Sanitary Quality of Lettuce (Lactuca sativa L.) and Mint (Mentha spicata L.) Grown at the Dogona Market Garden in Burkina Faso
Hadara DABRE *
National Office for Water and Sanitation (ONEA), Regional Water Analysis Laboratory, 01 BP 55 Bobo-Dioulasso 01, Burkina Faso and Soil-Water-Plant Laboratory, National Centre for Scientific and Technological Research/Institute for the Environment and Agricultural Research, Farako-Ba Station, 01 BP 910 Bobo-Dioulasso 01, Burkina Faso.
Alain Peoule Kouhouyiwo GOMGNIMBOU
Soil-Water-Plant Laboratory, National Centre for Scientific and Technological Research/Institute for the Environment and Agricultural Research, Farako-Ba Station, 01 BP 910 Bobo-Dioulasso 01, Burkina Faso.
Abdramane SANON
Thomas SANKARA University/ Tenkodogo University Centre, Soil Fertility Study and Research Laboratory/Nazi Boni University of Bobo Dioulasso, 12 BP 417 Ouagadougou 12, Burkina Faso.
Michel Kiropori GOMGNIMBOU
Higher Institute of Health Sciences, MURAZ Centre Research Laboratory, 01 BP 390 Bobo-Dioulasso 01, Burkina Faso.
Ibrahim SANGARE
Higher Institute of Health Sciences, Sanon Sourô University Hospital Centre Laboratory, 01 BP 1091 Bobo-Dioulasso 01, Burkina Faso.
*Author to whom correspondence should be addressed.
Abstract
Background: Consumption of vegetables irrigated with wastewater from the Houet backwater exposes the population to significant health risks. Using wastewater for irrigation, producers use chemical and organic fertilisers and pesticides to increase agricultural yields and control pests. However, these agricultural practices can harm the health and properties of soil, water resources and crops.
Aim: This study was conducted to assess the sanitary quality of vegetables produced at the Dogona site.
Methodology: A total of 24 samples of lettuce (Lactuca sativa L.) and mint (Mentha spicata L.) were taken at random from the Dogona market garden site. Four sampling sites (P1, P2, P3, P4) were selected along the irrigated perimeter. The heavy metal concentrations in the plants sampled were analysed by atomic absorption spectrometry on the dried vegetables. XLSTAT 2016.02.27444 software was used for variance analysis.
Results: The results obtained showed a significant accumulation of heavy metals. Indeed, mint accumulated more heavy metals than lettuce. The average concentrations in mg/kg DM of Cr, Fe and Pb in mint were 3.96, 1896 and 0.64, respectively. Meanwhile, the concentrations found in lettuce were 3.25 for Cr, 1522.38 for Fe and 4.04 for Pb. These values greatly exceeded the thresholds recommended by the Codex Alimentarius, set at 2.3 mg/kg for chromium, 425.5 mg/kg for iron and 0.3 mg/kg for lead.
Conclusion: The presence of heavy metals in lettuce and mint grown at the Dogona site compromises the safety of these foods. The results obtained from this study reveal that the levels of heavy metals present in lettuce and mint grown on the SMD far exceed the regulatory thresholds for human consumption. In view of the results obtained, there is therefore a need to take appropriate measures to secure the food chain. These findings suggest the need for better irrigation and monitoring practices.
Keywords: pollution, heavy metals, vegetables, food safety, lettuce, mint