A nurse is over twice as likely to suffer from occupational asthma, compared to the rest of the population, according to an article in The Lancet this week. The risk for cleaners is 71% higher.

This new study, carried out by Dr Manolis Kogevinas, Centre for Research in Environmental Epidemiology, Municipal Institute of Medical Research, Barcelona, Spain and team, also found that conditions in the workplace may be causing up to 25% of new asthma cases in the developed world.

The study looked at 6,837 people from 13 countries. They had all participated in the European Community Respiratory Health Survey, 1990-1995. None of them had reported any symptoms or history of asthma at the time of the study. Nine years later each participant was followed-up and tested for asthma. They also completed a questionnaire on symptoms. Potential exposures to substances that cause asthma were calculated using an ‘asthma-specific job exposure matrix’. A computer model was then utilized to evaluate the risk of new-onset asthma, with age, sex and smoking factored in.

Exposure to known substances that trigger occupational asthma raises the risk of developing it by 60%, say the researchers. While risks were highest for asthma defined by bronchial hyper-activity in addition to symptoms (140% increased risk).

The following occupations had the highest excess risk:

— printing – 137%
— nursing – 122%
— woodworking – 122%
— agriculture/forestry – 85%
— cleaning – 71%

If a person was exposed to asthma-causing irritants, during specific incidents, his/her risk of developing new-onset asthma was found to be three-times more likely than the general public. Such events/products as a fire, mixing cleaning products or chemical spillages are considered as asthma-causing irritants.

“Nurses could be exposed to sensitising substances, respiratory allergens, and irritants including sterilisers and disinfectants such as glutaraldehyde or bleach,” say the researchers. They added that although nurses’ exposure to latex may have gone up as gloves became more commonly used during the early 1990s, exposure probably fell as the latex content in these products was reduced over time.

“Findings from this large international study suggest that the frequency is systematically underestimated. The heightened asthma risk after inhalation accidents suggests that workers having such accidents should be monitored closely. Reduction of exposure, and early and complete identification of workers with symptoms suggestive of asthma, would help prevent the disease and effectively manage workers who develop occupational asthma,” conclude the authors.


Written by: Christian Nordqvist