Far-reaching cytogenotoxic effects of mine waste from the Fundão dam disaster in Brazil.

On November 2015, one of Brazil's most important watersheds was impacted by the mine waste from Fundão dam collapse in Mariana. The mine waste traveled over 600 km along the Doce River before reaching the sea, causing severe devastation along its way. Here we assessed trace element concentrations and cytogenotoxic effects of the released mine waste. Water samples were collected along the Doce River ten days after the disaster in two impacted sites and one non-impacted site. Sampling points were located hundreds of kilometers downstream of the collapsed dam. Water samples were used for trace element quantification and to run an experiment using Allium cepa to test cytogenotoxicity. We found extremely high concentrations of particulate Fe, Al, and Mn in the impacted sites. We observed cytogenotoxic effects such as alterations in mitotic and phase indexes, and enhanced frequency of chromosomal aberrations. Our results indicate interferences in the cell cycle in impacted sites located hundreds of kilometers downstream of the disaster. The environmental impacts of the dam collapse may not only be far-reaching but also very likely long-lasting, because the mine waste may persist in the Doce River sediment for decades.

Pyrethroids in chicken eggs from commercial farms and home production in Rio de Janeiro: Estimated daily intake and diastereomeric selectivity.

In this study, pyrethroids were determined in chicken eggs from commercial farm (n = 60) and home egg production (n = 30). These pyrethroids were investigated: bifenthrin, phenothrin, permethrin, cyfluthrin, cypermethrin and fenvalerate, including most diastereomers. Quantification was done using GC-MS in a negative chemical ionization mode. Pyrethroids residues were found in 79% of the analyzed samples. Cypermethrin presented the highest occurrence, being quantified in 62 samples (69%) in concentrations (lipid weight - l w.) varying between 0.29 and 6408 ng g-1, followed by phenothrin (24%), 21-3910 ng g-1, permethrin (14%), 2.96-328 ng g-1, and bifenthrin (11%), 3.77-16.7 ng g-1. Cyfluthrin and fenvalerate were not detected. Home-produced eggs had a higher occurrence of pyrethroids (97%), with a greater predominance of phenothrin. In commercial production, 70% of the samples presented pyrethroid residues (predominantly cypermethrin). This is the first report about the presence of pyrethroids in home-produced eggs and the first description of a selectivity pattern with the predominance of cis diastereomers in chicken eggs. In general, estimated daily intake does not present a risk to human consumption, according to Brazilian and international standards (FAO/WHO). However, one third of the samples (30 eggs) had concentrations above the maximum residue limits (MRLs). The maximum cypermethrin concentration was 66 times the MRL, while the maximum phenothrin concentration was 11 times the limit. Further studies about transfer dynamics, bioaccumulation and metabolic degradation of stereoisomers are required, as well as determining if this selectivity pattern in food can increase consumer's health risk.

Relationship between legacy and emerging organic pollutants in Antarctic seabirds and their foraging ecology as shown by δ13C and δ15N.

Foraging ecology and the marine regions exploited by Antarctic seabirds outside of breeding strongly influence their exposure to persistent organic pollutants (POPs). However, relationships between them are largely unknown, an important knowledge gap given that many species are capital breeders and POPs may be deleterious to seabirds. This study investigates the relationship between Antarctic seabird foraging ecology (measured by δ13C and δ15N) and POPs accumulated in their eggs prior to breeding. Organochlorinated pesticides, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and dechlorane plus (DP) were measured in eggs of chinstrap, Adélie, and gentoo penguins (Pygoscelis antarctica, P. adeliae, P. papua), as well as south polar skua (Catharacta maccormicki), sampled on King George Island. Total POP levels were as follows: skua (3210±3330ng/g lipid weight)>chinstrap (338±128ng/g)>Adélie (287±43.3ng/g)>gentoo (252±49.4ng/g). Trophic position and pre-breeding foraging sites were important in explaining POP accumulation patterns across species. The most recalcitrant compounds were preferentially accumulated in skuas, occupying one trophic level above penguins. In contrast, their Antarctic endemism, coupled with influence from cold condensation of pollutants, likely contributed to penguins exhibiting higher concentrations of more volatile compounds (e.g., hexachlorobenzene, PCB-28 and -52) than skuas. Regional differences in penguin pre-breeding foraging areas did not significantly affect their POP burdens, whereas the trans-equatorial migration and foraging sites of skuas were strongly reflected in their pollutant profiles, especially for PBDEs and DPs. Overall, our results provide new insights on migratory birds as biovectors of POPs, including non-globally regulated compounds such as DP, from northern regions to Antarctica.