Switzerland is to support calls for a global convention on the eventual elimination of some of the world's most dangerous chemicals, including DDT, at a conference in Johannesburg.
The meeting, which ends on Friday, brings together 120 countries with the aim of approving a global agreement on the reduction and eventual elimination of Persistent Organic Pollutants (POPs).
These are blamed for causing fatalities, birth defects and serious diseases, and are used in an array of industrial and farming activities, from paint additives to pesticides.
Conservationists say that because POPs can last for years or decades before breaking down, they have a devastating impact on human and wildlife populations worldwide. Even the Arctic and Antarctic habitats are affected, despite being thousands of kilometres from the original source of pollution.
The Swiss environment ministry said the conference, which is backed by the United Nations Environment Programme, would focus on the implications of 12 key organic pollutants (dubbed the "Dirty Dozen"), which have particularly devastating effects in the developing world.
The European Union will reportedly be leading the campaign for the elimination of these pesticides, as well as the banning of new chemicals with POP characteristics.
But, conservationists complain that the United States, Canada, Australia, New Zealand and Japan are seeking to weaken certain aspects of the treaty.
Dozens of activists from the environmental pressure group, Greenpeace, held a demonstration outside the conference.
In a statement, Greenpeace said governments meeting this week would be "deciding on the fundamental right of people to live in a world free of toxic chemical pollution".
The host country, South Africa, is pushing to retain the use of DDTs for malaria control, a position many believe will be accepted.
swissinfo with agencies