Occurrence and distribution of PAHs in stranded dolphin tissues from the Northwestern Mediterranean.

There are few cetacean tissue-specific polycyclic aromatic hydrocarbon (PAH) concentration studies in the Mediterranean, despite this region is among the most subjected to chemical contamination. PAH analyses were conducted in different tissues of striped dolphins (Stenella coeruleoalba, N = 64) and bottlenose dolphins (Tursiops truncatus, N = 9) stranded along the French Mediterranean coastline from 2010 to 2016. Comparable levels were measured in S. coeruleoalba and T. trucantus (1020 and 981 ng g-1 lipid weight in blubber, 228 and 238 ng g-1 dry weight in muscle, respectively). The results suggested a slight effect of maternal transfer. The greatest levels were recorded by urban and industrial centers, and decreasing temporal trends were observed in males muscle and kidney, but not in other tissues. As a conclusion, the elevated levels measured could represent a serious threat to dolphins populations in this region, particularly by urban and industrial centers.

Pollution gradient leads to local adaptation and small-scale spatial variability of communities and functions in an urban marine environment.

Urbanization of coastal habitats, of which harbors and marinas are the paragon, has led to various ecological paradigms about their functioning. Harbor infrastructures offer new hard substrata that are colonized by a wide variety of organisms (biofouling) including many introduced species. These structures also modify hydrodynamism and contaminant dispersal, leading to strong disturbance gradients within them. Differences in sessile community structure have previously been correlated to these gradients at small spatial scale (<100 m). Local adaptation might be involved to explain such results, but as correlation is not causation, the present study aims to understand the causal link between the environmental gradients and community structure through a reciprocal transplant experiment among three sites of a marina (inner, middle, entrance). Our results highlighted strong small-scale spatial variations of contaminants (trace metals, PCB, pesticides, and PAH) in sediments and animal samples which have been causally linked to changes in community composition after transplant. But historical contingency and colonization succession also play an important role. Our results provided strong evidence for local adaptation since community structure, respiration, and pollutant uptake in Bugula neritina, as well as the metabolomes of B. neritina and Ciona intestinalis were impacted by the transplant with a disadvantage for individuals transplanted from the entrance to the inner location. The here observed results may thus indicate that the disturbance gradient in marinas might constitute a staple for selecting pollutant-resistant species and populations, causing local adaptation. This highlights the importance of conducting further studies into small scale local adaptation.

Trends of banned pesticides and PCBs in different tissues of striped dolphins (Stenella coeruleoalba) stranded in the Northwestern Mediterranean reflect changing contamination patterns.

Although banned for years, organochlorine pesticides and PCBs continue to affect aquatic life, dolphins being particularly exposed. The concentrations of 31 PCB congeners, and 15 banned pesticides or metabolites were measured in 5 tissues of 68 striped dolphins stranded in the Northwestern Mediterranean coast in 2010-16. The results were compared to historical data (1988-2009) and, even though there is a slow decreasing trend, the levels in the 2010-2016 samples were still elevated based on common cetacean toxicological thresholds. A transition period in 2007-08, probably caused by a morbillivirus epizootic amplified the stranding, espacially of highly contaminated specimens. From 2010, higher proportions in parent compounds towards metabolites were observed yet again. These changing patterns were likely reflect the exposure of dolphins to the remobilization of pollutants from contaminated soils and sediments, with a prominent role of rivers. This should lead to an even slower decline of these contaminants that could last for decades, requiring new efforts to reduce their dispersal to aquatic ecosystems.

Effects of meteorological conditions and topography on the bioaccumulation of PAHs and metal elements by native lichen (Xanthoria parietina).

The bioaccumulation of PAHs and metal elements in the indigenous lichens Xanthoria parietina was monitored during two years at a quarterly frequency, in 3 sites of contrasted anthropic influence. The impact of the meteorological factors (temperature, relative humidity, rainfall, wind speed) was first estimated through principal component analysis, and then by stepwise multilinear regressions to include wind directions. The pollutants levels reflected the proximity of atmospheric emissions, in particular from a large industrial harbor. High humidity and mild temperatures, and in a lower extent low wind speed and rainfall, also favored higher concentration levels. The contributions of these meteorological aspects became minor when including wind direction, especially when approaching major emission sources. The bioaccumulation integration time towards meteorological variations was on a seasonal basis (1-2 months) but the wind direction and thus local emissions also relied on a longer time scale (12 months). This showed that the contribution of meteorological conditions may be prevalent in remote places, while secondary in polluted areas, and should be definitely taken into account regarding long-term lichen biomonitoring and inter-annual comparisons. In the same time, a quadruple sampling in each site revealed a high homogeneity among supporting tree species and topography. The resulting uncertainty, including sampling, preparation and analysis was below 30% when comfortable analytical conditions were achieved. Finally, the occurrence of unexpected events such as a major forest fire, permitted to evaluate that this type of short, although intense, events did not have a strong influence on PAH and metals bioaccumulation by lichen.

Feasibility of an inhaled antibiotic/adjuvant dry powder combination using an experimental design approach.

The global increase of multidrug resistant bacteria and the lack of new classes of antibiotic especially those targeting Gram-negative pathogens are leaving the clinicians disarmed to treat numerous bacterial infections. Recently, the design of adjuvants able to enhance antibiotics activities appears to be one of the most promising investigated solutions to circumvent this problem. In this context, we have recently identified a new polyamino-isoprenyl derivative NV716 able to potentiate, at a very low concentration the activity of doxycycline against resistant P. aeruginosa bacterial strains by increasing its intracellular concentration. In this study we will report an experimental protocol to optimize a dry powder for inhalation ensuring the simultaneous delivery of an antibiotic (doxycycline) and an adjuvant (the polyaminoisoprenyl derivative NV716 since aerosol therapy could allow a rapid drug administration and target the respiratory system by avoiding the first pass effect and minimizing undesirable systemic effects. Thus, an experimental design was carried out permitting to identify the influence of several factors on the aerosolization efficiency of our combination and allowing us to find the right composition and manufacture leading to the best optimization of the simultaneous delivery of the two compounds in the form of an inhalable powder. More precisely, the powders of the two active ingredients were prepared by freeze drying and their aerosolization was improved by the addition of carrier particles of lactose inhalation grade. Under these conditions, the best formulation was defined by combining the optimal factors leading to the best aerodynamic properties' values (the lowest MMAD (Mass Median Aerodynamic Diameter) and the highest FPF (Fraction of Fine Particles)) without even using sophisticated engineering techniques. Finally, our results suggest that these molecules could be successfully delivered at the requested concentration in the lungs and then able to decrease drug consumption as well as increase treatment efficacy.

Characterization of a new aerosol antibiotic/adjuvant combination for the treatment of P. aeruginosa lung infections.

The lack of novel classes of antibiotics as well as the constant increase of multidrug resistant bacteria are leaving the clinicians disarmed to treat bacterial infections, especially those caused by Gram-negative pathogens. Among all the investigated solutions, the design of adjuvants able to enhance antibiotics activities appears to be one of the most promising. In this context, a polyamino-isoprenyl derivative has been recently identified to be able to potentiate, at a very low concentration the activity of doxycycline against P. aeruginosa bacterial strains by increasing its intracellular concentration. On the other hand, since aerosol therapy allows a rapid drug administration and targets the respiratory system by avoiding the first pass effect and minimizing undesirable systemic effects, we have developed the first adjuvant/antibiotic combination in an aerosolized form and demonstrated the feasibility of such an approach. Thus, combination aerosol droplets have been demonstrated in sizes suitable for inhalation (3.4 and 4.4 µm mass median aerodynamic diameter and 54 and 60% of the aerodynamic particle size distribution less than 5 µm, as measured for the adjuvant NV716 and doxycycline, respectively and with properties (stoichiometric 1:1 ratio of NV716 salt to drug) that would support further development as an inhaled dosage form. Taken together, our results suggest that these molecules could be successfully delivered at the requested concentration in the lungs and then able to decrease drug consumption as well as increase treatment efficacy.

Characterization of atmospheric emission sources in lichen from metal and organic contaminant patterns.

Lichen samples from contrasted environments, influenced by various anthropic activities, were investigated focusing on the contaminant signatures according to the atmospheric exposure typologies. Most of the contaminant concentrations measured in the 27 lichen samples, collected around the industrial harbor of Fos-sur-Mer (France), were moderate in rural and urban environments, and reached extreme levels in industrial areas and neighboring cities (Al up to 6567 mg kg-1, Fe 42,398 mg kg-1, or ΣPAH 1417 µg kg-1 for example). At the same time, a strong heterogeneity was noticed in industrial samples while urban and rural ones were relatively homogeneous. Several metals could be associated to steel industry (Fe, Mn, Cd), road traffic, and agriculture (Sb, Cu, Sn), or to a distinct chemical installation (Mo). As well, PCDFs dominated in industrial samples while PCDDs prevailed in urban areas. The particularities observed supported the purpose of this work and discriminated the contributions of various atmospheric pollution emission sources in lichen samples. A statistical approach based on principal component analysis (PCA) was applied and resolved these potential singularities into specific component factors. Even if a certain degree of mixing of the factors is pointed out, relevant relationships were observed with several atmospheric emission sources. By this methodology, the contribution of industrial emissions to the atmospheric metal, PAH, PCB, and PCDD/F levels was roughly estimated to be 60.2%, before biomass burning (10.2%) and road traffic (3.8%). These results demonstrate that lichen biomonitoring offers an encouraging perspective of spatially resolved source apportionment studies.

A chronicle of the changes undergone by a maritime territory, the Bay of Toulon (Var Coast, France), and their consequences on PCB contamination.

This study evaluated the distribution of polychlorinated biphenyls (PCBs) in 39 surface sediment samples and four cores collected in Toulon Bay, a semiclosed area submitted to various anthropogenic inputs. The concentration of PCBs in the superficial sediment samples ranged from 1.7 to 2530 ng g(-1) dry weight. The spatial distribution of these compounds suggested that the high concentrations of these contaminants are located in the small bay and are related to human activities. In the larger bay, the concentrations were in the same order of magnitude than those reported in others locations around the world. Comparison of the levels with target values from the French legislation shows that, except for four polluted sites with critical values (N2: values ≥1 mg kg(-1) dry weight) in the smaller bay, PCBs levels throughout the larger and the smaller bay are lower than the accepted values (N1: values <0.5 mg kg(-1) dry weight). The PCBs in the sediment cores ranged from 0.8 to 739 ng g(-1) dry weight dependent core. Vertical profiles indicated earlier usage of PCBs which coincided with the history of the Toulon Bay. In this study, using alkane, we could follow the PCBs pollution history over about 80 years and estimate a sedimentation rate of about 0.32 cm year in the small Bay of Toulon.

PCBs and DDTs in Stenella coeruleoalba dolphins from the French Mediterranean coastal environment (2007-2009): current state of contamination.

Organochlorinated compounds including PolyChloroBiphenyles, Dichloro-DiphenylTrichloroethan and metabolites are determinated in Stenella coeruleoalba (n = 37) stranded on the french Mediterranean coasts from 2007 till 2009. Studies are carried out on lung, muscle, kidney, liver, and blubber. The sought-after compounds are all detected to variable levels in each tissue and organ. In general, total PCBs are the most abundant, followed by total DDTs. The concentration (in ng g(-1) of lipid weight) in blubber of S. coeruleoalba, varied from 2,052 to 158,992 for PCBs and from 1,120 to 45,779 for DDTs. The ratios DDE/tDDTs are higher than 80% in almost all samples. The overall results of this work, compared to previous studies concerning the Mediterranean Sea, seems to confirm the tendency to a decrease of the contamination by organics compounds for the cetaceans in the Western Mediterranean Sea.

Organic pollution and genotoxicity of sediments of the Palun marshes (Berre lagoon, France).

The impact of industrial, rural, and urban activities on two runnels (B1, B2, and B3 from Beausset runnel and V1 and V2 from Vallat du Ceinturon runnel) located in the Palun marshes (Berre lagoon, France) was evaluated by analyzing 16 polycyclic aromatic hydrocarbons (PAHs), 1-nitropyrene (1-NP), 1-aminopyrene (1-AP), and six pesticides in sediment samples. The mutagenicity was assessed with the Salmonella mutagenicity test using tester strains TA98+S9 Mix and YG1041 +/- S9 Mix. The clastogenicity was evaluated with the micronucleus assay on Chinese Ovarian cells +/- S9 Mix. A gradient of PAHs concentrations was observed from B1 (3359 microg kg(-1) dry weight [dw]), close to industrial zones, to V2 (497 microg kg(-1) dw), away from the source of pollution. Similar gradient was noted for 1-AP (from B1: 11.8 microg kg(-1) dw to V2: 0.6 microg kg(-1) dw). However, this trend was not observed in 1-NP concentrations (concentrations ranged from 1.2 microg kg(-1) dw [V1] to 0.4 microg kg(-1) dw [B1]). Pesticides were detected in all samples. Diazinon and dieldrin were found in high concentrations in B1 extracts (74.5 and 39.9 microg.kg(-1) dw, respectively). All the sediments except V2 were mutagenic with strain TA98+S9 Mix. The mutagenicity was linked to the presence of PAHs (V1), nitroarenes (B1 and B3) and aromatic amines (B2). All sediments were clastogenic with and without S9 Mix except V1 extract, which was negative without S9 Mix. Overall, the two runnels in the Palun marshes were found to be polluted by many organic compounds that originate from direct human activities and pose a significant genotoxic risk.

Accumulation and distribution of organochlorines (PCBs and DDTs) in various organs of Stenella coeruleoalba and a Tursiops truncatus from Mediterranean littoral environment (France).

The objective of the present study is to determine the levels of contamination by PCBs, DDT and its metabolites in dolphins failed on the coasts of the Mediterranean sea. Samples are represented by six Stenella coeruleoalba and a Tursiops truncatus collected in 2000 and 2003. The studies are achieved on the blubber, the heart, the liver, the kidney, the muscle and the lung. The concentrations of PCBs and DDT are very high in all tissues and organs analyzed. For the PCBs, the concentrations vary between 43,838 and 110,343 microg/kg lipid basis in the blubber, 601 and 39444 microg/kg dried weight in the liver, 1375 and 34512 microg/kg dried weight in the muscle, 3151 and 17082 microg/kg dried weight in the heart, 674 and 12365 microg/kg dried weight in the kidney and finally between 648 and 4118 microg/kg dried weight in the lung. These values are comparable to those previously obtained in our laboratory and by other authors during the years 1990 on the Mediterranean environment. Significant differences in concentrations are noted in tissues and organs, neither according to the age, nor according to the gender. In all the analyzed samples, the contents in PCBs are higher than those of DDT. The average ratios of pp'-DDE/SigmaDDT are close to 0.6 which shows the metabolization of these compounds along the years. The examination of the profiles of congeners shows that the hexachlorinated molecules are dominating in all tissues and organs which supposes the different animals were especially exposed to Pyralen-type compounds of transformer (Dp6).

Marine sponges as biomonitor of polychlorobiphenyl contamination: concentration and fate of 24 congeners.

The aim of this study was first to assess the relevance of a marine sponge, Spongia officinalis, as a biomonitor of PCB. Twenty-four chlorobiphenyl congeners have been measured along a pollution gradient both in sponges and seawater. S. officinalis displays a capacity to accumulate all types of congeners. The highest concentration factors were found for hexa- and heptachlorobiphenyls. Concentrations recorded in sponges agreed quite well with the PCB concentrations of study sites. The prevalence of CB138 and CB153 definitely demonstrated the urban origin of the PCB detected, despite the ban on their production and the existence of a wastewater treatment plant since 1987. The CB138/CB153 ratio is approximately 1.2 in commercial mixtures as well as in seawater. In sponges, this ratio varies strongly in space and time, from 1 in sponges at the most polluted site to 0.3 at the reference site. This change in the ratio of these two very persistent congeners, which is not observed in seawater, indicates a metabolism of CB138 in sponges. As it was recently demonstrated for nonpersistent organic contaminants, sponges might well be able to degrade PCB, but further work is needed to identify the processes involved.