According to a recent study, high levels of lead have been found in various samples of turmeric sold in India, Nepal and Pakistan.

These levels exceed the regulatory limit of 1,000 micrograms per gram (µg/g) per dose. The Food Safety and Standards Authority of India (FSSAI) sets the maximum acceptable lead content in turmeric at 10 µg/g.

The study, published in Science of the Total Environment, analyzed turmeric from 23 cities in India, Pakistan, Sri Lanka and Nepal, revealing that about 14% of the samples had lead levels greater than 2 micrograms per gram.

Researchers at Stanford University in collaboration with Pure Earth and India’s Independence Employment Academy said the metal may interfere with essential bodily functions by mimicking calcium and accumulating in the bones.

In total, lead levels in turmeric exceeded 10 micrograms per gram in seven cities: Patna, Guwahati and Chennai in India, Kathmandu in Nepal, and Karachi, Islamabad and Peshawar in Pakistan.

In India, Patna recorded the highest level of 2,274 µg/g, followed by Guwahati at 127 µg/g. Interestingly, polished turmeric roots, which are often used to enhance looks, were found to have the highest levels of contamination, followed by loose powder.

Packaged and branded turmeric products contain relatively low levels of lead, which suggests that loose and less-regulated forms of turmeric may be more susceptible to contamination.

Although lead contamination in turmeric is not illegal, it can cause serious harm, especially to children. It has been linked to issues like low intelligence, behavioral problems and developmental delays in children.

Previous studies have found that elevated lead exposure in children, even at blood levels as low as 3.5 μg/dL, can impair cognitive and behavioral outcomes.

Worldwide, it is estimated that more than 800 million children have blood lead levels well above safe limits.

According to the researchers, lead chromate, a yellow pigment commonly used in industrial products such as paint, is likely the main contaminant.

This mixture enhances the color of turmeric but adds toxic lead, which has been linked to lead poisoning incidents in Bangladesh and other countries, including the United States.

Previous investigations of the turmeric supply chain in Bangladesh have revealed that the practice of adding lead chromate to low quality turmeric roots to improve appearance has been practiced for decades.

The researchers called for further investigation of South Asia’s turmeric supply chains.

“Given the highly elevated lead levels in turmeric from these locations, urgent action is needed to stop the practice of adding lead chromate into the turmeric supply chain,” the researchers wrote in the study.