Occupational asthma caused by chloramines in indoor swimming-pool air

The first series of three workers who developed occupational asthma following exposure to airborne chloramines in indoor chlorinated swimming pools is reported. Health problems of swimmers in indoor pools have traditionally been attributed to the chlorine in the water. Chlorine reacts with bodily proteins to form chloramines; the most volatile and prevalent in the air above swimming pools is nitrogen trichloride. Two lifeguards and one swimming teacher with symptoms suggestive of occupational asthma kept 2-hourly measurements of peak expiratory flow at home and at work, analysed using the occupational asthma system (OASYS) plotter, and/or had specific bronchial challenge testing to nitrogen trichloride, or a workplace challenge. Air measurement in one of the pools showed the nitrogen trichloride levels to be 0.1-0.57 mg x m(-3), which was similar to other studies. Two workers had peak expiratory flow measurements showing occupational asthma (OASYS-2 scores 2.88 and 3.8), both had a positive specific challenge to nitrogen trichloride at 0.5 mg x m(-3) with negative challenges to chlorine released from sodium hypochlorite. The third worker had a positive workplace challenge. Swimming-pool asthma due to airborne nitrogen trichloride can occur in workers who do not enter the water because of this chloramine. The air above indoor swimming pools therefore needs to be assessed and managed as carefully as the water.

Occupational asthma due to glutaraldehyde

In recent years glutaraldehyde has emerged as the main cause of occupational asthma among healthcare workers. Presently glutaraldehyde is the best biocide agent for high-level disinfection and cold sterilization and its use has become widespread in hospitals. Surveillance schemes in the UK, Finland and the USA have reported an increasing number of cases of occupational asthma due to glutaraldehyde. The real magnitude of the problem is not well known as epidemiological studies carried out on a large scale among healthcare workers are not yet available. In countries where surveillance schemes are implemented, reports of occupational asthma cases due to glutaraldehyde should be circumstantiated by more diagnostic details and the diagnosis confirmed by objective means, to avoid an overestimation of frequency of disease. The pathogenetic mechanisms of occupational asthma due to glutaraldehyde are debatable as with other low molecular weight chemicals. A recent study has documented the first evidence of immunological sensitization in healthcare workers exposed to this chemical. Occupational asthma caused by glutaraldehyde can develop at levels of exposure well below the standards accepted in most countries. In the UK the Occupational Exposure Standard (OES) of this agent will be lowered from 0.2 ppm (parts of vapour per million parts of air by volume) to 0.05 ppm. Substitution of glutaraldehyde with an alternative agent is not currently feasible. Intervention in the workplace and education of personnel handling this chemical remain irreplaceable parts of any prevention strategy. Early detection of disease and prompt removal of personnel from further exposure are the only ways of avoiding any deterioration of occupational asthma.