Survey of pesticide residues in maize, cowpea and millet from northern Cameroon: part I

Abstract

In northern Cameroon, the misuse of pesticides for pest control is common among small-scale farmers. Therefore, monitoring of pesticide residues was carried out on stored maize, cowpea and millet from eight localities. The determination of residues of organochlorines (lindane, α-endosulfan and β-endosulfan), organophosphorus compounds (malathion and pirimiphos-methyl), synthetic pyrethroids (permethrin) and carbamates (carbufuran) was performed using GC-ECD/NPD and GC-MS for confirmation. Organochlorine pesticides were detected more frequently and in higher concentrations, ranging from 0.02 ± 0.01 mg kg(-1) for β-endosulfan in millet to 9.53 ± 4.00 mg kg(-1) lindane in maize, than organophosphorus compounds, with concentrations varying from 0.04 ± 0.03 mg kg(-1) for pirimiphos methyl to 0.23 ± 0.38 mg kg(-1) for malathion in maize. Permethrin was found only in maize at 0.39 ± 0.23 mg kg(-1). No carbofuran was found. More than 75% of samples contained pesticide residues above the maximum residue limit (MRL); showing a potential human dietary risk related to consumption of these grains.

Evaluation of 99 Pesticide Residues in Major Agricultural Products from the Western Highlands Zone of Cameroon Using QuEChERS Method Extraction and LC-MS/MS and GC-ECD Analyses

“…In maize, cowpea, and millet samples from northern Cameroon, organochlorine and organophosphorus pesticides including β-endosulfan, lindane, pirimiphos-methyl, and malathion were detected more frequently [10]. Moreover, Sonchieu et al [5] found that in cowpea samples from the markets of Ngaoundéré in northern Cameroon, residues of the organophosphorus pesticides dichlorvos, methyl-parathion, malathion, profenofos, diazinon, and chlorpyrifos were found in concentrations ranging from 0.02 to 5.4 mg/kg.…”

“…Our results are comparable to the findings of Bempah and Donkor [29], who reported 32.8% of fruit samples with residues above MRLs, and Mekonen et al [2], in which one-third of samples were above the MRLs. However, Sonchieu et al [10] obtained higher values, with 75% of samples containing pesticide residues above MRLs. These disparities could be due to the single food item (cowpea) used in their study.…”

“…Ten years ago, Gimou et al [9] revealed low dietary exposure to pesticide residues in the capital city, Yaoundé. But more recently it was found that 75% of maize, cowpea, and millet samples from northern Cameroon contained pesticide residues above the maximum residue limits (MRLs) [10], and high amounts of organophosphorous pesticide residues were found in stored cowpea and two by-products [5], revealing a potential human dietary risk related to consumption of these grains. …”

“…Recent studies [4] suggested that the male farmers of Djutitsa in West Cameroon are exposed to agro-pesticides due to improper personal protective equipment (PPE), and this exposure may impair their reproductive function. Inappropriate use of pesticides by Cameroonian farmers has been documented in many studies from different parts of the country [4,7,10,11,12,13]. This was because farmers did not receive sufficient training on pesticide application and proper assistance from agricultural extension agents [7], which could result in high levels of pesticide residues in local foods.…”

Development and Validation of a Method for the Simultaneous Determination of 20 Organophosphorus Pesticide Residues in Corn by Accelerated Solvent Extraction and Gas Chromatography with Nitrogen Phosphorus Detection

“…The use of OPPs as post harvest pesticides is mainly due to the lower rate of degradation under the storage conditions that exist in storehouses.The post-harvest pesticides have been attracting much attention because their residues in stored cereal grains may be hazardous to human health [8]. The presence of OPPs residues in corn is still reported [9,10]. The monitoring of pesticide residues in corn and corn products is of a significant importance in terms of consumer safety.…”