| Other pollutants include Radioactivity, Fluoride, Selenium. |
| Sources and notes: |
| 1 Principally from Revenga and Mock, 2000. Their compilation
from Taylor and Smith, 1997; Shiklomanov, 1997; UNEP/GEMS, 1995 |
| 2 From R. Peters, W. Beck, personal communication, 2004. |
| 3 Micro-organic pollutant list now includes a suite of
endocrin disrupters, antioxidants, plasticizers, fire retardants, insect
repellents, solvents, insecticides, herbicides, |
| fragrances, food additives, prescription drugs and
pharmaceuticals (e.g., birth control, antibiotics, etc.), non-prescription
drugs (e.g., caffeine, nicotine and derivatives, stimulants). |
| 1 Organic matter |
Industrial wastewater and domestic sewage. |
Depletion of oxygen from the water column as it decomposes, stress or
suffocating aquatic life. |
Biological Oxygen Demand (BOD), Dissolved Organic Carbon (DOC), Dissolved
Oxygen (DO) |
| 2 Pathogens and microbial contaminants |
Domestic sewage, cattle and other livestock, natural sources. |
Spreads infectious diseases through contaminated drinking water supplies
leading to diarrhoeal disease and intestinal parasites, increased childhood
mortality in developing countries. |
Shigella, Salmonella, Cryptosporidium, Fecal coliform (Coliform),
Escherichia coli (mammal faeces – E. Coli) |
| 3 Nutrients |
Principally runoff from agricultural lands and urban areas but also from
some industrial discharge. |
Over-stimulates growth of algae (eutrophication) which then decomposes,
robbing water of oxygen and harming aquatic life. High levels of nitrate in
drinking water lead to illness in humans. |
Total N (organic + inorganic), total P (organic + inorganic) For
eutrophication: (Dissolved Oxygen, Individual N species (NH4, NO2, NO3,
Organic N), Orthophosphate) |
| 4 Salinization |
Leached from alkaline soils by over irrigation or by over-pumping coastal
aquifers resulting in saltwater intrusion. |
Salt build-up in soils which kills crops or reduces yields. Renders
freshwater supplies undrinkable. |
Electrical conductivity, Chloride (followed, post characterization by full
suite of major cations (Ca, Mg), anions |
| 5 Acidification (precipitation or runoff) |
Sulphur, Nitrogen oxides and particulates from electric power generation,
industrial stack and auto/truck emissions (wet and dry deposition). Acid
mine drainage from tailings as well as mines. |
Acidifies lakes and streams which negatively impacts aquatic organisms and
leaches heavy metals such as aluminium from soils into water bodies. |
pH |
| 6 Heavy metals |
Industries and mining sites. |
Persists in freshwater environments such as river sediments and wetlands for
long periods. Accumulates in the tissues of fish and shellfish. Can be toxic
to both aquatic organisms and humans who consume them. |
Pb, Cd, Zn, Cu, Ni, Cr, Hg, As (particularly groundwater) |
| 7 Toxic organic compounds and micro-organic pollutants.3 |
Wide variety of sources from industrial sites, automobiles, farmers, home
gardeners, municipal wastewaters. |
A range of toxic effects in aquatic fauna and humans from mild immune
suppression to acute poisoning or reproductive failure. |
PAHs, PCBs, pesticides (lindane, DDT, PCP, Aldrin, Dieldrin, Endrin,
Isodrin, hexachlorobenzene) |
| 8 Thermal |
Fragmentation of rivers by dams and reservoirs slowing water and allowing it
to warm. Industry from cooling towers and other end-of-pipe above-ambient
temperature discharges |
Changes in oxygen levels and decomposition rate of organic matter in the
water column. May shift the species composition of the receiving water body. |
Temperature |
| 9 Silt and suspended particles |
Natural soil erosion, agriculture, road building, deforestation,
construction and other land use changes. |
Reduces water quality for drinking and recreation and degrades aquatic
habitats by smothering them with silt, disrupting spawning and interfering
with feeding. |
Total suspended solids, turbidity |
