Agricultural activities, chemicals from

This high agriculture activity compromises the chemical and ecological status of the Ebro delta. Pesticides used in the area migrate into the delta building up, together with the pollution produced by some industries, a contamination that can be dangerous to its both fauna and flora, and this contamination increases when water from the rice fields is drained into the delta [17]. 

Primary organics are emitted to the atmosphere by industrial sources (oil refineries, chemical plants, producers and users of solvents and plasticizers), vehicles (as a result of incomplete fuel combustion, oxygenated degradation products of lubricating oil, polymers from tires), and agricultural activities (use of pesticides). An exhaustive literature survey is beyond the scope of this section, but can be found in Air Quaiity Criteria for Particulate Matter many useful references are also available. 

Synthetic organic chemicals have been isolated by either resin adsorption or direct methylene chloride liquid—liquid extraction. Analyses for 48 distinct chemical entities in river water from a river located in North Carolina s Piedmont area were carried out. The river was sampled at three locations several times during a 13-month period (41). Most frequendy included among the 48 chemicals found were atrazine, methyl atraton (triazine herbicides), dimethyl dioxane, 1,2,4-trichlorobenzene, tributylphosphate, triethylphosphate, trimethylindolinone, and tris(chloropropyl) phosphate. Many of these chemicals are indigenous to industrial and agricultural activities in Piedmont. The concentrations were in the ng/L to mg/L range. 

Many important agricultural processes involve providing nutrients and chemicals to organisms to maximize their rate and yields of growth or of formation of some product such as grain. A more systematic and rational analysis of transport of the active material from the preparation applied into... 

Chemicals from agricultural activities (including pesticides)... 

Part B provides practical guidance on identifying specific chemicals that are likely to be of concern in individual water supply systems. It groups chemical contaminants into five categories on the basis of their potential sources naturally occurring, from agriculture activities, from human settlements, from industrial activities, and from water treatment and distribution processes themselves. 

Wildlife associated with agricultural activities are more likely to be exposed to pesticides than those distant from human habitat. Aquatic species living in estuaries are more likely to contain chemical pollutants than those found in mountain lakes and streams. Moreover,... 

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