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18 1. Air and ater Pollution W

biological oxygen demand (BOD), which is a measure of the amount of dissolved oxy-
gen needed by aquatic microorganisms for the degradation of waste.
Pollution by Persistent Organic Chemicals (POPs)

Besides biodegradable organic compounds, there are also organic substances that sho w
great resistance and high lifespan in the environment, thus constituting a long-term danger
to life. Dioxins, polychlorinated biphenyls (PCBs), and pesticides (DDT and others) are
man-made compounds that remain intact for months in the environment. Consequently ,
people and animals at the top of the food chain eentually consume food containing these v
, compounds. DDT a popular compound that helped in the elimination of malaria, w as
proved to have many adverse effects on natural life. Paul Muller, who discovered the effec-
tiveness of DDT as an insecticide in 1939 was aarded the Nobel Prize in medicine and w
physiology in 1948 for this discovery. Today, DDT is banned in most developed countries.

Eutrophication by Nitrates and Phosphorus
Eutrophication is the rapid depletion of dissolved oxygen in a body of water because of an
increase in biological productivity. It is connected to the excess presence of plant nutrients
vironment,
in the en mainly nitrates and phosphorus. These compounds are connected to
xcessi the eve use or production of fertilizers.
Inorganic Pollutants
Metals, nonmetals, and acids/bases released by human acti ater v vities se erely deteriorate w
quality, since they are toxic een at concentrations of parts per million. It has to be noted v
that heavy metals are extremely dangerous to human health and aquatic life. But what is
worse is that there is nocycle of natural treatment of these substances. Ine hea , vitably vy
metals remain intact in the environment and finally, they are accumulated in the food chain
(bioaccumulation).
Unless we take the right course of action, problems associated with both quality and
quantity of water are going to be encountered, e gions that seem to ha v v en in re icient f e suf
amounts of clean water today. After the disputes and wars over the possession of oil in the
past, water may be the next conflict territory between adjacent countries, een in Europe. v
According to the EC, 20% of all surface water in the European Union is seriously threat-
uted in Europe and enly distrib ened with pollution. Furthermore, w v ar from being e ater is f
xample,
this is one major reason for resource problems. For e whereas freshwater a v ail-
ability is more than 100,000 m 3 per capita per year in Iceland, it is less than 10,000 m 3 per
capita per year in Switzerland, Portugal, and Spain.
v The aailable water in a country or region depends on the rainfall and on the net result
xample,
of flows from and to its neighbors, mainly through riers. For e in Iceland,
v
,
Norway, Sweden, Denmark, the United Kingdom, Italy Spain, France, and Finland, more
,
than 98% of freshwater is generated within the country whereas in Hungary and the
Netherlands more than 50% of freshwater is due to river flows from other countries (Nixon
et al ., 2004).
So, most European countries rely more on surface water than groundwor e . F ater xam-
ple, Finland and Lithuania take more than 90% of their total supply from surface w aters