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endangered by toxic, mutagenic, carcinogenic, reprotoxic, sensitizing, endocrine and
immune system disrupting chemical substances (see Chapter 2). These chemical sub-
stances enter the environment as emission from production, transport and technologies
or during the waste phase of the material or product.
The consequences of pollution may be direct, through the toxic effect of a substance
on humans or ecosystem members or indirect, as a consequence of physical, chemical
and biological processes in the environment. These processes include transport, parti-
tion, chemical reactions, biotransformation, bioaccumulation and food chain effects
of the contaminating chemical substances. Accidental spills of pesticides entering a
river may well have an immediate direct effect and can be very harmful to the aquatic
life. Their indirect effect may harm higher members of the food chain by killing prey
species or by accumulation along the food chain. The same pesticide may not be acutely
toxic for humans but if it is persistent in the environment, it can cause long-term car-
cinogenic, immune or endocrine disrupting effects through drinking water or food
consumption. Typical and well-known outcome of a complex deterioration process in
surface waters is eutrophication, caused by enhanced phosphorus levels in the water
(that contains adequate amounts of nitrogen) through the stimulation of excessive algal
growth. The decay of excess algal biomass reduces the dissolved oxygen content of the
water and damages fish and other aquatic life (FWR, 2013). Devastation of aquatic
animals enhances the oxygen consuming processes, resulting in an aquatic catastrophe
killing all aerobic life.

2.1.2 Typical pollution sources

Examples of potential sources of air and water pollution are given below:

- Water and air transportation, the burning of fossil fuels for heat and energy pro-

duction, as well as industry and mining are major air polluters: in addition to
GHGs, they produce sulfur and nitrogen oxides and toxic gases or volatile organic
and inorganic compounds. Smelters and incinerators are still highly risky poten-
tial sources today even though protective and control equipment is available and
obligatory. The most exposed areas are big cities and industrial and mining areas.
There are insecticides, herbicides, radioactive fallout, and dust (particulate matter,
PM) from industry and agriculture among air pollutants.

- Landfill sites can be sources of water pollution due to leachate generation from

rainfall;

- Contaminated land ( contaminants : toxic metals, hydrocarbons and organic

chemicals) may result in surface water, sediment and groundwater contamination;

- The principal form of water contamination from mining is acid mine drainage

(AMD) and acid rock drainage (ARD). Coal and metal ore seams and their asso-
ciated rock strata contain pyrite (FeS 2 , iron disulfide) which oxidizes when in
contact with air and in the presence of bacteria to form sulfuric acid. Conse-
quently, drainage from a mine has very low pH (i.e. high acidity) and contains
high concentrations of sulfur, iron and a range of heavy metals. This becomes
more prevalent when mines are closed and water, which has previously been pre-
vented from entering the mine through pumping, is allowed to have unrestricted