Occupational Cancer Research Center

Toronto, Canada

Occupational Cancer Research Center

Toronto, Canada

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Harris S.A.,Population Studies and Surveillance | Harris S.A.,University of Toronto | Harris S.A.,Occupational Cancer Research Center
American Journal of Infection Control | Year: 2010

Background: Little is known about compliance with universal precautions (CUP) or occupational exposures to blood and body fluids among Emergency Medical Services (EMS) providers. The objective of this study was to obtain estimates of CUP and knowledge of universal precautions (KUP), occupational exposures, and needle and lancet sticks in the prehospital environment. Methods: A convenience sample of workers (n=311, 51% response) from 17 agencies in Virginia that provided emergency ground transportation (volunteer, commercial, government rescue squads, and fire departments) completed a questionnaire on certification and training, KUP, CUP, exposures and needlesticks, risk perceptions, and demographic variables. Results: Nearly all EMS providers reported exposures and were concerned about risk of HIV and hepatitis. Providers reported inconsistent CUP when treating patients or using needles, including failure to wear gloves (17%) and to appropriately dispose of contaminated materials (79%), including needles (87%), at all times. Certification type (advanced and basic) was related to both KUP and CUP. Of those respondents reporting current sharps use, 40% recapped needles. A lancet stick was reported by 1.4% (n=5), and 4.5% reported a needlestick (n=14). Conclusion: EMS providers working in the prehospital environment experience significant exposures but are not consistently using universal precautions. © 2010 Association for Professionals in Infection Control and Epidemiology, Inc.


Wong I.S.,University of British Columbia | Ostry A.S.,University of Victoria | Demers P.A.,Occupational Cancer Research Center | Davies H.W.,University of British Columbia
Journal of Occupational and Environmental Hygiene | Year: 2012

This pilot study is one of the first to examine the impact of job strain and shift work on both the autonomic nervous system (ANS) and the hypothalamic-pituitary-adrenal (HPA) axis using two salivary stress biomarkers and two subclinical heart disease indicators. This study also tested the feasibility of a rigorous biological sampling protocol in a busy workplace setting. Paramedics (n=21) self-collected five salivary samples over 1 rest and 2 workdays. Samples were analyzed for α-amylase and cortisol diurnal slopes and daily production. Heart rate variability (HRV) was logged over 2 workdays with the Polar RS800 Heart Rate monitors. Endothelial functioning was measured using fingertip peripheral arterial tonometry. Job strain was ascertained using a paramedic-specific survey. The effects of job strain and shift work were examined by comparing paramedic types (dispatchers vs. ambulance attendants) and shift types (daytime vs. rotating day/night). Over 90% of all expected samples were collected and fell within expected normal ranges. Workday samples were significantly different from rest day samples. Dispatchers reported higher job strain than ambulance paramedics and exhibited reduced daily α-amylase production, elevated daily cortisol production, and reduced endothelial function. In comparison with daytime-only workers, rotating shift workers reported higher job strain, exhibited flatter α-amylase and cortisol diurnal slopes, reduced daily α-amylase production, elevated daily cortisol production, and reduced HRV and endothelial functioning. Despite non-statistically significant differences between group comparisons, the consistency of the overall trend in subjective and objective measures suggests that exposure to work stressors may lead to dysregulation in neuroendocrine activity and, over the long-term, to early signs of heart disease. Results suggest that further study is warranted in this population. Power calculations based on effect sizes in the shift type comparison suggest a study size of n=250 may result in significant differences at p=0.05. High compliance among paramedics to complete the intensive protocol suggests this study will be feasible in a larger population. © 2012 JOEH, LLC.


Constanza Camargo M.,University of Illinois at Chicago | Stayner L.T.,University of Illinois at Chicago | Straif K.,International Agency for Research on Cancer | Reina M.,University of Illinois at Chicago | And 3 more authors.
Environmental Health Perspectives | Year: 2011

Objective: A recent Monographs Working Group of the International Agency for Research on Cancer (IARC) concluded that there is sufficient evidence for a causal association between exposure to asbestos and ovarian cancer. We performed a meta-analysis to quantitatively evaluate this association. Data sources: Searches of PubMed and unpublished data yielded a total of 18 cohort studies of women occupationally exposed to asbestos. Data extraction: Two authors independently abstracted data; any disagreement was resolved by consulting a third reviewer. Data synthesis: All but one study reported standardized mortality ratios (SMRs) comparing observed numbers of deaths with expected numbers for the general population; the exception was a study that reported standardized incidence ratios. For simplicity, we refer to all effect estimates as SMRs. The overall pooled SMR estimate for ovarian cancer was 1.77 (95% confidence interval, 1.37-2.28), with a moderate degree of heterogeneity among the studies (I2 = 35.3%, p = 0.061). Effect estimates were stronger for cohorts compensated for asbestosis, cohorts with estimated lung cancer SMRs > 2.0, and studies conducted in Europe compared with other geographic regions. Effect estimates were similar for studies with and without pathologic confirmation, and we found no evidence of publication bias (Egger's test p-value = 0.162). Conclusions: Our study supports the IARC conclusion that exposure to asbestos is associated with increased risk of ovarian cancer.


Harris M.A.,University of British Columbia | Harris M.A.,Occupational Cancer Research Center | Tsui J.K.,University of British Columbia | Tsui J.K.,UBC Hospital | And 3 more authors.
Movement Disorders | Year: 2012

The ultimate causes of idiopathic Parkinson's disease (PD) are not fully known, but environmental and occupational causes are suspected. Postencephalitic parkinsonism has been linked to influenza, and other viral infections have also been suspected to relate to PD. We estimated the relationship between PD and both infections and possible vectors of infection (i.e., animal and human) in a population-based, case-control study in British Columbia, Canada. We recruited 403 cases detected by their use of antiparkinsonian medications and 405 controls from the registrants of the provincial universal health insurance plan. Severe influenza was associated with PD (odds ratio [OR]: 2.01; 95% confidence interval [CI]: 1.16-3.48), although this effect was attenuated when reports were restricted to those occurring 10 or more years before diagnosis. Childhood illnesses were inversely associated with PD, particularly red measles (OR: 0.65; 95% CI: 0.48-0.90). Several animal exposures were associated with PD, with statistically significant effects for cats (OR: 2.06; 95% CI: 1.09-3.92) and cattle (OR: 2.23; 95% CI: 1.22-4.09). Influenza infection may be associated with PD. The inverse relationships with childhood infections may suggest an increased risk with subclinical or asymptomatic childhood infections. Occupational exposure to animals may increase risk through transmission of infections or may indicate exposure to another agent of interest (e.g., bacterial endotoxin). © 2012 Movement Disorder Society.


Hon C.-Y.,University of British Columbia | Hon C.-Y.,Ryerson University | Teschke K.,University of British Columbia | Chu W.,University of British Columbia | And 2 more authors.
Journal of Occupational and Environmental Hygiene | Year: 2013

We previously reported that there is a potential for antineoplastic drug contamination throughout the hospital medication system (process flow of drug within a facility from delivery to waste disposal) due to the various surfaces contacted by health care workers. This article describes the contamination of these frequently contacted surfaces as well as identifies factors that may be associated with surface contamination. Surfaces which health care workers frequently contact were wiped and the concentration of cyclophosphamide (CP) was determined using high-performance liquid chromatography-tandem mass spectrometry. Descriptive and inferential statistical analyses were performed. A backward stepwise multiple linear regression was conducted to identify determinants associated with surface contamination. Overall, 229 surfaces were sampled, most on two occasions, for a total of 438 surface wipes. The mean CP concentration was 0.201 ng/cm2, the geometric mean 0.019 ng/cm 2, and the geometric standard deviation 2.54, with a range of less than detection (LOD) to 26.1 ng/cm2. (Method LOD was 0.356 ng/wipe; factoring in the surface area of the wiped surface, results in a sample LOD ranging from 0.00 to 0.049 ng/cm2). Our study found that frequently contacted surfaces at every stage of the hospital medication system had measureable levels of antineoplastic drug contamination. Two factors were statistically significant with respect to their association with surface contamination: (1) the stage of the hospital medication system, and (2) the number of job categories responsible for drug transport. The drug preparation stage had the highest average contamination. Those hospitals that had two or more drug transport job categories had higher levels of surface contamination. Neither the reported handling of CP prior to wipe sampling nor the cleaning of surfaces appeared to be associated with contamination. © 2013 JOEH.


Wong I.S.,University of British Columbia | McLeod C.B.,University of British Columbia | Demers P.A.,Occupational Cancer Research Center
Scandinavian Journal of Work, Environment and Health | Year: 2011

Objective The aim of this study was to examine the risk of work injury across shift work types in a representative sample of Canadian workers. Methods We used the Survey of Labour and Income Dynamics to investigate trends in work injury by shift type between 1996-2006. Work injury was defined by receipt of workers' compensation. Logistic regression was used to estimate the risk between shift type and worker injury after adjusting for potential confounders. Results The rate of work injury decreased overall between 1996-2006, but did not decline for night shift workers. Night shift work was associated with work injury for women [odds ratio (OR) 2.04, 95% confidence interval (95% CI) 1.13-3.69] and men (OR 1.91, 95% CI 1.21-3.03), while rotating shift work was associated with work injury for women (OR 2.29, 95% CI 1.37-3.82). The excess risk of work injury attributed to shift work was 14.4% for women and 8.2% for men based on population attributable fraction estimates. Conclusions Rotating and night shift workers appear to have a higher risk of work injury, particularly among women. Regulatory agencies and employers need to identify and mitigate factors that give rise to increased work injury among these types of shift workers.


Hystad P.,University of British Columbia | Demers P.A.,Occupational Cancer Research Center | Johnson K.C.,Public Health Agency of Canada | Carpiano R.M.,University of British Columbia | Brauer M.,University of British Columbia
Epidemiology | Year: 2013

BACKGROUND: There is accumulating evidence that air pollution causes lung cancer. Still, questions remain about exposure misclassification, the components of air pollution responsible, and the histological subtypes of lung cancer that might be produced. METHODS: We investigated lung cancer incidence in relation to long-term exposure to three ambient air pollutants and proximity to major roads, using a Canadian population-based case-control study. We compared 2,390 incident, histologically confirmed lung cancer cases with 3,507 population controls in eight Canadian provinces from 1994 to 1997. We developed spatiotemporal models for the whole country to estimate annual residential exposure to fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) over a 20-year exposure period. We carried out a subanalysis in urban centers, using exposures derived from fixed-site air pollution monitors, and also examined traffic proximity measures. Hierarchical logistic regression models incorporated a comprehensive set of individual and geographic covariates. RESULTS: The increase in lung cancer incidence (expressed as fully adjusted odds ratios [ORs]) was 1.29 (95% confidence interval = 0.95-1.76) with a ten-unit increase in PM2.5 (μg/m), 1.11 (1.00-1.24) with a ten-unit increase in NO2 (ppb), and 1.09 (0.85-1.39) with a ten-unit increase in O3 (ppb). The urban monitor-based subanalyses generally supported the national results, with larger associations for NO2 (OR = 1.34; 1.07-1.69) per 10 ppb increase. No dose-response trends were observed, and no clear relationships were found for specific histological cancer subtypes. There was the suggestion of increased risk among those living within 100 m of highways, but not among those living near major roads. CONCLUSIONS: Lung cancer incidence in this Canadian study was increased most strongly with NO2 and PM2.5 exposure. Further investigation is needed into possible effects of O3 on development of lung cancer. Copyright © 2013 by Lippincott Williams & Wilkins.


Neil-Sztramko S.E.,University of British Columbia | Pahwa M.,Occupational Cancer Research Center | Demers P.A.,Occupational Cancer Research Center | Demers P.A.,University of Toronto | And 2 more authors.
Scandinavian Journal of Work, Environment and Health | Year: 2014

Objectives Associations between shift work and chronic disease have been observed, but relatively little is known about how to mitigate these adverse health effects. This critical review aimed to (i) synthesize interventions that have been implemented among shift workers to reduce the chronic health effects of shift work and (ii) provide an overall evaluation of study quality. Methods MeSH terms and keywords were created and used to conduct a rigorous search of MEDLINE, CINAHL, and EMBASE for studies published on or before 13 August 2012. Study quality was assessed using a checklist adapted from Downs & Black. Results Of the 5053 articles retrieved, 44 met the inclusion and exclusion criteria. Over 2354 male and female rotating and permanent night shift workers were included, mostly from the manufacturing, healthcare, and public safety industries. Studies were grouped into four intervention types: (i) shift schedule; (ii) controlled light exposure; (iii) behavioral; and, (iv) pharmacological. Results generally support the benefits of fast-forward rotating shifts; simultaneous use of timed bright light and light-blocking glasses; and physical activity, healthy diet, and health promotion. Mixed results were observed for hypnotics. Study quality varied and numerous deficiencies were identified. Conclusions Except for hypnotics, several types of interventions reviewed had positive overall effects on chronic disease outcomes. There was substantial heterogeneity among studies with respect to study sample, interventions, and outcomes. There is a need for further high-quality, workplace-based prevention research conducted among shift workers. © Scandinavian Journal of Work, Environment & Health.


Kirkham T.L.,University of British Columbia | Koehoorn M.W.,University of British Columbia | Davies H.,University of British Columbia | Demers P.A.,Occupational Cancer Research Center
Annals of Occupational Hygiene | Year: 2011

Objectives: To characterize exposures to noise and carbon monoxide (CO) among firefighters in British Columbia, Canada.Methods: Subjects were recruited from 13 fire halls across three municipalities in Metro Vancouver. Personal full-shift noise and CO samples were collected using datalogging noise dosimeters and CO monitors on both day and night shifts. Determinants of exposure (DoE) information were recorded by trained research staff and hygienists through direct observation during the measurement period.Results: In total, 113 noise and 156 CO samples were collected from 45 male firefighters, aged 41.0 ± 7.2 years with 14.2 ± 9.0 years of experience. Mean Leq and peak noise levels were 81.1 ± 4.8 dBA and 137.1 ± 5.2 dB, respectively; 45% of samples exceeded occupational limits. Noise levels were significantly greater on day shifts, among firefighters in non-supervisory jobs, for those working on engine and rescue trucks, by number of emergency calls they attended and in particular for motor vehicle accident (MVA) and building alarms calls, if subjects worked near or used fire equipment, or if they participated in active firefighting training activities. Full-shift and peak CO levels were 1.0 ppm [geometric mean (GM) = 0.7, geometric standard deviation (GSD) = 1.8] and 42.9 ppm (GM = 9.95, GSD = 5.6), respectively; 1% of CO samples exceeded occupational limits. Both full-shift and peak CO levels were significantly correlated by number of MVAs and building alarms calls.Conclusions: Our results show that firefighters may be at an increased risk of exposure to high noise levels, but CO exposures were lower than anticipated. Additional exposure studies are needed to confirm our results and to better understand the DoE to noise and CO among this occupational group. © The Author 2011.


Blair A.,U.S. National Cancer Institute | Blair A.,Occupational Cancer Research Center | Marrett L.,Occupational Cancer Research Center | Beane Freeman L.,U.S. National Cancer Institute
Environmental Health: A Global Access Science Source | Year: 2011

Studies of occupational exposures have made major contributions to our understanding of human carcinogenesis. About one third of the factors identified as definite or probable human carcinogens were first investigated in the workplace and these exposures exact a considerable toll on working populations. There are many additional workplace exposures that are suspect carcinogens that require further evaluation to ensure a safe work environment. Information from occupational investigations is also relevant to the general population because many occupational exposures can be found outside the workplace. Much of our understanding about occupational cancer has been obtained from studies largely composed of white men in developed countries. The movement of industry from developed to developing countries underscores the need for future investigations to include more diverse populations. © 2011 Blair et al.

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