Real time mass spectrometric analysis of biomarkers in exhaled breath after exposure to an irritant

Approximately 16 % of adult onset asthma is caused by occupational exposure. The need for early detection of irritant caused asthma is key in treating and preventing the progression of the disease. The aim of the work was to investigate if exposure to irritants cause change in gas composition in exhaled breath, the “exhalome”. We studied 15 female hairdressers exposed to a controlled dose of aerosolized bleach powder in a sealed climate chamber. The subjects’ self-reported symptoms, spirometry and gas components were monitored. The exhalome was collected for breath holding times of 2 and 10 seconds from central (400 ml) and peripheral lung (1500 ml), once prior to and twice after exposure. Thus, subjects were their own controls. The composition of the gas was analyzed using a Proton Transfer Reaction – Time of Flight – Mass Spectrometer (PTR-ToF-MS) where volatile organic compounds of mass up to 253 atomic mass units are identified with high time resolution. Preliminary analysis of the data shows a variation of the concentrations of the different gases in exhalome over the course of the day and that levels of isoprene and acetone are higher for longer breath holding time. More analysis is needed to evaluate if the technique is able to detect differences in the exhalome caused by the exposure. Detailed information on the relationships between the exhalome and inflammation processes in the respiratory tract induced by irritants is also required. This may contribute to a deeper understanding of asthma. In the future a PTR-ToF-MS could potentially be used as a real-time non-invasive tool for early detection asthma in exposed workers.