Autoimmune diseases higher than before; long-term effect of pesticides need to be studied: expert

The high prevalence of autoimmune diseases in the population compared to previous years should provide us with enough reason to study the long-term effects of pesticides and Genetically Modified Organisms (GMOs) to understand the correlation or causality, if any, according to Sougata Bardhan, Associate Professor in the Department of Environmental Sciences at Tennessee State University (TSU), USA.

“I am not trying to make correlation causality, but I want to investigate if the correlation is actually the causality,” he noted. A soil scientist by training, Dr. Bardhan has trained his research towards the concept of ‘One Health’, an integrated approach that seeks to understand the interconnections between human health and that of animals, plants, and the environment.

Existing studies that have pronounced pesticides and GMOs to be safe were conducted over the short term of a few weeks to a few months, Dr. Bardhan said, adding that a recent study conducted on mice has indicated the probability of a long-term effect that spans at least two generations. The article in question, which appeared in the Science of the Total Environment website in September 2025, studied the impact of glyphosate, a widely used herbicide in North America, and found disruptions to multiple physiological systems among the mice across generations.

In a conversation with The Hindu in Chennai, Dr. Bardhan said that he was partnering with Anirban Chakraborty, Director, Nitte University Centre for Science Education and Research, Mangalore, who is an expert on zebrafish. “Our goal is to take juvenile zebrafish and expose them to various things, pesticides, and GMOs and see what is the long term result of the exposure,” he said. The zebrafish has a four-year life cycle and is over 70% similar in genetic makeup with human beings. They are being used in drug discovery and oncology research. For Dr. Bardhan, this research was personal as well, since he suffers from an autoimmune condition that has affected his kidneys.

“Our gut microbiome and those in plants, soil, and microbes talk to each other. The crop we consume may be associated with some microbes or the plant may have some metabolites that our gut microbiome may see as antagonistic. This could also lead to autoimmune conditions – our body attacking itself,” he said, explaining the importance of consuming local produce.

His visit to India was to seek partnerships and collaborations for a recently established consortium called The 1890 Centre of Excellence for Land, Water and Resource Management (COE-LWRM), housed at the TSU.

Touching upon sustainable agricultural practices, he averred that heavy dependence on fertilisers was an “inefficient” method and required a course correction. A total switch to organic farming would put food security at risk, as was evident in Sri Lanka in 1991, Dr. Bardhan said, suggesting a balanced approach and the use of modern technology, like slow release fertilisers and precision application of nutrients, both in temporal and spatial way – when the plant needs it and depending upon the landscape and soil health. “AI and machine learning gives us an opportunity to analyse all the data we collect, which was otherwise not possible, and then make better predictions on how to manage and come up with better management practices,” he maintained.