Multi-model inference analysis of toxicological responses and levels of heavy metals in soft tissue of land snail Cornu aspersum caged in proximity to an industrial setting

The use of indicator species has become a standard monitoring approach in environmental risk assessment; however, pollutant bioavailability and its geographical distribution as well as species-sensitiveness could be affected by different factors. The present study investigated the potential use of the land snail Cornu aspersum as bioindicator of industrial air pollution by using cytological and biochemical responses and trace element levels in individuals caged in proximity to an industrial setting. Eleven sites were selected based on wind direction and distance. Snails were placed in holed plastic cages, transplanted to each site and maintained for 30 days fed at libitum and under constant humidity. Several oxidative stress responses including catalase (CAT) and glutathione-s-transferase (GST) activities, levels of malondialdehyde (MDA) and total metallothioneins (MTs) content were determined in snail hepatopancreas while lysosomal membrane stability (LMS) and loss of DNA integrity through micronuclei frequency (MN) were assessed in haemocytes. Trace elements were also analysed in snail whole soft tissues. Multi-model inference used to predict snail's biological responses in relation to trace elements levels and distance from the industrial setting was able to disentangle the relative contributions of different influencing predictors and could be successfully applied in environmental risk assessment by using land snail as bioindicator species.