2.21 PESTICIDES
Manahan (19..) discusses pesticides as water pollutants. DDT was introduced after World War II which accelerated pesticide use. Manahan (19..) states that by the mid-1990s agricultural use of pesticides was over 300 million kg per year and millions more kg of pesticides were used in non-agricultural applications.
Manahan: Insecticides such as diazinon, carbaryl and chlorpyifos are most commonly found in water. Insecticides are found in urban streams. Herbicides used in agricultural production are found in water from rural watersheds.
Furthermore Bartram states that pesticides and herbicides used in agriculture frequently lead to the contamination of surface water and groundwater.
According to Harrison pesticides in water aquifers are not easily degraded and persist in the aquifers due to reduced microbial activity, lower
…show more content…
The variables measured are nitrate, nitrite, total phosphorus, ammonia and transparency.
Harrison also states that river and Lake Eutrophication is a problem across most of Europe because of excessive nitrogen and phosphorus levels from agricultural, industrial and domestic effluents.
Harrison states that natural organic matter is present in most natural eco systems.
According to Harrison Eutrophication is the excessive production of algae and higher plants through the enrichment of waters by nitrogen and phosphorus. Phosphorus in the form of phosphate is the limiting nutrient as the amount of biologically available phosphorus is small in relation to the amount needed for algal growth.
Harrison states that sources of nutrients can be discrete, (sewage), or diffuse, (farmland fertilizers).
Harrison describes Eutrophic lakes as highly productive and turbid due to algae being present. Furthermore Harrison states that oligotrophic lakes have low productivity and are clear in the