Vehicles are unique indoor environments, with interiors dominated by plastic/synthetic materials and exposure to extremes of temperature and radiation, leading to substantial potential for emissions of plastic additives from vehicle materials and subsequent exposure to drivers and passengers. Flame retardants (FRs) and per- and polyfluoroalkyl substances (PFAS) were measured in 30 dust samples collected from dashboards, seats, and trunks of cars of the same make and model (year of manufacture 1996-2021) to evaluate levels in dust and time patterns in additive use across cars of different ages. PFAS were detected in all dust samples at low levels, while FRs were detected in all samples, with some compounds consistently exceeding µg/g levels, especially tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and decabromodiphenyl ether (BDE-209), substantially higher than in other indoor environments. Although cars were of the same model, large variations were observed in FR concentrations in dust between cars, emphasizing the challenge in generalizing FR exposures from vehicle dust. Concentrations of BDE-209 in vehicle dust did not decrease over the 1996-2021 period, suggesting that restrictions on DecaBDE have had limited impact, likely due to exemptions in regulations for the automotive industry. The high FR levels indicate ongoing use of both organophosphate and brominated FRs in vehicles on the European market, although flammability standards for interior car materials are not mandated by European regulations, and the continued presence of long-restricted FRs suggests the presence of recycled plastics in vehicles; this potential exposure source may be increasing as vehicle producers aim to improve material circularity.

• Keywords
• Cars, Dust exposure, Flame retardants, PFAS, Time trends,
• MeSH
• Automobiles * statistics & numerical data   MeSH
• Halogenated Diphenyl Ethers analysis   MeSH
• Air Pollutants * analysis   MeSH
• Environmental Monitoring * MeSH
• Organophosphates * analysis   MeSH
• Dust * analysis   MeSH
• Flame Retardants * analysis   MeSH
• Air Pollution, Indoor * analysis   statistics & numerical data   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Halogenated Diphenyl Ethers MeSH
• Air Pollutants * MeSH
• Organophosphates * MeSH
• Dust * MeSH
• Flame Retardants * MeSH

A total of 74 high volume air samples were collected at a background site in Czech Republic from 2012 to 2014 in which the concentrations of 20 per- and polyfluoroalkyl substances (PFASs) were investigated. The total concentrations (gas + particle phase) ranged from 0.03 to 2.08 pg m-3 (average 0.52 pg m-3) for the sum of perfluoroalkyl carboxylic acids (∑PFCAs), from 0.02 to 0.85 pg m-3 (average 0.28 pg m-3) for the sum of perfluoroalkyl sulfonates (ΣPFSAs) and from below detection to 0.18 pg m-3 (average 0.05 pg m-3) for the sum of perfluorooctane sulfonamides and sulfonamidoethanols (ΣFOSA/Es). The gas phase concentrations of most PFASs were not controlled by temperature dependent sources but rather by long-range atmospheric transport. Air mass backward trajectory analysis showed that the highest concentrations of PFASs were mainly originating from continental areas. The average particle fractions (θ) of ΣPFCAs (θ = 0.74 ± 0.26) and ΣPFSAs (θ = 0.78 ± 0.22) were higher compared to ΣFOSA/Es (θ = 0.31 ± 0.35). However, they may be subject to sampling artefacts. This is the first study ever reporting PFASs concentrations in air samples collected over consecutive years. Significant decreases in 2012-2014 for PFOA, MeFOSE, EtFOSE and ∑PFCAs were observed with apparent half-lives of 1.01, 0.86, 0.92 and 1.94 years, respectively.

• Keywords
• Gas-particle partitioning, Long-range atmospheric transport, Multi-year variations, Per- and polyfluoroalkyl substances, Seasonal variations,
• MeSH
• Fluorocarbons analysis   MeSH
• Carboxylic Acids MeSH
• Environmental Monitoring MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic MeSH
• Europe MeSH
• Names of Substances
• Fluorocarbons MeSH
• Carboxylic Acids MeSH