Cancer has become a major killer in Zimbabwe. As a correlation has been reported between pesticide use and several types of cancer, the aim of the present study was to carry out a GC-MS survey for carcinogenic or suspected carcinogenic and other toxic substances in agriculture in the country. The Bromley farming area, about 20 km east of Harare, was selected for the study. Soil samples were collected from 8 farms randomly selected in the area. In addition, borehole water and river water from one farm each were also collected. All the samples were analysed using GC-MS after appropriate sample pre-treatment and concentration. Pesticide detection software was employed for peak assignment. All together 48 toxic substances were detected in soil samples and include 14 carcinogenic or suspected carcinogenic substances (DDT, DDE, DDD, acetachlor, atrazine, diaznon, furilazole, iprovalicarb I and II, methiocarb, methoxychlor, metolachlor, propamocarb, tetraconazole and toxaphene palar 26). Eight pesticides were detected in the river water sample, of which 3 are suspected carcinogens (Atrazine, acetachlor, and methoxychlor), and while 7 pesticides were detected in the borehole water sample, of which 3 are suspected carcinogens (Chlordimeform, Iprovalicarb II and methidathion). The study confirms contamination of soil, river water and underground water in the Bromley Farming area by suspected carcinogenic substances.
Keywords: carcinogenic substances; GC-MS survey; terrestrial environment; pesticides; persistent organic pollutants; DDT