Beneath the peaceful veneer, unrest stirs: a deep exploration of simmering conflicts.
Under the relentless sun, the Kok River sparkles as it snakes through the northern provinces of Chiang Mai and Chiang Rai, eventually merging into the Mekong River. Once a vital artery for local farms, fisheries, and tourism, the river now casts a shadow of dread and uncertainty.
Hidden beneath its glistening surface lurks a perilous toxic secret: arsenic, a harmful heavy metal, has been found in frightening concentrations, leaving the villagers who rely on it for their water, livelihoods, and health with a growing sense of despair.
In the tranquil village of Ban Huai Kum, nestled in Chiang Rai's Muang district, Supin Kamjai, 63, stares sadly at her shriveled vegetables. "We've ceased using river water," she laments. Her voice echoes hollowness. "But what good does that do now?" Her gnarled hands, etched by decades of farming, gesture towards the wilting crops – a harvest that should have sustained her family for months.
Nearby, Boonchai Phanasawangwong, a local activist for community rights, shares her concern: "Our children frolic in the river, and now they have red, itchy rashes. We don't know if it's due to arsenic, but no one has checked on us."
The crisis escalated in late 2024 when the once-clear water turned murky. In Ban Kwae Wua Dam, kids began developing rashes upon playing in the river.
In Huai Chomphu, farmers observed their crops withering despite consistent watering. By early 2025, laboratory tests verified their worst fears: the river was contaminated with high levels of arsenic.
The contamination was particularly severe in Mae Ai district, Chiang Mai, where arsenic levels reached 0.026 milligrammes per litre (mg/L) – well surpassing the safety standard of 0.01 mg/L. Lead was also detected at 0.076 mg/L, exceeding the permissible limit of 0.05 mg/L.
Dr Amporn Benjaponpitak, Director-General of the Department of Health, confirmed the presence of both arsenic and lead in the river, warning that heavy metals pose serious health risks to the local population. These include skin rashes, diarrhea, nausea, vomiting, and long-term dangers like skin cancer and neurological disorders.
The Root of the Problems
At the foundation of the predicament lies mining activity upstream in Myanmar's Shan State, near the Kok River's source. Environmental groups and researchers suspect 23 illicit gold mining sites, operating without thorough environmental impact assessments (EIAs), are responsible for the contamination – although the connection has yet to be confirmed.
Sen Cheewapap Cheewatham, chairman of the Senate Natural Resources and Environment Committee, explains: "Satellite imagery reveals the presence of mining operations in the upper reaches of the river in Myanmar's Shan State. These industries pose the risk of chemical contamination, as evidenced by the detection of arsenic and lead in the water reaching Thailand."
He emphasized the necessity for the government to determine whether the chemicals originate from neighboring mining operations and find a solution swiftly. "We cannot let Klity Creek repeat itself," he cautioned, referring to the infamous 30-year-long lead contamination tragedy in Klity Creek of Kanchanaburi that left generations of Karen villagers poisoned.
Suebsakul Kitnukorn, a lecturer at the Faculty of Social Innovation, Mae Fah Luang University, also found arsenic contamination in the Sai, Ruak, and Mekong rivers in Chiang Rai's Mae Sai and Chiang Saen districts from nine water samples collected on April 30.
The results showed arsenic levels exceeding the standard of 0.01 mg/L in several locations, with the highest recorded at 0.19 mg/L.
He expressed concerns about the potential risks if floodwaters caused contamination to impact local communities: "It's concerning. If the public encounters the water, they may be in danger. We need to continue monitoring this closely."
Arsenic in water is particularly subtle – colorless, tasteless, and odorless, it quietly permeates the body. Prolonged exposure can lead to skin lesions, organ damage, cancer, and developmental issues in children, warns the Environmental and Pollution Control Office in Chiang Mai.
In addition to finding arsenic and lead in the river, the office also found alarming levels of arsenic and other heavy metals in sediment samples collected from six spots along the Kok River in Mae Ai district, Chiang Mai, and Muang district, Chiang Rai, between March 31 and April 1.
The concentrations of other heavy metals, including lead, nickel, and chromium, were also found to be in excess of national limits.
Disrupted Lives
The ripples of contamination extend far beyond health. At the Karen Ruammit Elephant Camp, tourism – already battered by severe floods in September last year – faces significant challenges.
"We lost 80% of our visitors after the arsenic information spread," said a handler named Da. "No more bathing elephants in the river. No tourists, no income."
Handlers who once earned 2,000 baht a day now make almost nothing. Elephants, once attractions, were led into nearby forests to forage. "We're back to survival mode," Da added.
Downstream, farmers like Supin watch their crops wither as they resort to collecting rainwater or digging shallow wells – but even groundwater may be at risk.
"I don't trust the well anymore," said 40-year-old farmer Thanet Maneekorn. "No one tells us if it's safe or not."
The growing fear and agitation led to a public outcry on April 30, when residents from 13 affected communities in Chiang Rai submitted a petition to the Chiang Rai governor.
They demanded immediate testing of surface and groundwater, sediment, and farmland; transparent and timely reporting of the results; and urgent identification and resolution of contamination sources.
They also urged access to medical screenings and community participation in crisis response planning.
"We have been advised against using the river water, leading to confusion and fear about the safety of drinking water, groundwater, and riverbank crops," said Thaweesak Maneewan, a representative.
"People are anxious, and the government must address them directly – not in bureaucratic language," he said.
Boonsri Panasawangwong, a community rights advocate in Chiang Rai, echoes the residents' concerns, stating that the river is vital to their daily lives, providing water and food. "The ban on using the river has disrupted our way of life," he said.
A Fresh Start
Faced with mounting public pressure and scientific evidence of widespread contamination, the government convened a high-level emergency meeting on April 30. Chaired by Deputy Prime Minister Prasert Jantararuangtong, the session brought together the ministries of Natural Resources, Public Health, Defence, and Foreign Affairs.
Deputy Minister of the Interior, Theerarat Samrejvanich, emphasized the urgent need for inter-agency coordination. She said the meeting also decided that the Ministry of Defence and the Ministry of Foreign Affairs would gather information concerning gold mines in Myanmar. "This is to expedite negotiations with the agencies responsible for granting mining permissions in Myanmar, to temporarily halt mining operations and improve mining practices," she stated.
For the families who have bathed in the river's waters and tended crops along its banks for generations, one prayer remains: clean water, and a path to restore the river's lifeblood.
The Kok River still flows, but the fight to preserve it is just beginning.
- The contamination in the Kok River, a vital resource for local farms, fisheries, and tourism, has sparked concerns in the field of environmental science and health-and-wellness, as high levels of arsenic and lead have been discovered.
- Fitness-and-exercise routines, an integral part of many people's lives, have been disrupted due to the uncertainty surrounding the safety of the river's water, as contaminants like arsenic can lead to long-term effects such as skin cancer and neurological disorders.
- Skin-care practices, which often involve water for cleaning and hydration, have become a cause for concern due to the presence of arsenic in the water supply. This heavy metal, colorless, tasteless, and odorless, can permeate the body and lead to skin lesions and other health issues.
