**6. Distribution of endosulfan in the environment**

Endosulfan is widely distributed in the environment and can be detected in all media, soil, sediments, air, water, and vegetation, over long distances from the application source. Levels of endosulfan in the air samples are very variable depending on the location. Recent measurements indicate that around 320 d is the half-life in the atmosphere [18].

Endosulfan is one of the most abundant organic pesticides in the atmosphere and is capable of reaching remote locations such as the Arctic. The presence of endosulfan in the Arctic at concentrations between 3 and 8 pg m−<sup>3</sup> has been detected. Endosulfan concentration was obtained using an XD-based passive sampler with samples collected in monitoring stations.

It has been suggested that the transport of endosulfan occurs when the compound volatilizes from warmer regions, experiences long-range atmospheric transport, and condenses again, permitting an accumulation of the substance in temperate regions, higher mountains, and the Arctic. Endosulfan residues in snow and ocean waters in the Artic indicate that atmospheric deposition of endosulfan is taking place, and it can promote bioaccumulation in zooplankton and various species of fish. For some biota, a biomagnification factor for α-endosulfan from fish to seal is also occurring [3, 19–21].

formation of endosulfan diol. A positive correlation between hydrolysis rate (khydro) and pH, with base-driven hydrolysis, a predominant degradation process in seawater conditions, allows a rapid degradation of endosulfan into endosulfan sulfate, whereas it takes longer in

Dissemination of Endosulfan into the Environment http://dx.doi.org/10.5772/intechopen.81094 9

Furthermore, hydrolysis of endosulfan sulfate to endosulfan diol is markedly slower com-

The biodegradation of endosulfan has been reported in anaerobic conditions; these conditions predominate in sediments and the results can contradict the interpretation of the isomer deposition in freshwater sediments. At neutral pH and aerobic conditions, the degradation of endosulfan by biological oxidation has also been reported, being sulfate of endosulfan, the

It has been reported that the decomposition of endosulfan in aqueous solution can take place, but some natural environmental factors lead to the formation of sulfate indicating that some oxidation pathway is followed. The values are much lower than the persistence criteria designated for a POP, although in the colder marine waters at high latitudes, base-driven hydrolysis half-lives for endosulfan are likely to be greatly extended, compared to warmer waters in

pure water.

pared to the hydrolysis of α-endosulfan.

**Figure 2.** Degradation of isomers α- and β-endosulfan.

compound with the heaviest concentration.

temperate or tropical regions [3, 15, 23].
