Influence of Arsenic, Chromium, Mercury and Lead Concentrations in Irrigation Water on the Evolution of Heavy Metals Concentration in Soil

The market gardening in developing countries plays a huge important socioeconomic role in confronting the challenge of eradicating hunger, improving food security and the social daily life of the population. However, the quality of agricultural soils and irrigation is important to guarantee a good quality of market garden products. The purpose of this study was to investigate the concentration of metals (Cr, Pb, As and Hg) in irrigation water and soils from Loumbila, Goudrin et Paspanga, and simulate concentration evolution over the time in soil, in order to evaluate the potential impact of irrigation water. The research was conducted in four sites characterized by intensive market gardening performed. The results show that the concentrations of Cr, Pb, As and Hg in soils were lower than the recommended limit. The average heavy metals concentration in the irrigation waters from Loumbila was 0.116 ± 0.028 mg/L for Cr, 0.272 ± 0.004 mg/L for Pb, 0.016 ± 0.004 mg/L for As and 0.034 ± 0.002 mg/L for Hg. The average concentrations of the irrigation waters of Paspanga 1 were 0.016 ± 0.004 mg/L for Cr, and 0.092 ± 0.001 mg/L for Pb. The concentrations of Cr, Pb, As and Hg detected in the waters of Paspanga 2 were below the limit accepted by FAO. In Goudrin irrigation water only lead was detected with average concentrations of 0.086 ± 0.006 mg/L. The average concentrations of Cr, and Hg in irrigation water from Loumbila were above the accepted limit established by the FAO. The heavy metal concentration in irrigation water contribute to increases the heavy metal concentration in soil.