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Sea turtles face several threats and pollution has become a major concern for their conservation worldwide. We analyzed samples of the liver, muscles, and kidneys of 38 Chelonia mydas stranded along the Potiguar Basin, northeastern Brazil, between 2015 and 2018 to determine the total Hg concentration (THg), as well as the concentrations of Cu, Cd, Ag, and Se. The relation between turtle size and element concentrations revealed a negative correlation for THg and Se (liver, muscles, and kidneys), Cu and Cd (liver and kidneys) and a positive correlation for Ag in the three organs analyzed. Concentrations of THg, Cu, Ag, and Se were high in the liver, highlighting the Cu concentration (median = 25.1150 μg g -1 w.w.), while the kidneys had the highest Cd levels (median = 12.2200 μg g -1 w.w.). There was significant difference between element concentrations and the three organs analyzed, except for Ag and Se concentrations in the muscle and kidney samples. Our study showed that green turtles found in Potiguar Basin, northeastern Brasil, have bioaccumulated inorganic elements which indicate the need of further investigations on the environmental quality of the region., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Arthritic lesions have been frequently diagnosed in the fossil record, with spondyloarthropathy (a type of erosive and pan-mammalian arthritis) being one of the most common types described to date for mammals, though not restricted to this group. Here, we identify spondyloarthropathy in fossil bones from the late Pleistocene in Brazil assignable to a large glyptodont individual. Bone erosions in the peripheral joints (viz., the ulna, radius, left femur and tibiae-fibulae) associated with osteosclerosis allow the diagnosis of spondyloarthropathy. The presence of osteophytes in seven bones of the forelimbs (viz., the ulna and radius) and hind limbs (viz., the tibiae-fibulae, left femur and patellae) and a subchondral cyst in one element (viz., the left femur) indicate secondary osteoarthritis. A calcified deposition on the articular surface of the left patella indicates the presence of calcium pyrophosphate deposition disease, which, like the observed osteoarthritic alterations, likely represents a complication of spondyloarthropathy. This is the first report of spondyloarthropathy for xenarthrans.

Top marine predators present high mercury concentrations in their tissues as consequence of biomagnification of the most toxic form of this metal, methylmercury (MeHg). The present study concerns mercury accumulation by Guiana dolphins (Sotalia guianensis), highlighting the selenium-mediated methylmercury detoxification process. Liver samples from 19 dolphins incidentally captured within Guanabara Bay (Rio de Janeiro State, Brazil) from 1994 to 2006 were analyzed for total mercury (THg), methylmercury (MeHg), total organic mercury (TOrgHg) and selenium (Se). X-ray microanalyses were also performed. The specimens, including from fetuses to 30-year-old dolphins, comprising 8 females and 11 males, presented high THg (0.53-132 µg/g wet wt.) and Se concentrations (0.17-74.8 µg/g wet wt.). Correlations between THg, MeHg, TOrgHg and Se were verified with age (p<0.05), as well as a high and positive correlation was observed between molar concentrations of Hg and Se (p<0.05). Negative correlations were observed between THg and the percentage of MeHg contribution to THg (p<0.05), which represents a consequence of the selenium-mediated methylmercury detoxification process. Accumulation of Se-Hg amorphous crystals in Kupffer Cells was demonstrated through ultra-structural analysis, which shows that Guiana dolphin is capable of carrying out the demethylation process via mercury selenide formation.

Blubber samples from 33 Guiana dolphins (Sotalia guianensis) from three estuaries (Guanabara, Sepetiba/Ilha Grande and Paranaguá Bays) of Southern and Southeastern Brazil were analyzed for organochlorine compounds (DDTs, PCBs and HCB). The sampled individuals were incidentally captured in gillnet fishery between 1995 and 2005. The concentrations (in ng/g lipids) varied from 652 to 23 555 for SigmaDDT; from 765 to 99 175 for SigmaPCB; and from <4.4 to 156 for HCB. The results have shown that cetaceans from Brazil present organochlorine concentrations that are comparable to those reported for highly industrialized regions of Northern Hemisphere. Using discriminant analysis it was possible to verify that the dolphin populations from the three bays present different organochlorine accumulation patterns. This feature allows the use of this set of pollutants as an auxiliary tool for identification of different populations of the species off Brazilian Coast., (Copyright 2009 Elsevier Ltd. All rights reserved.)

In Brazil, there is no restriction to the use of organotins (OTs). Previous investigations have shown that hepatic SigmaSn in cetaceans is predominantly organic. Hepatic SigmaSn concentrations were determined by GFAAS in 67 cetaceans (13 species) that stranded on Rio de Janeiro (RJ) and Espirito Santo (ES) states. Concentrations (in ng/g wet wt.) of marine tucuxis (n=20) from the highly contaminated Guanabara Bay (in RJ) varied from 1703 to 9638. Concentrations of three marine tucuxi foetuses and one newborn calf (all from Guanabara Bay) varied between 431 and 2107. Contrastingly, the maximum level among 19 oceanic dolphins was 346, and 15 out of these 19 specimens presented concentrations below detection limit. The levels of Sn in six marine tucuxis from a less contaminated area (ES) varied from below detection limit to 744. Comparing to the literature, coastal cetaceans from Brazil appear to be highly exposed to OTs.

Perfluorooctane sulfonate (PFOS) and other perfluoroalkyl compounds (PFCs) were measured in liver samples from 29 marine tucuxi dolphins from Rio de Janeiro state (RJ), Brazil. PFC measurement combined liquid chromatography and mass spectrometry, using a CapLC system connected to a Quadrupole-LIT mass spectrometer. PFOS was the only PFC detected and it was so in all samples. PFOS concentrations (ng x g(-1) dw) of dolphins (n=23) from the highly contaminated Guanabara Bay (in RJ) varied between 43 and 2431 as well as between 76 and 427 from areas of RJ other than the quoted bay (n=6). Concentrations of three fetuses and one neonate varied between 664 and 1590. Fetus/mother ratios were calculated in two situations (2.75 and 2.62). It seems that mother-to-calf transference plays important role for relationships between PFOS and age. When a one-year-old male calf presenting 2431 ng x g(-1) dw was excluded from the test, significant correlations were observed between PFOS concentrations and both age and total length. Despite the placental transference, PFOS concentrations were not significantly lower in females than in males. PFOS levels in marine tucuxi dolphins from Guanabara Bay are among the highest detected to date in cetaceans, and this may represent a threat to the small population concerned.