Pollution

What is pollution?

Pollution is the introduction of harmful materials into the environment. These harmful materials are called pollutants. Pollutants can be natural, such as volcanic ash. They can also be created by human activity, such as litter/trash or runoff produced by factories.

What are the 4 types of pollution?

The major kinds of pollution, usually classified by environment, are:

Modern society is also concerned about specific types of pollutants, such as noise pollution, radiation, light pollution, and plastic pollution.

What is a pollutant?

A pollutant is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like oil) or anthropogenic in origin (i.e. manufactured materials or by-products from biodegradation).

Pollutants can be categorized in a variety of different ways. For example, it is sometimes useful to distinguish between stock pollutants and fund pollutants. Another way is to group them together according to more specific properties, such as organic, particulate, pharmaceutical, et cetera. The environment has some capacity to absorb many discharges without measurable harm, and this is called “assimilative capacity (or absorptive capacity); a pollutant actually causes pollution when the assimilative capacity is exceeded

Persistent Organic Pollutants (POPs)

POPs are a set of toxic chemicals that are persistent in the environment and able to last for several years before breaking down (UNEP/GPA 2006a). POPs circulate globally and chemicals released in one part of the world can be deposited at far distances from their original source through a repeated process of evaporation and deposition. This makes it very hard to trace the original source of the chemical (http://web.worldbank.org/). POPs are lipophilic, which means that they accumulate in the fatty tissue of living animals and human beings (http://www.unece.org/spot/s01.htm). In fatty tissue, the concentrations can become magnified by up to 70 000 times higher than the background levels (http://web.worldbank.org/). As you move up the food chain, concentrations of POPs tend to increase so that animals at the top of the food chain such as fish, predatory birds, mammals, and humans tend to have the greatest concentrations of these chemicals, and therefore are also at the highest risk from acute and chronic toxic effects.

“Dirty Dozen”. These is a group of 12 highly persistent and toxic chemicals which is called "the dirty dozen":

Aldrin
Chlordane
DDT
Dieldrin
Endrin
Heptachlor
Hexachlorobenzen
Mirex
Polychlorinated biphenyls
Polychlorinated dibenzo-p-dioxins
Polychlorinated dibenzofurans
Toxaphen

Many of the pesticides in this group are no longer used for agricultural purposes but a few continue to be used in developing countries.