It is very important to discuss four most-repeated myths about pesticides in order to expose the truth. Myth One: All forms of agricultural poison (pesticides) are scientifically and rigorously tested to ensure safe use. But this is simply not the case. Before a pesticide is sold in the market, it has to be registered under the Insecticides Act 1968 and Insecticide Rules 1971 under the purview of Central Insecticide Board and Registration Committee (CIBRC).
Application, in the prescribed application format, for registration of any pesticide should contain some vital information regarding safety, the common name, the chemical name (active ingredients and associated ingredients), literature of chemistry, residues, bio-efficacy, and toxicity and registered status in other countries etc. Based on bio-efficacy, toxicity and the data on pesticide residues, the CIBRC approves pesticide registrations and bans or restricts pesticide usage, according to the case. As on 8 March 2018, as many as 279 pesticides including bio-pesticides had been registered in India.
These pesticides are made available in more than 675 kinds of formulations for use in agriculture, domestic and other uses. The regulatory authority comprising CIBRC and the Food Safety and Standard Authority of India (FSSAI) approves multiple pesticides for a crop on the basis that all of them can be used in normal production. But several scientific studies raise serious concern. It has been observed that many chemical cocktails can act synergistically, meaning that instead of one plus one equaling two, lthe extra effect ~ known as ‘cocktail effect’ ~ of the mixture can lead to one plus one equaling five or even higher degree in terms of toxicity and damaging health effects.
It means, chemicals in combination may be far more dangerous than each single chemical on its own. For example, several combinations of organophosphate pesticides are lethal at concentrations that has been sub-lethal in single chemical trials. It may be concluded that the current risk assessment used by regulatory authorities in most cases underestimate the effects of these insecticides when they occurred in combinations. Myth Two: The residues are too low to cause any problems. In fact, the active ingredient is the only chemical in the formulation that is tested for some of the known health problems caused by chemicals, such as cancer, damage to organs, birth defects, and cell mutations, to determine a safe level for the Acceptable Daily Intake (ADI) and the Maximum Residue Limit (MRI).
Testing shows that the pesticide residues in food generally remain below the MRLs and ADIs in case of the registered pesticides. This approach hardly endures safety. In China, a number of incidents have occurred where the wrong pesticide was used. The maxim of Paracelsus, the originator of toxicology, runs thus: ‘All things are poison and nothing is without poison; only the dose makes a thing not a poison.’ The maxim may be condensed to : ‘The dose makes the poison.’ In the 1990s the maxim was proved wrong. In the two books ~ Our Stolen Future and The Feminization of Nature ~ it has been shown that many chemicals, including agricultural chemicals, are almost similar to such hormones as estrogen.
Moreover, the lowest doses of some chemicals can be more toxic instead of least toxic. The current methodology of determining the ADI by lowering the threshold level of exposure is therefore problematic. Children are thought to be especially vulnerable to exposure to pesticide residues. This is because they consume higher amounts of food and water relative to their body weight. They have higher surface areas relative to their volume, and have a more permissible blood-brain barriers.
Myth Three: Modern pesticdies rapidly biodegrade. In fact, we are misled into believing that modern pesticides break down and don’t persist in our food like older organochlorine chemicals such as DDT, BHC etc. Organophosphorous pesticides, carbamate pesticides are mostly biodegradable and they don’t tend to persist in the environment. One of the biggest myths is the assumption that once a chemical degrades, it disappears. The fact is that most agricultural poisons leave residues of breakdown products or subordinate chemicals when they degrade.
The breakdown products are also called metabolites which also cause health and reproductive problems. Studies have also shown many agricultural pesticides, such as diazinon, malathion, chlorpyrifos etc. break down into metabolites called oxons which can cause significant damage to animals’ nervous system. Little or no research has been done so far to determine ADI of metabolites of agricultural pesticides. Myth Four: We will starve to death without pesticides. The worst of all myths is that it is impossible to grow enough food without the widespread use of pesticides.
Pesticides are one of the invaluable inputs in sustaining agricultural production and ushering in the Green Revolution. However, for protecting future generations it is time to dispense with the myth that foods from farming systems that use synthetic pesticides are safe to eat. This includes low-or reduced-pesticide farming systems, as there is no credible science to guarantee that any level of exposure to pesticides is safe. Pest control is an issue of conflict because pests are our major competitors on earth.
But from our experience gathered so far, it remains a fact that war against a pest is neither necessary nor effective. Pesticides themselves beget more virulent pests, they do not control them. Pests are controlled when there is an ecological balance between diverse components of the farming system. One possible alternative could be application of non-toxic environment friendly formulations and solutions to combat pests. Bio-pesticides, typically microbial biological pest control agents, are the appropriate substitutes for toxic chemical pesticides.
Use of biopesticides as a component of Integrated Pest Management (IPM) program can considerably decrease the use of chemical pesticides. Ecological or organic farming is also considered as environmentally suitable, economically viable and socially adaptable through which sustainable agricultural development (SAD) can be attained. Finally, we may recall what Nobel laureate Norman Borlaug, the father of the Green Revolution, said in his Nobel acceptance speech: “The right thing in the right place at the right time” ‘ In accordance with his sage advice, instead of commercialization of agriculture, we should emphasise the importance of relatively small scale local production in agriculture, using the technology appropriate to the given set of social/ historical/ ecological condition.
(The writer is a retired IAS officer)