645 FO68 – Assessing PM2.5 Exposure During Athletic Events in South Africa: Implications for Athletes’ Respiratory Health

Background The environment in which athletes compete impacts respiratory health and performance. Particulate Matter 2.5 (PM2.5) bypasses the body's natural air filtration system and can result in acute and chronic respiratory illness. Athletes competing in environments with harmful PM levels might be disproportionately affected by high PM2.5 concentrations as total inhalation increases up to 30-fold. At the same time, oral breathing becomes the dominant respiratory process further decreasing the efficiency of the body's natural filtration mechanisms. Objective To measure and describe PM2.5 levels at athletics events across different geographical locations. Design Prospective longitudinal study. Setting Athletics stadia across central South Africa. Participants National track and field athletes. Risk Factors PM2.5 concentrations were assessed at events in three distinct settings (rural, central metropolitan, and industrial metropolitan). Outcome Measurements PM2.5 and environmental variables (temperature, rainfall, humidity, wind speed/direction) were measured using a DS-2 sonic anemometer, CS215 temperature and relative humidity, TR-525USW rain gauges, and SidePak AM510 (PM2.5 monitor). Results The mean concentrations at the various sites were: rural site=29μg/m3, central metropolitan=61μg/m3 and the industrialised metropolitan=135μg/m3. At all sites, maximum values exceeded 170μg/m3 at some point during the competition. The industrialised metropolitan site displayed the highest maximum instantaneous PM2.5 level at 385μg/m3. Factors such as local industries, food stalls in the stadia and wind conditions might contribute to these elevated levels, warranting further investigation. Conclusions The extrapolation from the existing 24-hour exposure risk levels recommended by health organisations (PM2.5<25μg/m3 according to the World Health Organisation) and the fact that the PM levels were continually high at one event and exceeded harmful concentrations for several short-term periods at others indicates a potential risk to athletes. Therefore, in light of the data presented and the potential health implications, organisers, coaches and athletes should consider the air quality at their proposed venue for events and training.