Abstract Although several occupational exposures have been linked to the risk of COPD; limited data exists on sex-specific differences. This study aimed to identify at-risk occupations and sex differences for COPD risk. Cases were identified in a large surveillance system established through the linkage of former compensation claimants’ data (non-COPD claims) to physician visits, ambulatory care data, and hospital inpatient data (1983–2020). Cox proportional hazard models were used to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CI) for occupation groups (occupation at time of claim), stratified by sex. HRs were indirectly adjusted for cigarette smoking using another population dataset. A total of 29,445 male and 14,693 female incident cases of COPD were identified. Increased risks were observed in both sexes for construction (HR male 1.15, 95% CI 1.12–1.19; HR female 1.54, 95% CI 1.29–1.83) transport/equipment operating (HR male 1.32, 95% CI 1.28–1.37; HR female 1.53, 95% CI 1.40–1.68) farming (HR male 1.23, 95% CI 1.15–1.32; HR female 1.19, 95% CI 1.04–1.37) and janitors/cleaners (HR male 1.31, 95% CI 1.24–1.37; HR female 1.40, 95% CI 1.31–1.49). Increased risks were observed for females employed as chefs and cooks (HR 1.44, 95% CI 1.31–1.58), bartenders (HR 1.38, 95% CI 1.05–1.81), and those working in food/beverage preparation (HR 1.34, 95% CI 1.24–1.45) among other occupations. This study demonstrates elevated risk of COPD among both male and female workers potentially exposed to vapours, gases, dusts, and fumes, highlighting the need for occupational surveillance of COPD.
The coronavirus disease 2019 (COVID-19) pandemic, caused by the SARS-CoV-2 virus, has rapidly evolved since late 2019, due to highly transmissible Omicron variants. While most Canadian paramedics have received COVID-19 vaccination, the optimal ongoing vaccination strategy is unclear. We investigated neutralizing antibody (NtAb) response against wild-type (WT) Wuhan Hu-1 and Omicron BA.4/5 lineages based on the number of doses and past SARS-CoV-2 infection, at 18 months post-initial vaccination (with a Wuhan Hu-1 platform mRNA vaccine [BNT162b2 or mRNA-1273]). Demographic information, previous COVID-19 vaccination, infection history, and blood samples were collected from paramedics 18 months post-initial mRNA COVID-19 vaccine dose. Outcome measures were ACE2 percent inhibition against Omicron BA.4/5 and WT antigens. We compared outcomes based on number of vaccine doses (two vs. three) and previous SARS-CoV-2 infection status, using the Mann-Whitney U test. Of 657 participants, the median age was 40 years (IQR 33–50) and 251 (42 %) were females. Overall, median percent inhibition to BA.4/5 and WT was 71.61 % (IQR 39.44–92.82) and 98.60 % (IQR 83.07–99.73), respectively. Those with a past SARS-CoV-2 infection had a higher median percent inhibition to BA.4/5 and WT, when compared to uninfected individuals overall and when stratified by two or three vaccine doses. When comparing two vs. three WT vaccine doses among SARS-CoV-2 negative participants, we did not detect a difference in BA.4/5 percent inhibition, but there was a difference in WT percent inhibition. Among those with previous SARS-CoV-2 infection(s), when comparing two vs. three WT vaccine doses, there was no observed difference between groups. These findings demonstrate that additional W https://www.covid19immunitytaskforce.ca/citf-databank/#accessing https://www.covid19immunitytaskforce.ca/citf-databank/#accessing uhan Hu-1 platform mRNA vaccines did not improve NtAb response to BA.4/5, but prior SARS-CoV-2 infection enhances NtAb response.
BackgroundWe examined the 11-month longitudinal antibody decay among 2-dose mRNA vaccinees, and identified factors associated with faster decay.MethodsThe study included samples from the CORSIP longitudinal observational study of paramedics in Canada. Participants were included if they had received two mRNA vaccines without prior SARS-CoV-2 infection and provided two blood samples post-vaccination. The outcomes of interest were quantitative SARS-CoV-2 antibody concentrations. We employed spaghetti and scatter plots (with kernel-weighted local polynomial smoothing curve) to describe the trend of the antibody decay over 11-months post vaccine and fit a mixed effect exponential decay model to examine the loss of immunogenicity and factors associated with antibody waning over time.ResultsThis analysis included 652 blood samples from 326 adult paramedics. Total anti-spike antibody levels peaked on the 21st day (antibody level 9,042U/mL) after the second mRNA vaccine dose. Total anti-spike antibody levels declined thereafter, with a half-life of 94 [95% CI: 70, 143] days, with levels plateauing at 295 days (antibody level 1021 U/mL). Older age, vaccine dosing interval <35 days, and the BNT162b2 vaccine (compared to mRNA-1273 vaccine) were associated with faster antibody decay.ConclusionAntibody levels declined after the initial mRNA series with a half-life of 94 days, plateauing at 295 days. These findings may inform the timing of booster vaccine doses and identifying individuals with faster antibody decay.
To pilot recruitment methods for bicycle delivery workers in Toronto, Canada and to assess workers' experiences with COVID-19 and personal protective equipment (PPE).This was a cross-sectional study. An online survey was deployed and advertised via social media with both paid and free postings in July and August of 2020. An incentive draw was used to motivate participation. These analyses summarized descriptive statistics of the sample and variables relevant to COVID-19.Complete responses were received from 35 participants. No participants reported a diagnosis of COVID-19, however four participants indicated experiencing symptoms. Most participants reported they used PPE, especially masks and/or respirators (97.1%) and 71.4% of participants indicated their employer provided them with PPE (masks or gloves). Participants expressed concern about precarious work and uncertainty about their own COVID-19 exposure risk.Bicycle delivery workers are a precarious working population that may be difficult to reach for research recruitment purposes. Given their essential role in deliveries during the COVID-19 pandemic, further work is needed to characterize exposures and risks in this population.
To characterize exposures to noise and carbon monoxide (CO) among firefighters in British Columbia, Canada.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.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 L(eq) 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.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.
Previous results suggest that COVID-19 adversely impacted a number of health and coping measures among Canadian paramedics, particularly females. Estimated prevalence for meeting screening criteria for mental health disorders and suicidal thoughts were higher than previously reported.
Objectives
To provide an update on the impact of the COVID-19 pandemic on the wellbeing of Canadian paramedics with the inclusion of an additional year of participant data.
Methods
Self-reported questionnaire data was collected from paramedics across five Canadian provinces as part of the COVID-19 Occupational Risks, Seroprevalence and Immunity among Paramedics (CORSIP) project. Validated psychological assessment tools were used to screen for major depressive disorder (MDD, PHQ-9 questionnaire) and probable post-traumatic stress disorder (PTSD, PC-PTSD-5 questionnaire). Satisfaction with life (SWL) scores were adapted from validated Canadian Census questions and confirmed by reliability analysis. All measures were compared before versus during the pandemic using Wilcoxon signed-ranked, Cliff's d, and differences in proportions tests where appropriate.
Results
Questionnaires from an additional 1662 recruited paramedics were included, now totaling 3568 participants. Prevalence meeting screening criteria remained similar for MDD (31.6%) and PTSD (41.4%), with PTSD risk continuing to not be impacted by COVID-19. Paramedics continued to report higher median SWL scores (20 vs. 17, p<.001) prior to the pandemic, with a large effect size (d=0.58) that suggests a greater probability of reporting higher SWL prior to COVID-19. Suicidal ideation (i.e., 'thoughts that you would be better off dead, or of hurting yourself in some way') was reported by 9.0% of paramedics, which was consistent with original findings.
Conclusion
Original findings appear stable with the addition of another year of participant data. Future analyses will be employed to investigate whether health and satisfaction measures differed between the original cohort and added participants by adjusting for questionnaire responses with respect to the pandemic timeline.
Brian J. Boyarsky, MD; William A. Werbel, MD; Robin K. Avery, MD; Aaron A. R. Tobian, MD, PhD; Allan B. Massie, PhD; Dorry L. Segev, MD, PhD; Jacqueline M. Garonzik-Wang, MD, PhD
Diesel engine exhaust (DEE) is a known lung carcinogen and a common occupational exposure in Canada. The use of diesel-powered equipment in the construction industry is particularly widespread, but little is known about DEE exposures in this work setting. The objective of this study was to determine exposure levels and identify and characterize key determinants of DEE exposure at construction sites in Ontario.Elemental carbon (EC, a surrogate of DEE exposure) measurements were collected at seven civil infrastructure construction worksites and one trades training facility in Ontario using NIOSH method 5040. Full-shift personal air samples were collected using a constant-flow pump and SKC aluminium cyclone with quartz fibre filters in a 37-mm cassette. Exposures were compared with published health-based limits, including the Dutch Expert Committee on Occupational Safety (DECOS) limit (1.03 µg m-3 respirable EC) and the Finnish Institute of Occupational Health (FIOH) recommendation (5 µg m-3 respirable EC). Mixed-effects linear regression was used to identify determinants of EC exposure.In total, 149 EC samples were collected, ranging from <0.25 to 52.58 µg m-3 with a geometric mean (GM) of 3.71 µg m-3 [geometric standard deviation (GSD) = 3.32]. Overall, 41.6% of samples exceeded the FIOH limit, mostly within underground worksites (93.5%), and 90.6% exceeded the DECOS limit. Underground workers (GM = 13.20 µg m-3, GSD = 1.83) had exposures approximately four times higher than below grade workers (GM = 3.56 µg m-3, GSD = 1.94) and nine times higher than above ground workers (GM = 1.49 µg m-3, GSD = 1.75). Training facility exposures were similar to above ground workers (GM = 1.86 µg m-3, GSD = 4.12); however, exposures were highly variable. Work setting and enclosed cabins were identified as the key determinants of exposure in the final model (adjusted R2 = 0.72, P < 0.001). The highest DEE exposures were observed in underground workplaces and when using unenclosed cabins.This study provides data on current DEE exposure in Canadian construction workers. Most exposures were above recommended health-based limits, albeit in other jurisdictions, signifying a need to further reduce DEE levels in construction. These results can inform a hazard reduction strategy including targeted intervention/control measures to reduce DEE exposure and the burden of occupational lung cancer.
