Temporal trends of halogenated and organophosphate contaminants in striped dolphins from the Mediterranean Sea

PBDEs, HBCD, novel DBDPE, PBEB and HBB, dechloranes, OPFRs and natural MeO-PBDEs were monitored in muscle of striped dolphins (Stenella coeruleoalba) from the Mediterranean Sea collected in three time periods (1990, 2004-2009 and 2014-2018). PBDEs levels decreased about 60% in under three decades, from 5067 ± 2210 to 2068 ± 2642ngg^-1 lw, evidencing the success of their ban. Most PBDEs were found in all the samples, with BDE-47, -99, -154, -100 and -153 as the main contributors. Found in 71.4% of the samples, α-HBCD was stable through time and usually <LOQ. DBDPE concentrations decreased by 89% from 1990 to 2004-2009 and have remained stable since. HBB occurred rarely and decreased by 94% to a current few ngg^-1 lw. Dec 602 was the main dechlorane with stable concentrations around 1200 ngg^-1 lw, but a declining trend might have started in the last years. OPFRs concentrations were stable and showed the highest concentrations of all FRs in 2014-2018: 6253 ± 11,293ngg^-1 lw. TBOEP and TNBP contributed to most of the OPFR concentration, the former with decreasing levels by 96%. MeO-PBDEs showed mean concentrations between 600 and 700ngg^-1 lw in all periods. Non-targeted analysis allowed the identification and semi-quantification of additional chlorinated pollutants, such as polychlorinated terphenyls (PCTs) (levels decreasing by 81% to a current 770 ngg^-1 lw mean) and polychlorinated diphenyl ethers (PCDEs) (decreasing by 83% to a current 3200ngg^-1 lw) in Mediterranean marine mammals for the first time.