Exposure to Acid Aerosols in the Visiting Areas of the Poás Volcano National Park, Costa Rica

Abstract

Poás Volcano made a magmatic eruption in April 2017. The volcanic outburst resulted in an ash and vapor column towering over three kilometers high. Since that time, there has been a continual release of gases, aerosols, and more recently, ash, posing potential issues for visitors and park rangers. In this work, the potential for exposure to acid gases and aerosols faced by park rangers, officials, and visitors to the Poás Volcano National Park was evaluated, and the concentrations found were compared with the exposure limits established by the Occupational Safety and Health Administration (OSHA). The study was conducted between October 2021 and November 2022. the concentrations of HCl(g), HNO3(ac), HF(g), and H2SO4(ac) were determined at three strategic points: the ranger station, the visitor center, and the main crater viewpoint. The maximum concentrations obtained were (7.0 ± 1.6) ppb for HCl(g), (6.2 ± 2.8) ppb for HNO3(ac), and (0.029 ± 0.044) ppm for H2SO4(ac). There were no concentration values above the detection limit (0.94 μg/m3) for HF(g). By comparing the data obtained with similar studies, it is concluded that the measured values in Poás Volcano National Park are low and only show similarities to the results found in volcanoes within the national territory. The exposure limit established by OSHA (0.02 ppm) was only surpassed by H2SO4(ac), and could be the cause of health effects experienced over the years by park rangers. To minimize these risks, the use of personal protective equipment and air quality monitoring is essential.