Chiang Mai: The Department of Fisheries has tested for contaminants in the Kok River and Sai River, and found heavy metals not exceeding the standard, but it is not recommended for consumption at this time. It will continue to randomly collect samples twice a month, covering risk areas in Chiang Rai and Chiang Mai provinces.
According to Thai News Agency, Ms. Thitiporn Lawprasert, Deputy Director-General of the Department of Fisheries, revealed that from the pollution situation in the Kok River and the Sai River, the Department of Fisheries has set up a special action plan to monitor and closely monitor contaminants in aquatic animals by randomly collecting samples of aquatic animals at least twice a month in four important risk areas in Chiang Mai and Chiang Rai provinces from May to September 2025.
From the analysis of samples of herbivorous and carnivorous fish such as the silver barb, the pla sa, the pla khao, and the catfish in the past three rounds, it was found that four types of heavy metals, namely arsenic (As), mercury (Hg), lead (Pb), and cadmium (Cd), are still at levels not exceeding the standard values according to safety criteria. However, for the safety of the public, the Fisheries Department does not recommend consuming aquatic animals caught from the Sai and Kok Rivers at this time.
In the case of fish with red bumps caught in the area, the Department of Fisheries diagnosed the disease as being caused by parasites of the Digene group and bacteria in the skin, but no viruses or germs were found in the internal organs. Further surveillance is still ongoing along with continuous bacteriological, virological, and pathological examinations.
For the survey points, there are three points in Chiang Rai Province: Ban Pong Na Kham to Kwae Wua Dam (CR1), Mae Fah Luang Bridge to Chiang Rai Weir (CR2), and behind Wat Santhat to Sop Kok, Tambon Yonok, Amphoe Chiang Saen (CR3), and another point in Chiang Mai Province, on the Thai-Myanmar border, Ban Kaeng Tum Yom, Tambon Tha Ton, Amphoe Mae Ai (CM1). Each aquatic animal sample will be tested for both toxin levels, heavy metals, and diseases that may be harmful to consumption.
The deputy director-general of the Fisheries Department emphasized that most aquatic animals sold in the market for consumption come from aquaculture systems that do not use water from the Sai and Kok rivers. Therefore, people can still safely consume aquatic animals from aquaculture sources. The Fisheries Department will urgently monitor and report the results of its surveillance continuously in order to closely assess the situation.