Death certificate case-control study of cancers of the prostate and colon and employment in the textile industry

A case-control study was conducted to investigate possible relationships between employment in the textile industry and cancers of the prostate and colon. Death certificate information on occupation and industry was obtained for 1037 male prostatic cancer cases, 820 male and female colon cases, and matched controls who died during 1970-1978 in South Carolina. Black males were the only race-sex group to show an excess risk of prostate or colon cancer among employees of the textile industry. Nonstatistically significant excesses of prostate cancer were seen in dyeing and finishing businesses and broad woven fabric mills. Overall, there was no strong evidence indicating a relationship between the textile industry and either prostate or colon cancer. It is unlikely that limitations of the data masked real risks since previously reported associations with nontextile industries were confirmed.

Farming and mortality from multiple myeloma: a case-control study with the use of death certificates

A case-control study of multiple myeloma among males was conducted with the use of digitized mortality listings for 1968-76 from the State of Wisconsin. Age, year of death, race, county of usual residence, marital status, and usual occupation were available for the 411 male deaths due to multiple myeloma and for a matched series of deaths due to other causes. Farmers were at an elevated risk compared to nonfarmers [odds ratio (OR) = 1.4], with decedents 65 years of age or older having a stronger association (OR = 1.5) than younger farmers (OR = 1.1). County levels of selected agricultural characteristics were used as surrogate measures of exposure. Significantly elevated OR were observed for farmers residing in counties high in chicken inventory (OR = 1.6), fertilizer use (OR = 1.7), and acres treated with insecticides (OR = 1.9). Further investigation of multiple myeloma among farmers is warranted.

Causes of death among workers in the tobacco industry

The number of deaths by cause, race, and sex among 2,709 workers (1,003 white males, 789 black males, 517 white females, and 400 black females) in the tobacco industry identified from obituary listings of the Tobacco Workers' International Union from 1957 to 1978 were compared to expected numbers based on the experience of the U.S. population. The frequency of deaths from cancer of the colon was slightly elevated among each race-sex group [proportionate mortality ratios (PMRs) from 129 to 163]. Although unexplained, this resembles the excess of cancer of the digestive system previously reported among cigarette manufacturers. The excess deaths from cancer of the lung occurred only among white females and may represent chance findings. Among non-neoplastic causes of death, PMRs for arteriosclerotic heart disease, motor vehicle accidents, and suicides were high among most race-sex groups, while PMRs for respiratory disease and cirrhosis of the liver were low.

Lung cancer and other causes of death among licensed pesticide applicators

The mortality experience of a cohort of 3,827 white men licensed to apply pesticides in Florida was evaluated to investigate health effects associated with chronic exposure to pesticides. Although the overall standardized mortality ratio (SMR) for these structural pest control workers was not significantly elevated (SMR = 103), excess deaths were observed for leukemia, particularly acute myeloid leukemia (3 observed vs. 0.9 expected), and cancers of the brain (SMR = 200) and lung (SMR = 135). The risk of lung cancer rose with the number of years licensed with SMR of 101, 155, and 289 among those licensed for less than 10 years, for 10-19 years, and for 20 years or more, respectively. Ratios of directly adjusted rates showed similar patterns with observed-to-expected ratios of 100, 175, and 186 for the length of licensure categories. Mortality from lung cancer was greater among persons first licensed before age 40 (SMR = 234) than among those first licensed after age 40 (SMR = 115). Although information on tobacco use was not available, the increasing risk of lung cancer with number of years licensed and the capacity of certain pesticides to produce neoplasms in laboratory animals suggested that some pesticides may be carcinogenic in humans.

Mortality among chemical workers exposed to benzene and other agents

A historical cohort mortality study was conducted of 259 male employees of a chemical plant where benzene has been used in large quantities. The study group included all persons who were employed by the Company any time between January 1, 1947 and December 31, 1960. The cohort was followed through December 31, 1977 at which time 58 known deaths were identified. The only unusual finding was four deaths from lymphoreticular cancers when 1.1 would have been expected on the basis of national mortality rates. Three of the deaths were due to leukemia and one was caused by multiple myeloma. In addition, one of the leukemia deaths had multiple myeloma listed on the death certificate. The findings are consistent with previous reports of leukemia following occupational exposure to benzene and raise the possibility that multiple myeloma could be linked to benzene, also.

Mortality patterns among US veterinarians, 1947-1977: an expanded study

Causes of death among 5016 white male veterinarians identified from obituary listings in the Journal of the American Veterinary Medical Association were compared to a distribution based on the general US population. Proportions of deaths were significantly elevated for cancers of the lymphatic and haematopoietic system, colon, brain, and skin. Fewer deaths were observed than expected for cancers of the stomach and lung. Although socio-economic and methodological factors may be involved, the patterns suggest that sunlight exposure is responsible for the excess of skin cancer among veterinarians whose practices are not exclusively limited to small animals, and ionizing radiation exposure contributes to the excess of leukaemia among veterinarians practising during years when diagnostic radiology became widely used. Mortality was also high for motor vehicle accidents and suicides, but low for diseases of the respiratory system.

Inhibition of renal creatinine secretion by cimetidine in humans

The renal clearance of inulin (Cl_in), ¹⁴C-creatinine (Cl_14C._cr) and endogenous creatinine (Cl_cr) were measured in 6 healthy subjects before and after a single intravenous bolus of cimetidine (5 mg/kg). The initial Cli4_C._cr/Cl_in ratio (mean ± SD) was 1.68 ± 0.17; this fell to a nadir of 1.35 ± 0.18 soon after cimetidine was infused and rose again as the drug was excreted. This is the first cationic drug to show substantial inhibition of tubular secretion of creatinine in humans.

Cancer risks associated with agriculture: epidemiologic evidence

Despite their generally favorable mortality experience, general occupational surveys of farmers suggest they have elevated risks of cancer of the lymphatic and hematopoietic systems, stomach, prostate, brain, and skin. Since farmers often serve in the role of mechanic, carpenter, welder, pesticide applicator, and veterinarian, they may be exposed to many potentially hazardous substances. The types and levels of exposures have been discussed by others earlier in the program. The evidence is strongest for the association between farming and risk of leukemia. However, the specific leukemogenic agent or agents have yet to be identified. Leukemia excesses among poultrymen and dairy farmers suggest involvement of zoonotic viruses, while associations with crop production is more indicative of pesticide usage. The associations regarding other cancers (i.e., Hodgkin's disease, non-Hodgkin's lymphoma, multiple myeloma, soft-tissue sarcoma, and cancers of the stomach, brain, and prostate) are even less clear. However, the Swedish reports of high risk of soft-tissue sarcomas and lymphomas among persons exposed to herbicides is particularly disconcerting and underscores the urgent need for similar epidemiologic studies in the U.S. Several case-control interview studies are underway that should help clarify the role of agricultural factors in the origin of various cancers. NCI is sponsoring studies of leukemia and non-Hodgkin's lymphoma among men from Minnesota and Iowa. Detailed information on farm practices and pesticide usage is being gathered. A study of soft-tissue sarcoma, Hodgkin's disease, and non-hodgkin's lymphoma also has just been initiated. This investigation is located in Kansas, a major wheat producing area. A wheat producing area was selected because herbicides are more heavily used on this crop than insecticides. The major objective of this project is to evaluate the role of herbicides in the origin of these cancers. A case-control study of brain cancer has also recently been initiated. Although this study focuses on contact with petrochemicals, a complete work history will be obtained and would note any farm experience. These data may help clarify the reported association between brain cancer and farming.

Multiple myeloma in the United States, 1950--1975

A total of 68,400 whites and 10,533 nonwhites were reported to have died from multiple myeloma (MM) in the continental United States between 1950 and 1975 (excluding 1972 because of incomplete case ascertainment). Age-adjusted mortality rates for nonwhites were approximately twice as high as for whites. During the 25-year period of this survey, there was a twofold to threefold increase in MM mortality. The increase was seen in both races, but was greater in nonwhites than whites and primarily occurred in people over 55 years of age. The increases were uniform in all geographic regions and urban/rural categories. MM mortality from 1950--1969 was correlated with geographic, demographic, and occupational factors at the county level. The rates were highest in the far west and mid-central regions for whites and in the northeast for nonwhites. Urban areas had the highest rates and rural areas had the lowest, and positive associations were seen with indices of socioeconomic level and the percentage of residents with Scandinavian ancestry. For white males, MM mortality rates were elevated in areas with high petroleum and paper production, and a slight increase was seen in furniture manufacturing areas.

Death certificate study of leukemia among farmers from Wisconsin

The risk of leukemia among farmers and dairy farmers in particular was studied with the use of mortality records from Wisconsin, 1968-76. A comparison of occupation as noted on the death certificate for 1,499 cases and a like number of matched controls revealed a slight [odds ratio (OR) = 1.10], but statistically nonsignificant, excess risk of leukemia among farmers. The risk was highest among those born after 1897 (OR approximately 1.50) or dying before age 71 years (OR approximately 1.35) among dairy farmers (whether noted on death certificates or identified by county agricultural agents of the Cooperative Extension Programs of the University of Wisconsin) and all farmers alike. The under-representation of farmers among controls with smoking-related causes of death, however, may partially account for these findings. Stratification by county of residence showed significantly elevated risks among farmers from counties with heavy dairy production (OR = 1.40) and fertilizer use (OR = 1.42).

Mortality among workers in the metal polishing and plating industry, 1951--1969

The numbers of deaths by cause among 1,292 white male metal polishers and platers identified from obituary listings in the Journal of the Metal Polishers, Buffers, Platers, and Allied Workers International Union were compared to an expected distribution based on the white male population of Illinois and the U.S. The proportions of deaths due to cancers of the esophagus and the liver were high, particularly among those over 65 and those listed as metal polishers or platers on the death certificate. The PCMRs for these two tumors were also moderately elevated. Despite methodologic limitations, these findings, along with the known use in this industry of chromium and nickel, strong acid and alkaline solutions, and the solvents trichloroethylene and tetrachloroethylene, suggest that metal polishers and platers may be subject to exposures capable of inducing cancer.

Cancer mortality in United States counties with metal electroplating industries

A survey of cancer mortality from 1950 to 1969 was conducted in U.S. counties where greater than 0.1% of the county's population was employed in the metal electroplating and coating industry. The mortality rates for several cancers, particularly of the esophagus and larynx, in these counties were higher than rates for a group of control counties with comparable demographic characteristics. Further study is needed to determine if these patterns result for worker exposures to substances such as caustic acids and alkalies, metals, and organic solvents commonly used in this industry.

Cancer and other causes of death among U.S. veterinarians, 1966-1977

Causes of death among 1,551 white male veterinarians identified from obituary listings in the Journal of the American Veterinary Medical Association were compared to an expected distribution based on the general US population. The proportion of deaths was significantly high for particular neoplasms, especially leukemia and Hodgkin's disease, and cancers of the brain and skin. Although socioeconomic and methodologic factors may be involved, the excesses were primarily among veterinarians in clinical practice, raising the possibility that specific occupational exposures may be carcinogenic. Mortality was also relatively high for motor vehicle accidents, suicides and asthma, but low for lung cancer and other diseases of the respiratory system.

Leukemia among Nebraska farmers: a death certificate study

The risk of leukemia among farmers was studied using records of death certificates from Nebraska, 1957--1974. Comparison of occupation, as recorded on the death certificate, for 1084 leukemia deaths and 2168 deaths from other causes, matched for age at death, year of death, county of residence, race, and sex, revealed an elevated risk of leukemia among farmers (odds ratio = 1.25). The risk was greatest among farmers born after 1900 and dying before age 66 (odds ratio = 1.83). Stratification by county of residence showed a significantly elevated risk for farmers from heavy corn producing counties.

Causes of death among laundry and dry cleaning workers

To make a preliminary determination as to whether a potential health hazard exists for workers exposed to dry cleaning solvents (carbon tetrachloride, trichloroethylene, and tetrachloroethylene), we analyzed the causes of death of 330 deceased laundry and dry cleaning workers by the proportionate mortality method. The increased risk for malignant neoplasms resulted primarily from an excess of lung and cervical cancer and slight excesses of leukemia and liver cancer. Although the number of deaths was small, the increased risk of cancer noted in this investigation underscores the need for additional epidemiologic studies of this occupational group.

Geographic patterns of prostate cancer in the United States

Age-adjusted rates of mortality from prostate cancer during 1950-69 were correlated by race with demographic, industrial, and agricultural data from 3,056 U.S. countries. Mortality among nonwhites was 50% higher than that among whites in all parts of the country where blacks comprise most of the nonwhite population. The rising rate associated with population density among nonwhites, but not whites, suggested that environmental exposures related to urban living may account for the predisposition of American blacks to prostate cancer. Despite a clustering of counties with elevated mortality in certain North Central and Northeastern States, the geographic variation among whites with prostate tumors was considerably less than that among whites with other tumors. Mortality was elevated in counties with a high percentage of residents of Scandinavian descent, in counties with metal-using and textile industries, and in regions with high consumption of high-fat foods.