The researchers made the call at the launch of a new herbicide (Lifeline) at the International Institute of Tropical Agriculture (IITA), Ibadan, in a statement made available to the News Agency of Nigeria (NAN) on Monday in Abuja.

They said the Paraquat, which was being used by thousands of farmers in the control of weeds was a time bomb that must be gotten rid of as soon as possible.

The researchers urged NAFDAC to do the needful and save Nigerian farmers from an imminent calamity.

Paraquat is the active ingredient in some popular brands of herbicides currently on sale and in wide use in Nigeria and some other developing countries.

It is said to be associated with several diseases including cancer, disease of the liver, lung, kidney and the nervous system.

Dr Udensi Udensi, a researcher at the University of Port Harcourt, Rivers, while speaking on the theme of his report: “The Rural Appraisal on the use of Paraquat in Nigeria”, described the chemical as one of the most highly acute toxic herbicides marketed in the last 60 years.

“Paraquat remains one of the pesticides responsible for more fatal poisonings than any other pesticides substances. Workers who are exposed to Paraquat over a long period have been found to be at an increased risk of developing Parkinson’s disease later in life.”

He said his study on the herbicide, which covered six states, Abia, Benue, Enugu, Ogun, Oyo and Rivers States, showed that about 56 per cent of farmers and other Nigerians had been unduly exposed to paraquat while about 33 per cent of the cases across the states had confirmed symptoms to exposure.

Udensi expressed concern that most of those exposed to the chemical did not seek medical attention because “some of the manifested symptoms are not different from everyday symptoms of normal life stresses.”

In the same vein, a study carried out by Prof. Steve Weller, a retired professor from the Purdue University, U. S.; and Dr Charles Riches, from Agherba Consultants in the UK corroborated Udensi’s position.

The report stated that the negative effect of Paraquat on humans and potential for short- and long-term negative effect were overwhelmingly strong.

Their reports showed that human contact with Paraquat had been associated with health issues affecting the liver, lungs, kidneys, cancer and the nervous system.

Weller and Riches expressed concerns that even though farmers perceived Paraquat as very effective, its level of toxicity demanded high handling skills and stricter regulatory measures which Nigeria and several other countries did not have.

They pointed out that undue exposure due to poor handling and weak regulations had led to the ban of the chemical in more than 32 countries.

“We strongly encourage NAFDAC to ban Paraquat sale and use in Nigeria.

“This is based on the current situation in Nigeria that no mechanism or regulations exists to establish or enforce licensing of applicators or regulations of Paraquat’s sale or use as a Restricted Use Pesticide,” they said.

The scientists said in their reports titled: “Status of Paraquat in Nigeria: Why a Ban is Necessary”, argued that contrary to claims that there were no adequate alternatives to paraquat, there were safer and effective options in other herbicides like glufosinate, diphenyl ether, arlyoxyphenoxy propionate and cyclohexanediones.

Dr Usman Bukar, NAFDAC’s Director of Veterinary Medicine and Allied Products, said the call was coming at a time when new herbicides that are safer and environmentally friendly were being registered in Nigeria.

It will be recalled that in June, NAFDAC hinted that it had plans to ban Paraquat as a result of mounting evidence that they were harmful to applicators and the environment.