Ecological and Health Risks of Heavy Metals to the Residents affected by a Volcanic Eruption in the Philippines

Volcanic eruption can be a source of heavy metal contamination and such contamination may cause certain risks to the environment and to those who are exposed to the volcanic contents. This study aimed to determine the ecological and health risks from heavy metal exposure in the soil after a volcanic eruption. The agricultural soil samples were collected from Cuenca and Talisay, Batangas and Tagaytay City, Cavite, and were processed for arsenic, cadmium and mercury detection and quantification. The detected metal concentrations were compared to the standard values of the Department of Environmental and Natural Resources for arsenic and United States Environmental Protection Agency for cadmium and mercury while the ecological and human health risks were assessed by computing for the potential ecological risk, hazard quotient and hazard index, respectively. Arsenic was the only heavy metal with high mean concentration in the soil samples of Talisay, Batangas and Tagaytay City, Cavite while cadmium and mercury in the soil were within the acceptable level in the three municipalities. The soil from Talisay, Batangas had two-fold arsenic increase while the samples from Tagaytay City, Cavite had one-fold arsenic elevation. The soil’s post-volcanic eruption’s arsenic contamination was probably due to the direction of the wind during the eruption and groundwater contamination. Low ecological risk and no human health risk were observed despite the recent arsenic concentration in the soil. A two-fold increase in arsenic concentration in the soil will not yet cause ecological and human health risk.