Occupational titles as risk factors for Parkinson's disease

BACKGROUND: Job title or employment sector may be associated with Parkinson's disease (PD). METHODS: In a case-control study, in four European centres, lifetime occupational histories were coded using modified International Standard Industrial Classification (ISIC) and Dictionary of Occupational Titles (DOT). We employed multiple logistic regression analyses adjusting for age, gender, smoking and family history of PD. RESULTS: A total of 649 cases and 1587 controls were recruited. Scottish data showed a non-significant increased risk for agriculture (DOT: OR 1.32, 95% CI 0.81-2.16; ISIC: OR 1.30, 95% CI 0.84-2.02) and reduced risk for 'transport and communication' (ISIC: OR 0.60, 95% CI 0.37-0.97). Subsequent four-centre analyses showed reduced risk for processing occupations (DOT: OR 0.69, 95% CI 0.5-0.95). An association with pesticide exposure, found using detailed exposure assessment, was not apparent using job classification. CONCLUSIONS: In contrast to retrospective exposure assessment, job or industrial sector is a weak indicator of toxic exposures such that true associations may be missed.     

Occupational categories at risk for Parkinson's disease

BACKGROUND: The etiology of Parkinson's disease (PD) is considered to have a strong environmental component, but relatively few studies have investigated the potential association between occupation and the disease. METHODS: In a population-based case-control study, we collected comprehensive occupational histories from all study participants, 144 case and 464 control subjects. RESULTS: Chi-square analysis revealed that working in an agricultural occupation increased estimated PD risk (OR = 1.74; 95% CI = 0.85, 3.60). In contrast, a history of ever working in a service occupation was negatively associated with PD risk (OR = 0.69; 95% CI = 0.47, 1.00). Risk estimates were close to one for specific service occupations. Adjusted odds ratios for all non-service occupational and industrial categories were similar, and working in a service occupation was the only significant inverse predictor of PD risk. CONCLUSIONS: Future investigations focusing on lifestyle factors and environmental exposures within the agricultural and service occupational categories are warranted.     

Occupational risk factors for congenital heart disease

Summary To investigate possible associations between cardiovascular malformations and maternal occupational exposure to various factors during the first trimester of pregnancy, 406 cases and 756 controls were studied retrospectively. The cases were taken from all infants diagnosed with cardiovascular malformations born in Finland during 1982 and 1983. The controls were randomly selected from all normal births in the country during the same period. All mothers were interviewed approximately 3 months after delivery by a midwife, using a structured questionnaire. Maternal overall exposure to chemicals at work was more prevalent among the case group (35.8%) than the control group (26.2%,P < 0.01). Among the specific chemical groups, maternal exposure to dyes, lacquers, or paints was significantly associated with the risk of congenital heart disease. Exposure to organic solvents during the first trimester seemed to increase to risk of ventricular septal defect (P < 0.05). Work at video display terminals was slightly more prevalent among the case group (6.3%) than among the control group (5.0%). The mothers' education level, regular exposure to passive smoking at work, or temperature at the workplace were not risk factors for congenital heart disease in the offspring, neither was maternal exposure to microwave ovens, disinfectants, pesticides, or anesthetic gases. It is concluded that many maternal exposures at work seem not to have a teratogenic effect on the fetal heart, although the limited power of this investigation needs to be borne in mind.     

Occupational risk factors for the sporadic form of Creutzfeldt-Jakob disease

Some case reports among European farmers and a few case-control studies suggested the hypothesis of an increased risk of the sporadic form of CJD (sCJD) associated with livestock farming or work as a butcher. Also, the discovery of the possibility of transmission of the disease via blood or by contact following corneal or dura madre transplant suggested that health occupations might also run higher sCJD risks. However, a meta-analysis of three case-control studies and a multicentre European study did not find any positive association between sCJD and health-related jobs or occupational contact with livestock, such as cattle and sheep, or animal products. To explore possible occupational risk factors for Creutzfeldt-Jakob disease (CJD), we used a publicly available US database including about 6 million deaths in 24 states during 1984-95. Cases were 636 deaths (300 men and 336 women) with CJD (ICD-9 code 046.1) as the underlying cause of death. Controls were 3,180 deaths randomly selected from among those who died from all other diseases except those affecting the central nervous system. CJD cases represented a wide variety of occupations (159) and industries (147). Among occupations and industries, for which previous reports suggested potential exposure to a transmissible spongiform encephalopathy (TSE) agent, the OR for CJD was significantly increased among butchers (OR = 6.8, 95% C.I. 1.5, 30.1, based on 4 cases and 3 controls), and persons working in offices of physicians (OR = 4.6, 95% C.I. 1.2, 17.6 based on 5 cases and 4 controls). Nine other occupations and seven other industries, for which no previous suggestion existed in the literature, also showed significant associations. Overall, our results suggest that occupational exposures are not an important source of sCJD infection. However, as the excess among butchers and some workers in health occupations was consistent with previous reports, more indepth research is warranted to address the hypothesis.     

Environmental risk factors and Parkinson's disease: a metaanalysis.

The study aim was to examine the association between Parkinson's disease (PD) and exposure to environmental factors such as living in a rural area, well water use, farming, exposure to farm animals, or living on a farm, and pesticides. A series of metaanalyses of peer-reviewed studies were performed, using 16 studies for living in rural area, 18 studies for well water drinking, 11 studies for farming, and 14 studies for pesticides. Prior to the metaanalyses, all studies were reviewed and evaluated for heterogeneity and publication bias. Significant heterogeneity among studies was detected and combined odds ratio (OR) was calculated using the random and the fixed-effect models. The majority of the studies reported consistent elevation in the risk of PD with exposure to environmental factors such as rural living and farming. The combined OR for rural residence was 1.56 [95% confidence interval (95% CI) 1.18-2.07] for all the studies, and 2.17(95% CI 1.54-3.06) for studies performed in United States. The combined OR for well water use was 1.26 (95% CI 0.97-1.64) for all the studies, and 1.44(95% CI 0.92-2.24) for studies done in United States. The combined OR for farming, exposure to farm animals, or living on a farm was 1.42 (95% CI 1.05-1.91) for all studies, and 1.72(95% CI 1.20-2.46) for studies done in United States. The combined OR for pesticides exposure was 1.85(95% CI 1.31-2.60) for all studies, and 2.16(95% CI 1.95-2.39) for studies done in United States. Dose-response relationships could not be established due to the imprecise nature of the reported data. Our findings suggest that living in a rural area, drinking well water, farming, and exposure to pesticides may be a risk factor for developing PD.     

Occupational differences in ischemic heart disease mortality and risk factors in Australia

Mortality rates from ischemic heart disease in Australia declined by about 25% over the period 1969-1978. The greatest declines were experienced by the professional occupations, while lower socioeconomic groups had higher mortality rates at the beginning of the period and experienced smaller declines. From a national survey in 1980, significantly and consistently lower risk levels of blood pressure, triglyceride, cigarette smoking, body mass and exercise were found among higher status occupation groups. This suggests that there is a pattern of coronary prevention behavior spanning multiple risk factors that is associated with a reduction in ischemic heart disease.     

Occupational risk factors for sarcoma subtypes

Herbicides, chlorophenols, and other occupational exposures are suspected risk factors for soft-tissue sarcoma, but the epidemiologic evidence is inconsistent. Given that soft-tissue sarcomas represent a heterogeneous mix of cancer subtypes and that these subtypes have different disease patterns by race, sex, and age at diagnosis, studying all soft-tissue sarcomas combined may mask subtype-specific associations. Using the Selected Cancers Study, a large population-based case-control study of sarcoma conducted among U.S. men aged 30 to 60 in 1984 to 1988, we explored the occupational risk factors for soft-tissue sarcoma subtypes and skeletal sarcoma. The analysis included 251 living sarcoma cases (48 dermatofibrosarcoma protuberans, 32 malignant fibrohistiocytic sarcoma, 67 leiomyosarcoma, 53 liposarcoma, and 51 skeletal sarcoma) and 1908 living controls. Exact conditional logistic regression models suggested patterns of subtype specificity for occupational exposures. Self-reported herbicide use was associated with malignant fibrohistiocytic sarcoma (OR = 2.9, 95% CI = 1.1-7.3). We found elevated risks for chlorophenol exposure and cutting oil exposure and malignant fibrohistiocytic sarcoma and leiomyosarcoma. We found no occupational risk factor for liposarcoma. Polytomous regression models identified different odds ratios across subtypes for plywood exposure and exposure to wood and saw dust. Although exploratory, this analysis suggests that occupational risk factors for sarcoma are not uniform across subtypes.     

Occupational risk factors for prostate cancer

BACKGROUND: Occupational risk factors for prostate cancer have been investigated with inconsistent findings. METHODS: This was a population-based case-control study of men in Northeastern Ontario, Canada. Cases (n = 760) were from the Ontario Cancer Registry, 50 to 84 years old, and diagnosed with prostate cancer between 1995 and 1998. Age-frequency matched controls (n = 1,632) were obtained from telephone listings. A questionnaire yielded information on occupational history and self-reported exposures to a list of occupational hazards. Exposures to these hazards were assessed by an occupational hygienist. RESULTS: An odds ratio estimate (OR) of 1.21 (95 percent confidence interval (% CI) 1.01, 1.46) was found for employment in trades, transport and equipment operators and related occupations, possibly related to exposure to whole-body vibration (OR = 1.38, 95% CI 1.07, 1.78). For the highest quartile of lifetime cumulative workplace physical activity an OR of 1.33 (95% CI 1.02, 1.74) was found. No statistically significant associations were found for any other occupational category or exposure. CONCLUSIONS: This study does not provide strong evidence for significant occupational risk factors for prostate cancer. However, whole-body vibration exposures, as well as physical activity, may be worth pursuing in future occupational studies.     

Occupational risk factors for developing tuberculosis

We sought to assess whether there is an increased risk of tuberculosis among individuals who work in certain industries or occupations. A case-referent study of 149 male tuberculosis (TB) patients reported to the New Jersey Health Department from 1985 to 1987 and 290 referents was performed. Standardized interviews were conducted via the telephone or in person. Increased risk of TB was highest in heavy drinkers (OR = 3.33, 95% CL 1.99-5.59) and those who had a history of living with someone who had a history of TB (OR = 10.92, 95% CL 4.92-24.22). Occupations and industries associated with elevated risk for TB included: four silica-using industries—quarrying (OR = 3.96, 95% CL 0.36-44.02), pottery and related products (OR = 1.99, 95% CL 0.49-8.06), nonmetallic mineral and stone products (OR = 4.00, 95% CL 0.72-22.10), and ship and boat building and repair (OR = 1.84, 95% CL 0.76-4.43); hospitals (OR = 2.10, 95% CL 1.08-4.10); light truck drivers (OR = 2.49, 95% CL 1.30-4.77); agriculture (OR = 2.31, 95% CL 0.82-6.50); eating and drinking establishments (OR = 2.83, 95% CL 1.11-7.20); and janitors/cleaners (OR = 2.00, 95% CL 0.63-6.31). Except for janitors/cleaners, these elevated odds ratios remained for the above occupations/industries after controlling for alcohol or a history of having lived with someone with tuberculosis. Limitations of the study include a poor response rate (38%) and the exclusion of women from the study. © 1996 Wiley-Liss, Inc.     

Parkinson's disease: a case-control study of occupational and environmental risk factors

We compared personal histories of 57 cases and 122 age-matched controls to identify possible environmental determinants of Parkinson's disease (PD). Odds ratios (OR) adjusted for sex, age, and smoking were computed using stepwise logistic regression. We found a statistically significant increased risk for working in orchards (OR = 3.69, p = 0.012, 95% CI = 1.34, 10.27) and a marginally significant increased risk associated with working in planer mills (OR = 4.11, p = 0.065, 95% CI = 0.91, 18.50). A Fisher's exact test of the association between PD development and (1) paraquat contact, and (2) postural tremor gave statistically significant probability estimates of 0.01 and 0.03, respectively. The relative risk of PD decreased with smoking, an inverse relationship supported by many studies.     

Environmental risk factors for Parkinson's disease and parkinsonism: the Geoparkinson study

Objective

To investigate the associations between Parkinson''s disease and other degenerative parkinsonian syndromes and environmental factors in five European countries.

Methods

A case–control study of 959 prevalent cases of parkinsonism (767 with Parkinson''s disease) and 1989 controls in Scotland, Italy, Sweden, Romania and Malta was carried out. Cases were defined using the United Kingdom Parkinson''s Disease Society Brain Bank criteria, and those with drug‐induced or vascular parkinsonism or dementia were excluded. Subjects completed an interviewer‐administered questionnaire about lifetime occupational and hobby exposure to solvents, pesticides, iron, copper and manganese. Lifetime and average annual exposures were estimated blind to disease status using a job‐exposure matrix modified by subjective exposure modelling. Results were analysed using multiple logistic regression, adjusting for age, sex, country, tobacco use, ever knocked unconscious and family history of Parkinson''s disease.

Results

Adjusted logistic regression analyses showed significantly increased odds ratios for Parkinson''s disease/parkinsonism with an exposure–response relationship for pesticides (low vs no exposure, odds ratio (OR) = 1.13, 95% CI 0.82 to 1.57, high vs no exposure, OR = 1.41, 95% CI 1.06 to 1.88) and ever knocked unconscious (once vs never, OR = 1.35, 95% CI 1.09 to 1.68, more than once vs never, OR = 2.53, 95% CI 1.78 to 3.59). Hypnotic, anxiolytic or antidepressant drug use for more than 1 year and a family history of Parkinson''s disease showed significantly increased odds ratios. Tobacco use was protective (OR = 0.50, 95% CI 0.42 to 0.60). Analyses confined to subjects with Parkinson''s disease gave similar results.

Conclusions

The association of pesticide exposure with Parkinson''s disease suggests a causative role. Repeated traumatic loss of consciousness is associated with increased risk.     

Occupational risk factors for brain cancer in Canada

OBJECTIVE: We sought to examine the impact of occupational exposure on brain cancer risk. METHODS: Mailed questionnaires were used to collect information on lifetime employment history, occupational exposure to 18 chemicals, and other risk factors for 1009 incident cases of brain cancer and 5039 control subjects in Canada in 1994 to 1997. RESULTS: People exposed to asphalt and welding had respective odds ratio (and 95% confidence interval) of 1.29 (1.02-1.62) and 1.26 (0.98-1.45). An increased risk of brain cancer might be associated with exposure to asbestos, benzene, mineral or lubricating oil, isopropyl oil, and wood dust and with following occupations: teaching; protective service; metal processing and related jobs, and metal shaping and forming; knitting in textile processing; construction trades; and transport equipment operating. CONCLUSIONS: Our study suggests a possible role for occupational exposure in the etiology of brain cancer.     

Occupational risk factors for renal cell carcinoma in Montreal

BACKGROUND: Little is known about the role of workplace exposures on the risk of renal cell cancer. METHODS: A population-based case-control study was undertaken in Montreal to assess the association between hundreds of occupational circumstances and several cancer sites, including the kidney. A total of 142 male patients with pathologically confirmed renal cell carcinoma, 1900 controls with cancer at other sites and 533 population-based controls were interviewed. Detailed job histories and relevant data on potential confounders were obtained. A group of chemists-hygienists evaluated each job reported and translated them into a history of occupational exposures using a checklist of 294 substances. Multivariate logistic regression models using either population, cancer controls, or a pool of both groups were used to estimate odds ratios. RESULTS: There were some indications of excess risks among printers, nursery workers (gardening), aircraft mechanics, farmers, and horticulturists, as well as in the following industries: printing-related services, defense services, wholesale trade, and retail trade. Notwithstanding the low precision of many of the odds ratio estimates, the following workplace exposures showed some evidence of excess risk: chromium compounds, chromium (VI) compounds, inorganic acid solutions, styrene-butadiene rubber, ozone, hydrogen sulphide, ultraviolet radiation, hair dust, felt dust, jet fuel engine emissions, jet fuel, aviation gasoline, phosphoric acid and inks. CONCLUSIONS: For most of these associations there exist no, or very little, previous data. Some associations provide suggestive evidence for further studies.     

Occupational risk factors for work-related disorders in greenhouse workers

Aim This study reviews the evidence on the association between working in greenhouses and the occurrence of muscelosckeletal, reproductive and respiratory disorders, dermal effects, cancer and neurobehavioral effects. Subjects and methods PUBMED, MEDLINE and EBSCO literature bases were searched to identify epidemiological studies conducted over 1996–2006 that focused on the health outcomes of greenhouse workers. Three exclusion criteria were used to limit the selection to studies with quantitative assessment of the association between work-related risk factors and health disorders: lack of data on work-related risk factors, lack of a suitable risk estimate for work-related risk factors or of sufficient information that allowed calculation of a risk estimate and serious methodological concerns in relation to the purpose of this review (strong selection bias, very low response rate, recall bias). Results The analysis indicates that greenhouse exposure is associated with an increased risk of respiratory disorders, sensitization to allergens and skin reactions. Exposure to dust, bacteria, allergens, fungi and gases may cause or exacerbate asthma, asthma-like syndrome, mucous membrane irritation, chronic bronchitis and dermatitis. The results of the review showed that male workers employed in greenhouse horticulture for more than 10 years had a decreased median sperm concentration. The data on the effect of working in greenhouses on the time to pregnancy are unequivocal, but most of them indicate a relationship between a decreased fecundability ratio and greenhouse work, this referring mostly to pesticide exposure. There are also some indications that greenhouse work may contribute to musculoskeletal and neurobehavioral disorders, but only a few epidemiological studies have corroborated these findings. Some studies present evidence for the carcinogenicity of the pesticides used in greenhouses. Conclusion The results of this literature review imply a necessity to increase an awareness of the possible adverse health effects among greenhouse workers occupationally exposed to pesticides, biological agents or other factors of their specific work environment. On behalf of the DIRERAF partners: 1. Department of Hygiene and Epidemiology, Medical School University of Athens a. Associate Professor Athena Linos M.D., M.P.H., F.A.C.E b. Mr. Christos Chatzis M.D. c. Mr. Dimitrios Zikos RN d. Dimitrios Kouimintzis M.D. e. Euagelia Hronopoulou M.D. 2. Institute of Preventive Medicine, Environmental and Occupational Health a. Ioanna Kotsioni BA, MSc b. Eirini Papageorgiou BA, MSc 3. Nofer Institute of Occupational Medicine, Lodz 4. International Centre for Pesticides and Health Risk Prevention 5. Institut Municipal d’Investigacio Medical 6. Erasmus University, Rotterdam 7. Dresden University of Technology 8. Charles University of Prague 9. Finnish Institute of Occupational Health 10. Medical University of Sofia 11. Institute of Rural Health, Bratislava Review J. Jurewicz, D. Kouimintzis, A. Burdorf, W. Hanke, C. Chatzis, A. Linos