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Kirkwood et al. pub recognized as "NIEHS Paper of the Month"


Pine needles work as passive samplers for PFAS

NIEHS-funded researchers showed that pine needles can be used as a tool to monitor the presence and distribution of per- and polyfluoroalkyl substances (PFAS) over time. The pine needle’s waxy coating traps PFAS and other airborne pollutants, providing a record of contamination.

The study included 60 pine needle samples from six North Carolina counties. For historical comparison, the researchers examined 15 archived samples, dating back to the 1960s, collected from the same counties. The team analyzed each sample using a non-targeted, multidimensional approach that allowed them to distinguish between PFAS based on molecular structure.

More than 70 different PFAS were identified in the pine needles. The types of PFAS detected in samples correlated with known changes in PFAS use over time. For example, samples from the past three decades had an increasing number of newer PFAS, such as GenX, compared with samples collected before the newer substances had emerged. The pine needles, taken at varying distances from contamination sources such as airports, firefighter training sites, and chemical plants, revealed where specific PFAS were being used. For example, samples collected near a contamination source had extremely elevated levels of a type of PFAS commonly used in firefighting foams compared with samples collected further away.

According to the researchers, study results showed that using pine needles in combination with non-targeted multidimensional analyses is a viable method for monitoring the distribution of diverse PFAS.

CitationKirkwood KI, Fleming J, Nguyen H, Reif DM, Baker ES, Belcher SM. 2022. Utilizing pine needles to temporally and spatially profile per- and polyfluoroalkyl substances (PFAS). Environ Sci Technol 56(6):3441-3451.

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