Mass Balance of Perfluoroalkyl Acids in the Baltic Sea

Abstract

A mass balance was assembled for perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorodecanoic acid (PFDA), and perfluorooctanesulfonic acid (PFOS) in the Baltic Sea. Inputs (from riverine discharge, atmospheric deposition, coastal wastewater discharges, and the North Sea) and outputs (to sediment burial, transformation of the chemical, and the North Sea), as well as the inventory in the Baltic Sea, were estimated from recently published monitoring data. Formation of the chemicals in the water column from precursors was not considered. River inflow and atmospheric deposition were the dominant inputs, while wastewater treatment plant (WWTP) effluents made a minor contribution (<5%). A mass balance of the Oder River watershed was assembled to explore the sources of the perfluoroalkyl acids (PFAAs) in the river inflow. It indicated that WWTP effluents made only a moderate contribution to riverine discharge (21% for PFOA, 6% for PFOS), while atmospheric deposition to the watershed was 1–2 orders of magnitude greater than WWTP discharges. The input to the Baltic Sea exceeded the output for all four PFAAs, suggesting that inputs were higher during 2005–2010 than during the previous 20 years despite efforts to reduce emissions of PFAAs. One possible explanation is the retention and delayed release of PFAAs from atmospheric deposition in the soils and groundwater of the watershed.

What is the effect of phasing out long-chain per- and polyfluoroalkyl substances on the concentrations of perfluoroalkyl acids and their precursors in the environment? A systematic review

“…PFOS and other PFSAs are widely distributed in the global environment [34][35][36][37][38], biota [39][40][41][42][43][44] and humans [15,[45][46][47][48][49][50][51][52]. Due to the dominance of POSF-based products historically, PFOS is usually the most abundant PFSA found.…”

Characterizing direct emissions of perfluoroalkyl substances from ongoing fluoropolymer production sources: A spatial trend study of Xiaoqing River, China

“…It should, however, be noted that the spatial trend of P PFASs was dominated by C4eC9 PFCAs which are primarily associated with FP production. The lack of clear spatial trends for PFSAs indicates that input of these substances are likely caused by other sources from the densely populated area including street run-off and waste water treatment discharges (Müller et al, 2011;Filipovic et al, 2013).…”

Occurrence and transport of 17 perfluoroalkyl acids in 12 coastal rivers in south Bohai coastal region of China with concentrated fluoropolymer facilities

“…Although the salinity of some EDA water was less than the freshwater threshold during ebb-tide, considering the frequent mixing, upstream sites of EDA were used to estimate loadings of PFAAs from rivers to the Bohai Sea. The mass flux was calculated based on instantaneous concentrations of PFAAs multiplied by the average annual water discharge data to give a rough yet valuable approximation (Table 1) (McLachlan et al, 2007;Filipovic et al, 2013). The mass flux of PFOA and P PFAAs in the Xiaoqing River were 3.6 tons and 4 tons per year, which accounted for 90% and 80% of those among all the rivers, respectively.…”