Ninety-nine human blood samples were collected from the riverine region of northern Sudan and the traditional and mechanized rain-fed areas of western and eastern Sudan, representing areas of limited pesticide use in Sudan. Blood samples were analyzed for organochlorine pesticides by gas liquid chromatography (GLC) followed by electron-capture detection (ECD). p,p′-DDE (a metabolite of DDT), heptachlor epoxide, β-hexachlorocyclohexane (β-HCH), and dieldrin were detected in all locations surveyed. The level of total organochlorine burden was highest in the traditional rain-fed area, followed by the mechanized rain-fed area, and the riverine area. A highly significant correlation was observed between total organochlorine blood burden and the age of the donors (r = 0.608**).
The potential of sunlight photolysis in remediation of pesticide-polluted soils in Sudan is reported. The common pollutants endosulfan (alpha- and beta- isomers) and pendimethalin were exposed to sunlight over glass and soil surfaces and the periodically drawn samples were analyzed by GC-ECD and GC-MS. Photo-degradation followed biphasic model. The half-lives of direct photolysis of the two pesticides over glass and soil surfaces ranged between 1.840-6.720 d and 2.711 to 9.760 d respectively. The respective values for indirect photolysis of the two pesticides with ß-carotene over glass surface were 0.846-1.605 d and for benzophenone 1.050-1.626 d. Values for soil ß-carotene sensitized photolysis of the two pesticides were 2.260-3.158 d while the corresponding values for benzophenone sensitized photolysis on soil were 1.193-2.880 d. Meteorological factors did not show significant impact on photolysis rates. Despite the significant decrease in starting material in direct no photoproducts were detected. However, many photoproducts were detected on the indirect sets. Photo-degradation efficiency can be arranged in the order benzophenone > ß-carotene > direct exposure.