Hyderabad: Environmental scientists have raised concerns about the likely impact of grain-based ethanol manufacturing units in India, claiming that green clearances for these projects fail to account for the pollutants generated during its production.
The Union ministry of environment has cleared several ethanol projects based on grain and sugarcane to support the Ethanol Blended Petrol (EBP) programme. Most of the proposed plants in Telangana and Andra Pradesh are grain-based. According to Scientists for People, an environmental advocacy group, the environmental clearance documents for these projects list only boiler emissions from coal or biomass combustion, omitting process emissions from ethanol production itself.
Citing studies in the United States, retired chief scientist of Indian Institute of Chemical Technology Babu Rao, a key member of the group, said grain-based ethanol plants release hazardous air pollutants (HAPs) such as acetaldehyde, formaldehyde, acrolein and hexane. These chemicals, known to cause health issues ranging from respiratory irritation to cancer, were identified in research conducted by the University of Nebraska in 2019 and 2020. The studies used biotrickling filters (BTFs) to control emissions from ethanol plants and quantified the pollutants, he said.
He emphasised the risks posed by these pollutants, stating their low odour threshold values meant they can be detected even at minimal concentrations by nearby communities. He said that acetaldehyde is classified as “possibly carcinogenic to humans”, formaldehyde as “carcinogenic to humans”, and acrolein as “probably carcinogenic to humans”, according to international classifications. Exposure to hexane can cause severe neurological effects, including numbness, tingling and weakness.
The group said the omission of these pollutants from environmental clearance reports in India exposes rural communities near ethanol plants to considerable health risks.
“The experts appraising these projects seem to lack full knowledge of the environmental hazards involved. Their decisions appear to be influenced by political agendas rather than scientific evidence,” Rao said
The group also questioned the credibility of the Ethanol Blended Petrol policy, asserting that it relies on incomplete or flawed scientific data. They urged a re-evaluation of the environmental assessment process for ethanol projects to ensure public health and environmental safety are prioritised.
