Ficus retusa L. as possible indicator of air metallic pollution in urban environment.

The aim of this study was to explore the accumulation potential of heavy metals (HMs) by Ficus retusa L. and its possible use for air pollution biomonitoring in urban areas. Plant material was sampled along the national roads in Constantine city (NE-Algeria), characterized by an intense traffic load. The concentrations of cadmium, copper, lead and zinc were determined in the washed and unwashed leaves. The mean concentrations of HMs decrease in the following order: Zn > Pb > Cu > Cd for both studied leaves, and were about 0.68 and 0.98 mg/kg d.m for Cd, 7.26 and 8.74 mg/kg d.m for Cu, 20.35 and 37.61 mg/kg d.m for Pb and 63.33 mg/kg d.m and 75.94 mg/kg d.m for Zn, for washed and unwashed leaves respectively. The studied metal contents were significantly higher than those cited in the literature; this indicates the traffic road impact on HMs emissions and uptake by plants. Higher values of metal accumulation index (MAI) indicate the effectiveness of the studied species for monitoring air metallic pollution in urban areas. Results of this study could be beneficial as preliminary reference values for HMs uptake by F. retusa in urban environments.

In this paper, we report the usefulness of woody species for the biomonitoring of air metallic pollution. The aim is to explore the accumulation potential of heavy metals (HMs) by Ficus retusa L. and its possible use for air pollution biomonitoring in urban areas. To our knowledge, there are few studies on the use of the genus Ficus for air quality monitoring. The determination of heavy metal contents has been focused on leaves of Ficus benjamin and Ficus microcarpa in urban areas by some researchers, but never on Ficus retusa. The use of this species is significant because it can be cultivated in urban area and can help to remediate the soils and atmospheric pollution due to heavy metals.

Dose-dependent effects of lead and cadmium and the influence of soil properties on their uptake by Helix aspersa: an ecotoxicity test approach.

Three soil types with different physicochemical properties were selected to evaluate their effect on lead and cadmium bioavailability and toxicity in the land snail Helix aspersa. In 28-day ecotoxicity tests, H. aspersa juveniles were exposed to increasing concentrations of Pb or Cd. EC50s, concentrations reducing snail growth by 50%, differed between the soils and so did Cd and Pb uptake in the snails. For lead, EC50s were 2397-6357 mg Pb/kg dry soil, while they ranged between 327 and 910 mg Cd/kg dry soil for cadmium. Toxicity and metal uptake were highest on the soil with the lowest pH, organic matter content and Cation Exchange Capacity (CEC). Growth reduction was correlated with metal accumulation levels in the snails' soft body, and differences in toxicity between the soils decreased when EC50s were expressed on the basis of internal metal concentrations in the snails. These results confirm the effect of soil properties; pH, CEC, OM content, on the uptake and growth effect of Pb and Cd in H. aspersa, indicating the importance of properly characterizing soils when assessing the environmental risk of metal contaminated sites.