Assessment of average exposure to organochlorine pesticides in southern Togo from water, maize (Zea mays) and cowpea (Vigna unguiculata)

Abstract

Drinking water, cowpea and maize grains were sampled in some potentially exposed agro-ecological areas in Togo and analysed for their contamination by some common organochlorine pesticides. A total of 19 organochlorine pesticides were investigated in ten subsamples of maize, ten subsamples of cowpea and nine subsamples of drinking water. Analytical methods included solvent extraction of the pesticide residues and their subsequent quantification using gas chromatography-mass spectrometry (GC/MS). Estimated daily intakes (EDIs) of pesticides were also determined. Pesticides residues in drinking water (0.04-0.40 microg l(-1)) were higher than the maximum residue limit (MRL) (0.03 microg l(-1)) set by the World Health Organization (WHO). Dieldrin, endrin, heptachlor epoxide and endosulfan levels (13.16-98.79 microg kg(-1)) in cowpea grains exceeded MRLs applied in France (10-50 microg kg(-1)). Contaminants' levels in maize grains (0.53-65.70 microg kg(-1)) were below the MRLs (20-100 microg kg(-1)) set by the Food and Agriculture Organization (FAO) and the WHO. EDIs of the tested pesticides ranged from 0.02% to 162.07% of the acceptable daily intakes (ADIs). Population exposure levels of dieldrin and heptachlor epoxide were higher than the FAO/WHO standards. A comprehensive national monitoring programme on organochlorine pesticides should be undertaken to include such other relevant sources like meat, fish, eggs and milk.

Insecticide residues in soil and water in coastal areas of vegetable production in Togo

“…The mean concentrations of organochlorine insecticides detected in groundwater and surface water samples in this study were much lower than those detected in our previous studies (Mawussi et al 2009) of water samples from coffee and cotton areas in Togo. This study found that 4,4-DDD was the most predominant metabolite of DDT in water samples (Table 1).…”

“…The analytical standard of all insecticides had purities of between 97 and 99.5 %. Residues were extracted from water samples using a liquid-liquid partition method with dichloromethane (Mawussi et al 2009). The extracts were filtrated through granular Na 2 SO 4 , evaporated with a rotary evaporator at 35°C and recovered in hexane.…”

“…A previous study in inland coffee and cotton areas showed that organochlorine residues were present in crops and groundwater exceeding the acceptable levels of the World Health Organization (WHO) (Mawussi et al 2009). Because the soils used for growing vegetables in coastal areas are sandy, they are more susceptible to leaching and therefore pose a high risk to groundwater contamination by insecticides.…”

Efficacité des extraits de neem (<i>Azadirachta indica</i>) et de papayer (<i>Carica papaya</i>) dans la lutte contre les insectes ravageurs du gombo (<i>Abelmoschus esculentus</i>) et du chou (<i>Brassica oleracea</i>) en Côte d’Ivoire

“…Une étude menée par Houenou (1996) révèle que l'abus d'engrais et de pesticides dans les champs cultivés nuit à la qualité de l'eau du lac Buyo et de son bassin hydrographique. Ce type de pollution par des pesticides organochlorés a été mis en évidence au Togo par Mawussi et al (2009).…”

Organochlorine pesticide contamination of foods in Africa: incidence and public health significance

“…Cereal crops : Assessment of cowpea grains and maize grains in Togo detected several OCPs, including dieldrin, endrin, heptachlor epoxide and endosulfan [59]. Although levels in maize (up to 65.70 µ g/g) were below the MRL set by the World Health Organization (WHO) (Table 2), those in cowpea grains exceeded this level (up to 98.79 µ g/g) (Table 1).…”