Pollution is the introduction of harmful substances (chemicals, such as heavy metals, pesticides, industrial organics, etc.) or physical factors (light, noise) into the environment. Pollutants can be harmful for species and ecosystems as well as for humans.
Toxic substances can result in death or altered reproductive capability. Substances that accumulate in the tissues of living organisms affect species that are higher on the food chain far more than those below them, resulting in high mortality among the top predators, thus unbalancing the entire chain.
Fertilizers used in agricultural practices (particularly nitrogen) and phosphates from domestic detergents may have dramatic impacts on the biodiversity of surrounding or downstream areas (e.g. algal blooms, creating dead zones in lakes and oceans).
In Canada, governmental intervention in controlling pollution has resulted in significant reductions in many kinds of pollutants over the past few decades. However, this is not the case in many developing countries. Not only must they be encouraged to tackle pollution effectively, but they must also be supported in these efforts by concrete measures and actions on the part of the developed world, at all levels, from central governments to concerned individuals. A similar cooperative approach between developed and developing nations is also essential in dealing with climate change.
These texts have been provided by the Université de Montréal Biodiversity Centre.