They are a central part of Northwest Coast aboriginal culture, not to mention the construction industry and provincial economy, but western red cedar trees — B.C.’s official tree — also cause serious lung problems for those who inhale their dust on the job.
Hans Brezina, 57, knows this too well. The Mission-area man happily worked in the forestry industry for three decades, but had to give it up a few years ago because of serious asthma.
“I had a mild form of asthma when I first went into tree cutting in 1984, but no one thought about whether these kinds of jobs would make it worse,” he said in an interview. The wheezy, frequently breathless Brezina is now waiting to hear about whether his long-term disability claim with WorkSafeBC will be approved. Although at least five per cent of tree fellers and mill workers develop such asthma, only three claims for allergy (asthma) to red cedar dust have been accepted in the past decade, according to WorkSafeBC.
Gillian Burnett, government and media relations officer with WorkSafe, said there are standards for cedar dust control in sawmills and requirements for employers to control exposures. A pamphlet that WorkSafeBC distributes to those in the forestry industry about western red cedar asthma says employers must control dust levels, take ventilation measures, inform workers about health hazards and use respirator masks when necessary. But Brezina said many loggers or mill workers who struggle with asthma find the masks impinge their breathing even more.
Until his claim is heard, Brezina is living on social assistance and seeing medical specialists who have prescribed various medications to reduce inflammation in his lungs.
“My lungs are clogged, and so are my sinuses,” said Brezina, who was diagnosed with red cedar asthma several months ago after decades of exposure. Asked if he would have picked a different trade had he known that working with red cedar trees would be so toxic for him, he said: “No, I loved working in the forest. You experience a complete rush when you find a good tree. That’s why they call it ‘cedar fever’.”
Researchers at the University of B.C. first investigated occupational allergies and asthma in the red cedar forestry sector in the 1970s. Now, respiratory specialists are focused on finding an easier test to confirm asthma when workers develop symptoms or when disability claims are made. Since a naturally occurring chemical called plicatic acid in red cedar dust is released in the air when cedar trees or products are cut, forestry workers are brought into a lab at Vancouver General Hospital to inhale plicatic acid. If they develop telling respiratory symptoms, western red cedar can then be confirmed as the cause of their asthma.
But the testing takes about three days and Brezina said it is extremely uncomfortable when the inhalation tests trigger an asthmatic response. So researchers are looking for a quick and easy blood test, one that would show a particular pattern in blood samples among those with asthma as a result of exposure to western red cedar trees.
Respirologist Dr. Chris Carlsten said he and his collaborators have long hoped to find a blood test that can be used as a “surrogate for what’s going on in the lungs.”
In a recently published study, he and his collaborators showed that there are distinct clusters of molecules produced by genes in the blood samples of such asthmatics, molecules that are associated with inflammation. The study involved only a handful of individuals, so now the researchers are seeking funding from WorkSafeBC for a more definitive study to prove whether the blood test can be used with confidence when diagnosing western red cedar asthma.
“The existing inhalation challenge testing is a lengthy process and difficult for patients, so we want to replace it,” Carlsten said, adding that a blood test would also be used to detect asthma earlier so patients could then choose whether to change jobs before their conditions worsen. The respiratory medicine specialist said he tells his forestry sector patients struggling with asthma that they should take precautions by using fitted masks covering their nose and mouth.
“At the same time, we don’t want to put the sole responsibility for precautions on workers for preventive measures,” he adds.
In 2006, a WorkSafe report based on UBC research showed that few workers could recall ever being trained regarding the hazards of exposure, and most red cedar tree workers became aware of risks only after they were diagnosed.
