Getting rid of POPs

With the coming into force of the Stockholm Convention on Persistent Organic Pollutants (POPs) from Monday, mankind has in place for the first time a legally binding mechanism to control highly hazardous chemicals, whose toxicity lingers long after their use.

The convention intends to ban or severely restrict the production and use of chemicals that are linked to cancer, birth defects, neurological derangement and other serious illnesses.

Significantly, the use of POPs, being the cheapest and effective pathogen control agents, is more in the developing countries where the awareness of their danger is much less than in the developed countries, where many of them are already banned.

Fortunately, of the nearly 150 countries that have signed the convention, and about 60 that have also ratified it, a sizeable number consists of the developing nations where such a treaty is needed the most.

To begin with, 12 pesticides have been identified for replacement with safer and better alternatives. These include some of the most widely used toxins like DDT, aldrin, dioxins and furans (the last two categories being the most poisonous of all the POPs).

More chemicals are likely to be added to the list with time, as the world uses no fewer than 70,000 chemicals in agriculture, health and other sectors, and about 1,500 new ones are added every year. The most worrisome aspect of POPs is that every human in the world is already carrying traces of them in their bodies.

Besides, they circulate globally through the process known as the "grasshopper effect" and spread through the atmosphere to regions far away from the original source.

Moreover, though not soluble in water, POPs are readily absorbed in fatty tissue, where concentrations can become magnified thousands of times. Fish, predatory birds, mammals and humans are high up the food chain and so absorb the greatest concentrations. And when they travel, the POP residues travel with them.

However, merely enforcing the Stockholm convention is unlikely to eliminate the menace of POPs, though it may stop their production. Their stockpiles, running into thousands of tonnes, have already accumulated in even those countries where their use has been stopped, and similar stock are likely to build up in the other countries as well.

Ways and means will have to be found for their safe disposal. Besides, the developing countries will need liberal financial assistance for switching to alternatives that will be more expensive.

Otherwise, the sudden stoppage of their use would create new problems. For, not only crop pests and diseases but even vectors of human maladies would multiply faster in the absence of proper control agents.

Thus, the global community (mainly the developed countries) will not only have to contribute liberally for assistance with enforcing the convention and also fund research on discovering new cost-effective and environmentally safer alternatives to POPs. Only then will the world be safe from this evil.