Evaluation of glyphosate drift and anthropogenic atmospheric trace elements contamination by means of lichen transplants in a southern Italian agricultural district

Ecophysiological biomarkers and atmospheric contamination due to glyphosate and trace elements were monitored in a southern Italian agricultural district by means of transplanted thalli of the lichen Pseudevernia furfuracea. Glyphosate exhibited a significant geographical pattern (east side > west side) and a drift source area equal to 32% of the monitoring sites. Moreover, based on the surface area of the study area and a wind quantitative relationship (WQR) with glyphosate thalli concentrations, our data support the idea that pesticide drift extends over an area of several square kilometers. Of the eight elements preliminarily classified as enriched, four were considered prevalently of geogenic origin (Al, Ti, Ni, Co) and four of anthropogenic origin (Cu, Mn, Sn, Sb), although only Sb and Cu passed rigorous statistical testing supporting a real difference from pre-exposure levels. The contribution of local sources was evaluated based on the relative increase of Cu, Mn, Sb, and Sn versus Ti. Cu and Mn were associated mainly with a biomass power plant (BPP), with Cu showing extremely high levels of contamination involving 20% of the monitoring sites. Sb and Sn were associated with spatial variation of the traffic rate. The mycobiont and photobiont showed an evident zonation of the levels of their physiological parameters, with oxidative stress being significantly associated with both the biomass power plant and Cu/Ti. Our results suggest that croplands are potentially exposed to various hazards: overexposure to pesticides due to drift processes, diffuse low traffic levels promoting Sb enrichment, and acute Cu pollution affected by BPP emissions.