Assessment of Selected Food Products for Pesticide Residue in Major Markets of Oyo State, Nigeria

A study was carried out on the assessment of selected food produce for pesticide residue in Oyo State. With the aid of multi stage sampling technique, 8 selected markets were surveyed in the major constituencies of Oyo State which included Oje and Bodija Market in Ibadan, Arada and Sabo Markets in Ogbomoso, Ajegunle and Araromi Market in Oyo, Owode and Sango Markets in Igboho and Saki respectively in Oke-Ogun. Information on type of pesticide use, reason for choosing the pesticide, method of applying the pesticide and duration of post application storage, were collected. Food produce sampled were yam chips, cowpea, maize and smoked fish for residual analysis. The residual analysis includes extraction of samples, cleaning of extraction and screening of the pesticide using GC-MS to detect any chemical metabolites. The survey reveals that majority (87.5%) of respondents were involved in selling of maize, yam chips and cowpea and the most used pesticide in the market was Aluminium phosphide marketed as phostoxin. Many of respondents applied pesticide by fumigation and the choice of these pesticides was base on customary practices. These food produce are stored for less than a month before being disposed of to consumers. Result from residual analysis shows sample from all the markets contains high percentage of alkane compounds especially the heptadecanes, eicosane, hexadecane and octadecane. Organochlorines were also found in the samples at high percentage. Banned pesticides are still in use in the visited markets and the use of banned pesticide should be prohibited and extension scheme on the use of pesticide on stored produce should be sponsored by government. This will help educate pesticide users on the use of pesticides and its health implications. Consumers are also implored to wash their food very well before consumption so as to remove pesticides that may be present on the seed coat or surface of food produce.