1
|
Westra S, Goldberg MS, Labrèche F, Baumgartner J, Ho V. The association between the incidence of postmenopausal breast cancer and occupational exposure to selected organic solvents, Montreal, Canada, 2008-2011. Am J Ind Med 2023; 66:911-927. [PMID: 37565624 DOI: 10.1002/ajim.23525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 07/17/2023] [Accepted: 07/27/2023] [Indexed: 08/12/2023]
Abstract
BACKGROUND Breast cancer is the most diagnosed cancer among women and recognized risk factors explain 25%-47% of cases. Organic solvents are used widely in the workplace and exposure may increase the risk of developing breast cancer, yet there are insufficient data to confirm this hypothesis. We sought to determine whether past occupational exposures to selected organic solvents were associated with the incidence of invasive breast cancer in postmenopausal women in Montréal, Canada. METHODS From a population-based case-control study (2008-2011), using in-depth interviews we elicited information on risk factors and lifetime occupational histories. Industrial hygienists and chemists translated job descriptions into specific chemical and physical exposures. We assessed 11 individual solvents and four solvent groups. Unconditional logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for metrics of past exposures to selected solvents. Exposure metrics included any previous exposure, average frequency in hours per week, duration in years, and average cumulative concentration weighted by hours per workweek exposed. RESULTS We enrolled 695 cases and 608 controls. We found increased ORs for average cumulative concentration of exposure to mononuclear aromatic hydrocarbons (OR: 1.52, 95% CI: 1.04, 2.28), chlorinated alkanes (OR: 2.42, 95% CI: 1.23, 5.68), toluene (OR: 1.59, 95% CI: 1.02, 2.59), and a group of organic solvents with reactive metabolites (OR: 1.53, 95% CI: 1.08, 2.24). Positive associations were found across all exposure metrics and were higher among women with estrogen-positive/progesterone-negative tumors. CONCLUSION Our findings suggest occupational exposure to certain organic solvents may increase the risk of incident postmenopausal breast cancer.
Collapse
Affiliation(s)
- Sydney Westra
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Québec, Canada
| | - Mark S Goldberg
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Québec, Canada
- Department of Medicine, McGill University, Montréal, Québec, Canada
| | - France Labrèche
- Department of Environmental and Occupational Health, School of Public Health and Centre de recherche en santé publique (CReSP), University of Montréal and CIUSSS Centre-Sud, Montréal, Québec, Canada
- Institut de recherche Robert-Sauvé en santé et en sécurité du travail, Montréal, Québec, Canada
| | - Jill Baumgartner
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Québec, Canada
- Department of Ethics, Equity and Policy, McGill University, Montréal, Québec, Canada
| | - Vikki Ho
- Health Innovation and Evaluation Hub Université de Montréal Hospital Research Centre (CRCHUM), Montréal, Québec, Canada
- Department of Social and Preventive Medicine, Université de Montréal School of Public Health (ESPUM), Montréal, Québec, Canada
| |
Collapse
|
2
|
Xiao W, Huang J, Wang J, Chen Y, Hu N, Cao S. Occupational exposure to organic solvents and breast cancer risk: a systematic review and meta-analysis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:1605-1618. [PMID: 34686960 DOI: 10.1007/s11356-021-17100-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 10/14/2021] [Indexed: 06/13/2023]
Abstract
Breast cancer is the most common cancer worldwide. Recent studies suggest that organic solvent exposure could be closely related to breast cancer, although the evidence remains controversial. Thus, we evaluated existing epidemiological evidence for the association between occupational solvent exposure and breast cancer. PubMed, Embase, and Cochrane Library were searched to identify published case-control and cohort studies that addressed occupational exposure to organic solvents and breast cancer, up to April, 2021. Meta-analyses using random-effects models were conducted to obtain the pooled odds ratios (OR) and 95% confidence intervals (CI) on the incidence of breast cancer in relation to occupational exposure. The pooled OR of breast cancer among workers exposed to organic solvents overall was 1.18 (95%CI, 1.11 ~ 1.25; I2 = 76.3%; 24 studies), compared to those with no exposure. After stratification by menopause and study location, it was revealed that the association between occupational exposure to organic solvents and the risk of breast cancer in postmenopausal women (OR, 1.35; 95% CI, 1.09 ~ 1.67; I2 = 73.4%; 7 studies) was significant, and there was also a clear association in workers in Europe (OR, 1.21; 95% CI, 1.12 ~ 1.32; I2 = 82.9%; 13 studies). We observed a significant association between occupational exposure to organic solvents and breast cancer in both cohort and case-control studies.
Collapse
Affiliation(s)
- Wenxuan Xiao
- Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Jinglong Huang
- Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Jianing Wang
- School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Youli Chen
- Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Nan Hu
- Department of Neurology, Peking Union Medical College Hospital, Beijing, 100730, China
| | - Shiyi Cao
- School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| |
Collapse
|
3
|
Lope V, García-Pérez J, Pérez-Gómez B, Pedraza-Flechas AM, Alguacil J, González-Galarzo MC, Alba MA, van der Haar R, Cortés-Barragán RA, Pedraz-Pingarrón C, Moreo P, Santamariña C, Ederra M, Vidal C, Salas-Trejo D, Sánchez-Contador C, Llobet R, Pollán M. Occupational exposures and mammographic density in Spanish women. Occup Environ Med 2017; 75:124-131. [PMID: 29074552 DOI: 10.1136/oemed-2017-104580] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/20/2017] [Accepted: 09/28/2017] [Indexed: 12/29/2022]
Abstract
OBJECTIVES The association between occupational exposures and mammographic density (MD), a marker of breast cancer risk, has not been previously explored. Our objective was to investigate the influence of occupational exposure to chemical, physical and microbiological agents on MD in adult women. METHODS This is a population-based cross-sectional study based on 1476 female workers aged 45-65 years from seven Spanish breast cancer screening programmes. Occupational history was surveyed by trained staff. Exposure to occupational agents was assessed using the Spanish job-exposure matrix MatEmESp. Percentage of MD was measured by two radiologists using a semiautomatic computer tool. The association was estimated using mixed log-linear regression models adjusting for age, education, body mass index, menopausal status, parity, smoking, alcohol intake, type of mammography, family history of breast cancer and hormonal therapy use, and including screening centre and professional reader as random effects terms. RESULTS Although no association was found with most of the agents, women occupationally exposed to perchloroethylene (eβ=1.51; 95% CI 1.04 to 2.19), ionising radiation (eβ=1.23; 95% CI 0.99 to 1.52) and mould spores (eβ=1.44; 95% CI 1.01 to 2.04) tended to have higher MD. The percentage of density increased 12% for every 5 years exposure to perchloroethylene or mould spores, 11% for every 5 years exposure to aliphatic/alicyclic hydrocarbon solvents and 3% for each 5 years exposure to ionising radiation. CONCLUSIONS Exposure to perchloroethylene, ionising radiation, mould spores or aliphatic/alicyclic hydrocarbon solvents in occupational settings could be associated with higher MD. Further studies are needed to clarify the accuracy and the reasons for these findings.
Collapse
Affiliation(s)
- Virginia Lope
- Cancer and Environmental Epidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain.,Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública - CIBERESP), Madrid, Spain
| | - Javier García-Pérez
- Cancer and Environmental Epidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain.,Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública - CIBERESP), Madrid, Spain
| | - Beatriz Pérez-Gómez
- Cancer and Environmental Epidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain.,Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública - CIBERESP), Madrid, Spain
| | - Ana María Pedraza-Flechas
- Cancer and Environmental Epidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain
| | - Juan Alguacil
- Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública - CIBERESP), Madrid, Spain.,Centro de Investigación en Salud y Medio Ambiente (CYSMA), Universidad de Huelva, Huelva, Spain
| | | | - Miguel Angel Alba
- Área de Higiene Industrial, PREMAP Seguridad y Salud S.L.U, Barcelona, Spain
| | | | | | | | - Pilar Moreo
- Aragon Breast Cancer Screening Program, Aragon Health Service, Zaragoza, Spain
| | - Carmen Santamariña
- Servicio de Alertas Epidemiolóxicas, Programa Galego Diagnostico Precoz Cancro de Mama, Unidade Central A Coruña, Conselleria de Sanidade, A Coruña, Spain
| | - María Ederra
- Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública - CIBERESP), Madrid, Spain.,Public Health Institute, Navarra Breast Cancer Screening Programme, Pamplona, Spain
| | - Carmen Vidal
- Prevention and Control Program, Catalan Institute of Oncology, Barcelona, Spain
| | - Dolores Salas-Trejo
- Valencia Breast Cancer Screening Program, General Directorate Public Health, Valencia, Spain
| | | | - Rafael Llobet
- Institute of Computer Technology, Universitat Politècnica de València, Valencia, Spain
| | - Marina Pollán
- Cancer and Environmental Epidemiology Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain.,Consortium for Biomedical Research in Epidemiology and Public Health (CIBER Epidemiología y Salud Pública - CIBERESP), Madrid, Spain
| |
Collapse
|
4
|
Ruckart PZ, Bove FJ, Shanley E, Maslia M. Evaluation of contaminated drinking water and male breast cancer at Marine Corps Base Camp Lejeune, North Carolina: a case control study. Environ Health 2015; 14:74. [PMID: 26376727 PMCID: PMC4571057 DOI: 10.1186/s12940-015-0061-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 09/08/2015] [Indexed: 05/28/2023]
Abstract
BACKGROUND Solvents contaminated drinking water supplies at Marine Corps Base Camp Lejeune during 1950s-1985. METHODS We conducted a case-control study among Marines to evaluate associations between residential exposure to contaminated drinking water at Camp Lejeune and male breast cancer risk. The study included 71 male breast cancer cases and 373 controls identified from the Department of Veteran's Affairs (VA) cancer registry whose military personnel records were available. Controls were selected from cancers not known to be associated with solvent exposure and included 270 skin cancers, 71 mesotheliomas, and 32 bone cancers. Base assignment and risk factor information came from military personnel and VA records. Groundwater contaminant fate/transport and distribution system models provided monthly estimated residential contaminant levels. We conducted exact logistic regression using the 50th percentile level among exposed controls to create low and high exposure categories. We calculated 95% confidence intervals (CIs) to indicate precision of effect estimates. Exploratory analyses used proportional hazards methods to evaluate associations between exposures and age at diagnosis. RESULTS After adjusting for age at diagnosis, race, and service in Vietnam, the odds ratio (OR) for ever stationed at Camp Lejeune was 1.14 (95% CI: 0.65, 1.97). Adjusted ORs for high residential cumulative exposures to tetrachloroethylene (PCE), t-1,2 dichloroethylene (DCE), and vinyl chloride were 1.20 [95% CI: 0.16-5.89], 1.50 [95% CI: 0.30-6.11], 1.19 [95% CI: 0.16-5.89], respectively, with a monotonic exposure response relationship for PCE only. However these results were based on two or three cases in the high cumulative exposure categories. Ever stationed at Camp Lejeune and high cumulative exposures to trichloroethylene (TCE), PCE, DCE and vinyl chloride were associated with earlier age at onset for male breast cancer; hazard ratios ranged from 1.4-2.7 with wide confidence intervals for cumulative exposure variables. CONCLUSION Findings suggested possible associations between male breast cancer and being stationed at Camp Lejeune and cumulative exposure to PCE, DCE, and vinyl chloride. TCE, PCE, DCE and vinyl chloride cumulative exposures showed possible associations with earlier age at onset of male breast cancer. However, this study was limited by small numbers of cases in high exposure categories.
Collapse
Affiliation(s)
- Perri Zeitz Ruckart
- Agency for Toxic Substances and Disease Registry, Division of Toxicology and Human Health Sciences, Atlanta, USA.
| | - Frank J Bove
- Agency for Toxic Substances and Disease Registry, Division of Toxicology and Human Health Sciences, Atlanta, USA.
| | - Edwin Shanley
- National Center for Environmental Health/Agency for Toxic Substances and Disease Registry, Office of the Director, Atlanta, USA.
| | - Morris Maslia
- Agency for Toxic Substances and Disease Registry, Division of Community Health Investigations, 4770 Buford Highway, MS F-58, Atlanta, GA, 30341, USA.
| |
Collapse
|
5
|
Kim MH, Kim H, Paek D. The health impacts of semiconductor production: an epidemiologic review. INTERNATIONAL JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HEALTH 2013; 20:95-114. [PMID: 24999845 DOI: 10.1179/2049396713y.0000000050] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Despite concerns over the harmful health effects of semiconductor production, epidemiological studies have shown mixed results. OBJECTIVES We aim to critically appraise epidemiologic studies to date, and to suggest future research and actions to protect workers in semiconductor industry. METHODS Epidemiologic studies were identified through electronic database searches, review of reference lists of relevant published works, and expert consultations, and were narratively reviewed. RESULTS Most evidence suggests reproductive risks from fabrication jobs, including spontaneous abortion (SAB), congenital malformation, and reduced fertility. Although chemicals have been suspected as causal agents, knowledge of the likely contribution(s) from specific exposures is still limited. Evidence of cancer risk seems to be equivocal. However, the available studies had serious limitations including healthy worker effects (HWEs), information bias, and insufficient power, all of which are associated with underestimation. Nevertheless, excess risks for non-Hodgkin's lymphoma (NHL), leukemia, brain tumor, and breast cancer were observed. CONCLUSIONS Monitoring and innovative research based on international collaboration with a focus on sentinel events are required.
Collapse
|
6
|
Paget-Bailly S, Cyr D, Luce D. Occupational exposures to asbestos, polycyclic aromatic hydrocarbons and solvents, and cancers of the oral cavity and pharynx: a quantitative literature review. Int Arch Occup Environ Health 2011; 85:341-51. [PMID: 21785866 DOI: 10.1007/s00420-011-0683-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Accepted: 07/04/2011] [Indexed: 11/25/2022]
Abstract
PURPOSE The role of occupational risk factors in oral and pharyngeal cancer is not well known and is possibly underestimated. This quantitative review summarizes epidemiological findings on exposure to asbestos, polycyclic aromatic hydrocarbons and solvents, and cancers of the oral cavity and pharynx. METHODS A systematic literature search was performed. We analyzed 63 publications: 8 from case-control studies and 55 from cohort studies. For agents with at least five available studies with homogenous exposure, a series of meta-analyses was conducted to provide quantitative pooled estimates of risks, using random effect models. RESULTS Exposure to asbestos (meta-RR 1.25; 95% CI 1.10-1.42) and to polycyclic aromatic hydrocarbons (meta-RR 1.14; 95% CI 1.02-1.28) was found to be associated with oral and pharyngeal cancer risk. On the other hand, no association was found with exposure to solvents in general (meta-RR 0.98; 95% CI 0.77-1.23) but the strong heterogeneity between studies suggested differences in exposures. The small number of studies with homogeneous exposure did not allow meta-analyses for specific solvents. CONCLUSIONS Future investigations should overcome common weaknesses of past studies, in terms of sample size, characterization of exposure, and classification of cancer sites.
Collapse
Affiliation(s)
- Sophie Paget-Bailly
- Inserm UMRS 1018, CESP, Epidemiology of Occupational and Social Determinants of Health, Centre for Research in Epidemiology and Population Health, 15/16, avenue Paul Vaillant Couturier, 94807, Villejuif, France
| | | | | |
Collapse
|
7
|
Gallagher LG, Vieira VM, Ozonoff D, Webster TF, Aschengrau A. Risk of breast cancer following exposure to tetrachloroethylene-contaminated drinking water in Cape Cod, Massachusetts: reanalysis of a case-control study using a modified exposure assessment. Environ Health 2011; 10:47. [PMID: 21600013 PMCID: PMC3125233 DOI: 10.1186/1476-069x-10-47] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 05/21/2011] [Indexed: 05/08/2023]
Abstract
BACKGROUND Tetrachloroethylene (PCE) is an important occupational chemical used in metal degreasing and drycleaning and a prevalent drinking water contaminant. Exposure often occurs with other chemicals but it occurred alone in a pattern that reduced the likelihood of confounding in a unique scenario on Cape Cod, Massachusetts. We previously found a small to moderate increased risk of breast cancer among women with the highest exposures using a simple exposure model. We have taken advantage of technical improvements in publically available software to incorporate a more sophisticated determination of water flow and direction to see if previous results were robust to more accurate exposure assessment. METHODS The current analysis used PCE exposure estimates generated with the addition of water distribution modeling software (EPANET 2.0) to test model assumptions, compare exposure distributions to prior methods, and re-examine the risk of breast cancer. In addition, we applied data smoothing to examine nonlinear relationships between breast cancer and exposure. We also compared a set of measured PCE concentrations in water samples collected in 1980 to modeled estimates. RESULTS Thirty-nine percent of individuals considered unexposed in prior epidemiological analyses were considered exposed using the current method, but mostly at low exposure levels. As a result, the exposure distribution was shifted downward resulting in a lower value for the 90th percentile, the definition of "high exposure" in prior analyses. The current analyses confirmed a modest increase in the risk of breast cancer for women with high PCE exposure levels defined by either the 90th percentile (adjusted ORs 1.0-1.5 for 0-19 year latency assumptions) or smoothing analysis cut point (adjusted ORs 1.3-2.0 for 0-15 year latency assumptions). Current exposure estimates had a higher correlation with PCE concentrations in water samples (Spearman correlation coefficient = 0.65, p < 0.0001) than estimates generated using the prior method (0.54, p < 0.0001). CONCLUSIONS The incorporation of sophisticated flow estimates in the exposure assessment method shifted the PCE exposure distribution downward, but did not meaningfully affect the exposure ranking of subjects or the strength of the association with the risk of breast cancer found in earlier analyses. Thus, the current analyses show a slightly elevated breast cancer risk for highly exposed women, with strengthened exposure assessment and minimization of misclassification by using the latest technology.
Collapse
Affiliation(s)
- Lisa G Gallagher
- Department of Environmental Health Boston University School of Public Health 715 Albany Street, Talbot 4 West, Boston, MA 02118, USA
| | - Veronica M Vieira
- Department of Environmental Health Boston University School of Public Health 715 Albany Street, Talbot 4 West, Boston, MA 02118, USA
| | - David Ozonoff
- Department of Environmental Health Boston University School of Public Health 715 Albany Street, Talbot 4 West, Boston, MA 02118, USA
| | - Thomas F Webster
- Department of Environmental Health Boston University School of Public Health 715 Albany Street, Talbot 4 West, Boston, MA 02118, USA
| | - Ann Aschengrau
- Department of Epidemiology Boston University School of Public Health 715 Albany Street, Talbot 3 East, Boston, MA 021, USA
| |
Collapse
|
8
|
Brody JG, Moysich KB, Humblet O, Attfield KR, Beehler GP, Rudel RA. Environmental pollutants and breast cancer: epidemiologic studies. Cancer 2007; 109:2667-711. [PMID: 17503436 DOI: 10.1002/cncr.22655] [Citation(s) in RCA: 248] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Laboratory research has shown that numerous environmental pollutants cause mammary gland tumors in animals; are hormonally active, specifically mimicking estrogen, which is a breast cancer risk factor; or affect susceptibility of the mammary gland to carcinogenesis. An assessment of epidemiologic research on these pollutants identified in toxicologic studies can guide future research and exposure reduction aimed at prevention. The PubMed database was searched for relevant literature and systematic critical reviews were entered in a database available at URL: www.silentspring.org/sciencereview and URL: www.komen.org/environment (accessed April 10, 2007). Based on a relatively small number of studies, the evidence to date generally supports an association between breast cancer and polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in conjunction with certain genetic polymorphisms involved in carcinogen activation and steroid hormone metabolism. Evidence regarding dioxins and organic solvents is sparse and methodologically limited but suggestive of an association. Methodologic problems include inadequate exposure assessment, a lack of access to highly exposed and unexposed populations, and a lack of preclinical markers to identify associations that may be obscured by disease latency. Among chemicals identified in toxicologic research as relevant to breast cancer, many have not been investigated in humans. The development of better exposure assessment methods is needed to fill this gap. In the interim, weaknesses in the epidemiologic literature argue for greater reliance on toxicologic studies to develop national policies to reduce chemical exposures that may be associated with breast cancer. Substantial research progress in the last 5 years suggests that the investigation of environmental pollutants will lead to strategies to reduce breast cancer risk.
Collapse
|
9
|
Increased standardized incidence ratio of breast cancer in female electronics workers. BMC Public Health 2007; 7:102. [PMID: 17559641 PMCID: PMC1906757 DOI: 10.1186/1471-2458-7-102] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2006] [Accepted: 06/08/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In 1994, a hazardous waste site, polluted by the dumping of solvents from a former electronics factory, was discovered in Taoyuan, Taiwan. This subsequently emerged as a serious case of contamination through chlorinated hydrocarbons with suspected occupational cancer. The objective of this study was to determine if there was any increased risk of breast cancer among female workers in a 23-year follow-up period. METHODS A total of 63,982 female workers were retrospectively recruited from the database of the Bureau of Labor Insurance (BLI) covering the period 1973-1997; the data were then linked with data, up to 2001, from the National Cancer Registry at the Taiwanese Department of Health, from which standardized incidence ratios (SIRs) for different types of cancer were calculated as compared to the general population. RESULTS There were a total of 286 cases of breast cancer, and after adjustment for calendar year and age, the SIR was close to 1. When stratified by the year 1974 (the year in which the regulations on solvent use were promulgated), the SIR of the cohort of workers who were first employed prior to 1974 increased to 1.38 (95% confidence interval, 1.11-1.70). No such trend was discernible for workers employed after 1974. When 10 years of employment was considered, there was a further increase in the SIR for breast cancer, to 1.62. Those workers with breast cancer who were first employed prior to 1974 were employed at a younger age and for a longer period. Previous qualitative studies of interviews with the workers, corroborated by inspection records, showed a short-term high exposure to chlorinated alkanes and alkenes, particularly trichloroethylene before 1974. There were no similar findings on other types of cancer. CONCLUSION Female workers with exposure to trichloroethylene and/or mixture of solvents, first employed prior to 1974, may have an excess risk of breast cancer.
Collapse
|
10
|
Alexander DD, Kelsh MA, Mink PJ, Mandel JH, Basu R, Weingart M. A meta-analysis of occupational trichloroethylene exposure and liver cancer. Int Arch Occup Environ Health 2007; 81:127-43. [PMID: 17492303 DOI: 10.1007/s00420-007-0201-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2006] [Accepted: 04/17/2007] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Findings from epidemiologic studies of trichloroethylene (TCE) exposure and liver cancer have been inconsistent. To quantitatively evaluate this association and to examine sources of heterogeneity, we conducted a meta-analysis of occupational studies of TCE exposure and liver/biliary tract cancer. METHODS We identified 14 occupational cohort studies of TCE exposed workers and one case-control study that met our inclusion criteria. Nine studies specifically identified TCE as a workplace exposure, and were classified as Group I cohort studies. Subcohorts of workers, identified within eight of these studies as more likely exposed to TCE than the total cohort, were analyzed separately. RESULTS The combined liver/biliary cancer summary relative risk estimate (SRRE) for all studies was 1.08 (95% CI 0.91-1.29; heterogeneity (H)-P-value=0.12). For the total study populations in the Group I cohorts, the SRRE was 1.14 (95% CI 0.93-1.39; H-P-value=0.05) and for the subcohorts, the SRRE was 1.30 (95% CI 1.09-1.55). Within this subcohort analysis, the association for the European studies of workers from various industries (SRRE=1.38; based on four studies) was higher than the association for the US studies of aerospace and aircraft workers (SRRE=0.97, based on four studies). CONCLUSION Although positive associations were observed for some analyses, results were inconsistent across occupational groups (aerospace/aircraft vs. other industries combined), study location, and incidence versus mortality endpoints. In addition, exposure-response trends were not observed consistently across studies. Interpretation is also limited by the potential impact of uncontrolled confounding by other occupational or lifestyle exposures such as smoking or alcohol consumption. Given these limitations, the currently available epidemiologic data are not sufficient to support a causal relation between occupational TCE exposure and liver/biliary cancer.
Collapse
Affiliation(s)
- Dominik D Alexander
- Exponent Health Sciences, 185 Hansen Ct, Suite 100, Wood Dale, IL 60191, USA.
| | | | | | | | | | | |
Collapse
|
11
|
Scott CS, Chiu WA. Trichloroethylene cancer epidemiology: a consideration of select issues. ENVIRONMENTAL HEALTH PERSPECTIVES 2006; 114:1471-8. [PMID: 16966107 PMCID: PMC1570052 DOI: 10.1289/ehp.8949] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
A large body of epidemiologic evidence exists for exploring causal associations between cancer and trichloroethylene (TCE) exposure. The U.S. Environmental Protection Agency 2001 draft TCE health risk assessment concluded that epidemiologic studies, on the whole, support associations between TCE exposure and excess risk of kidney cancer, liver cancer, and lymphomas, and, to a lesser extent, cervical cancer and prostate cancer. As part of a mini-monograph on key issues in the health risk assessment of TCE, this article reviews recently published scientific literature examining cancer and TCE exposure and identifies four issues that are key to interpreting the larger body of epidemiologic evidence: a) relative sensitivity of cancer incidence and mortality data ; b) different classifications of lymphomas, including non-Hodgkin lymphoma ; c) differences in data and methods for assigning TCE exposure status ; and d) different methods employed for causal inferences, including statistical or meta-analysis approaches. The recent epidemiologic studies substantially expand the epidemiologic database, with seven new studies available on kidney cancer and somewhat fewer studies available that examine possible associations at other sites. Overall, recently published studies appear to provide further support for the kidney, liver, and lymphatic systems as targets of TCE toxicity, suggesting, as do previous studies, modestly elevated (typically 1.5-2.0) site-specific relative risks, given exposure conditions in these studies. However, a number of challenging issues need to be considered before drawing causal conclusions about TCE exposure and cancer from these data.
Collapse
Affiliation(s)
- Cheryl Siegel Scott
- National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC, USA.
| | | |
Collapse
|
12
|
Alexander DD, Mink PJ, Mandel JH, Kelsh MA. A meta-analysis of occupational trichloroethylene exposure and multiple myeloma or leukaemia. Occup Med (Lond) 2006; 56:485-93. [PMID: 16905622 DOI: 10.1093/occmed/kql083] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Trichloroethylene (TCE) has been widely used as an industrial solvent and degreasing agent. AIMS We conducted a meta-analysis of epidemiologic studies of occupational TCE exposure and multiple myeloma (MM) or leukaemia. METHODS We identified a total of eight cohort or case-control studies that enumerated a TCE-exposed study population and presented relative risk (RR) estimates for MM (n = 7) and/or leukaemia (n = 7). The individual studies included aerospace or aircraft workers (n = 3 studies), workers from a transformer manufacturing plant (n = 1 study) and workers from numerous occupations who, based on biomonitoring or extensive industrial hygiene exposure measurements, were likely exposed to TCE (n = 4). We used random effects models to calculate summary relative risk estimates (SRRE). In addition, we examined heterogeneity across studies and the relative influence of each individual study on the overall meta-analysis. RESULTS No association was observed for MM (SRRE = 1.05, 95% CI: 0.80-1.38; P value for heterogeneity = 0.94) or leukaemia (SRRE = 1.11, 95% CI: 0.93-1.32; P value for heterogeneity = 0.50), based on TCE-exposed subgroup meta-analyses. Study-specific RR estimates for MM ranged between 0.57 and 1.62. RRs for leukaemia ranged between 1.05 and 1.15 in five studies, while one study reported a 2-fold increased RR and another study reported an inverse association of 0.60. All confidence intervals (CIs) for study-specific estimates included 1.0. CONCLUSIONS The results of this meta-analysis do not support an etiologic association between occupational TCE exposure and risk of MM or leukaemia.
Collapse
Affiliation(s)
- Dominik D Alexander
- Exponent-Health Sciences, 185 Hansen Court, Suite 100, Wood Dale, IL 60191, USA.
| | | | | | | |
Collapse
|