Assessment of polycyclic aromatic hydrocarbons (PAHs) in mediterranean top marine predators stranded in SE Spain.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants. Although they are not bioaccumulated in vertebrates, chronic exposures might still derive on serious toxic effects. We studied concentrations of 16 reference PAHs on blubber of two dolphin species (striped dolphin, n = 34; and bottlenose dolphin, n = 8) and one marine turtle (loggerhead turtle, n = 23) from the Mediterranean waters of SE Spain, an important or potential breeding area for these and other related species. Σ16 PAHs concentrations were relatively similar between the three species, but they were in the lower range in comparison to worldwide data. Of the six PAHs detected, fluoranthene was the only high molecular weight (HMW) PAH, so low molecular weight (LMW) PAHs predominated. Naphthalene and phenanthrene were invariably those PAHs with higher detection rates as well as those with higher concentrations. In accordance with the literature, sex and length did not have significant influence on PAHs concentrations, probably due to high metabolization rates which prevent for observation of such patterns. Despite LMW PAHs are considered less toxic, we cannot dismiss toxic effects. This is the first work assessing PAHs concentrations in cetaceans and sea turtles from the SE Spain, which could serve as the baseline for future research.

POPs concentrations in cetaceans stranded along the agricultural coastline of SE Spain show lower burdens of industrial pollutants in comparison to other Mediterranean cetaceans.

Despite the Mediterranean Sea being one of the world's marine biodiversity hotspots, it is a hotspot of various environmental pollutants. This sea holds eight cetacean with resident populations whose numbers are considered to decline in the last decades and which are particularly susceptible to POPs bioaccumulation due to their peculiar characteristics. In this work, we studied blubber concentration of various OCPs and several PCBs and PBDEs congeners in cetaceans stranded in the northern coast of the Gulf of Vera (Region of Murcia, SE Spain) between 2011 and 2018. Most compounds and congeners were above the limit of detection in most samples, although some pesticides like endosulfan stereoisomers or endrin were never detected. DDT and its metabolites, PCBs and metoxychlor appear as the dominant compounds while PBDEs shows concentrations of lower magnitude. Striped dolphin was the species accounting for higher concentrations of most pollutants. There were differences in concentrations and profiles between species which could be partially explained by differences on diet and feeding behavior. We also observed differences based on life history parameters suggesting maternal transfer for most POPs, in accordance with other works. DDE/ ΣDDT ratio suggest no recent exposure to these pesticides. Despite showing lower concentrations than some previous works, PCB concentrations accounted for higher total TEQ than many studies. According to toxicity thresholds in the literature, we cannot guarantee the absence of health consequences on populations studied, especially for those caused by PCBs. These findings are of major importance considering the relevance of the study area in the conservation of Mediterranean cetaceans.

Human biomonitoring of persistent organic pollutants in elderly people from the Canary Islands (Spain): A temporal trend analysis from the PREDIMED and PREDIMED-Plus cohorts.

The population of the Canary Islands has been exposed to high levels of persistent organic pollutants (POPs). Biomonitoring studies are essential to know the temporal trend in residue levels, particularly of substances banned decades ago. The purpose of this study was to analyze the distribution of plasma concentrations of 59 POPs in 175 participants from the PREDIMED-Plus trial (2014-2016), and to compare them with the distribution of these POPs in 343 participants in the PREDIMED trial (2006-2009). All participants had metabolic syndrome. No difference in the distribution of age, gender or BMI was observed between trials. POPs were determined by gas chromatography-mass spectrometry. Density plots -POP Geoffrey Rose curves- were used to represent the full population distribution of each compound. Three out of 59 POPs were detected and quantified in ≥95% of the samples (p,p'-DDE, median = 694.7 ng/g lipid; HCB, median = 57.0 ng/g lipid; and ß-HCH, median = 75.7 ng/g lipid). PCB congeners 138, 153 and 180 were detected in 64.6, 40.0 and 88.0% of the samples. Females showed highest concentrations of organochlorine pesticides and those subjects who lost ˃ 5 kg showed significant higher plasma concentrations of POPs. In a range of 6-14 years, plasma concentrations of POPs decreased 3.3-21.6 fold, being notable the decrease of 28.7-fold observed for HCB among women. Despite this sharp decline, levels of POPs are still higher than those reported in other regions, since one third of the subjects included in the present report had high concentration of more than three pollutants. Continuous biomonitoring studies are required to know the evolution of the levels of residues and to evaluate the effectiveness of environmental policies.