Dust harms sawmill workers
WELLINGTON – New Zealand sawmill workers have a significant reduction in lung function and are more likely to have
allergies compared with other workers, according to a new study by the Centre for Public Health Research.
A previous study showed that pine sawmill workers had an increased risk of asthma. The new study, published in the
European Respiratory Journal, aimed to assess the association between dust exposure, lung function and allergies.
Researchers from the Centre, part of the College of Humanities and Social Sciences, measured lung function and allergic
reactions among 226 pine sawmill workers. They also measured levels of inhalable dry and green dust.
Dust associated with processing fresh timber before it is kiln-dried is known as green dust, while dust associated with
processes that take place after kiln drying is dry dust.
“We found that sawmill workers exposed to high levels of dust had more asthma,” says the Associate Director of the
Centre, Associate Professor Jeroen Douwes.
The study, supported by the Health Research Council, also found that sawmill workers exposed to green pine sawdust had
more allergies – the first time in the world such an association has been shown.
Workers exposed to high levels of green dust had significantly lower lung function, as measured by total lung capacity
and airflow. This means they are more likely to wheeze or run out of breath.
Dr Douwes says the problem needs to be taken seriously. The New Zealand sawmill industry employs more than 10,000
workers.
“As with any other occupational disease, this is preventable.”
Previous studies have shown that reduced lung function is associated with increased illness and mortality.
Dr Douwes says there is a range of solutions, starting with reducing workers’ exposure to dust through technical
measures. “You can install exhaust ventilation, shield machinery, or change the layout of the sawmill to reduce exposure
to dust.”
Due to the cross-sectional nature of this study it is not clear whether sawmill exposures cause respiratory disease or
whether they exacerbate pre-existing respiratory conditions. It is also not clear which specific exposures cause
symptoms and lung function decline. Dr Douwes says his team will address these issues in future studies.
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