Use of pigeons as bioindicators of air pollution from heavy metals at Rabat-Salé (Morocco)

Adult Columba livia pigeons were used as bioindicators of atmospheric pollution by heavy metals, from different sources (road traffic, earthenware workshops). Concentrations in pigeon tissues varied according to metals. Lead and cadmium showed higher accumulation in kidneys, while zinc was the found in whole organs. Except for Oulja, where lead is commonly used in earthenware production, lead and cadmium were accumulated according to the density of road traffic, thus the highest lead concentrations were found in the town centre, followed by Kamra where car traffic is moderate, and with the lowest concentrations of lead in rural areas. On average, high concentrations of cadmium were observed in the kidneys of pigeons in the town centre, and a lower content ratio (25 times) was found in rural areas (Allal Behraoui). The low metal concentrations in the pigeons blood and organs was due to the limited presence of industry in Rabat-Salé.