortality in a cohort of 770 workers with potential pentachlorophenol (PCP) exposure was evaluated from 1940 through 1989. The study cohort is a subset of a larger cohort of workers with potential exposure to higher chlorinated dioxins. Total mortality and cancer mortality in the PCP cohort were slightly lower than expected in comparison to the U.S. white male population. There were 229 total deaths with 242.5 expected (SMR = 94, 95% confidence interval 83-108), and 50 cancer deaths with 52.6 expected (SMR = 95, 95% confidence interval 71-125). In comparison with unexposed employees, the risk ratio for total mortality was 1.03 (95% confidence interval 0.90-1.17), and the risk ratio for all cancer mortality was 0.95 (95% confidence interval 0.71-1.26). In most cause of death categories of a priori interest no deaths were observed in the cohort. A small excess of other and unspecified lymphopoietic cancer deaths was observed but did not appear to be related to exposure. Excesses of deaths due to cancer of the kidney, gastric and duodenal ulcer, cirrhosis of the liver, and all accidents were observed in comparison with the U.S. white male population and with unexposed employees. These were associated with increasing estimated cumulative PCP exposure after lagging exposures by 5 and 15 years. Despite the limited size and the generally favorable total mortality experience of the cohort, it was concluded that cohort members may have incurred increased risk of death due to some specific causes. The risks could not, however, be attributed conclusively to PCP exposure and may have been associated with other occupational and nonoccupational factors. Additional mortality surveillance of this cohort will be performed.

Accidents↗
PubMed1995

Update of the mortality experience of employees with occupational exposure to 1,2-dibromo-3-chloropropane (DBCP).

DBCP (1,2-dibromo-3-chloropropane), a nematocide, was used in the United States from the mid-1950s until 1977. The U.S. Environmental Protection Agency (EPA) restricted and eventually banned its use after the 1977 discovery of DBCP-induced sterility in production workers. The present study is an update of the mortality (1957-1989) experience of a cohort of 548 male employees who had potential for exposure in the production and formulation of DBCP. While adjusting for age, calendar-year, and pay status of all other Midland-area Dow Chemical male employees, there were 68 total observed deaths in the cohort compared to 72.1 expected (Mantel Haenszel Relative Risk 0.9, 95% Confidence Interval 0.7-1.2) and 19 deaths from all malignancies compared to 19.0 expected (RR 1.0, 95% CI 0.6-1.6). Of the a priori anatomic cancer sites of interest, there were no deaths from stomach, liver, kidney, testes, or nasal cavity cancers. Altogether, there were 7 deaths from lung cancer compared to 6.6 expected (RR 1.1, 95% CI 0.5-2.3). Among the 81 employees with exposure categorized as direct for 1 or more years, there were 3 observed lung cancer deaths compared to 0.9 expected (RR 3.3, 95% CI 1.1-9.6). Smoking was a confounding factor in the interpretation of this observation. Although the present analysis nearly doubled the number of person-years from the original study, the conclusions remain limited by the cohort's size and duration of follow-up.

Antinematodal Agents↗
PubMed1994

Half-century of cause-specific mortality experience of chemical manufacturing employees.

Cause-specific mortality was surveyed among 23,180 male (580,000 person-years) and 3,860 female (86,898 person-years) employees with 1 or more years of service from 1940 through 1989 at a large chemical plant. Vital status was ascertained for 99.1% of the males (n = 5,658 deaths) and 98.6% of the females (n = 355 deaths). Comparisons of observed mortality with expected levels based on any of three population comparisons (United States, Texas, or five local counties) showed lower mortality for all causes of death, diseases of the circulatory system, diabetes mellitus, and cirrhosis of the liver. There was an increased risk for lung cancer mortality among male operations employees when compared to the U.S. and Texas populations but not to the local five-county region. Additional evidence suggests this increase was primarily attributable to cigarette smoking. Male operations employees also had an elevated, although not statistically significant, risk for kidney cancer. Prior research had shown an association with work in the cell maintenance area of chlorine production. As a result of a high prevalence of deaths certified by justices of the peace, a mortality excess was observed of cancer of other and unspecified sites and symptoms, senility, and ill-defined conditions. Although specific chemical exposures were not studied, the generally favorable mortality experience suggests that major hazards are unlikely.

Chemical Industry↗
PubMed1992

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↗
PubMed1992

The mortality experience of Dow Chemical Louisiana Division employees, 1956-1986.

A major objective of the epidemiology department of the Dow Chemical Company is to report at periodic intervals the cause-specific mortality experience of its employees. This study analyzed the cause-specific mortality experience of 4,229 male and female employees of the Louisiana Division who were employed for at least 1 year from 1956 through 1986. Regardless of the comparison population used to calculate expected numbers (United States, Louisiana, or the surrounding five parish area), fewer deaths were observed for all causes combined as well as for all malignant neoplasms, diseases of the circulatory system, and external causes of death.

Chemical Industry↗
PubMed1987

Cause-specific mortality among male chemical workers.

Cause specific mortality was surveyed among 37,682 male employees with three or more days of service between 1940 and 1982 at the Midland or Bay City, Michigan, locations of Dow Chemical USA. Vital status was ascertained through 1982 for 97.5% of the cohort members, and death certificates were obtained for 97.1% of the 7,751 decedents. Comparisons of observed mortality with expected levels based on any of three general population groups (US, Michigan, or seven local counties) consistently demonstrated lower mortality in the cohort from each of the major causes of death, including total malignant neoplasms. Unique among hourly employees was significant excess mortality in the categories of cancer of other lymphatic tissue, and motor vehicle accidents, and both hourly and salaried nonexempt employees experienced significantly higher mortality from other and ill-defined cancers. The influence of duration of employment and age at and period of hire were explored with the Mantel-Haenszel method as adapted for a cohort study. Results were evaluated both including and excluding the mortality experience of subsets of employees with past exposure to known human carcinogens (arsenic, asbestos, bis-chloromethyl ether, benzene, organic dyes, and vinyl chloride). The use of the general mortality survey in monitoring whether or not there are major health problems among the employees and in setting research priorities is emphasized.

Accidents, Occupational↗
PubMed1987

Mortality among female employees of a chemical company.

There have been few mortality studies conducted on working women despite their increasing presence in the work environment. This paper presents the findings of a cohort mortality study of 10,839 female employees with three or more days of service between 1940 and 1982 at the Midland or Bay City, Michigan, locations of the Dow Chemical Company. The cohort included substantial numbers of production and research personnel but was primarily comprised of clerical and office workers. Vital status was ascertained through 1982 for 89.4 percent of the cohort members, and death certificates were obtained for 94.0 percent of the 467 decedents. Comparisons of observed mortality with expected levels based on mortality rates for the U.S., Michigan, and a local 7-county area revealed consistently lower mortality in the cohort from the major causes of death, indicating a strong "healthy worker effect." Mortality from cancer of the cervix was significantly below expected levels, especially among women who were hired before 25 years of age. This observation, when combined with a nonsignificant excess of breast cancer, suggests a different distribution of maritally and sexually related risk factors between working and general populations of women. This and other findings are discussed relative to methodologic problems likely to accompany studies of working women.

Adult↗
PubMed1986

Nested case-control study of lung cancer among chemical workers.

A recent cohort mortality study of 19,608 male employees of a major Texas chemical production facility had suggested that they might be at higher risk of lung cancer compared with the male population of the United States or Texas but not with the male population of the five-county area in which they reside. An occupational exposure was a possible explanation for this pattern, and a nested case-control study was undertaken of the 308 lung cancer deaths observed between 1940 and 1981. Two control groups, one a decedent and the other a "living" series, were individually matched to cases one-for-one. Interviews were conducted with subjects or their next of kin to collect information on smoking and other potential confounders. These data were combined with employee work history records and industrial hygiene data to form the basis of the analyses. Traditional stratification methods and conditional logistic regression were employed to examine for effect modification and to control confounding. Statistically significant, positive and negative associations were found for assignment to several work areas within the facility. Suggestive associations were observed for exposure to sulfur dioxide and heat. These and additional associations are discussed relative to evidence from other studies.

Adult↗
PubMed1985

Mortality among a large cohort of chemical manufacturing employees.

Cause-specific mortality was surveyed among 19,608 male employees with 1 or more years of service between 1940 and 1980 at the Texas Operations of Dow Chemical U.S.A. Vital status was ascertained through 1980 for 97.3% of the cohort members, and death certificates were obtained for 96.4% of the 3,444 decedents. Mortality risks were found to vary, depending upon which of 3 population groups (United States, Texas, and local counties) was used for comparison, although significantly fewer than expected deaths from all causes was a common finding due to significant deficits in diabetes, diseases of the circulatory system, and cirrhosis of the liver. Significantly more deaths were from ill-defined conditions and cancers of unspecified sites. Lung cancer was significantly elevated in comparisons with the incidences in the United States and Texas, but not in comparison with those in the local counties. The influence of age at hire, period of hire, duration of employment, interval since entry into cohort, employment status, and two measures of social class--educational level and job category--were explored with the use of the Mantel-Haenszel method as adapted for a cohort study. Findings from these analyses are discussed in relation to the observations of other investigators and in the context of the possible impact of these findings on future studies of this work force.

Chemical Industry↗