Organophosphate use was high in carrot and potato cultivation

A study of fruits and vegetables grown in the Nilgiris has found that some of the produce might be harbouring high levels of pesticide, beyond what is considered advisable. This was mainly true of potato and carrot. The study was published in the journal Food Chemistry.

While the Food Safety and Standards Authority of India (FSSAI) prescribes a maximum residual level (MRL) for some of the organophosphate pesticides used, it does not prescribe it for some other pesticides used in the cultivation of fruit and vegetables. Hence, the team of researchers took the maximum residual levels from European standards.

Sensitive method

Using liquid chromatography in tandem with mass spectrometry, the team developed a sensitive method to estimate the levels of organophosphates in the fruits and vegetables. “Our detection method has a limit that ranges from 0.1 microgram per kilogram to 1 microgram per kilogram. It has a higher sensitivity than methods used earlier,” says S. N. Meyyanathan from Department of Pharmaceutical Analysis, JSS College of Pharmacy, JSS Academy of Higher Education and Research, Udhagamandalam who led the study.

It is known that organophosphate pesticides such as acephate, malathion, profenofos, chlorpyrifos and quinalphos are used in the cultivation of fruits and vegetables. The study measured the levels of these pesticides in 659 samples of fresh fruit and vegetables collected during the agricultural season of 2018-2019. Samples of 18 varieties of fruit and vegetable were collected from four cities of the Nilgiris – Ooty, Gudalur, Kothagiri and Coonoor. Of these, the researchers did not detect pesticides in approximately 57% of the samples. Close to 34% had pesticides used below the MRLs and the remainder — about 8% — showed usage of pesticides above the MRLs.

Potato and carrot

Of the 659 randomly picked fruit and vegetable samples studied, 53 had higher levels of pesticide. These were mainly in strawberry, potato, cabbage, cauliflower, carrot, garlic and broccoli. “About 85% of these samples contained chlorpyrifos, which was the most common, followed by quinalphos at 72%, acephate at 56.6%, profenofos at 54% and malathion at 17%,” says S.T. Narenderan who is a PhD student in JSS Academy of Higher Education and Research and the first author of the paper. Among the varieties of vegetables and fruits studied, potato and carrot had the highest usage of these pesticides. “It is essential to control and reduce the level of pesticide. Residual monitoring in fruits and vegetables is important to ensure minimal pesticide residue level to safeguard consumer health,” says Narenderan.