Long-Term Lysimeter Experiment To Investigate the Leaching of Perfluoroalkyl Substances (PFASs) and the Carry-over from Soil to Plants: Results of a Pilot Study

Abstract

To study the behavior of perfluoroalkyl substances (PFASs) in soil and the carry-over from soil to plants, technical mixtures of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) at a concentration of 25 mg/kg soil were applied to 1.5 m(3) monolithic soil columns of a lysimeter. Growth samples and percolated water were analyzed for PFASs throughout a period of 5 years. In addition to PFOA/PFOS plant compartments and leachate were found to be contaminated with short-chain PFASs. Calculation showed significant decreasing trends (p < 0.05) for all substances tested in the growth samples. Short-chain PFASs and PFOA pass through the soil much more quickly than PFOS. Of the 360 g of PFOA and 367.5 g of PFOS applied to the soil, 96.88% PFOA and 99.98% PFOS were still present in the soil plot of the lysimeter after a period of 5 years. Plants accumulated 0.001% PFOA and 0.004% PFOS. Loss from the soil plot through leachate amounted to 3.12% for PFOA and 0.013% for PFOS.

Loss and in situ production of perfluoroalkyl chemicals in outdoor biosolids–soil mesocosms

“…One recent study showed that about 0.001% of PFOA and 0.004% of PFOS accumulated in plants from soil (Stahl et al, 2013). Additionally, the presence of these compounds in remote locations suggests long-range transport of volatile precursors of PFASs, making volatilization one possible route of loss from soil (Prevedouros et al, 2006).…”

Pathways and factors for food safety and food security at PFOS contaminated sites within a problem based learning approach

“…The contribution to the intake from fruit, cereals, legumes, leafy and root vegetables (24 ng kg À1 bw d À1 , see S1) have been accounted for according to the uptake factors of PFOS from soil to the edible parts (0.003 reported for corn ear, 0.1 for oat grains, 0.01 for potatoes, and 0.05 for carrots, Yoo et al, 2011;Stahl et al, 2013). Under the conservative approach of a 0.05 uptake factor extended also to fruit, the contribution of all food of vegetable origin to the overall intake represents roughly 10% of the contribution given from food of animal origin under the modeled conditions.…”

“…According to Sepulvado et al (2011) it was then possible to model the occurrence of PFOS on agriculture soils and pasture as consequence of the regular land application of municipal biosolid, through the equation: y = 0.896x + 0.423. The transfer factor from contaminated soil to forages was derived from Yoo et al (2011) for hay from grass (Â0.25, as average for PFOS and PFOA and from Stahl et al (2013) for mais silage (Â0.17), on dry matter basis (Table 2). Therefore, for dairy and beef animals, it was possible to estimate the PFOS intake, expressed as ng kg À1 -body weight (bw) d À1 , accounting for the default animal nutrition and production parameters reported in Table 1.…”

Field study on the uptake and translocation of perfluoroalkyl acids (PFAAs) by wheat (Triticum aestivum L.) grown in biosolids-amended soils

“…Moreover, greenhouse pot experiments and artificially polluted soils do not present the actual behavior of weathered PFAAs in field soils. Stahl et al (2013) described a long-term lysimeter experiment that demonstrated the carry-over of PFAAs from spiked soil to plant under field conditions. Evidence for accumulation of PFAA congeners and fluorotelomer alcohols in the above-ground part of grasses grown in sludge contaminated soils was provided by Yoo et al (2011).…”