Occupational Disease

Print Content - Version imprimable


Occupational diseases are caused by exposure to physical, chemical, or biological agents in the workplace. This chapter provides an overview of allowed occupational disease claims registered at the WSIB over the past 10 years for Schedule 1 and 2.

Between 2008 and 2017, the WSIB allowed about 130,000 occupational disease claims which accounted for over $940 million in benefit costs*. As occupational disease includes a broad spectrum of conditions, we have grouped these claims into four major categories: long latency illness, noise induced hearing loss, chronic exposures and effects, and acute exposures and effects.

*Benefit costs represent the life-to-date costs associated with the claim as of March 31, 2018.


Long latency illness claims

Many occupational diseases do not develop until long after a harmful exposure took place. Long latency illnesses can involve a delay of many years between the period of exposure to a disease-causing agent and the appearance of disease symptoms. While long latency claims account for only 3 per cent of all allowed occupational diseases registered at the WSIB between 2008 and 2017, they account for the largest proportion of allowed benefit costs and include some of the most serious illnesses. One example is mesothelioma, which is a cancer of the pleura or peritoneum that can develop today from exposure to asbestos decades ago.

Pleural plaques, mesothelioma, lung cancer, asbestosis, and chronic obstructive pulmonary disease are the five leading diagnoses, which account for 70 per cent of all allowed long latency illness claims over the past 10 years. The leading causal agent for these diagnoses is asbestos.

The five leading sectors are construction, Schedule 2, manufacturing, primary metals, and municipal with construction accounting for 27 per cent of allowed long latency claims. 

Noise induced hearing loss claims

Noise induced hearing loss (NIHL) is a permanent loss of hearing, usually in both ears, resulting from inner ear damage due to prolonged, continuous, or intermittent hazardous noise exposure. This type of hearing loss is a cumulative process that develops over many years. As a result, noise induced hearing loss often does not become apparent until workers are older and often retired from the workforce.

Allowed noise induced hearing loss claims registered between 2008 and 2017 accounted for about 24 per cent of all allowed occupational disease claims. The top five sectors for allowed noise induced hearing loss claims over the last 10 years are: manufacturing, construction, Schedule 2, services, and transportation.


Claims for chronic exposures and effects

Occupational diseases in this category involve medical conditions that develop gradually over time from prolonged or chronic exposures in the workplace. Symptoms often have a temporal association with workplace exposures; the disease often becomes apparent while the individual is still working in the exposure environment.

Chronic exposures can occur through inhalation or skin absorption. Conditions like dermatitis and some respiratory diseases can be caused by chronic exposure to chemical or biological agents in the workplace. Allergy to latex is an example of a condition that can develop in workers exposed to that agent in the workplace. Dermatitis claims make up 44 per cent of allowed chronic exposures and effects cases.

Workers aged 25 to 54 years form the majority of allowed chronic exposures and effects claims over the past 10 years. The leading industry sector was schedule 2, followed closely by services. There is a relatively even split in the percentage of allowed claims for male (56%) and female workers (44%) in this category.

Claims for acute exposures and effects

Acute exposures and effects describe medical conditions that arise immediately after exposure to a chemical, biological or physical agent in the workplace. Between 2008 and 2017, these claims accounted for nearly two-thirds of allowed occupational disease claims while still having the smallest proportion of benefit costs. Exposures to infectious disease from needle sticks or bites account for the majority of these claims.

Health care and Schedule 2 were the two leading industry sectors in the last decade. These two sectors combined accounted for 41 per cent of allowed claims for acute exposures and effects.