Haloacetic Acids as Contaminants of Emerging Concern in Arctic Aerosol

Haloacetic acids are concerning emerging contaminants defined mainly as disinfection byproducts. Extensively studied in water environments, they are still poorly investigated in atmospheric aerosols and only in midlatitude anthropized countries. To our knowledge, this is the first study reporting the evidence of 12 brominated, chlorinated, and iodinated-acetic acids in the Arctic particulate matter. This paper had three main goals: 1) to evaluate the occurrence of the 12 haloacetic acids in the Arctic atmospheric aerosol, 2) to identify their possible sources, and 3) to understand their transport patterns. Samples were collected in Ny-Ålesund (Svalbard Islands, Norwegian Arctic) during an entire sampling year, starting from February 2022 to March 2023. Trace concentrations of these species were determined using a high pressure anion exchange coupled with a triple quadrupole, defining the monohaloacetic acids as the most ubiquitous compounds. In particular, the most abundant species was monochloroacetic acid with a mean concentration of 35 ± 32 pg m–3. The statistical approach was applied to accomplish our goals: it highlighted the long-range transports and therefore anthropogenic input as the most important contribution for the investigated species. Considering their photosensitivity, future studies will be addressed to investigate the photochemical reactions of haloacetic acids in the complex polar atmosphere.