by Dr. Fabio Arjona

· Mr. James Willis, Director of the Area of Chemical Substances of UNEP:

· Respected Lecturers:

· Distinguished Delegates:

It is for me an honor to welcome you to the city of Cartagena de Indias and to this Subregional Workshop on Persistent Organic Pollutants.

Every day there is more evidence of the impact that human activities have on the environment and of the changes that they generate in the natural balance of the ecosystems.

More than ten years ago, the hole in the ozone layer demonstrated the effects of the chlorofluorocarbons on the atmosphere. More recently, we have confirmed that the emissions of greenhouse gases are generating an impact on the global climate. Today we see how the use of other chemical substances can generate a series of effects harmful to the environment and man.

The international community has been responding to each of these challenges with greater or lesser success. The latest challenge is posed by the persistent organic pollutants, whose effects on the environment and rational management still leave many questions.

Thus far we know little; a variety of chemical substances have been identified: pesticides, materials used in industry, and degradation products.

These stable substances, which persist in the environment, have a series of toxic effects on living organisms and ecosystems.

Unlike other environmental problems that have indirect effects on man, the use of persistent organic pollutants has a powerful direct effect on human health and compromises the well-being of future generations.

The key components of an adequate response to this new threat to our health, that of our children, and the integrity of our ecosystems are the availability of information, trained staff, and development of research capacity. Unfortunately, these management tools are scarce in our countries.