In the summer of 2023, MS student Alexandra Scearce led a paired greenhouse/field study to evaluate uptake of PFAS into three commonly grown crops. Alex and her team tested the effects of intercropping, or companion planting, on fescue, lettuce, and tomatoes.

Four key findings emerged from this research:

1.) Tall fescue showed the greatest transfer of PFAS in both environments. Lettuce was often in the middle of the ranking order, and tomato fruit often had the least transfer, except for high levels of short-chained PFBA in greenhouse tomatoes.

2.) Generally, uptake was increased under intercropping scenarios, suggesting that companion planting is not a reliable method for decreasing crop uptake.

3.) PFAS were distributed randomly across the field, with the most drastic example (NEtFOSAA) ranging from 170 ng/g to 547 ng/g, a 3.2-fold difference just within a 25 feet distance. This shows that contaminated fields can have highly variable PFAS concentrations even within a single field.

4.) Soil to plant transfer of PFAS was significantly higher in the greenhouse than the field. This highlights that transfer can vary as a function of environmental conditions (e.g., potting media, plant spacing, growth environment), and inferences about TFs from greenhouse studies may be limited.

The full description of the study, and the results, are published in Alex’s MS Thesis, which is embargoed until publication. A fact sheet detailing the high points of the study has recently been released (see below).

Uptake takeaways: Lessons on PFAS in crops from a paired greenhouse and field study

Alex is now continuing her studies as a PhD student, co-advised by Drs. Rachel Schattman and Seanna Annis. In her new work, she will investigate the relationship between ericoid mycorrhiza and nectar quality in wild blueberries under climate change scenarios.