Legionella pneumophila as a Health Hazard to Miners: A Pilot Study of Water Quality and QMRA

( ), the causative agent of legionellosis, is an aquatic bacterium that grows in warm water. Humans are only presented with a health risk when aerosolized water containing is inhaled. In mining operations, aerosolized water is used as dust control and as part of the drilling operations, a currently ignored exposure route. This study characterized concentrations in the mine's non-potable water and the relationship between and chlorine concentrations. These concentrations informed a quantitative microbial risk assessment (QMRA) model to estimate the infection risk to miners exposed to aerosolized water containing . Fourteen water samples were collected from seven locations at a mine and analyzed for temperature, pH, chlorine, and serogroup. Most samples (93%) tested positive for cells. The faucet from the sprinkler system on the adit level (entrance to the underground mine levels) showed the highest concentration of (8.35 × 10 MPN/L). Disability adjusted life years (DALYs) were estimated in the QMRA model and showed that the risk for all miners was significantly lower ( < 0.0001) with the ventilation system on than when the system was off. Our study showed that the use of a ventilation system at the adit level of the mine reduced the risk of infection with aerosolized .