Analysis of Organic Contaminants in Uasin Gishu County Wood Treatment Facilities and their Associated Etiological Risks

The environmental and public health caused by organic contaminants in wood treatment plants has been a longstanding problem for decades. This study investigates the introduction of persistent organic pollutants to the environment from wood preservatives such as pentachlorophenol and creosote in Uasin Gishu wood treatment plants.

Twenty gram (20 g) soil samples collected in sterilized bags were subjected to Soxhlet extraction between 60 ºC and 70 ºC in a binary solvent mixture of hexane and ethanol, ratio 4:6 for 48 h, and the extract analysed using a Gas chromatograph coupled to a mass selective detector (MSD). Elemental analysis of soil sample was performed using Perkin Elmer PE 2400 CHNS/O elemental analyzer.

The study showed the elemental composition of carbon ranged between 40 and 48% whereas that of hydrogen ranged between 29 and 35%. The concentration range of organic contaminants was 0.50 – 177.41 ppm with 56.92% of the total dibenzofuran recorded in Sikunanga (SK) wood treatment site. Benzo[a]anthracene (BAA), considered an important class of environmental genotoxins was found to be in relatively high concentration in SK at 67.4% and 29.2% in Outspan (OS), while the rest of about 3.3% was found in Cheplaskei (CK). The Toxic equivalent factor in the sampled area ranged from 0.001 – 5.083.

The incremental life-time carcinogenic risks for all the study sites were above 10⁻⁴, indicating severe etiological risks. Therefore, this study is beneficial to local authorities in regulating the use of toxic chemicals in wood treatment facilities while advocating for continuous environmental monitoring.