Testing of fish sold in Guwahati markets has found unsafe levels of lead in several commonly eaten species
Every Bhagon sample tested exceeded safe limits, raising concern over daily dietary exposure
Contamination was also detected in other popular freshwater fish, alongside unsafe arsenic levels
The findings point to long-standing pollution of wetlands and rivers and a growing public health risk
In Assam, fish is central to everyday life, shaping food habits, culture and long-standing ties with rivers and wetlands that have sustained generations. New testing of fish sold in Guwahati’s markets by Pahle India Foundation, however, points to a troubling reality. Several commonly consumed species were found to carry traces of lead, a heavy metal associated with serious long-term health risks.
The research, which has not been published yet, found that a largely unseen crisis is developing in rivers and ponds across the region. The most alarming findings concern Bhagon (Labeo bata). Every sample tested contained lead above safe limits. Bhagon is inexpensive, widely available and cooked daily in countless households, placing a routine meal at the centre of potential chronic exposure.
The problem extends beyond a single species. Lead was also detected in other fish that feature regularly in local diets, including Naro, a freshwater catfish, and Bariola (Opsarius bendelisis). This points to widespread exposure through everyday food choices. All fish samples with unsafe lead levels were also found to contain arsenic, increasing the overall toxic load and suggesting deeper environmental contamination.
Contamination in such widely eaten local fish signals extensive ecological damage and an emerging public health emergency that has gone largely unnoticed.
Lead accumulates in the body and is difficult to eliminate. It settles in bones and vital organs, where it can remain for decades. Children face the greatest danger, as even low-level exposure can reduce IQ, impair learning and affect behaviour. Pregnant women, infants and people with existing health conditions are particularly vulnerable.
Adults are also at risk. Long-term exposure is linked to kidney damage, raised blood pressure and declining cognitive function. When routine meals become a source of toxic exposure, the need for intervention becomes urgent.
Years of neglect lie behind this crisis. Guwahati’s wetlands, once effective natural filters, now receive untreated sewage and industrial effluents with minimal oversight. Toxic leachate from the municipal dumping site continues to seep into major wetlands. These pressures have entered the food chain, with their effects now visible in fish markets across the city.
Addressing this challenge requires swift and coordinated action:
Monitoring and research: Launch a statewide assessment of rivers, wetlands and market fish to map contamination patterns.
Food safety and regulation: Require regular testing of fish sold in local markets, make results public and penalise the sale of unsafe produce.
Public health guidance: Issue clear advisories for households, with particular attention to children and pregnant women.
Pollution control: Contain leachate from dumping sites and strictly enforce limits on untreated industrial discharge.
Independent oversight: Create a well-resourced environmental monitoring body with powers to inspect, sample, enforce standards and publish findings.
Community health screening: Introduce blood lead testing for children in areas identified as high risk.
Comparable risks have prompted action elsewhere. Bangladesh operates a National Residue Control Programme for fish and fish products. Vietnam routinely monitors metal contamination in coastal communities, while the Philippines runs a National Residue Monitoring Plan for aquaculture. India’s Marine Products Export Development Authority has a residue control system in place, but this focuses on exports rather than fish sold in domestic markets. Freshwater fish consumed daily by Indian families remain outside any comprehensive national safety framework.
The presence of lead in commonly eaten fish reflects the cost of prolonged environmental neglect. Safeguarding Assam’s rivers and wetlands is directly linked to protecting public health. The scale of the findings demands decisive action, before the damage to ecosystems and communities becomes deeper and harder to reverse.
Pompy Konwar is senior research associate, Pahle India Foundation; and Urvashi Prasad is former director, NITI Aayog and senior fellow, Pahle India Foundation. Views expressed are the author’s own and don’t necessarily reflect those of Down To Earth