Occurrence of rare earth elements in fledgelings of Thalasseus sandvicensis

Distinct trophic transfer of rare earth elements in adjacent terrestrial and aquatic food webs

Growing demand and usage of rare earth elements (REEs) lead to significant pollution in wildlife, but trophic transfer of REEs in different food webs has not been well understood. In the present study, bioaccumulation and food web transfer of 16 REEs (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, and Sc) were investigated in different terrestrial and aquatic species. Median concentrations of REEs in plant, invertebrate, fish, amphibian, reptile, bird, and vole samples were 488-6030, 296-2320, 123-598, 17.5-88.1, 88.0, 14.2-92.0, and 170 μg/kg, respectively. The REE concentrations decreased as plants > invertebrates > fishes > amphibians and snakes > birds. The biomagnification factors (BMFs) and trophic biomagnification factors of most REEs were lower than 1, indicating trophic dilution of REEs. Most poikilotherms including fishes, amphibians, and snakes presented higher BMFs of REEs than homotherms including birds and voles (p < 0.05). Negative correlations were observed between REE concentrations and δ13C (p < 0.01), not δ15N (p > 0.05) in terrestrial organisms, while REE concentrations were negatively correlated with δ15N (p < 0.05), not δ13C (p > 0.05) in aquatic organisms. The result implies diet source and trophic level as key factors affecting the cycling of REEs in terrestrial and aquatic food webs, respectively.

Age-related bioaccumulation of rare earth elements in feathers of Magellanic penguins (Spheniscus magellanicus) from the Chilean Patagonia

The presence of rare earth elements (REE) in the southern hemisphere, particularly marine ecosystems of Patagonia, have received little attention. The Magellanic penguin, which is also known as the Patagonian penguin, inhabits only in austral regions of South America. Although seabird feathers have been used extensively as a bio-monitoring tool, no studies have addressed the effect of age on REE accumulation in Magellanic penguins. In this study, the concentrations of REE were determined by ICP-MS to detect La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Sc, Lu and Y in the feathers of Magellanic penguins from Magdalena Island, an important rookery in the Strait of Magallan. Age-related differences were studied to investigate the different patterns of REE bioaccumulation between adults and juveniles. The data showed that juvenile penguins exhibit higher REE-levels than adult individuals (p < 0.05). Mean REE-values (μg g-1 d.w) differed several orders of magnitude, ranging from 0.002 for Lu in adults to 1.15 for Ce in juvenile individuals. The results are useful to understand the bioaccumulation of REE in fauna from remote and cold regions of the southern hemisphere.

Mercury and rare earth elements (REEs) show different spatial trends in feathers of Kentish plover (Charadrius alexandrinus) breeding along the Adriatic Sea coast, Italy

Feather analysis is an ethical and effective method for assessing the exposure of wild birds to environmental contamination due to trace elements and organic pollutants. We used feather to monitor the exposure to three toxic and non-essential metals (Hg, Cd, and Pb) and rare earth elements (REEs) of Kentish plover (Charadrius alexandrinus) breeding in different coastal areas (Veneto, Emilia-Romagna, Marche, Abruzzo, and Apulia) along the Italian coast of the Adriatic Sea. Feathers (n = 113) were collected from April to June. Feather concentrations evidenced a significant exposure to Hg (13.05 ± 1.71 mg kg-1 dw) and REEs (447.3 ± 52.8 ng g-1 dw) in the Kentish plover breeding in Veneto (n = 21) compared to the other coastal areas, with several individuals showing Hg concentrations above the adverse effect (5 mg kg-1 dw) and high-risk (9.14 mg kg-1 dw) thresholds reported for birds. Higher REE concentrations compared to Marche (n = 29), Abruzzo (n = 11) and Apulia (n = 13) were also reported for birds breeding in Emilia-Romagna (474.9 ± 41.9 ng g-1 dw; n = 29). The exposure to Cd and Pb was low in all the coastal areas, and only a few samples (n = 6 and n = 4 for Cd and Pb, respectively) exceeded the adverse effect thresholds (0.1 and 4 mg kg-1 for Cd and Pb, respectively). A significant sex-related difference was observed for REE-concentrations, with females showing higher concentration than males. These data highlight the need to monitor the exposure of the Kentish plover to Hg and REEs, especially in the northern basin of the Adriatic Sea, since these elements might negatively affect species' reproductive success and threaten its conservation.

Distribution of rare earth elements (REEs) in the feathers of gentoo penguins (Pygoscelis papua) from different geographical locations of the Antarctic peninsula area

Antarctica is the most remote and coldest regions of the planet, but the presence of REEs there has received little attention. This study assessed REE-contents in the feathers of adult gentoo penguins from Ardley Island, Kopaitic Island and Base O'Higgins. Field work was accomplished during 2011 (austral summer), and determination of elements was performed with ICP-MS. In general, REE-levels showed descending relations as follows: Ce > La > Y > Nd > Sc > Pr > Gd > Sm > Dy >Er > Yb > Eu > Ho > Tb > Tm > Lu. The data showed an increase of the levels of REEs from the lower part of the feather to the tip. This finding seems to be spatially dependent, but geochemical, anthropogenic conditions, feeding habits, sex, or even health status of birds should also be considered. It is a subject that requires deeper attention in future studies.

Burden of rare earth elements and trace elements in feathers of magellanic penguins (Spheniscus magellanicus) from the southern Chilean Patagonia

Patagonia is one of the last pristine regions on the southern hemisphere. The impact of rare earth element (REEs) and trace elements (TEs) in this region have received little attention. The main goal was to assess REEs burden in feathers of adult magellanic penguins (Spheniscus magellanicus). Sampling was performed at Magdalena Island of the Chilean Patagonia during the austral summer of 2011. Multi-elemental determination of 16 REEs and 24 TEs was performed with ICP-MS. The levels of REEs, TEs, and stable isotopes (δ15N, δ13C, and δ34S) were measured to assess the factors that condition the avian exposure to environmental contaminants. The results showed an increase of the levels of REEs and TEs from the calamus to the feather's tip. In the whole feather, the highest levels corresponded to Ce, which exhibited more than two order of magnitude than Lu and Tm levels. Similar to other penguin species, magellanic penguins can be vectors of REEs and metals in remote regions. Stable isotopes revealed that trophic ecology may influence some of the element concentrations in feathers of magellanic penguins, an issue that requires deeper attention.

Rare earths and other elements content in hen eggs sold in Italy: comparison among main types of farming methods and consumer's health risk assessment

Recently, in Italy, consumers are choosing hen eggs from farming systems with higher ethical value, due to their perception of a related higher quality and safety. The purposes of this study were to evaluate the existence of differences in elemental content in Italian eggs from organic, barn, and caged hen farming methods and to determine the related potential consumer exposure risk to inorganic contaminants due to the consumption of eggs. One hundred seventy-six egg samples were collected and analyzed using Q-ICP-MS to investigate the content of 14 elements (Pb, As, Hg, Cd, Tl, Fe, Zn, Mn, Cu, Se, Co, Ni, V, and Cr) and 13 rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb). The scenarios of exposure to rare earth and other elements from eggs were estimated for three age groups of consumers. The daily intake values were always lower than the respective safety reference values. In conclusion, Italian hen eggs contain low levels of rare earth and other elements, and therefore, their consumption does not represent a risk of exposure. Finally, no significant differences in contaminants between conventional and organic farming methods were found.

Occurrence of rare earth elements (REEs) and trace elements (TEs) in feathers of adult and young Gentoo penguins from King George Island, Antarctica

Penguins are sentinel species for marine pollution, but their role as potential biovectors of REEs or TEs to ecosystems has been poorly studied. The present study analyzed (ICP-MS) feathers of young and adult Gentoo penguins from Fildes Bay, for 63 elements (including 15 REEs). Most of the REEs were present at very low levels, ranging from 0.002 (Lu) to 0.452 (Sm) μg g^-1 d.w., several orders of magnitude lower than TEs. The content of TEs varied widely, with Al, Fe, Zn, Sr, Ba, Ti and Mn as the seven having the highest concentrations in the feathers of both age groups. The results show that P. papua deposits REEs and TEs through the feathers on the penguin rockery, whose potential actual impacts and long-term fate in remote regions need deeper research. This work presents essential baseline data that will be useful for further studies on Antarctic penguins.

Seabirds as Biomonitors of Mercury Bioavailability in the Venice Lagoon

Seabirds accumulate mercury (Hg) due to their long-life span together with their high trophic position. A Hg monitoring in Venice's Lagoon using three seabird species occupying different trophic habitat (Thalasseus sandvicensis, Ichthyaetus melanocephalus, and Chroicocephalus ridibundus) confirmed that fledgelings might effectively be used as sentinels of Hg bioavailability. The significant differences in Hg residues in feathers observed among the species highlighted a possible differential exposure due to different diets, with C. ridibundus accumulating more Hg than the other species. Average residues in feathers were not above the threshold associated with adverse effects on birds (5 mg kg^- 1). Nevertheless, a large part of the C. ridibundus individuals (58%) exceeded the adverse effect level, underlining the need for strengthening Hg monitoring. Seabirds indeed may provide relevant insight on Hg transfer in food webs and a better picture of the hazards to men when bird species forage on species exploited for human consumption.

The ubiquity of neonicotinoid contamination: Residues in seabirds with different trophic habits

Neonicotinoids are one of the most diffusely used classes of pesticides whose level of danger toward non-target invertebrate and vertebrate species has raised increasing concern in the last decades. Among vertebrates, birds are particularly susceptible to unintentional neonicotinoid poisoning since they can be exposed through different pathways, including ingestion of dressed seeds, sucking of contaminated pollen, ingestion of sprayed insects, predation on contaminated aquatic and terrestrial preys. In the present study, we investigated the possible exposure of seabirds by measuring the residues of five neonicotinoids (acetamiprid, clothianidin, imidacloprid, thiacloprid and thiamethoxam) in samples of pooled feathers collected from fledglings of the strictly piscivorous Sandwich tern (Thalasseus sandvicensis) and the mixotrophic species Mediterranean gull (Ichthyaetus melanocephalus). At least one neonicotinoid was quantified in all the Mediterranean gull samples (n = 11) and 89% of the analysed Sandwich tern samples (n = 36). The active principles with the highest quantification rates were imidacloprid (100% in Mediterranean gulls and 58% in Sandwich terns) and clothianidin (100% in Mediterranean gulls and 61% in Sandwich terns), while thiacloprid was the less frequently detected pesticide (<20% of samples in both species). Mean concentrations ± standard error for imidacloprid, clothianidin and thiamethoxam were 8.8 ± 1.4, 4.5 ± 0.19 and 0.16 ± 0.02 ng g^-1 for the Mediterranean gull, and 5.8 ± 0.55, 0.60 ± 0.08 and 0.36 ± 0.03 ng g^-1for the Sandwich tern, respectively. Our data evidenced the exposure of seabirds to neonicotinoids and the further need to investigate the extent of neonicotinoid contamination in non-agricultural ecosystems.