After a tense all night session, officials from 150 governments have agreed to ban the production of nine of the world's most hazardous chemicals.  These substances join a list of 12 other so-called persistent organic pollutants, or POPS, that are prohibited under a 2001 international treaty known as the Stockholm Convention.  The week-long meeting was held under the auspices of the United Nations Environment Program.

UN Environment Program Executive Director Achim Steiner calls\ed the agreement historic.  He said the nine chemicals that have joined the list of persistent organic pollutants, or POPS, are extremely harmful to the environment and to health.  "Some of these chemicals, on their own, may not show up on the radar of public health.  But, in their cumulative and interactive nature in the way that they are absorbed by living organisms, be they plants, animals or human beings, they can develop far-reaching consequences.  But just five years after this Convention having come into force, we will have nine new chemicals added to the list of those that the world community agrees we need to control and ultimately get rid of or manage them more effectively," he said.

The newly targeted chemicals include products that are widely used in pesticides and flame-retardants, and in a number of other commercial uses, such as a treatment for head lice.

These nine toxic chemicals will join the Stockholm Convention's original list of 12 Persistent Organic Pollutants, referred to as the "dirty dozen."

The pollutants are especially dangerous because they cross boundaries and travel long distances, from the Equator to the Arctic.  They persist in the atmosphere and take many years, often decades, to degrade into less dangerous forms.

They pose great risks to the environment and human health, especially to young people, farmers, pregnant women and the unborn.

The executive secretary of the Stockholm Convention, Donald Cooper, said the pollutant chemicals accumulate in the fatty tissues of humans and animals."It bio-accumulates in more than just humans.  It bio-accumulates up the food chain.  So, it goes from the plankton on up to the squid to the fish to you.  So, you are not only exposed to them in the environment, you are eating them?The affects of the chemicals are wide-ranging from the negative impact reproductive systems and mental capacity, growth and intelligence.  They cause cancers.  So, it is a whole array of these things," he said.

The governments also decided to continue the use of the pesticide DDT on a limited basis to combat malaria.   The goal, they say, is to eventually eliminate DDT.  But, they recognize that some countries will continue to use the pesticide to protect their citizens from malaria and other diseases.