Biomedical subjects

Mustafa Dosemeci

Publications and source records attributed to Mustafa Dosemeci.

At least 55 records · Page 3Linked to original sources

PubMed2004

Occupational exposures and salivary gland cancer mortality among African American and white workers in the United States.

We conducted a large death certificate-based case-control study to assess occupational risks for salivary gland cancer. African American (168 cases, 672 controls) and white (2237 cases, 8748 controls) cases from 24 states (1984-1989) were matched to controls by age, sex, race, and region. Race- and sex-stratified multiple logistic regression models calculated adjusted odds ratios. The proportion of young cases (<50 years) was greatest among African Americans (20.8% vs. 8.8%). Higher socioeconomic status, ionizing radiation, formaldehyde, solvents, outdoor work, and animal contact were associated with elevated risk among white men. Physical activity reduced mortality risks among men, although significantly only among whites. Odds ratios for formaldehyde, solvents, benzene, and animal contact were 2.0 or greater among African American women, although not statistically significant. These findings suggest occupational and demographic factors needing further investigation.

Adult↗

PubMed2003

Use of agricultural pesticides and prostate cancer risk in the Agricultural Health Study cohort.

The authors examined the relation between 45 common agricultural pesticides and prostate cancer incidence in a prospective cohort study of 55,332 male pesticide applicators from Iowa and North Carolina with no prior history of prostate cancer. Data were collected by means of self-administered questionnaires completed at enrollment (1993-1997). Cancer incidence was determined through population-based cancer registries from enrollment through December 31, 1999. A prostate cancer standardized incidence ratio was computed for the cohort. Odds ratios were computed for individual pesticides and for pesticide use patterns identified by means of factor analysis. A prostate cancer standardized incidence ratio of 1.14 (95% confidence interval: 1.05, 1.24) was observed for the Agricultural Health Study cohort. Use of chlorinated pesticides among applicators over 50 years of age and methyl bromide use were significantly associated with prostate cancer risk. Several other pesticides showed a significantly increased risk of prostate cancer among study subjects with a family history of prostate cancer but not among those with no family history. Important family history-pesticide interactions were observed.

Adult↗

PubMed2003

Occupational history and exposure and the risk of adult leukemia in Shanghai.

PURPOSE: Evaluation of the association of selected occupational exposures with leukemia risk. METHODS: Population-based case-control study of 486 leukemia subjects and 502 healthy controls residing in Shanghai from 1987 to 1989. Adjusted odds ratios (OR) were calculated for the association between occupational factors and leukemia risk. RESULTS: Significant increase in leukemia risk was observed in chemical manufacturing industry workers (OR=3.1, 95% CI=1.0-9.8). Increased risks for leukemia were observed from self-reported exposures to benzene (OR=1.7, 95% CI=1.1-2.6), radioactive materials (OR=3.7, 95% CI=1.3-10.2), synthetic fiber dust (OR=2.0, 95% CI=1.2-3.5), and toluene (OR=1.6, 95% CI=1.0-2.5). Dose-response relations of leukemia risk was observed with the duration of exposure to benzene (OR=3.3, 95% CI=1.6-6.9 for >or=15 years exposure; p for trend<0.01), radioactive materials (OR=5.2, 95% CI=1.1-24.7 for >or=15 years exposure; p for trend=0.02), paints (OR=2.3, 95% CI=1.2-4.7 for >or=15 years exposure; p for trend=0.09), and toluene (OR=2.9, 95% CI=1.3-6.7 for >or=15 years exposure; p for trend=0.02). CONCLUSIONS: Adult leukemia risk may be associated with working in the chemical industry, and exposure to benzene, synthetic fiber dust, radioactive materials, and toluene in the study population.

Adult↗

PubMed2003

Cancer incidence among male Swedish veterinarians and other workers of the veterinary industry: a record-linkage study.

OBJECTIVE: To investigate the risk of cancer among veterinarians in a large record-linkage study from Sweden. METHODS: We used the nationwide, Swedish Cancer Environment Registry III, which links the Cancer Register data for 1971-1989 to the national population censuses from 1960 and 1970, to compare the incidence of cancer among male veterinarians to that of the remaining part of the active population using multivariable Poisson regression models and standardized incidence ratios. One thousand one hundred and seventy eight men classified as veterinarians or workers in the veterinary industry at either census were identified. RESULTS: Veterinarians in the veterinary industry experienced increased risk of esophageal (relative risk (RR) 3.78, 95% confidence interval (CI) 1.42-10.09), colon (RR: 2.36, 95% CI: 1.42-3.91), pancreatic (RR: 2.10, 95% CI: 0.94-4.68) and brain (RR: 2.51, 95% CI: 1.04-6.03) cancers as well as melanoma of the skin (RR: 2.77, 95% CI: 1.24-6.17). Similar excess risks were observed when veterinarians were compared with individuals of similar socioeconomic status. CONCLUSION: The increased risks of esophageal, colon, pancreatic and brain cancers as well as melanoma observed among veterinarians did not seem to be explained by the high socio-economic status of this occupational group. Therefore, it is possible that some of these results reflect the carcinogenicity of occupational exposures, including animal viruses, solar or ionizing radiations and anesthetics.

Adult↗

PubMed2003

Risk of laryngeal cancer by occupational chemical exposure in Turkey.

Laryngeal cancer is the second most common cancer among men in Turkey. In this hospital based case-control study, we evaluated laryngeal cancer risks from occupational chemical exposures. We analyzed 940 laryngeal cancer cases and 1519 controls. Occupational history, tobacco, and alcohol use and demographic information were obtained by a questionnaire. The job and industries were classified by special seven-digit codes. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) based on a developed exposure matrix for chemicals, including diesel exhaust, gasoline exhaust, polycyclic aromatic hydrocarbons (PAHs), formaldehyde, and solvents. An excess of laryngeal cancer occurred with diesel exhaust (OR=1.5, 95% CI=1.3-1.9), gasoline exhaust (OR=1.6, 95% CI=1.3-2.0), and PAHs (OR=1.3, 95% CI=1.1-1.6). There was a dose-response relationship for these substances with supraglottic cancers (P<0.000). The PAH association only occurred among those who also had exposure to diesel exhaust.

Adult↗

PubMed2003

Attenuation of exposure-response curves in occupational cohort studies at high exposure levels.

Numerous occupational cohort mortality studies have observed exposure-response curves to have an increasing slope at low exposure levels that attenuates or even turns negative at high exposure levels. Examples discussed in this paper include dioxin, silica, 1,3-butadiene, cadmium, beryllium, radon daughters, diesel fumes, nickel, arsenic, and hexavalent chromium. Possible explanations for this phenomenon include (i) bias introduced by the healthy worker survivor effect, (ii) a depletion of the number of susceptible people in the population at high exposure levels, (iii) a natural limit on the relative risk for diseases with a high background rate, (iv) mismeasurement or misclassification of exposures, (v) the influence of other risk factors that vary by the level of the main exposure, and (vi) the saturation of key enzyme systems or other processes involved in the development of disease.

Causality↗

PubMed2002

Non-linear production of benzene oxide-albumin adducts with human exposure to benzene.

Benzene is initially metabolized to benzene oxide, which either undergoes further metabolism or reacts with macromolecules including proteins. Previously reported levels of benzene oxide-albumin adducts (BO-Alb) are analyzed from 30 workers exposed to 0.2-302 ppm benzene and 43 controls from Shanghai, China. Although both exposed workers and controls had significant levels of BO-Alb in their blood, exposed subjects' adduct levels (GM=378 pmol/g protein) were much greater than those of controls (GM=115 pmol/g protein). When the natural logarithm of the BO-Alb level was regressed upon the natural logarithm of exposure among the 30 exposed subjects, a strong effect of benzene exposure was observed (R(2)=0.612; p<0.0001). Because the slope of the relationship between BO-Alb and benzene exposure was significantly less than one in log-space, we infer that production of benzene oxide was less than proportional to benzene exposure. Since benzene is a substrate for CYP2E1, these results are consistent with saturation of CYP450 metabolism. They indicate that deviations from linear metabolism began at or below benzene exposures of 10 ppm and that pronounced saturation was apparent at 40-50 ppm. To our knowledge, this is the first study to investigate the linearity of human metabolism of a carcinogen based upon protein adducts.

Albumins↗

PubMed2002

Predictors of herbicide exposure in farm applicators.

OBJECTIVES: Most epidemiological studies of pesticides have used self-reports rather than quantitative measurements to assess exposures. The purpose of this study was to identify factors likely to affect exposure under actual field conditions and to measure the sensitivity and specificity of self-reported indications of exposure against urinary measures of herbicide exposure. METHODS: A sub-set of the participants in a retrospective cohort study of Ontario farm families volunteered for a pesticide exposure assessment study. Immediately prior, and subsequent to, handling the phenoxy-herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) or 4-chloro-2-methylphenoxyacetic acid (MCPA) for the first time during the season, 126 pesticide applicators provided pre-exposure spot urine samples and a subsequent consecutive 24-h urine sample. At the same time, they completed a questionnaire on pesticide use and handling practices for the first day of pesticide application. RESULTS: Assuming that the presence of 2,4-D in the urine was a measure of true exposure and that questionnaire indications of 2,4-D use were the exposure classification subject to error, then the questionnaire's prediction of exposure had a sensitivity of 56.7% and specificity of 86.4%. The comparable values for MCPA were sensitivity and specificity of 91.6% and 67.4%, respectively. In multivariate models, the variables pesticide formulation, protective clothing/gear, application equipment, handling practice, and personal hygiene practice were significant as predictors of urinary herbicide levels in the first 24 h after application (or spraying) had been initiated (adjusted R(2)=44% for MCPA and 39% for 2,4-D). CONCLUSIONS: Although similar domains of factors were associated with exposure in both models, the specific factors identified and the signs of the coefficients were sufficiently different between the final models for each herbicide that additional investigations appear to be warranted to determine the sources of the differences and assess the validity of the models and their ability to be generalised.

2,4-Dichlorophenoxyacetic Acid↗

PubMed2002

Development of quantitative exposure data for a pooled exposure-response analysis of 10 silica cohorts.

BACKGROUND: Comprehensive quantitative silica exposure estimates over time, measured in the same units across a number of cohorts, would make possible a pooled exposure-response analysis for lung cancer. Such an analysis would help clarify the continuing controversy regarding whether silica causes lung cancer. METHODS: Existing quantitative exposure data for 10 silica-exposed cohorts were retrieved from the original investigators. Occupation- and time-specific exposure estimates were either adopted/adapted or developed for each cohort, and converted to milligram per cubic meter (mg/m(3)) respirable crystalline silica. RESULTS: Quantitative exposure assignments were typically based on a large number (thousands) of raw measurements, or otherwise consisted of exposure estimates by experts (for two cohorts). Median exposure level of the cohorts ranged between 0.04 and 0.59 mg/m(3) respirable crystalline silica. Exposure estimates were partially validated via their successful prediction of silicosis in these cohorts. CONCLUSIONS: Existing data were successfully adopted or modified to create comparable quantitative exposure estimates over time for 10 silica-exposed cohorts, permitting a pooled exposure-response analysis. The difficulties encountered in deriving common exposure estimates across cohorts are discussed.

Cohort Studies↗

PubMed2002

Occupational exposures and the risk of ovarian cancer in Sweden.

BACKGROUND: Studies of occupational exposures and ovarian cancer, often limited by few subjects or proportionate mortality data, have yielded inconsistent results. METHODS: Swedish women employed in 1960, 1970, or during both years were followed from 1971 to 1989 using census data linked to nationwide cancer and death registries. A total of 9,591 ovarian cancer cases were identified among 1,670,517 women. Poisson regression was used to estimate the relative risk of ovarian cancer in specific occupational groups and in women exposed to particular occupational exposures defined by job exposure matrices. We lacked data on reproductive factors. RESULTS: Jobs associated with elevated ovarian cancer rates in this and previous studies include dry cleaning, telegraph and telephone work, paper packaging, and graphic and printing work. In contrast to results of some previous studies, we found that hairdressers and beauticians were not at increased risk of ovarian cancer. Organic dusts, aromatic amines, aliphatic and aromatic hydrocarbons are suggested as specific etiologic agents. CONCLUSIONS: In this large study, we have confirmed some results from smaller studies and identified some new relationships that need to be confirmed elsewhere.

Adult↗

PubMed2002

Accuracy of self-reported pesticide use duration information from licensed pesticide applicators in the Agricultural Health Study.

Epidemiologists frequently rely on self-reported information regarding a variety of exposures including smoking history, medication use, and occupational exposure because other sources of information are either unavailable or difficult to obtain. One way to evaluate the accuracy of self-reported information is through logic checks using other sources. To assess the quality of the self-reported pesticide product use history of 57,311 licensed pesticide applicators in the Agricultural Health Study (AHS), we compared the self-reported decade of first use and total years of use to the year the pesticide active ingredient was first registered for use. We obtained pesticide active ingredient registration information from the United States Environmental Protection Agency (USEPA) and other publicly available sources for the 52 pesticides on the AHS initial questionnaires administered from 1994 to 1997. Based on the registration year, we assessed 19 pesticides for potential inaccuracies regarding duration of use or decade of first use. When calculating potential total years of use, we did not consider the impact of chemicals being removed from the market, since the possibility for continued use existed. The majority of respondents provided plausible responses for both decade of first use and total duration of use. On average, 1% of the subjects overestimated total possible duration of use, ranging from less than 1% for carbofuran and chlorpyrifos to 5% for imazethapyr. Decade of first use was also reasonably reported, although more subjects did not report decade of first use than duration of use, with an average of 6% of subjects missing decade information for an individual chemical. For subjects who reported a decade of first use, 98% gave plausible responses on average, with overestimates highest for cyanazine, introduced in 1971 (6% reported earlier use), and chlorimuron ethyl, introduced in 1985 (7% reported earlier use). This analysis provided the opportunity to consider only one source of potential overreporting of exposure, and while underreporting may have also occurred, we cannot evaluate its role nor the balance between these potential inaccuracies. While we are unable to validate directly the accuracy of a respondent's use of pesticides, this analysis suggests that participants provide plausible information regarding their pesticide use.

Epidemiologic Studies↗

PubMed2002

Prevalence of exposure to solvents, metals, grain dust, and other hazards among farmers in the Agricultural Health Study.

Exposures to multiple chemical, physical, and biological agents in agricultural work environments can result in confounding that may obscure or distort risks observed in epidemiologic studies. The Agricultural Health Study (AHS) is a large epidemiology study being conducted to investigate health risks among pesticide applicators and their families. During enrollment in the AHS, questionnaires were administered to over 52,000 licensed pesticide applicators from North Carolina and Iowa, who were mostly farmers. Questions about the frequency of various farming tasks were used to estimate the prevalence of exposure to solvents (25%), metals (68%), grain dusts (65%), diesel exhaust fumes (93%), and other hazards, including exposure to pesticides. Most of the farmers in the AHS reported performing routine maintenance tasks at least once a month, such as painting (63%), welding (64%), and repair of pesticide equipment (58%). The majority of farmers (74% in North Carolina; 59% in Iowa) reported holding nonfarm jobs, of which the most frequent were construction and transportation. The majority of the farmers enrolled in the AHS (55%) also reported that they mixed or applied pesticides on 10 or more days per year. The associations between the use of pesticides and the frequency with which the farmers in the AHS reported performing various types of specific farming activities were assessed to evaluate potential confounding. Confounding risk ratios calculated for these activities suggest that the magnitude of bias due to confounding is likely to be minimal.

Agriculture↗

PubMed2002

Evaluation of concurrent personal measurements of acrylonitrile using different sampling techniques.

In a retrospective assessment of employee exposure to acrylonitrile (AN) for an epidemiological study, investigators from the National Cancer Institute (NCI) and the National Institute for Occupational Safety and Health (NIOSH) evaluated the feasibility of using historic acrylonitrile air samples without modification. The evaluation discussed here was to determine whether the air sampling results across plants were comparable. During site visits to each plant conducted between 1984 and 1986, study investigators collected personal air samples for four days on approximately ten jobs per day. During these visits, IHs at seven of the eight plants also collected personal samples to compare their sample values to the study-collected sample values. Each plant's IH collected these concurrent measurements for their own use and independent of the IHs at the other plants. The plant IHs had no common sampling protocol but, rather, used professional judgment in deciding sampling logistics for their concurrent measurement. In addition, each plant IH used a different laboratory to analyze samples (the study industrial hygienists used one laboratory). Three sampling methods were used by plant industrial hygienists to collect concurrent measurements: charcoal tubes, passive monitors, and porous polymer tubes. The study investigators only used charcoal tubes. Two hundred and sixty four (264) pairs of concurrent measurements were collected. To assess the +/- comparability of the data sets, paired-observation tests were used. The two sets of charcoal tubes were found to compare favorably with each other. The study's charcoal tubes were 1.2 times higher than results from plant passive monitors. No correlation was found between the study's charcoal tube results and plant porous polymer tube results, although the means for 34 pairs of samples were equivalent. As a result of this evaluation, the investigators decided that no adjustments would be made to the plant measurements. This type of evaluation should be considered when using measurement data in multisite epidemiological studies.

Acrylonitrile↗

PubMed2002

A quantitative approach for estimating exposure to pesticides in the Agricultural Health Study.

We developed a quantitative method to estimate long-term chemical-specific pesticide exposures in a large prospective cohort study of more than 58000 pesticide applicators in North Carolina and Iowa. An enrollment questionnaire was administered to applicators to collect basic time- and intensity-related information on pesticide exposure such as mixing condition, duration and frequency of application, application methods and personal protective equipment used. In addition, a detailed take-home questionnaire was administered to collect further intensity-related exposure information such as maintenance or repair of mixing and application equipment, work practices and personal hygiene. More than 40% of the enrolled applicators responded to this detailed take-home questionnaire. Two algorithms were developed to identify applicators' exposure scenarios using information from the enrollment and take-home questionnaires separately in the calculation of subject-specific intensity of exposure score to individual pesticides. The 'general algorithm' used four basic variables (i.e. mixing status, application method, equipment repair status and personal protective equipment use) from the enrollment questionnaire and measurement data from the published pesticide exposure literature to calculate estimated intensity of exposure to individual pesticides for each applicator. The 'detailed' algorithm was based on variables in the general algorithm plus additional exposure information from the take-home questionnaire, including types of mixing system used (i.e. enclosed or open), having a tractor with enclosed cab and/or charcoal filter, frequency of washing equipment after application, frequency of replacing old gloves, personal hygiene and changing clothes after a spill. Weighting factors applied in both algorithms were estimated using measurement data from the published pesticide exposure literature and professional judgment. For each study subject, chemical-specific lifetime cumulative pesticide exposure levels were derived by combining intensity of pesticide exposure as calculated by the two algorithms independently and duration/frequency of pesticide use from the questionnaire. Distributions of duration, intensity and cumulative exposure levels of 2,4-D and chlorpyrifos are presented by state, gender, age group and applicator type (i.e. farmer or commercial applicator) for the entire enrollment cohort and for the sub-cohort of applicators who responded to the take-home questionnaire. The distribution patterns of all basic exposure indices (i.e. intensity, duration and cumulative exposure to 2,4-D and chlorpyrifos) by state, gender, age and applicator type were almost identical in two study populations, indicating that the take-home questionnaire sub-cohort of applicators is representative of the entire cohort in terms of exposure.

Accidents, Occupational↗

PubMed2002

Reliability of reporting on life-style and agricultural factors by a sample of participants in the Agricultural Health Study from Iowa.

Repeat interviews from 4,088 Iowa pesticide applicators participating in the Agricultural Health Study provided the opportunity to evaluate the reliability of self-reported information on pesticide use and various demographic and life-style factors. Self-completed questionnaires were administered 1 year apart when participants returned to county agricultural extension offices for pesticide certification or training. Percentage agreement for ever-/never-use of specific pesticides and application practices was quite high, generally ranging from 70% to more than 90%, and did not vary by age, educational level, or farm size. Agreement was lower (typically 50-60%) for duration, frequency, or decade of first use of specific pesticides. Level of agreement regarding pesticide use in this population is similar to that generally found for factors typically used in epidemiologic studies such as tobacco use and higher than typically reported for diet, physical activity, and medical conditions.

Agriculture↗

PubMed2002

Exposures in the painting trades and paint manufacturing industry and risk of cancer among men and women in Sweden.

Using data from the 1960 and 1970 Swedish censuses and the Swedish Cancer Register for 1971 to 1989, this study investigated variations in cancer risk by gender associated with employment in painting trades and paint manufacturing. Among men, standardized incidence ratios were significantly increased for lung cancer among painters and lacquerers; bladder cancer among artists; and pancreas cancer, lung cancer, and nonlymphocytic leukemia among paint and varnish plant workers. Risks for women were elevated for cancers of the esophagus, larynx, and oral cavity among lacquerers and for oral cancer among glaziers. These findings are consistent with the report of the International Agency for Research on Cancer that classified painting as an occupationally related cause of cancer and provide further evidence that the risk of certain cancers is increased by exposures in the paint manufacturing process.

Adult↗

PubMed2002

Occupational dust exposure and the risk of laryngeal cancer in Turkey.

OBJECTIVES: A hospital-based case-referent study was conducted to identify occupational risk factors for laryngeal cancer. In a previous report an association was found between laryngeal cancer and occupations with potential dust exposure; a job-exposure matrix was developed to aid further evaluation of laryngeal cancer risks from five occupational dust exposures. METHODS: Among 7631 cancer cases from the Okmeydani Hospital, Istanbul, between 1979 and 1984, 958 larynx cancer cases were identified among men. After exclusions, 940 laryngeal cancer cases and 1519 referents were available. A standardized questionnaire was used to obtain basic information on the patients. Seven-digit standard occupational and industrial codes were created to classify the job and industrial titles. A job-exposure matrix was developed for occupational dusts, including silica, asbestos, wood, cotton, and grain, and age-, smoking-, and alcohol-adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were calculated to evaluate risks of laryngeal cancer. RESULTS: An excess of laryngeal cancer occurred for workers potentially exposed to silica and cotton dust, particularly for supraglottic cancer (OR 1.8, 95% CI 1.3-2.3, for silica and OR 1.6, 95% CI 1.1-2.5, for cotton dust), and there was a significant dose-response relationship with silica exposure. No relationship was found between laryngeal cancer and asbestos, grain, or wood dust exposures. CONCLUSION: Laryngeal cancer, especially supraglottic tumors, is associated with silica and cotton dust exposures in Turkey.

Dust↗

PubMed2002

Interactive effect of chemical substances and occupational electromagnetic field exposure on the risk of gliomas and meningiomas in Swedish men.

The objective of our study was to investigate the possible interactive effect of occupational exposure to extremely low-frequency magnetic field (ELFMF) and to known or suspected carcinogenic chemicals on the incidence of the two main histological types of brain cancer, gliomas and meningiomas, in a cohort of male Swedish workers. The historical cohort of all Swedish men gainfully employed in 1970 were followed 19 years (1971-1989). Exposure to ELFMF and to nine chemicals were assessed using two Swedish job exposure matrices based on occupational codes and industrial activity. Relative risks adjusted for age, period, geographical area, and town size were computed using log-linear Poisson models. The main finding was the absence of ELFMF effect on glioma risk in the absence of a simultaneous exposure to chemical products. The effect of petroleum products was independent of the intensity of ELFMF exposure whereas solvents, lead, and pesticides/herbicides were only associated with glioma in workers also exposed to moderate or high levels of ELFMF. On the other hand, whereas ELFMF seemed to enhance the effect of specific chemicals in the causation of gliomas, we did not find a relationship between ELFMF exposure and meningiomas. The potential for ELFMF to act as an effect modifier of the association of chemical agents and glioma is an interesting new finding. It would be worthwhile to evaluate this hypothesis for other tumors. Also, it is necessary to confirm these results in epidemiological studies with individual exposure assessments, and in experimental studies that may elucidate whether there is a true causal mechanism for the results we observed.

Adult↗