Acute myocardial infarction (AMI) is the medical term for a heart attack and occurs when a blood clot forms around plaque in the arteries, blocking supply of blood to the heart [1]. Approximately 200 heart attacks per 100,000 adults over the age of 20 occur in Canada each year [2]. AMI risk is primarily attributed to lifestyle factors including smoking, poor diet, alcohol consumption, obesity, physical inactivity, and recreational drug use [3]. Evidence for occupational risk factors for AMI are inconsistent, but certain occupations have been associated with higher cardiovascular risk [4].
Possible occupational risk factors [5-10]
Almost 25,000 cases of AMI were diagnosed among workers in the ODSS between 2007 and 2016. Increased AMI risk was associated with employment in a large variety of occupation groups in the ODSS. This reflects the variety of possible occupational risk factors. Future studies are necessary to examine which work-related hazards might be contributing to these excess risks.
In general, AMI risk was higher among blue-collar workers compared to white-collar workers, and the most consistently elevated risks were observed for workers in industry and occupation groups related to logging and wood production and mining with increased risks observed for some construction sector and textile processing groups.
Despite exposure to psychosocial stress and shiftwork, employment in some protective services occupations including firefighting and police was associated with reduced risk of AMI. The reduced risk observed for these workers may reflect the stringent health-related requirements enforced across these occupations. Another factor may be that workers with an accepted claim for compensation related to AMI were excluded from this analysis, so the association estimated by our approach may underestimate the true risk.
Wood-related industries and occupationsThe most consistent excess risks for AMI in the ODSS cohort were for workers in industry and occupations groups related to wood and wood processing. These workers may be exposed to a variety of AMI risk factors including noise, stress and vibrations. Inhalation of wood dusts may cause irritation and inflammatory responses that could contribute to cardiovascular disease [11]. An increased risk of AMI associated with high noise exposure has been seen in BC sawmill workers [9]. An increased risk of AMI has also been observed among a cohort of Swedish pulp and paper mill workers [12], and attributed to a combination of workplace exposures including dust, sulfur compounds, shiftwork and noise.
Forestry and logging
Wood products
Pulp and paper
Mining and quarryingIncreased risks for acute myocardial infarction and other cardiovascular disease have been previously observed for mining industry workers, with potential links to exposure to high levels of noise [13,14], vibration [15] and radon gas, particularly for uranium mining workers [16]. Diesel engine exhaust, a common exposure in mining, is also a potential cause of acute cardiovascular events [17]. While elevated risks were observed for some mining industry workers, risks among mining and quarrying occupations groups were generally only slightly increased.
ConstructionConstruction workers are exposed to loud noise [18] and vibrations in their work. Construction workers can also be exposed to crystalline silica dust and diesel engine exhaust. In the ODSS, increased risk of AMI was greatest among workers involved in excavating, grading and paving, who are exposure to a variety of occupational risk factors for AMI.
Textile manufacturing and processingIncreased risk of AMI was observed for workers employed in the leather and textile manufacturing industries and related occupations. Evidence regarding AMI risk factors for these workers is limited, but textile dust exposures [19] and exposure to bacterial endotoxin [20] have been previously suggested.
Rubber and plastics manufacturingIncreased AMI risk was observed among workers in the ODSS employed in rubber and plastic products fabrication. Plastic stabilizers frequently include cadmium, which has been posited to increase AMI risk through atherosclerosis [21]. A cohort study of British rubber factory workers found increased risk of cardiovascular deaths associated with exposure to N-nitrosomorpholine, rubber dust, rubber fumes and N-nitrosamines sum [22].
Other groupsExcess AMI risk was detected in the ODSS for a variety of occupation groups, which likely reflects the numerous risk factors for cardiovascular disease including both workplace and lifestyle factors.
For more details: Troke, N, Logar‐Henderson, C, DeBono, N, et al. Incidence of acute myocardial infarction in the workforce: findings from the Occupational Disease Surveillance System. Am J Ind Med. 2021; 1– 20.
Figure 1. Risk of acute myocardial infarction diagnosis among workers employed in each industry group relative to all others, Occupational Disease Surveillance System (ODSS), 1983-2016
Figure 2. Risk of acute myocardial infarction diagnosis among workers employed in each occupation group relative to all others, Occupational Disease Surveillance System (ODSS), 1983-2016
Table 1. Surveillance of Acute Myocardial Infarction: Number of cases, workers employed, and hazard ratios in each industry (SIC)
Table 2. Surveillance of Acute Myocardial Infarction: Number of cases, workers employed, and hazard ratios in each occupation (CCDO) group
