'E-nose' created to sniff out pesticides in tea

Monday, June 06, 2016 by: David Gutierrez, staff writer
Tags: pesticide residue, India, tea

---

(NaturalNews) The Tea Research Association (TRA), a partnership between the Indian government and the tea industry, has announced the development of an "e-nose" that can "sniff out" pesticide residues on tea leaves, thus ensuring that contaminated leaves are not sold to consumers.

The research, which has led to the development of a prototype device, was carried out by researchers from the TRA and the Birla Institute of Technology and Science, with support from the Centre for Development of Advanced Computing.

Pesticide contamination of Indian tea is an issue of global concern, as India grows the bulk of the tea consumed in nearly all global markets, including the United States.

Nearly all tea contaminated

The CDAC announced the successful testing of the "e-nose" in a paper provided to India's Union Commerce Secretary. The method consists of cutting the tea leaves into small pieces, washing them, then treating them with a chemical process that causes pesticide-tainted leaves to change color. The tainted leaves are then fed into the "e-nose" device, which provides readings on the residue levels present.

India has struggled with the problem of high pesticide residues remaining on tea sold to consumers, including to global markets. This problem is partly the result of poor agricultural practices; farmers are supposed to pluck leaves at least six days after the last application of pesticides, but many do not follow this practice.

In a 2014 study, Greenpeace tested 11 brands of tea made by eight manufacturers: Hindustan Unilever Limited, Tata Global Beverages Limited, Wagh Bakri Tea, Goodricke Tea, Twinings, Golden Tips, Kho-Cha and Girnar. A shocking 94 percent of samples tested contained pesticide residue. Sixty percent of samples contained residues from more than 10 separate chemicals, while one sample contained 20.

Fifty-nine percent of samples tested contained residues of at least one pesticide at levels exceeding the maximum safe levels set by the European Union. Forty percent contained residues at more than 1.5 times those limits.

The chemicals detected included neonicotinoids – notorious for destroying pollinator populations – and pesticides classified as "highly hazardous" by the World Health Organization, including the organophosphate triazophos and the neurotoxin monocrotophos.

Illegal pesticides still found on tea

The problem with India's tea farming practices is obviously not just limited to poor timing of pesticide application or harvest – as evidenced by the presence of the monocrotophos, which is not approved for use on tea at all.

The Greenpeace study also found that 67 percent of samples tested – two out of every three – were contaminated with DDT, which is illegal in both India and the United States. DDT is a potent neurotoxin that was banned due to its cancer-causing effects in humans and devastating effects on the environment.

One of the samples also contained tebufenpyrad, an illegal pesticide suspected of being poisonous to the liver.

"Indian tea is a national pride and it should not be the one linked to toxic chemicals with serious environmental and health risks," said Neha Saigal, a senior campaigner for Greenpeace India. "All stakeholders in the tea industry should come forward and take steps to safeguard the reputation of our national drink."

Numerous companies responded to the report by promising to make their tea cultivation sustainable by 2020.

The "e-nose" may be one of the first steps down that road. The developers are now planning to move on to the next phase of testing.

"We now need field-trials before this system can be taken up for developing a commercially viable bio-sensing system," said Joydip Phukhan of the TRA.

The final product will also need to be developed into a form that is simple to use and requires minimal maintenance, Phukhan said, since tea growers often live in remote and relatively inaccessible areas.

Sources for this article include:

TheHindu.com

NaturalNews.com

Science.NaturalNews.com