Canadian Occupational Safety

24 Canadian Occupational Safety | www.cos-mag.com C laude Fortin was an electri- cian in the mining industry. He worked for Iamgold – Mine Doyon for 16 years. In 2005, in his mid-forties, he was diagnosed with lung cancer. He had lived a healthy life, was active and a non-smoker. His doctors concluded he was suffering from an occupational disease. The cancer had been caused by the diesel emissions produced by the heavy equipment that surrounded him every day at work. Quebec's Commission de Santé et Sécurité du Travail (now the Com- mission des normes, de l'équité, de la santé et de la sécurité du travail), the provincial health and safety regulator, agreed with the doctors and granted Fortin compensation for an occupa- tional injury. In 2012, three years after Fortin's death, the Superior Court of Quebec maintained the regulator's decision. It is believed to be the fi rst ruling that fatal lung cancer in an underground miner had been caused by exposure to diesel exhaust. Underground miners face serious health risks from exposure to diesel particulate matter, contained in the exhaust released from the heavy die- sel-powered vehicles and equipment used in mines for hauling, drilling and transporting personnel. The particu- late matter can cause irritation of the respiratory tract within a few minutes, while long-term exposure can lead to chronic health problems, includ- ing cancer. Mining operators need to know how to assess the hazard level of diesel particulate within their mines and how to limit worker exposure to this serious health risk. Diesel particulate matter is a com- ponent of diesel exhaust and is a complex mixture of soot particles that contain ash, carbon, metallic abra- sion particles, sulphates and silicates. Diesel particulate, which is visible as black smoke, is extremely fi ne. It is easily inhaled and can penetrate deep into the lungs. Inhaling diesel exhaust causes both short- and long-term adverse health effects, says Cheryl Peters, co- principal investigator with Burnaby, B.C.-based Carex Canada. In the short-term and in high-exposure situ- ations, like confi ned spaces, inhaling exhaust produces acute symptoms such as headaches, light-headedness and irritation of the respiratory system and nasal passages. Long-term expo- sure increases risk of cardiovascular disease and can lead to lung cancer. Diesel particulate matter is a known human carcinogen. "Diesel particulate is one exposure where it's so clear that it's basically one job: underground mining. Because the miners are working in areas where diesel exhaust can't disperse easily, they have this risk factor that's so dif- ferent from other workers who are exposed to diesel," Peters says. According to Carex fi gures on diesel particulate matter exposure in Canada, there are approximately 11,000 under- ground production and development miners and 2,500 underground mine service and support workers that are exposed at a high-exposure level. The best way to reduce worker expo- sure to diesel particulate is to control it at the source, says Michel Grenier, program manager for the Alterna- tive Energy Technology program at CanmetMINING, Natural Resources Canada, in Ottawa. Diesel particulate is extremely small and fi ne and hard to capture once it becomes airborne. Unlike mineral dust, diesel particulate matter does not settle quickly to the ground and a portion of diesel particu- late will likely remain airborne all the way to the mine exhaust. There are several engineering and administrative controls that can be used to reduce miners' exposure. For example, mine operators can purchase clean-engine technology, such as modern engines and cleaner- burning diesel fuels. In the past 12 to 15 years, engines have been developed that produce much lower amounts of diesel particulate and gaseous emis- sions. The United States Environmental Protection Agency's "Tier 4" emission standards have resulted in engines that are 95 to 98 per cent cleaner now than they were 15 years ago. Tier 4 engines use an ultra low sulphur fuel and reduce particulate matter and nitrogen oxide (NOx), says Marcel Demers, sales manager at Lively, Ont.-based Industrial Fab- rication, which manufactures electric mine utility vehicles. "So it's keeping a close watch on your NOx. Sometimes, I've seen with the Tier 4 or some of the diesel par- ticulate fi lters, you save on your diesel particulate matter, but your NOx read- ing goes up," Demers says. "So you have to watch that closely." CanmetMINING has a list of diesel engines approved for use in under- ground mines and provides a guide Reducing exposure to diesel particulate can help prevent chronic health problems, including lung cancer, in miners By Linda Johnson

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