Determination of Heavy Metals Concentration in Soil and Leafy Vegetables in Urban Expressway and Peri-urban Road Farms of Lagos State, Nigeria

Urban Farm DB summary

This study measured and compared lead (Pb), cadmium (Cd) and manganese (Mn) concentrations in soil and leafy vegetables (Amaranthus hybridus, Celosia argentea, Corchorus olitorius) using atomic absorption spectrophotometry at Urban Expressway Farms (UEF) and Peri-urban Road Farms (PRF) in Lagos State, Nigeria. It found the highest Pb concentration (0.93+/-0.06) in Celosia argentea at UEF, and the highest Cd (0.51+/-0.11) and Mn (0.98+/-0.02) concentrations in Amaranthus hybridus at UEF, with Pb in Celosia argentea 5 m from the expressway and Cd in Amaranthus hybridus 10 m from the expressway exceeding WHO/FAO permissible levels; heavy metal residue levels were driven more by farm location than by vegetable type, and the study calls for regular monitoring to prevent consumption of contaminated leafy vegetables and recommends farmers cultivate fields farther from expressways.