Atmospheric concentrations of PBDEs (108 samples in total) were measured at 2 rural/semirural sites in England and 1 remote site on the west coast of Ireland in the years 2001 and 2000, respectively. Detailed analysis of the factors affecting concentrations is performed. The United Kingdom (UK) has been a major producer and user of PBDEs. Concentrations of ΣPBDEs at Mace Head (MH), Ireland ranged between 0.22 and 5.0 pg m-3 with a mean of 2.6 pg m-3 and were controlled primarily by advection. ΣPBDEs concentrations at Hazelrigg (HR), northwest England, ranged between 2.8 and 37 pg m-3 with a mean of 12 pg m-3 and at Chilton (CH), southwest England between 3.4 and 33 pg m-3 with a mean of 11 pg m-3. The average mixture of PBDEs in air was similar to that of commercial penta-BDE products. Movement of air over local/regional sources influenced concentrations of PBDEs at all sites, particularly at MH. At the two English sites during the summer, concentrations of PBDEs were strongly influenced by temperature, indicating that air−surface exchange processes play an important role. Advection became more influential during winter, particularly at CH, where a different congener profile was observed in some samples as ambient air temperatures decreased and PBDE concentrations increased. It is hypothesized that this was due to increased emissions from diffuse combustion sources.