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Biomedical subjects

M Dosemeci

Publications and source records attributed to M Dosemeci.

At least 127 records · Page 7Linked to original sources
PubMed1994

Hematopoietic malignancies and related disorders among benzene-exposed workers in China.

Although the relationship between benzene and acute nonlymphocytic leukemia (ANLL) is well established, most of the analytic cohort investigations examining the relationship between benzene and hematologic neoplasms have evaluated only death certificates to validate diagnoses. In a follow-up study of 74,828 benzene-exposed and 35,805 non-exposed workers in China, pathology reports, medical records, and/or histopathologic material were reviewed for all patients with hematopoietic malignancies to ensure correct classification and to provide clinicopathologic descriptions. Eighty-two patients with hematopoietic neoplasms and related disorders were identified among benzene-exposed workers, including 32 cases of acute leukemia, 7--myelodysplastic syndrome (MDS), 9--chronic granulocytic leukemia (CGL), 20--malignant lymphoma or related disorder (ML), 9--aplastic anemia, and 5 others. Among the comparison group, 13 hematologic malignancies were observed, including 6 patients with acute leukemia, 2--CGL, 3--ML, and 2 others. The hematopathologic characteristics of the benzene-exposed ANLL cases resembled those following chemotherapy or radiotherapy. ANLL in workers exposed to benzene may represent a distinct clinicopathologic entity, with characteristics similar to treatment-related ANLL, including a preceding preleukemic phase in some patients. Results in our series, one of the largest to data, also indicate that a greater diversity of hematologic neoplasms is evident among benzene-exposed workers than previously described.

Adult↗
PubMed1994

Gender differences in hematopoietic and lymphoproliferative disorders and other cancer risks by major occupational group among workers exposed to benzene in China.

Gender differences in risk for leukemia and other selected and combined disease categories were examined by major occupational category for 74,828 benzene-exposed workers compared to 35,805 unexposed workers from 12 cities in China. No significant differences in the relative risks for total mortality and cancer mortality were found between female and male benzene-exposed workers, although risks tended to be somewhat higher among male than among female employees. Both female and male workers in several occupational categories had notably increased risks for all hematopoietic and lymphoproliferative (HLP) malignant and nonmalignant disorders combined and for total leukemia. Variation in risk for HLP disorders by occupational category was observed in both genders, with highest risks for male and female chemical manufacturing workers, female nonproduction employees, and male printers. However, the numbers of leukemia and other HLP malignancies in each category were small. The findings suggest that both female and male benzene-exposed workers in several occupational categories experience excess leukemia and other HLP disorders with relatively minor gender differences. Although this population is one of the largest cohorts of benzene-exposed workers studied to date, evaluation of the observed variation in risk for HLP neoplasms among the occupational groups for workers of each gender is limited by the small numbers of these relatively rare malignancies.

Benzene↗
PubMed1993

Non-viral risk factors for nasopharyngeal carcinoma in the Philippines: results from a case-control study.

In a case-control study of NPC conducted in the Philippines, 104 predominantly non-Chinese (< 10% ethnically Chinese) cases of nasopharyngeal carcinoma (NPC) and 205 hospital and community controls were recruited. Risk factor information was obtained through personal interview. The occupational history of each subject was reviewed "blind" by an industrial hygienist to determine estimates of exposure to formaldehyde, solvents, dusts, exhaust and pesticides. After control for confounding, subjects who were first exposed to formaldehyde 25 or more years prior to diagnosis/interview or wo were first exposed before the age of 25 were found, in relation to those never exposed, to be at a 4.0-fold excess risk of disease. Similarly, those first exposed to dust and/or exhaust 35 or more years prior to diagnosis/interview were at a 4.4-fold excess risk of disease and those first exposed before the age of 20 were at a 3.5-fold excess risk of disease. Salted fish consumption was not associated with risk, while consumption of processed meats protected against NPC. Smoking was positively associated with NPC, but only when cases were compared to community controls. Relative to non-smokers, subjects reporting more than 30 years of smoking were at an adjusted 7.2-fold excess risk of disease. Herbal medicine use and burning of anti-mosquito coils were both independently associated with risk of NPC, with ever-users of herbal medicines being at a 2.5-fold excess risk of disease and those reporting daily use of anti-mosquito coils being at a 5.9-fold excess risk of disease relative to never users. Exposure to solvents, pesticides, or use of betel nuts were not associated with NPC risk.

Adolescent↗
PubMed1993

Validity of exposure in one job as a surrogate for exposure in a cohort study.

Frequently, information pertaining to only one job is available or used to evaluate risk estimates of disease in occupational epidemiologic research. The amount of misclassification that such a practice could create has not, however, been examined. We used data from a mortality study of workers employed in 10 formaldehyde-producing or -using plants to address how closely several parameters of exposure based on the first, longest, or last job held in a company compared with those based on the worker's entire employment history at the plant. The best predictor for cumulative formaldehyde exposure at the plant was the longest job at that plant, with a correlation coefficient (r) of 0.70. The correlation with average exposure over the worker's employment was 0.77 for the first job and 0.74 for the longest and last jobs. Peak exposures and highest exposure levels experienced in the plant were more closely related to the first job (r = 0.72 and r = 0.74). The highest correlation with any of the measures was never with the last job. Variation between plants for each of these comparisons, however, was wide. These findings indicate that the use of a single job as a surrogate for exposure received at a particular worksite can result in different degrees of misclassification for different exposure measures. Even though the correlations were generally high, the associated misclassification of exposure could lead to a substantial underestimation of the relative risks in some situations. In this report two hypothetical examples show what effect the misclassification rates could have on estimates of disease risks.

Chemical Industry↗
PubMed1993

Cancer and other causes of death among male and female farmers from twenty-three states.

Occupation and industry codes on death certificates from 23 states for 1984-1988 were used to evaluate mortality risks among white and nonwhite, male and female farmers. Proportionate mortality and proportionate cancer mortality ratios were calculated using deaths among nonfarmers from the same states to generate expected numbers. Among farmers there were 119,648 deaths among white men, 2,400 among white women, 11,446 among nonwhite men, and 2,066 among nonwhite women. Deficits occurred in all race-sex groups for infective and parasitic diseases, all cancer combined, lung cancer, liver cancer, diseases of the nervous system, multiple sclerosis, hypertension, and emphysema. As reported in other studies, white male farmers had excesses of cancer of the lymphatic and hematopoietic system, lip, eye, brain, and prostate. Excesses of cancers of the pancreas, kidney, bone, and thyroid were new findings. Regional patterns were evident, particularly among white men. Significant excesses for accidents, vascular lesions of the central nervous system (CNS), and cancers of the prostate tended to occur in most geographic regions, while excesses for mechanical suffocation, non-Hodgkin's lymphoma, and cancers of the lip, brain, and the lymphatic and hematopoietic system were limited to the Central states. Increases among nonwhite men were similar to those in white men for some causes of death (vascular lesions of the CNS and cancers of the pancreas and prostate), but were absent for others (lymphatic and hematopoietic system, lip, eye, kidney, and brain). Women (white and nonwhite) had excesses for vascular lesions of the CNS, disease of the genitourinary system (white women only), and cancers of the stomach and cervix (nonwhite women only). Cancer of the buccal cavity and pharynx was slightly elevated among women, and white women had nonsignificant excesses of multiple myeloma and leukemia. Excesses for leukemia and non-Hodgkin's lymphoma occurred among white men and women, but not among nonwhites. Excesses for several types of accidental deaths were seen among all race-sex groups.

Agricultural Workers' Diseases↗
PubMed1993

Estimating historical exposure to silica among mine and pottery workers in the People's Republic of China.

A quantitative retrospective exposure assessment method was developed for use in a nested case-control study of lung cancer among mine and pottery workers exposed to silica dust in the People's Republic of China. Exposure assessment was carried out in 20 mines (10 tungsten, 6 iron/copper, and 4 tin) and nine pottery factories. A job title dictionary was developed and used in both the collection of historical exposure information and work histories of 1,668 (316 cases and 1,352 controls) study subjects. Several data abstraction forms were developed to collect historical and current exposure information and employees' work histories, starting in 1950. A retrospective exposure matrix was developed on the basis of facility/job title/calendar year combinations using available historical exposure information and current exposure profiles. Information on the amount of respirable, thoracic, and free silica content in total dust was used in estimating exposure to silica. Starting in 1950, 6,805 historical estimates had been carried out for 14 calendar-year periods. We estimated the average total dust concentration to be 9 mg/M3, with a range from 28 mg/M3 in earlier years to 3 mg/M3 in recent years. Several exposure indices [such as cumulative dust, average dust, cumulative respirable (< 5 mu in particle size) and thoracic (< 10 mu in particle size) silica dust, average respirable and thoracic silica dust, exposure-weighted duration, and the highest/longest exposure] were calculated for individuals by merging work history and historical exposure matrix for each study subject. We developed these various measures of exposure to allow investigators to compare and contrast different indices of historical exposure to silica.

Case-Control Studies↗
PubMed1993

Cancer mortality among jewelry workers.

Mortality was investigated for the years 1950-1980 for 1,009 male members of a New York jewelry workers union, and for the years 1984-1989 among 919 men and 605 women identified as jewelry workers on death certificates from 24 states. Malignant neoplasms were excessive for male union members (proportional mortality ratio [PMR] = 1.17; 95% confidence interval [CI]: 1.02-1.33) and female jeweler deaths from the 24 states (PMR = 1.24; 95% CI: 1.07-1.42). Deaths due to nonmalignant causes were not unusual, except for excesses, in union males, of the circulatory system (PMR = 1.10; 95% CI: 1.02-1.19), including arteriosclerotic heart disease (PMR = 1.25; 95% CI: 1.14-1.37) and rheumatic heart disease (PMR = 3.02; 95% CI: 1.94-4.50). Cancers of the digestive tract were proportionally elevated among union males (proportional cancer mortality rate [PMR] = 1.13; 95% CI: 0.89-1.41) and among deaths from the 24 states (PCMR = 1.22; 95% CI: 1.01-1.47). For the 24 states, excesses for digestive cancer were found for both males (PCMR = 1.19; 95% CI: 0.90-1.54) and females (PCMR = 1.26; 95% CI: 0.96-1.62). Regarding specific sites in the digestive tract, colon cancer excesses were found in union males (PCMR = 1.53: 95% CI: 1.05-2.15), and for men (PCMR = 1.27; 95% CI: 0.82-1.88) and women (PCMR = 1.36; 95% CI: 0.92-3.27) in 24 states.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular Diseases↗
PubMed1993

Occupational physical activity, socioeconomic status, and risks of 15 cancer sites in Turkey.

A multiple-site case-control study of 15 cancers (stomach; colon; rectum; larynx; lung; melanoma; skin; female breast; male breast; cervix; ovary; uterus; prostate; testis; and bladder) was conducted to evaluate their association with occupational physical activity and socioeconomic status (SES). A hospital-based study population (3,486 male cases and 379 female cases, and 2,127 male and 244 female controls) was established in an oncological treatment center in Istanbul, Turkey, from 1979-84. Assessment of physical activity and SES was based on job titles held by the study subjects. Two measures of physical activity were developed based on energy expenditure and 'sitting time' during working hours. Observed risks were adjusted for age, smoking, and SES. Elevated risks were observed among workers who held sedentary jobs for cancers of the colon (odds ratio [OR] = 1.6), rectum (OR = 1.3), melanoma (OR = 1.9), male breast (OR = 1.4), prostate (OR = 5.0), and ovary (OR = 2.0). Cancers of the cervix and uterus showed significantly decreasing risks with decreased activity. Risks of cancers of the colon, rectum, larynx, ovary, and melanoma were enhanced after risks for physical activity indices were adjusted for SES, while the associations between physical activity and cancers of the prostate, cervix, and uterus were weakened after SES adjustment. Risks of melanoma rose significantly with both activity indices after SES adjustment.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1993

Physical activity and occupational risk of colon cancer in Shanghai, China.

Using occupational data for over 2000 colon cancer cases diagnosed between 1980 and 1984 in Shanghai, and employment information from the 1982 census for the Shanghai population, standardized incidence ratios (SIR) were computed for occupational groups classified by job types and physical activity levels. Men employed in occupations with low physical activity levels had modest but significantly elevated risks of colon cancer. SIR for jobs with low activity based on sitting time was 121 (95% confidence interval, Cl: 108-135) and based on energy expenditure was 126 (95% Cl: 115-138). Corresponding SIR for women were 99 (95% Cl: 83-118) and 113 (95% Cl: 100-127). The data were also used to screen for specific occupations with elevated SIR to generate leads to occupational colon cancer. Increased incidence was observed for professional and other white collar workers, and male chemical processors and female textile workers. The findings add to the emerging evidence that workplace activity may influence the risk of this common cancer.

China↗
PubMed1992

Occupational physical activity and colon cancer risk in Turkey.

A case-control study of 107 colon cancer cases and 486 controls from an oncological clinic in Istanbul was conducted to examine the association between occupational physical activity and colon cancer in Turkey, where incidence of this disease is low. Only two of the four activity measures showed evidence of an increased colon cancer risk for sedentary jobs (time spent sitting OR = 1.5 and occupational energy expenditure OR = 1.6); neither was statistically significant. Subjects below age 55 showed higher risk associated with sedentary jobs than did the older age group, probably due to their adoption of a more western lifestyle, including dietary habits, less activity, and other factors that may interact to increase the risk of colon cancer.

Adolescent↗
PubMed1992

Mortality among laboratory workers employed at the U.S. Department of Agriculture.

We evaluated the mortality of 835 white male and 36 female laboratory workers employed by the U.S. Department of Agriculture who died between January 1, 1970, and December 31, 1979. For males, the mortality odds ratio for all cancers was 1.0 (95% confidence interval = 0.8-1.2). Colon cancer, lymphosarcoma and reticulosarcoma, nonmalignant diseases of the blood and blood-forming organs, and suicide showed elevated mortality odds ratios. Only colon cancer showed an association with duration of employment as a laboratory worker. In an accompanying case-control study, the risk of colon cancer rose to 3.2 among those who had 20 or more years of employment as a laboratory worker. Among females, breast cancer was elevated (mortality odds ratio = 5.3; 95% confidence interval = 2.8-10.1).

Female↗
PubMed1992

Mortality among dust-exposed Chinese mine and pottery workers.

A cohort study of approximately 68,000 persons employed during 1972 to 1974 at metal mines and pottery factories in south central China was conducted to evaluate mortality from cancer and other diseases among workers exposed to different levels of silica and other dusts. A follow-up of subjects through December 31, 1989 revealed 6,192 deaths, a number close to that expected based on Chinese national mortality rates. There was, however, a nearly 6-fold increase in deaths from pulmonary heart disease (standard mortality ratio, 581; 95% confidence interval 538 to 626), and a 48% excess of mortality from nonmalignant respiratory diseases (standard mortality ratio, 148; 95% confidence interval, 139 to 158), primarily because of a more than 30-fold excess of pneumoconiosis. Pulmonary heart disease and noncancerous respiratory disease rates rose in proportion to dust exposure. Cancer mortality overall was not increased among the miners or pottery workers. There was no increased risk of lung cancer, except among tin miners, and trends in risk of this cancer with increasing level of dust exposure were not significant. Risks of lung cancer were 22% higher among workers with than without silicosis. The findings indicate that respiratory disease continues to be an occupational hazard among Chinese miners and pottery workers, but that cancer risks are not as yet strongly associated with work in these dusty trades.

Air Pollutants, Occupational↗
PubMed1992

A nested case-control study of lung cancer among silica exposed workers in China.

In an attempt to assess whether silica induces lung cancer, a nested case-control study of 316 male lung cancer cases and 1352 controls was carried out among pottery workers and tungsten, copper-iron, and tin miners from five provinces in south central China. Exposure to dust and silica for each study subject was evaluated quantitatively by cumulative exposure measures based on historical industrial hygiene records. Measurements on confounders such as inorganic arsenic, polycyclic aromatic hydrocarbons (PAHs), and radon were also collected from the worksites. Information on cigarette smoking was obtained by interviews of the subjects or their next of kin. A significant trend of increasing risk of lung cancer with exposure to silica was found for tin miners, but not for miners working in tungsten or copper-iron mines. Concomitant and highly correlated exposures to arsenic and PAHs among tin miners were also found. Risk of lung cancer among pottery workers was related to exposure to silica, although the dose-response gradient was not significant. Risks of lung cancer were significantly increased among silicotic subjects in iron-copper and tin mines, but not in pottery factories or tungsten mines. The results of this study provide only limited support for an aetiological association between silica and lung cancer.

Arsenic↗
PubMed1991

Comparability of data obtained from farmers and surrogate respondents on use of agricultural pesticides.

Information from surrogates is increasingly being used in case-control studies to evaluate cancer risks from pesticides; however, little is known about the quality of this type of information. To address this concern, the authors compared interview data collected in 1987 from 95 male Iowa farmers and their wives or other surrogates on the use of specific agricultural pesticides. Agreement between direct and surrogate interviews was excellent (83-100%) for responses to dichotomous (yes/no) questions regarding past agricultural use of specific pesticides. Although there were more discrepancies for detailed questions (e.g., the number of days per year on which each pesticide was handled), responses from spouses appear to be adequate for epidemiologic studies of pesticides and cancer.

Adult↗
PubMed1991

Blind assignment of exposure does not always prevent differential misclassification.

The authors argue that one can never be certain whether an exposure variable which is measured with error is subject to differential misclassification in either a case-control study or a cohort study. They present hypothetic examples that demonstrate that even when misclassification is nondifferential in a 2 x 3 table, the observed odds ratios in the 2 x 2 table created by collapsing over two exposure levels can be either in the opposite direction from or more extreme than the odds ratio that would be obtained if exposures were classified correctly. The anomalies are explained by the observation that the 2 x 2 tables exhibit differential misclassification. In general, collapsing over categories which have different risks of disease and different probabilities of exposure misclassification can induce differential misclassification and even nonconservative estimates of relative risk. Collapsing of exposure levels can occur in the analysis or at the exposure assessment stage. Since indistinguishable categories can be collapsed implicitly, blind assessment of exposure, i.e., assignment without knowledge of disease status, does not guarantee that misclassification is nondifferential.

Case-Control Studies↗
PubMed1991

Bias despite masked assessment of clinical outcomes when an outcome is defined as one of several component events.

Hypothetical examples are presented that show that bias can result from misclassification of clinical outcomes defined as one of several events, even though the assessment of each component event was masked. In one example, the effect of the overall misclassification is to make a treatment that reduces the risk appear to increase it; in another example, misclassification causes the overall treatment effect to appear stronger than it actually is. These anomalies are due to the fact that the misclassification of the overall outcome can be differential, even though the misclassification of the individual components is nondifferential.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Mortality among industrial workers exposed to phenol.

We conducted a follow-up study to evaluate mortality among 14,861 workers employed in five facilities producing or using phenol and formaldehyde. More than 360,000 person-years of follow-up accrued. Mortality rates from all causes of death combined were similar to those in the general U.S. population. We observed excesses of cancer of the esophagus, cancer of the kidney, and Hodgkin's disease among workers exposed to phenol, but none of these excesses showed a dose-response relation with exposure to phenol. Excess lung cancer mortality (SMR = 1.2) showed no consistent pattern by any exposure index. Workers exposed to phenol had lower mortality ratios for cancer of the buccal cavity and pharynx, cancer of the stomach, cancer of the brain, arteriosclerotic heart disease, emphysema, disease of the digestive system, and cirrhosis of the liver. Of these, arteriosclerotic heart disease, emphysema, and cirrhosis of the liver were inversely related to duration of phenol exposure and to cumulative phenol exposure levels. Although these inverse associations may be due to chance or uncontrolled confounders, the ability of phenol to interfere with the generation of oxidants in experimental systems suggests that the pattern may have biologic plausibility.

Adult↗