Monitoring of pesticide residues in fresh fruits and vegetables available in Nigerian markets and assessment of their associated health risks.

The presence of pesticide residues in agricultural products is posing serious health concerns for consumers. This study monitored the concentrations of pesticide residues in some selected fruit and vegetables, and their potential health risks were also assessed. Organochlorine (OCPs) and organophosphate (OPPs) residues were extracted and quantified with a gas chromatography-pulsed flame photometric detector. A total of 38 pesticide residues were identified and the results showed mean concentration (mg/kg fresh weight) of (OCPs) residues ranging from 0.02 to 0.37 and (OPPs) residues ranging from 0.01 to 0.33. The concentrations (mg/kg) of isodrin, heptachlor, dicofol, prothiophos, profenofos and dichlorvos were above the maximum residue limit. The non-carcinogenic health risk estimates revealed a possible potential health risk from consumption of the fruits and vegetables in adults and children for most of the pesticide residues. The cancer risk assessment estimates gave values below 10-6 which suggests no probable cancer risk. As a result of the increasing trend in pesticide use in Nigeria, routine monitoring of pesticide residues in agricultural produce is a necessity to ensure the safety of consumers.

Pollution status of major rivers in an agricultural belt in Eastern Nigeria.

The physico-chemical and bacteriological analyses of four rivers namely: Ajali, Obinna, Karawa and Adada in Ezeagu and Uzo-uwani Local Government Areas (LGAs) of Enugu State, South-eastern Nigeria, were carried out to evaluate their suitability for consumption. Water samples from Ajali River were taken from a point where the river receives brewery effluents and other two points that were impacted by non-point pollution sources. A total of 54 water samples were collected during the dry season, early rainy season and rainy season proper for 2 years. For each trip, nine samples were collected from three sampling points in Ajali and two each in Adada, Obinna and Karawa. The water quality index (WQI) was calculated using the arithmetic index method. Significant seasonal and spatial variations (p < 0.05) were evident for sulphate, phosphate, sodium, magnesium, pH, total alkalinity, nitrate and total dissolved solids. Mean values of WQI were 71.75 ± 16.07 57.26 ± 5.39, 60.47 ± 13.12, and 66.75 ± 15.30 for Adada, Obinna, Karawa and Ajali, respectively.