Firms slow to cut asthma risks

By ANGELA GREGORY

One in five New Zealand asthmatics will be correct if they say their work makes them sick, although they may not know it.

Workplaces from welding sites to seafood processing plants can cause asthma, but the problem is largely either unrecognised or disregarded.

Professor Neil Pearce, at the Centre for Public Health Research in Wellington, said occupational respiratory problems were a big cause of asthma, but workplace asthma has had little attention.

It is counted as asthma that arises in the workplace, not simply underlying asthma aggravated by the work environment.

Professor Pearce said a lot was heard about workplace injuries, but the occupational respiratory diseases were a much worse problem.

Occupations in which workers have developed asthma include welding, laboratory work, sawmilling, baking, chemistry and seafood work.

Professor Pearce said mussel openers had strikingly high asthma rates, although it had yet to be proven why.

Research showed similar problems with oyster openers and prawn handlers. In Canada, a large study showed an asthma prevalence among crab industry workers.

He said the results seemed to indicate that hands-on workers may be reacting to some airborne seafood protein which sprays out of the shellfish.

Professor Pearce said more should be known about such occupational health matters, but it was not considered a high priority health area.

Employers could not be blamed for not taking workplace asthma seriously when various public agencies, including the Ministry of Health and Occupational Safety and Health, did not either.

"It is severely neglected."

But Professor Pearce is disappointed that even when employers have hard evidence of asthma risks put under their noses, they appear slow to change workplace procedures.

In a 1996 study of eight New Zealand welding sites, a research team including Professor Pearce said more effort was required to ensure such studies led to significant improvements.

The study, published in the New Zealand medical journal of July 2000, found that an acute decrease in lung function was more common in welders working without local exhaust ventilation.

The use of such ventilation was known to be the most practical way to minimise exposure to exhaust fumes.

The findings were given to the study participants and their managers, and reported in the media.

But when the sites were revisited two years later, four of them still had no exhaust ventilation and had not made any other changes to improve matters.

Of the surveyed welders, 23 per cent were still not using any respiratory face protection despite their closeness to the welding plume.

Another study had shown that respiratory protective devices were used in only 20 to 30 per cent of work situations in which they were needed.

The slackness was attributed to environmental conditions, physical work demands, psychological and social factors, and the individuals themselves.

OSH medical practitioner Dr Chris Walls said prosecutions had been taken against some employers for failing to monitor asthma rates in their employees.

Dr Walls said the department had also spent some time trying to raise the profile of occupational asthma.

But it could be a difficult condition to diagnose, and employers were often not told of their worker's breathing problems.

"There is a degree of ignorance about occupational asthma with employees, their managers and even within the medical professions."

Dr Walls said up to half those people who had suffered from occupational asthma were left with persisting asthma, which could be severe and disabling, after removal from exposure.

The department had published documents and tried to establish a system with GPs to record and treat workplace asthma cases as a notifiable occupational disease.

Dr Walls said some employers with an awareness of asthma hazards were doing very good preventive work.

The Ti Wai Point aluminium smelter in Invercargill, for instance, ran a comprehensive screening programme.

* The four most common agents causing occupational asthma in New Zealand are understood to be isocyanate paints (used by car and furniture painters), foams and plastics, animal fur and proteins (laboratory and animal workers), flour and grain dusts (farmers, grainworkers, bakers) and epoxy resins and other plastics (boat builders, mould manufacturers and plastic manufacturing processors).

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