Marine Ecosystems under Toxic Pressure - Vulnerability of Coastal Ecosystems and Adaptation - page 8

More than 37 million chemical substances are currently listed in the
world, for the most part substances resulting from biosynthesis. Around
100,000 chemical substances are produced, imported and used on the
European market, and 5,000 of them (5%) are considered to be dangerous for
mankind and the environment. Sources of contamination by metals are
multiple and include mining activity, the steel industry, transport, the use of
different types of batteries and the painting and dying industries, as well as
the use of phosphorous fertilizer (cadmium). Taking account of the diversity
of the molecules, the study of organic contaminants represents a very
important undertaking. Very schematically, it is possible to distinguish four
main substance groups:
- hydrocarbons, of which aromatic polycyclic hydrocarbons (APHs) are
the most worrying for aquatic environments;
- pesticides, with some 900 types in current use and a usage rate of
80,000 tons applied each year;
- biocides, which refers to substances used in a non-phytopharmaceutic
context, such as additives included in anti-fouling paints for use at sea, which
cause non-negligible contamination by different organometallic (TBT) or
organic (diuron or atrazine such as Irgarol 1057) or active metallic substances
(copper);
- other organic synthetic substances that represent a large number of
substances (chlorinated solvents, PCB, flame retardants, phthalates,
detergents, colorants, etc.). The selection criteria for chemical contaminants
judged to be a priority for the environment are based on three properties:
persistence (P) defining persistent substances in the environment (for
example, persistent organic pollutants (POPs) such as
DichloroDiphenylTrichloroethane (DDT)), bioaccumulation (B) defining
their capacity to accumulate in organisms and toxicity (T). These three
properties define a group of substances that are called PBT substances. To
this group should be added substances that have carcinogenic and mutagenic
properties and effects on the reproductive system that are called CMR
substances. Endocrine disruptors are also associated with this group.
Box 1.1. The chemical universe and the environment