Kok River Arsenic Crisis 2025: Unmasking Toxic Threat to Chiang Mai and Chiang Rai Communities

Under the relentless sun, the Kok River shimmers as it snakes its way through the scenic northern provinces of Chiang Mai and Chiang Rai, before finally merging with the mighty Mekong River. Once a life-giving force for local farmers, fiendishly fueling fisheries and drawing tourists, the river is now casting shadows of fear and unease across the lives of those who once revered it.

Beneath its glistening surface, a nefarious secret lurks: arsenic, a treacherous heavy metal, has been discovered in chilling concentrations, painting a grim picture of the river’s health. The villagers who depend on this vital waterway for sustenance and daily living are trapped in a web of anxiety—questioning the very water that once quenched their thirst.

In the unassuming hamlet of Ban Huai Kum, nestled in Chiang Rai’s serene Muang district, 63-year-old Supin Kamjai forlornly surveys her parched vegetable patch. “We’ve stopped using river water,” she murmurs, her voice tinged with despair. Her hands, testament to decades of toil, gesture toward the wilting greens that were once destined to nourish her loved ones for months. Yet, what purpose does forsaking the river’s water serve now?

Nearby, Boonchai Phanasawangwong, a staunch community rights advocate, shares the collective concern: “Our children splash in the river and return with angry, red rashes. Whether it’s the arsenic or something else, we’re left in the dark, crying out for someone to care.”

The tides began to turn in late 2024, as the crystalline waters turned murky—a sign of things to come. In Ban Kwae Wua Dam, children emerged from their riverside escapades with troublesome rashes. As the new year unfurled, the reality crystallized through lab tests, revealing what lay beneath: the river was contaminated with perilous arsenic levels.

The urgency was palpable in Mae Ai district, Chiang Mai, where arsenic levels hit an alarming 0.026 milligrams per liter (mg/L), woefully eclipsing the acceptable safety standard of 0.01 mg/L. Lead followed suit, grimly registering at 0.076 mg/L, overstepping the safe limit of 0.05 mg/L.

Dr. Amporn Benjaponpitak, the astute Director-General of the Department of Health, sounded the alarm over the river’s grim reality, warning of the grave health risks that heavy metals like arsenic and lead pose. The potential repercussions include skin maladies, digestive disturbances, and the long-term specter of skin cancer and neurological afflictions.

But where exactly does the blame lie? Analytical eyes gaze upriver, toward the mining activities in Myanmar’s Shan State, nestled near the Kok River’s origin. Although unverified, environmental advocates and scholarly minds suggest clandestine gold mining operations as the potential culprits—23 in number, skirting rigorous environmental impact assessments (EIAs).

Sen Cheewapap Cheewatham, head of the Senate Natural Resources and Environment Committee, confirmed the evidence with somber precision. “Satellite imagery captures the presence of mining activity upstream in Myanmar’s Shan State, suggesting a link to the contaminated waters now flowing into Thailand.”

He fervently called for the government to harry forth and determine the roots of this chemical intrusion, lest history repeat itself in a modern-day tragedy akin to Klity Creek—an infamous three-decade-long lead poisoning calamity.

Educators, like Suebsakul Kitnukorn from Mae Fah Luang University, corroborate the findings, detecting arsenic intrusion even in the auspicious waters of the Sai, Ruak, and Mekong rivers. Alarm bells ring loudly, heightened by the specter of potential floods amplifying contamination risks, warranting conscientious vigilance.

Insidiously silent, invisible, and lurking arsenic slips undetected into unsuspecting bodies, a prowler in the night. Lingering threats loom large, manifesting as skin lesions and serious organ damage alongside cancer risks, warns Chiang Mai’s Environmental and Pollution Control Office. Grim sediment samples mirror the river’s tale, whispering of more sorrows yet to surface.

The river’s contamination casts ripples beyond mere water woes. At the Karen Ruammit Elephant Camp, tourism—already bruised by recent deluges—grapples with nearly insurmountable odds. “We’ve lost 80% of our visitors since the arsenic woes unfolded,” disclosed Da, an elephant handler sans the usual bedazzlement of thriving tourists. The pachyderms wander from once-bustling riverbanks to forage in distant woods, leaving the camp in survival mode.

Farmers, like the determined Thanet Maneekorn, eye their shriveling crops warily, seeking solace in stored rainwater or feebly dug wells. Yet, in a jittery voice echoing resignation, he concedes, “I don’t trust the well anymore. We’re left wandering in doubt.”

Ruffling feathers across the region, a public outcry crescendoed on April 30 as the beleaguered communities pinned their hopes on the Chiang Rai governor. Pleas resounded for immediate scrutiny of surface and groundwater, heartfelt demand for transparency, along with an earnest call for resolution and medical assistance.

Boonsri Panasawangwong, burgeoning champion and staunch community advocate, echoed these concerns—emphasizing the river’s intrinsic role in daily life, nourishing the people through fish and fertile banks. Its sudden taboo has upended their world.

In response to mounting solicitous gazes, the government summoned an emergency meeting on April 30, presided over by Deputy Prime Minister Prasert Jantararuangtong. As agencies joined forces, inter-agency unity emerged as the key to dare tackle the issue. Detectives sifting through international relations and mining permissions in Myanmar strive to stem the toxic tide.

As villagers who have long lived by the river’s grace await an antidote to this upheaval, their earnest plea for pure waters and hope for a river reborn, reveal the myriad shades of human resilience.

Yes, the Kok River continues its passage—but the struggle to reclaim the life it once promised has truly begun.