Hydrogen fluoride concentrations in ambient air of an urban area based on the emissions of a major phosphogypsum deposit (SW, Europe)

Abstract

Hydrogen fluoride (HF) is one of the most toxic gaseous compounds in air, the primary anthropogenic source of which is industrial activity, specifically fertilizer and waste. HF concentrations in an urban area (Huelva, SW Spain) related to a nearby major phosphogypsum (PG) depositweremeasured by passive sampling during summer and winter months from 2014 to 2017 and high-resolution sampling during 2017 and 2017–2018 using an HF analyser. An HF geochemical anomalywas found in the PG pondwith average concentrations of up to 19.1 μg/ m3, and concentrations of up to 1.6 μg/m3 were exhibited in the nearest urban area. The concentrations were associated with the HF emissions fromthe PG deposit. Emission factorswere calculated by field and laboratory experiments, and the brines exhibited the highest emission factor (2.7 kg/ha day). Several impacts of HF (N0.1 μg/m3) in the citywere recorded throughout the year, occurring at noon in the summer and during fog events in the winter. Consequently, the PG system should be restored to protect the population living in Huelva from the impacts of HF emission.