Urban Farm DB
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Database research record2026·United States

PFAS in Peri-Urban Agricultural Water: Assessing the Hazard Index in an Organic Farming Environment in Maryland, USA

Candice M. Duncan, Fatemeh Ghezelsofla, Hlengilizwe Nyoni, Jazmin Escobar, Odette Mina

Toxics

Urban Farm DB summary

A study measuring per- and polyfluoroalkyl substances (PFAS) in irrigation water at two organic farms in Maryland, USA, with no known direct PFAS input, and assessing health risk via a Hazard Index (HI). At agricultural site 1 (AG1), the most abundant compounds were PFBS (37 ng/L), PFBA (24 ng/L) and PFHxA (22 ng/L); the HI showed compliance for branched PFHxS (0.39) but non-compliance for linear PFHxS (1.51). At agricultural site 2 (AG2), despite no known industrial or PFAS-related facilities nearby, HFPO-DA (GenX) was detected at 28 ng/L, and the HI exceeded the compliance threshold (HI = 2.83), with GenX accounting for most of the calculated risk. The findings show HI exceedances occurring at small farm sites with no identifiable contamination source.