Background

Excavation is a process that can produce unforeseen hazardous exposures to workers. Multiple clients have approached OHCOW to evaluate the risks posed during excavations. After two in-depth reviews, a generic report was prepared to help identify the risks of this activity. The two most significant risks are:

1. fungal infections,
2. chemical exposures if the soil / site being excavated is contaminated.

Intervention

OHCOW produced a report summarizing the main occupational risks of the fungal infections blastomycosis (affecting heart, skin, bones and other organs) and histoplasmosis (affecting lungs) posed by the activity of excavation.

Blastomycosis is an infection with a fungus called Blastomyces. This fungus normally grows in very wet soils and in wet rotten wood. In Ontario, Blastomyces is naturally occurring around lakes and rivers. It’s estimated that about half of blastomycosis infections are asymptomatic, making it a challenge to estimate the amount of infected. For those who do have symptoms, it often mimics a fever, with cough, body ache, and muscles ache. Severe respiratory dress including pneumonia can also occur. Workers in or near wet soil near waterways are at risk, including construction workers, excavation workers, forestry workers, environmental surveyors, and landscapers.

Histoplasmosis is an infection with the fungus Histoplasma capsulatum, which can grown anywhere in Ontario. The highest case rates are in Toronto and along the St. Lawrence River Seaway. Most of these infections are minor or asymptomatic (as many as 75%). For those who do have symptoms, it is usually mild or may be “flu-like”. In a small number of infections, individuals will get severe respiratory stress. Workers who are at risk of Histoplasmosis are those who work with or in soil such as excavation workers and forestry workers, as well as those who work with or near bird or bat droppings, such as demolition workers and farmers.

Chemical contaminants in the soil are present if past industrial or other exposures occurred. The hazards in the soil will vary depending on both its natural contents and the site’s former uses. Soil can naturally contain harmful levels of arsenic and lead, and past industrial or farming uses can result in soil containing asbestos, corrosive agents, insecticides or pesticides, lead, metals / metalloids, petroleum-based chemicals, and volatile organic compounds (VOCs). Prior to undertaking any excavation, surveying is recommended to assess risks.

OHCOW Impact

OHCOW prepared a report on the common risks that can occur from soil disturbances such as excavations. That said, the information on Blastomycosis, Histoplasmosis, and Chemical Contaminants can be applied to any occupation where the soil may be disturbed. The report is available for free download.

OHCOW's work with Pipefitters is ongoing. Lead exposure from pipework is the major concern. Workers continue to be exposed to dust on their hands and clothes, as well as contaminated surfaces, during (and after) pipefitting tasks. Leaded pipe sealant is still being used by pipefitters as well as other labourers across Ontario.

What did we accomplish this year?

• Preparations are well underway to test 40 workers with an Xray technology able to detect lead in bone, the L-XRF. This is significant as Canada currently has no XRF testing. Funding and qualified researchers to conduct the tests are being procured.
• A booklet has been published outlining lead exposure for specific workplaces and distributed to the workforce at the union Local level this year. Further distributions for this booklet are planned.
• Presentations have been conducted to Union members at an OHCOW Medical Rounds to let all staff understand the broad scope of this issue.
• A virtual conference for the American Association of Occupational Health Nurses (AAOHN) was conducted, given that the many US companies operate in Ontario.
• A publication is being considered by the AAOHN journal on the lead exposure in pipefitters
• An abstract for a poster consideration by the Association of Occupational Health Professions in Healthcare (AOHP) has been started.

What’s coming next?

• Broadening the lead booklet distribution
• Presentations will include a webinar that the Ministry of Labour, Immigration, Training and Skills Development (MLITSD) can attend. This will be initiated by the union.
• Updating OHCOW’s old lead brochure.
• Continuing to work with a researcher for XRF testing for more workers.
• Finalizing a health questionnaire for health care professionals to use in taking a lead history.
• Consulting with lead exposure patients whose claims have been denied.

Sometimes factors need to be considered additively rather than individually — in this case exposure to the mineral cadmium combined with night shift work.

Background

This summary concerns a worker who was diagnosed with prostate cancer and claimed entitlement to benefits through WSIB. The worker attributed his cancer to occupational exposure at General Electric's Peterborough facility, where he worked from 1961 to 1998 as a tool and die maker. His duties involved fabricating metal dies, molds, machine tools, cutting tools, gauges, and other items used in the manufacturing processes. Approximately 10% of his time was spent brazing, a process for joining metal pieces by soldering.

His claim was denied on the basis there was not enough evidence to show a causal relationship between workplace exposure and the worker’s cancer. Prostate cancer is not a scheduled disease or considered an occupational disease by WSIB. As such, the claim was adjudicated on an individual circumstance basis.

Intervention

OHCOW hygienists sought to support this claim by

1. characterizing his occupational exposures to arsenic, cadmium and working night shifts;
2. adjusting the era of employment with the era of the exposure data; and
3. highlighting a possible additive effect between multiple carcinogens for the same target organ.

The hygienists interviewed the worker and reviewed information from the claim file, such as the worker’s employment history, past workplace inspection reports and all employer-produced occupational hygiene documents. Relevant scientific technical reports centering on cadmium was reviewed. From all this data, an occupational hygiene report was created containing concise hygiene information and opinion for an appeal submission to the WSIB.

The OHCOW review re-examined the agents associated with prostate cancer, referring to the most current list of carcinogens from the International Agency for Research on Cancer (IARC). The review noted that the worker's night shift work and rotating shifts had not been considered by the WSIB in the initial assessment.

OHCOW hygienists identified technical documents from the time period that the worker was at GE. NIOSH Health Hazard Evaluations (HHE) are technical documents which contain detailed analyses of workplace health hazards, including data collection, exposure assessments, and advice on how to improve workplace conditions. The hygienists searched the HHE database using the key word “cadmium” and limited the search to the era of interest. Technical documents were reviewed to determine applicability and relevance to the worker’s job descriptions. The evidence suggested that the worker could have been exposed to higher levels of cadmium then determined by the WSIB during his initial work period, specifically in the 60s and 70s. An additional finding from this review was that all employees in an area of brazing could be indirectly exposed to noteworthy levels of cadmium, from the associated solder.

A review prepared by Dr. Paul Demers for the Ontario Ministry of Labour, Immigration, Training and Skills Development in 2020 concluded that carcinogens for the same target organ are presumed additive unless there is evidence to the contrary. OHCOW suggested that it was reasonable to conclude the worker was exposed to several agents (i.e., night shift and cadmium) that are positively associated with prostate cancer, and that these exposures may have been at least additive.

OHCOW Impact

OHCOW was able to introduce a new agent associated with prostate cancer in the form of night shift work. OHCOW identified that the worker’s exposure to cadmium should be adjusted upwards since the era of employment was inconsistent with the era of the exposure data. Further, the worker’s overall cancer risk calculation was strengthened by suggesting that cadmium and night shift should be considered additively rather than viewed as individual exposures.

Literature about IPF has been updated and can affect previously denied claims that are now being appealed.

Background

OHCOW was contacted by a union representative to evaluate the risk of idiopathic pulmonary fibrosis (IPF) in a miner. This individual was diagnosed at the age of 59, several years after retiring from mining. The initial WSIB claim was denied. OHCOW prepared a report reviewing the miner’s exposures, which the advocate submitted to the Workplace Safety and Insurance Board (WSIB) Appeals Resolution Officer. The appeal was denied. As this process took years, OHCOW was approached again to prepare an updated report reviewing the risks of occupational IPF. The advocate submitted the new report to the Workplace Safety and Insurance Appeals Tribunal (WSIAT).

The advocate asked if IPF could be related to occupational exposures. By definition, IPF is idiopathic, arising spontaneously, with no known risks factors or causal agents. However, a review of the peer vetted literature found there are occupational agents that increase the risk of developing IPF by a statistically significant margin.

Intervention

Two OHCOW Occupational Hygienists reviewed the updated literature. Four large reviews concluded that there are occupational risk factors associated with an increased risk of IPF. In addition, the American Thoracic Society and the European Respiratory Society produced a joint statement concluding that 26% of IPF diagnoses are caused by occupational exposures to vapours, gases, dusts, and fumes (VGDF).

The OHCOW Occupational Hygienists conducted interviews with the miner to verify the employer-provided job history and to determine what specific tasks he performed. The miner identified ventilation issues and lack of personal protective equipment (PPE), including respiratory protection equipment (RPE), over the time he worked there. The Hygienists then reviewed the exposure monitoring data provided by the miner’s employer, and exposure monitoring data in the Ontario Mining Exposure Database (OMED), to estimate the miner’s historical exposures based on the exact mines he worked in, or in similar mines. The process of estimating a workers’ past exposures is described as a retrospective exposure assessment.

The Hygienists turned to the peer-reviewed occupational epidemiology literature. Estimated risks of IPF were identified based on occupational epidemiological data that compared the exposure range the miner would have had to the increased risk of IPF. Based on the literature, they concluded it was probable that the miner’s historical exposures to asbestos, diesel exhaust (DE) (measured as elemental carbon (EC)), mixed metal dusts, nickel, respirable particulate, and silica, increased the miner’s risk of developing IPF.

A report was prepared estimating the miner’s past exposures and summarizing the increased risks of IPF from these exposures, as published in the peer-reviewed literature. The advocate provided this report to WSIAT.

OHCOW Impact

WSIAT reviewed the materials provided by the advocate and by the employer.WSIAT allowed the appeal.

Background

Recognizing the impact of this policy update, we established a dedicated working group comprising an Occupational Hygienist, an Occupational Health Coordinator, and a Legal Representative to provide expertise and guidance in navigating this updated framework in policy 16-02-11 (October 1, 2024).

Our primary focus is to review previously denied GI cancer claims and assess them within the framework of the updated policy. This involves conducting detailed re-examinations of work and exposure histories to determine if these claims meet the revised asbestos exposure criteria. By leveraging our expertise in occupational hygiene, and legal lens we are ensuring that each case is thoroughly reviewed.

Through this initiative, OHCOW is actively collaborating with workers, families, and advocates to facilitate the reconsideration of denied GI cancer claims. Our efforts are aimed at ensuring that those who have suffered occupational asbestos exposure leading to GI cancers receive the ability to have their claims re-adjudicated by the WSIB.

As we move forward, OHCOW remains committed to advocating for workplace health and safety, supporting workers through complex files, and addressing occupational disease with a science-based, worker-centered approach.

We want to hear from you! 

• Did you or your family member have a previously denied WSIB GI cancer claim and may have had asbestos exposure?
• Are you a worker representative and unsure if one of your files falls within the WSIB’s updated GI cancer framework?
• Do you have concerns about the impact of your work on your health?

Contact The Occupational Health Clinics for Ontario Workers (OHCOW)