Health risks associated with pesticide residues in sediments, fish, and plants from the Ouémé Valley in the Republic of Bénin

To determine possible human and environmental health risks, organochlorine pesticide residues were determined in vegetables grown in floodplains along the Ouémé River near Lowé in Bénin. Testing of vegetables found 13 pesticides with ΣDDT, α-endosulfan, Σdrin, and lindane being most important. The same pesticides were also detected in plants eaten by bovine cattle, sheep, and herbivorous fish. Human pesticide intake by vegetable consumption was compared with tolerable daily intake (TDI) values reported by the World Health Organization. Pesticide intake by fish consumption was estimated from residue levels in whole fish collected from the Ouémé River in 2004 and reported earlier. Fish consumption does not pose a risk for human health, but consuming vegetables that contain pesticide residues may lead to exceedance of TDI values. Based on these findings, concerns are warranted, and more work is needed to understand the full exposure profile for the local population. © 2013 Springer Science+Business Media New York

Influence of fishing technique on organochlorine pesticide accumulation in fish and its possible human health risk in the republic of Benin.

In Bénin different techniques are used for large-scale commercial fishing, Acadjas (enclosures constructed in the river) and Whédos (holes made in the river banks). This study aimed at assessing the extent of contamination related to these fishing techniques. Fish contained residues of DDT and its metabolites, α-endosulfan, dieldrin, aldrin, endrin and lindane. Pesticide levels were similar in fish from Acadjas and Whédos, except for higher α-endosulfan levels in fish from the Whédos. Comparing pesticide intake levels through fish consumption with tolerable daily intake levels showed that in all cases risk for human health is low. © 2013 Springer Science+Business Media New York

Pesticide residues in sediments and aquatic species in Lake Nokoué and Cotonou Lagoon in the Republic of Bénin

Lake Nokoué and Cotonou Lagoon are the most important and most productive continental freshwaters in Bénin, with an estimated fish production of over 2 tonnes per hectare in Lake Nokoué. Organochlorine pesticides are used in agriculture and to repel tsetse flies, malaria mosquitoes and other diseases raised. Sediment, fish, shrimp and oyster species were collected in Lake Nokoué and Cotonou Lagoon for pesticide residues analysis. The main pesticides identified in sediment were pp′-DDT and its metabolites pp-DDE and pp′-DDD, with residue levels between the detection limit and 24.4 μg/kg dry weight. Fish species commonly consumed such as Elops lacerta, Podamasys jubelini, Gobbienellus occidentalis, Ethmalosa fimbriata, Mugil cephalus and Hemichromis fasciatus were contaminated with residues of seven to nine pesticides, including pp-DDE, op′-DDD, pp′-DDD, op′-DDT, pp′-DDT, α-endosulfan, aldrin, dieldrin and γ-hexachlorocyclohexane. The levels ranged from detection limit to 289 ng/g lipid. The same pesticides were also detected in other aquatic species, such as shrimp and oysters. A summed risk assessment, comparing pesticide intake levels through fish consumption with tolerable daily intake levels proposed by the World Health Organization, showed in all cases a low risk for human health. © 2013 Springer Science+Business Media Dordrecht

Pesticide Contamination of the Dridji Cotton Plantation Area in the Republic of Bénin

Pesticides used for cotton production and pest control in the growing of food crops such as beans, maize and vegetables eventually may not only end up on the crops, but also in soil and surface water. As a consequence, aquatic organisms and humans consuming crops may experience pesticide exposure. This also is the case in developing countries in Africa, where pesticide use sometimes is less controlled and includes the use of older organochlorinated products. This study assessed the public health risk due to pesticide exposure along the Kiti River in the Dridji cotton-growing area in the Republic of Bénin. Aquatic organisms from the Kiti River and vegetable plants commonly consumed by the local people were analyzed for residues of organochlorinated pesticides. Kiti River sediment contained metabolites of DDT with levels up to 5.14 μg/kg dry weight. In fish, crabs and amphibians collected from the Kiti River DDT-like compounds and α-endosulfan reached levels up to 403 ng/g lipid. Leaves from beans grown in the river floodplain and consumed by the local population were contaminated with 10 pesticides including DDT-like compounds, α-endosulfan, dieldrin, lindane, hexachlorobenzene and heptachlor. Sum DDT concentrations in the bean leaves ranged between 274 and 1351 μg/kg dry weight, while these vegetables also contained endosulfan (23-210 μg/kg dry weight), dieldrin (<9-32 μg/kg dry weight) and lindane (<6 – 90 μg/kg dry weight) in high concentrations. To assess the risk to public health, pesticide intake by fish and vegetable consumption was estimated and compared with Tolerable Daily Intake (TDI) values reported by the World Health Organization. This comparison showed that fish consumption does not pose a risk for public health, but that consuming bean leaves as vegetables may lead to exceeding of TDI values. It is concluded that pesticide contamination in the Dridji cotton production area poses a risk to public health