Fabrication of PUF Filters for Assessment of Pesticides Residues in Ambient Air Around Kabete and GC/GCMS Analysis

Pesticides are substances used to destroy, prevent or repel pests. The hot and humid environmental conditions in the tropical countries promote the growth and development of a myriad of pests and disease vectors. Hence, pesticides are used for economic management of crops and livestock and in protection of public health. Although pesticides are developed through very strict regulations to function with reasonable certainty and minimal impact on human health and environment, serious concerns have been raised about health risks resulting from occupational exposure and from residues in food and drinking water. Environmental transport of pesticide through water, soil, air, contamination from leaching, runoff and spray drift cause adverse health effect on human as well as wildlife, plants and non- target organisms.

The main objective of this study was to fabricate passive air samplers using locally available PUF and test its performance to trap organochlorine pesticides in air.  Fubricated samplers were installed at a site in Kabete and samples collected periodically. Air and soil   samples were collected at a monthly interval and analysed for organochlorine pesticide residues. The soil samples were further characterized for physico-chemical properties.

Extraction of pesticides was done using dichloromethane for  air samplers and hexane   acetone (3;1,v/v) for soil samples. The samples were screen for 17 organochlorines including 4 HCHs, aldrin, heptachlor, heptachlor epoxide, DDT, DDD, endrin, endrin aldehyde, endosulfan 1 & 2, endosulfan sulphate, diedrin and methoxychlor using Gas chromatography equipped with Electron Capture Detector.

The results obtained showed varying ranges of pesticides from one month to the other. The concentration in soil was higher than the levels measured in ambient air. The result suggest that the locally made PUF can be used in passive sampling equipment to trap OCPs in ambient air. The presence of OC pesticide residues in ambient air suggests contamination and threat to human health. Further studies should be done to calibrate the passive samplers using local PUFs and to determine the sampling rate.

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