Marinduque Island in the Philippines
Field Investigation of Heavy Metals in Romblon, Philippines
Mapúa University, a leading engineering institution in the Philippines, conducted a field investigation of heavy metal contamination in river systems on Romblon Island, an offshore province of the Philippines. The research team deployed the MAS G1 water quality sensing system in combination with the M-series ion-specific test strips, which are capable of detecting copper (Cu), nickel (Ni), chromium (Cr), zinc (Zn), arsenic (As), and lead (Pb) ions. This in situ monitoring approach enabled real-time assessment of heavy metal concentrations in the river environment.
Research Background
Marinduque Island in the Philippines was the site of extensive mining operations from 1969 to 1996. In 1996, the collapse of a mine tailings dam resulted in the release of toxic minerals into the environment, causing severe ecological damage. Subsequent assessments revealed elevated concentrations of copper and zinc ions in the local population. Today, Marinduque remains one of the most heavily polluted former mining sites in the world. To analyze the potential risks of heavy metal contamination in this region, a research team led by professors from Mapúa University in the Philippines conducted an in-depth investigation.
Research Findings
Under the leadership of Dr. Delia Bantillo Senoro, the research team conducted an on-site assessment of heavy metal contamination on Marinduque Island. Using data obtained from field measurements, the team employed Monte Carlo Simulation (MCS) to evaluate carcinogenic risk. Given the site conditions and the need for efficient field testing, the team utilized portable X-ray fluorescence (pXRF, Olympus Vanta) and the MAS-G1 water quality sensing system developed by ACCUSENSING.
A total of 100 domestic water samples—including groundwater and tap water—were collected and analyzed for arsenic (As), copper (Cu), nickel (Ni), lead (Pb), zinc (Zn), barium (Ba), iron (Fe), and manganese (Mn).
The test results revealed that concentrations of arsenic (As), nickel (Ni), and lead (Pb) exceeded both the World Health Organization (WHO) standards and the Philippine National Standards for Drinking Water (PNSDW). Moreover, the study showed that arsenic (As) contributed the highest proportion to the total carcinogenic risk (TCR), accounting for 89.7% of the risk. All sampling locations exceeded the threshold carcinogenic risk value of 1.0 × 10⁻⁴ as recommended by the United States Environmental Protection Agency (USEPA).
This study also provides valuable scientific data to support the Philippine government's efforts in water resource development, utilization, and protection for the island.