Sources, distribution, and risk assessment of organochlorine pesticides in Nairobi City, Kenya.

The distribution and sources of organochlorine pesticides (OCPs) in air and surface waters were monitored in Nairobi City using triolein-filled semipermeable membrane devices (SPMDs). The SPMDs were extracted by dialysis using n-hexane, followed by cleanup by adsorption chromatography on silica gel cartridges. Sample analysis was done by GC-ECD and confirmed by GC-MS. Separation of means was achieved by analysis of variance, followed by pair-wise comparison using the t-test (p≤ 0.05). The total OCPs ranged between 0.018 - 1.277 ng/m in the air and Kibera > Industrial Area > City Square > Ngong' Forest. However, these were lower than the USEPA acceptable risks, 10 - 10. This study concluded that atmospheric OCPs did not pose significant cancer risks to the residents.