Geographical distribution and time trends of polychlorinated biphenyls in raft mussel from Galician coast (1998-2013)

Legacy and emerging pollutants in marine bivalves from the Galician coast (NW Spain)

The presence of pollutants in estuary and oceanic systems is a global problem and a serious concern to human and environmental health. Usually, environmental monitoring studies consider classical persistent organic pollutants (POPs). However, the lists of POPs keep continuously growing and new POPs and other emerging pollutants should be considered in new monitoring programs. So, this study aimed to investigate the distribution and profile of classical POPs (polychlorinated biphenyl (PCBs), organochlorine pesticides (OCPs), and polycyclic aromatic hydrocarbons (PAHs)), new POPs and emerging pollutants (polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs), novel halogenated flame retardants (NFRs) and UV filters) in bivalve mollusc samples (both raft-cultivated and wild mussel, Mytilus galloprovincialis; cockle, Cerestoderma edule; and clam, Ruditapes descussatus) collected in nine Galician Rias during the period February 2012 to February 2013. A predominance of PAHs (6.8-317 ng/g dry weight (dw)) followed by PCBs (0.47-261 ng/g dw), UV filters (1.4-157 ng/g dw), PFCs (0.53-62 ng/g dw), OCPs (0.07-29 ng/g dw), PBDEs (0.31-6.6 ng/g dw) and NFRs (0.07-3.2 ng/g dw) was found in the studied bivalves, being the UV filter octocrylene the compound found at the highest concentration (141 ng/g dw in a cockle sample), while the PAHs chrysene and benzo(b)fluoranthene were the compounds with the highest average concentration (20 and 14 ng/g dw, respectively). Inter-species, temporal and geographical variations on pollutants concentration were assessed by multifactorial analysis of variance. Statistically significant differences among the type of mollusc were observed for levels of organochlorinated and organobrominated pollutants considered (PCBs, OCPs and PBDEs), which were detected at higher concentrations in wild mussel. On the other hand, the main PFCs and UV filters showed a higher detection frequency in cockle samples. Location played significant role for PAHs, PCBs and the main PBDEs, being the most polluted rias those more industrialized and populated, i.e. A Coruña, Ferrol and/or Vigo. Finally, sampling timepoint was also a significant factor for most of the families considered but with different profiles. Thus, PAHs and PCBs showed higher concentrations in both February 2012 and 2013 and lower in August 2012, while the main PBDEs were measured at higher concentrations in November 2012 and lower in February 2012; and the main NFRs, PFCs and UV filters were present at lower levels in February 2013.

Polychlorinated dibenzo-P-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBS) in bivalve mollusk from Galician Rías (N. W., SPAIN)

The concentrations of PCDD/Fs (2,3,7,8-chlorosubstituted) and three dioxin-like PCBs (PCB 77, PCB 126 and PCB169) were analyzed in bivalve mollusk collected in several Galician Rías between 2006 and 2014. Levels of Total PCDD/Fs ranged from 0.03 to 0.62 pg WHO-TEQ g^-1 wet weight. Total dl-PCBs values were higher than Total PCDD/Fs and ranged from 0.01 to 2.11 pg WHO-TEQ g^-1 wet weight. These concentrations were below those considered safe for human consumption. The PCDD/Fs profile was dominated by 2,3,4,7,8-PeCDF and 2,3,7,8-TCDF with a percentage of 24.95 and 23.87 of the Total PCDD/Fs, respectively. In relation to Total dl-PCBs, CB126 was the priority congener with the highest TEF value (0.1). Principal component analysis (PCAs) indicated a clear separation between the northern (Rías de Ferrol and Coruña) and southern Rías (Ría de Pontevedra and Vigo). The northern Rías were the highest contaminated one. Temporal trends showed important reduction rates suggesting that the regulations on dioxin like contaminants have been effective for quality waters in Galician Rías.

Levels and temporal trends of organochlorine contaminants in mussels from Spanish Mediterranean waters

The levels and trends of organochlorine contaminants were determined along the Spanish Mediterranean coast from 2000 to 2013 using mussel, Mytilus galloprovincialis, as bioindicator species. The highest levels of PCBs and DDTs were found at industrial and urban locations, and at areas under the influence of the mouth of major rivers. Dieldrin and t-NNC were commonly detected, while HCHs, aldrin, isodrin, endrin and HCB were at levels not detectable at many areas. Significant declines on the levels of DDTs were observed at most of the areas studied. Conversely, no trends or weak downtrends for PCBs were observed in the areas more polluted by local sources, and in most areas less polluted, where PCBs inputs may be primarily from the atmosphere. Upward trends for PCBs were found in some areas from the Alborán Sea, probably related to the inputs of PCBs through the Strait of Gibraltar. Background concentrations for PCBs and p,p'-DDE have been calculated for this Mediterranean region.

Levels of PCBs in Oysters Coming from Galicia Coast: Comparison to Mussels from the Same Region

PCBs were analyzed in two species of oyster (Crassostrea gigas and Ostrea edulis) cultured in intertidal beds and rafts coming from the Galician Rías during the period 2011-2014. PCBs were also analyzed in mussel (Mytilus galloprovincialis) collected in the same Rías during 2011. The main objective of this work is to investigate the distribution of PCBs in Galician oysters and to study their suitability as bioindicator in comparison to mussels. The levels of ΣPCBs (ten congeners) ranged from 5.58 to 179.49 ng g(-1) d.w. The effect of biological parameters (shell length, lipid content and condition index) on bioaccumulation of PCBs was also evaluated. ANOVA showed a statistically significant difference between species for higher chlorinated biphenyls (CBs 153 and 138). The spatial patterns were investigated. Principal Component Analysis (PCA) showed differences between geographical areas (Rías Altas, Centrales and Baixas) in the distribution of PCBs.