BANGKOK, Thailand – Deputy Prime Minister and Natural Resources and Environment Minister Suchart Chomklin has ordered the Pollution Control Department (PCD) to intensify monitoring of arsenic contamination in the Kok River in Chiang Rai province, following public concern over possible health risks. The directive came after joint discussions between the Ministry of Natural Resources and Environment and the Ministry of Public Health on surveillance efforts and support for affected communities.
Preliminary water quality tests indicate that arsenic levels in the Kok River and village water supply systems remain within the national standard of 0.01 milligrams per liter. Since March 2025, the PCD has conducted 15 monitoring rounds. The latest survey in mid-January found most sampling points within acceptable limits, with slightly elevated readings of 0.011 to 0.012 milligrams per liter detected at a few sites in Mae Ai district, Chiang Mai. Other heavy metals, including cadmium, copper, nickel, chromium, zinc, and mercury, were within standard levels.
Public health officials said environmental and health data are being used to strengthen risk surveillance, after reports raised concerns about arsenic exposure among residents living along the river. Authorities stated that current findings do not indicate adverse health effects, and residents may continue normal daily activities. Provincial health offices and regional medical science centers are continuing to monitor drinking water, food safety, and vulnerable groups under established risk management plans.
Residents are advised to use water supplied by the Provincial Waterworks Authority or by certified village systems that undergo treatment and regular quality checks. Environmental health response teams are also working with local agencies to conduct field testing and provide safety guidance. Officials said any abnormal findings will be reported promptly to ensure swift protective action. (NNT)
