Probabilistic Human Health Risk Assessment of Inorganic Arsenic Exposure Following the 2020 Taal Volcano Eruption,...

Area of Science:

• Environmental Science
• Toxicology
• Public Health

Background:

• Volcanic eruptions mobilize naturally occurring toxic elements like arsenic into ecosystems.
• Arsenic contamination of soil, water, and food webs poses risks to human health.
• Comprehensive exposure assessments in post-eruption volcanic regions are limited.

Purpose of the Study:

• To quantify aggregate inorganic arsenic (iAs) exposure in residents near Taal Volcano post-eruption.
• To integrate dietary and drinking water pathways in a probabilistic risk assessment.
• To assess health risks associated with arsenic exposure in a volcanic region.

Main Methods:

• Probabilistic risk assessment using Monte Carlo simulation (10,000 iterations).
• Integrated environmental data (soil, water, clam tissues) with bioaccumulation factors.
• Applied two exposure scenarios (50% and 90% iAs fraction) to account for speciation uncertainty.

Main Results:

• Simulated iAs concentrations were highest in rice, followed by corn, vegetables, and root crops.
• Aggregate daily iAs doses averaged 3.0-4.0 µg/kg bw/day, with females having slightly higher exposure.
• Clam and rice intake, and arsenic levels in rice, clams, and drinking water were key exposure determinants.

Conclusions:

• All simulated individuals exceeded U.S. EPA reference dose and cancer risk benchmarks.
• Urgent need for environmental monitoring, arsenic speciation, biomonitoring, and public health programs.
• Findings underscore significant health concerns in arsenic-affected volcanic regions.