Raising awareness of occupational asthma
Sadly, there is no cure for asthma.
Asthma kills approximately 500 Canadians each year, according to the Canadian Lung Association.
Asthma is a common condition most prevalent in childhood, but it often starts or reappears in adult life.
In Ontario, as many as one in five children and one in 10 adults suffer from asthma.
Recent studies indicate exposure to toxic environmental agents account for up to 4 per cent of all asthma cases.
Therefore, it is not surprising asthma rates have quadrupled over the past 20 years making it one of the most prevalent chronic conditions in Canada.
Studies in the U.S. and Japan show about five to 15 per cent of adult asthma cases are work-related. Inhaling fumes, vapours, gases, dust or other potentially harmful substances while on the job causes a condition known as occupational asthma (OA)
. Occupational asthma is the most frequently reported work-related respiratory disease in the world. Approximately 300 to 400 lost time claims are reported each year in Ontario alone, according to the Workplace Safety and Insurance Board (WSIB).
David Morrison knows firsthand what it’s like to have occupational asthma. For seven years the 53-year old former machinist was exposed to petroleum-based cutting fluids, which he used to cool his tools. “We built conveyors for the auto industry, and the work environment was always dusty and dirty with guys welding in the area next to me. There was also a constant cloud of aerated coolant mist which I couldn’t escape.”
Over the years, Morrison experienced coughing, sneezing and excess phlegm while at work. Eventually he had two serious respiratory attacks and was hospitalized. After researching his condition, Morrison visited Windsor’s Occupational Health Clinics for Ontario Workers (OHCOW) for a consultation, where he was diagnosed with occupational asthma.
Says Morrison, “Having asthma is hell every hour of every day.” He adds, “I feel like I have a constant weight on my chest. My lungs are inflamed and I find it extremely difficult to breathe. In effect, I have a chemical burn in my lungs.” Irritants such as diesel exhaust or perfume make his situation worse. As a result Morrison has to carry his medication everywhere he goes, even though he says it gives him only limited relief.
Morrison is no longer able to work as a machinist. His condition is such that he, like many other workers, has been forced to leave his job and pursue another career.
No job is immune from occupational asthma. There are hundreds of occupations at risk including bakers, health care workers, electronics workers, laboratory workers, animal handlers, grain handlers, foam manufacturers, plastics factory workers, automotive parts manufacturing workers, painters, woodworkers, detergent manufacturing workers, and pharmaceutical workers. And the list goes on.
Occupational asthma is triggered by certain substances (about 250) in the workplace, which act as allergens or irritants. Examples of these substances include isocyanates, flour, latex, animal dander, colophony, epoxy-resin, wood dust (especially from Western red cedar trees), toluene, formaldehyde, solvents, and insecticides to name a few.
When workers inhale these harmful agents the airways of the lungs become aggravated over time making the airways extra-sensitive/twitchy (hyper-responsive) and inflamed (red and swollen). It is difficult to breathe when the airways are swollen because oxygen has trouble getting into the lungs and carbon dioxide has trouble being exhaled resulting in the symptoms described above.
Commonly, work-related asthma symptoms worsen throughout the workweek, improve on the weekends and holidays and only recur when the worker returns to the job. It may appear for the first time in previously healthy workers within months or even years of exposure. However, in the case of irritants the effects can be seen immediately within 24 hours of exposure to high concentrations of the chemical.
WSIB’s Research Advisory Council (RAC) program recently funded a study of occupational asthma among medical radiation technologists. Says Lisa McCaskell, senior health and safety officer with Ontario Public Service Employees Union (OPSEU) and co-investigator in the study, “The study validated what the union had long suspected. This particular work group has developed occupational asthma from processing X-ray films in poorly ventilated darkrooms, thus exposing them to toxic substances such as acetic acid, formaldehyde, glutaraldehyde and sulfur dioxide. Also, they dealt with chemical spills without adequate respiratory equipment or protective clothing.”
Adds McCaskell, “The good news is many of these facilities have substituted chemical film processing with digital processing which is safer and will decrease the risk of occupational asthma in future.”
Other workplaces have also introduced safer, less toxic chemicals in the workplace to eliminate or reduce occupational asthma. For example, automotive workers in Windsor, Ontario, have successfully replaced a petroleum-based coolant with canola-based oil. Health care workers are substituting latex rubber gloves with nitrile, vinyl or neoprene gloves, which are less toxic. However, it is not always easy to substitute toxic substances with safer ones (e.g. Isocyanates used in automobiles). In those instances, at least in the short term, other strategies are necessary.
One basic strategy is utilizing the right to know. According to Gary Liss, a well-known occupational asthma researcher at the Gage Occupational and Environmental Health Unit of the University of Toronto, workers should study the Material Safety Data Sheets (MSDS) in the workplace. Says Liss, “It’s important to know about the chemicals in the workplace so one can implement appropriate controls.”
Adds Liss, “It is also important for workers to inform their physicians about the chemicals or substances they work with or are exposed to in the workplace so they can make educated decisions about treatment and management of the patient.”
“This said, physicians need to be trained that any adult patient they see with new-onset asthma should be diagnosed immediately with occupational asthma unless a specialist proves otherwise,” says Liss.
Another key method of preventing occupational asthma is education. Says Mark Parent, director of OHCOW, Windsor, “Over the past few years, our staff have come to realize occupational asthma is severely under-recognized. Our plan is to educate the working public on this and other emerging respiratory diseases.”
To that end, the Windsor clinic has targeted small, high-risk industries where exposures to respiratory irritants and sensitizers occur. They launched several projects aimed at unionized and non-unionized industries such as auto body repair shops, agricultural settings and acrylic nail salons. Three brochures related to these topics have been produced and mailed out to hundreds of workplaces in Southwestern Ontario which is a highly industrialized area. Related workshops (which have been videotaped for a wider audience) have also been delivered in the community.
OHCOW’s Toronto office has launched a similar initiative. The project funded by Ministry of Labour and Ministry of Health, and in partnership with the Industrial Accident Prevention Association (IAPA), has provided in-house presentations to some 500 joint health and safety committees.
Says Mary Cook, Managing Director of OHCOW, “We are very pleased at the progress we have made in our outreach program. We hope to someday slow down this rapidly spreading disease and give workers the fresh air they so desperately need to live.”
The Workers Health & Safety Centre provides comprehensive training programs to identify, assess and control a variety of hazards that give rise to occupational asthma. To learn more contact a Workers Centre near you.