Uptake and translocation of perfluoroalkyl acids (PFAA) in red chicory (Cichorium intybus L.) under various treatments with pre-contaminated soil and irrigation water
By Andrea Gredelj, Carlo Nicoletto, Sara Valsecchi, Claudia Ferrario, Stefano Polesello, Roberto Lava, Francesca Zanon, Alberto Baraussea, Luca Palmeri, Laura Guidolin, and Marco Bonato
Sci. of The Total Environ.
November 12, 2019
Perfluoroalkyl acids (PFAAs), particularly short-chained ones, have high potential for crop uptake, posing a threat to human health in contaminated areas. There is a scarcity of studies using contaminated water as the medium for PFAAs delivery to crops, and a lack of data on the partitioning of PFAA mixtures in growing media. In this context, a controlled experimental study was carried out in a greenhouse to investigate the uptake of a PFAA mixture into red chicory, a typical crop from a major PFAA contamination hot-spot in northern Italy, under treatments with environmentally relevant concentrations in spiked irrigation water and soil, separately and simultaneously. To our knowledge, this is the first study involving multiple exposure media and laboratory adsorption/desorption batch tests as a way of assessing the decrease in the bioavailability of PFAAs from soil. Exposure concentrations for each of the 9 utilized PFAAs were 0, 1, 10 and 80 µg/L in irrigation water and 0, 100 and 200 ng/gdw in soil, combined into 12 treatments. The highest bioaccumulation was measured for PFBA in roots (maximum of 43 µg/gdw), followed by leaves and heads of the chicory plants in all treatments, with the concentrations exponentially decreasing with an increasing PFAA chain length in all plant compartments. The use of irrigation water as the delivery medium increased the transport of PFAAs to the aerial chicory parts, long - chain substances in particular. Additionally, the distribution of PFAAs in the soil was assessed by depth and compared with laboratory measured soil-water equilibrium partition coefficients, revealing only partial dependency of PFAAs bioavailability on the adsorption in soil.
• Short-chain PFAAs can strongly bioaccumulate in food crops but are not regulated.
• We explored the role of polluted soil and irrigation water as PFAAs delivery media.
• In red chicory, PFAA chain-length strongly correlated with root and shoot BCF.
• Concentrations of PFAAs were measured by soil depth and compared to laboratory Kds.
• Contaminated irrigation water use led to higher PFAA accumulation in chicory shoots.