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Sampling of pesticides in a river. |
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Tuesday, 06 May 2008 |
 Each year, is applied about 20 million kilograms of pesticides on crops in the Canadian Prairies. Scientists still do not understand quite the migration process pesticides depui the area of application or their impact on water quality.Since the 1940's, using synthetic pesticides chlorinated, but scientists have established for several decades that some of them causing serious environmental problems.
Although Canada has adopted regulations and established a process of environmental screening, many questions remain unanswered about the mode of penetration of pesticides and their residues in aquatic ecosystems.
We know the potential effects on the environment of less than 5% of the 23 000 substances manufactured, imported or used in Canada for commercial purposes.
The contaminants are found usually in the form of mixtures, whose toxic effects are still unknown. The interaction of mixtures such as nutrient-contaminants and metals is a problem that requires urgent environmental benefit research.
Recent studies suggest that a wide variety of potentially toxic substances entering the environment and many of them were not considered contaminants so far. These substances may have adverse effects on the environment at concentrations much lower than those previously recognized by scientists.
Researchers at the NWRI study the pesticide contamination of the aquifers and receiving water downstream that is attributable to the current methods of irrigation and assess the impact of current or new methods of tillage on the quality of Water. They also examine the transport of pesticides in runoff and effects on water quality of wetlands, ponds and reservoirs used on farms.
Scientists are studying the interactions between soil and water and transporting nutrients and contaminants; besides, they assess the transport and atmospheric deposition of contaminants in agricultural grassland ecosystems. They also examine the capacity of dissolved organic carbon to protect microbial communities wetlands against the harmful effects of herbicides and other priority substances.
The NWRI assesses the risks posed by the priority substances such as alkylphenols and Municipal Wastewater to the aquatic environment and compare options sanitation and best management practices to reduce chemical spills from toxic effluents and runoff. To determine the effectiveness of Canadian regulations on the use of tributyltin as antifouling product, NWRI is continuing its work to establish its presence in aquatic ecosystems and sediment in Canada and evaluate the toxicity benthic organisms .
Researchers are developing new tools to establish and measure the toxicity of complex mixtures, pesticides and manure textile mills, effluent stations municipal wastewater treatment products and agricultural runoff; moreover, they are developing modeling techniques Neuromimetic toxic effects. They also are studying the mechanisms of transport and disposal of contaminants associated with hydrocarbons from oil sands in rivers.
Scientists studying the impact of salt on freshwater ecosystems and the effects of contaminants on wetlands in Canada.
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Last Updated ( Monday, 30 June 2008 )
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