International Journal of Environmental and Health Sciences, 1(1), 2018 Joyce Oloo Asuke1, Marion Mutugi2, Yeri Kombe3 1. Technical University of Kenya, P.O. Box 52428 – 00200, Nairobi – Kenya. 2. Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62,000 – 00200, Nairobi, 3. Kenya Medical Research Institute (KEMRI), P.O. Box 54840 – 00200, Nairobi…