Acute respiratory effects of magnesia dust in climbing halls

Abstract

In climbing halls high dust levels have been observed. That dust mainly stems from magnesia which is used as a drying agent for hands. The mineral forms a rather coarse dust. Concentrations sometimes reach occupational limit values. Although magnesia is non-toxic a study was therefore warranted. Three climbing halls were studied that differed by size and dust levels. The mass concentration of dust (PM10) was monitored. Climbers visiting these halls were invited to participate in measurements of NO in exhaled air and spirometric lung function tests before and after the climbing session. It was hypothesized that a decline in lung function would be correlated to the dust levels during the climbing session. In total 109 climbers provided two valid lung function tests. The average interval between these tests and the duration of exposure was 1.8 hours. Higher dust levels led to an increased decline of lung function parameters. The decline was small but significant for FVC and FEV1 indicating an effect on the larger air-ways. Only in persons with higher exhaled NO levels before the climbing (indicating eosinophilic inflammation) there was also a significant decline in MEF50 and MEF25. This is in line with asthmatics reporting worsening of symptoms during climbing sessions. After less than 2 hours of exposure spirometry likely only captures the first phase (muscular) response. An inflammatory response of the bronchial tissues can only be observed after several hours. The clinical relevance of a small muscular response is less clear. Therefore more research with a longer observation of the climbers after the session is warranted. Nevertheless even now measures to prudently reduce dust levels in climbing halls are indicated.