Aflatoxins in maize and groundnuts on markets in Accra and consumers risk.

This study presents the results of aflatoxin contamination of maize and groundnuts in major markets in Accra and assesses the population's exposure to aflatoxins. Raw maize and groundnuts from 6 major markets in Accra were sampled and analysed for their aflatoxin content. A total of 92 samples comprising 48 maize and 44 groundnuts were analysed using high-performance liquid chromatography, after extraction with methanol/water and cleanup on an immunoaffinity column. Total aflatoxins were quantified in 98% of the maize samples and 70% of the groundnut samples, with concentrations ranging from 0.60 to 1065 µg/kg and 0.20 to 627 µg/kg, respectively. Exposure assessment showed an estimated daily intake of 0.436 µg/kg bw/day and 0.0632 µg/kg bw/day for maize and groundnut consumption, respectively, suggesting significant health risks for consumers. The high prevalence and concentrations of aflatoxins call for an urgent need for measures to control exposure of the Ghanaian population.

Knowledge, perception, and pesticide application practices among smallholder cocoa farmers in four Ghanaian cocoa-growing regions.

Pesticides are widely used in Ghana, especially in cocoa farming. However, the practice is suboptimal and unsupervised. Incorrect use of these chemicals can seriously harm human health, the environment, and economies that rely on these farmers' output. The study assessed cocoa farmers' pesticide knowledge, practices, and risk perception. Four hundred and four cocoa farmers were chosen randomly from 26 communities in four cocoa-growing regions of Ghana to answer questions about their risk knowledge, awareness, and practices, including personal protective equipment, storage and disposal of leftover pesticides, and used containers. The study revealed that 87% of the respondents belonged to cooperatives and certification groups. There was a significant positive relationship between group membership and benefits derived from inputs and training in pesticide use. About 70% of insecticides used were approved by the Ghana Cocoa Board, with neonicotinoids and pyrethroids being the most highly used insecticide classes in cocoa farms. Although farmers claimed adequate pesticide knowledge, this did not translate into practice, with the majority exhibiting improper pesticide storage, application, and disposal practices. Farmers appeared to know a lot but lacked the skills and attitude to put their knowledge to use. The improper practices appear to manifest in a variety of health symptoms experienced by farmers as a result of chemical exposure. The findings from this study suggest that cocoa farmers in Ghana require adequate practical training and support on pesticide use to reduce their associated health risks, protect the environment and ensure sustainable cocoa production in the world's second-largest cocoa bean exporter.

Sorption and degradation of neonicotinoid insecticides in tropical soils.

Neonicotinoids are the most widely applied class of insecticides in cocoa farming in Ghana. Despite the intensive application of these insecticides, knowledge of their fate in the Ghanaian and sub-Saharan African environment remains low. This study examined the behavior of neonicotinoids in soils from cocoa plantations in Ghana by estimating their sorption and degradation using established kinetic models and isotherms. Studies of sorption were conducted using the batch equilibrium method on imidacloprid, thiamethoxam, clothianidin, acetamiprid and thiacloprid, while degradation of imidacloprid, thiamethoxam and their respective deuterated counterparts was studied using models proposed by the European forum for coordination of pesticide fate and their use (FOCUS). Analytes were extracted using the quick, easy, cheap, effective, rugged and safe (QuEChERS) procedure and quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Average recoveries were high (≥ 85%) for all analytes. The findings from the study suggest that neonicotinoid insecticides may be persistent in the soils studied based on estimated half-lives > 150 days. The study also revealed generally low-sorption coefficients for neonicotinoids in soils, largely influenced by soil organic carbon.

Quantification of neonicotinoid insecticide residues in soils from cocoa plantations using a QuEChERS extraction procedure and LC-MS/MS.

The use of neonicotinoids as an insecticide group in Ghana has been quite significant particularly in cocoa production. The high usage has been mainly as a result of a government policy of free insecticide spraying on cocoa farms, in an effort to curb declining yields caused by pests and diseases and to prevent the use of unapproved or banned insecticides on cocoa farms. However the scale of cocoa farming, the frequency and intensity of usage coupled with the mode of application may result in large physical volumes of insecticides in the environment. This makes the knowledge of the concentration and fate of neonicotinoids in the environment extremely important. The present study was aimed at assessing the levels of five major neonicotinoids in soils from cocoa farmlands in Ghana. Extraction and cleanup of analytes were performed by use of a method based on the original QuEChERS procedure after optimizing salts, sorbents and instrumental conditions. Analyte extraction with NaCl and MgSO4 in acidified acetonitrile followed by cleanup with primary secondary amine (PSA) presented the optimum conditions for extraction. Quantification was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI). Validation of the procedure showed average recoveries ranging from 72.0 to 104.8% for all analytes at all fortification levels with relative standard deviation (RSD) ≤ 15.0. Limits of quantitation were <10 µg kg(-1) for all neonicotinoids studied. The results obtained from the analysis of 52 samples from cocoa farms revealed imidacloprid as the predominant neonicotinoid with concentrations ranging from 4.3 to 251.4 µg kg(-1) in >50% of samples analyzed.