Impact of landfill characteristics on the atmospheric exposure to halogenated flame retardants in gulls

Enlarging effects of microplastics on adsorption, desorption and bioaccessibility of chlorinated organophosphorus flame retardants in landfill soil particle-size fractions

Chlorinated organophosphorus flame retardants (Cl-OPFRs) and microplastics (MPs) are emerging pollutants in landfills, but their synergistic behaviors and triggering risks were rarely focused on, impeding the resource utilization of landfill soils. This study systematically investigated the adsorption/desorption behaviors, bioaccessibility and human health risks of Cl-OPFRs in landfill soil particle-size fractions coexisted with MPs under simulated gastrointestinal conditions. The results showed that the adsorption capacity and bioaccessibility of Cl-OPFRs in humus soil were higher than that in subsoil. MPs promoted the adsorption of tris(1-chloro-2-methylethyl) phosphate (TCPP) and tris(1,3-dichloro-2-propyl) phosphate (TDCPP) in landfill soils by up to 34.6 % and 34.1 % respectively, but inhibited the adsorption of tris(2-chloroethyl) phosphate (TCEP) by up to 43.6 %. The bioaccessibility of Cl-OPFRs in landfill soils was positively correlated with MPs addition ratio but negatively correlated with the KOW of Cl-OPFRs, soil organic matter and particle size. MPs addition increased the residual concentration of Cl-OPFRs and significantly increased the bioaccessibility of TCEP and TDCPP by up to 33.1 % in landfill soils, resulting in higher carcinogenic and noncarcinogenic risks. The study presents the first series of the combined behavior and effects of MPs and Cl-OPFRs in landfill soils, and provides a theoretical reference for landfill risk management.

Physiology and fertility of two gull species in relation to plastic additives' exposure

Understanding the impact of plastic and its additives on wild species is crucial as their presence in the environment increases. Polybrominated diphenyl ethers (PBDEs), once used as flame retardants, were restricted due to known toxic effects, but are still detected in the environment. Naturally occurring methoxylated PBDEs (MeO-BDEs) can result from PBDE transformation and may cause similar hazardous effects. Yellow-legged gulls (Larus michahellis, YLG) and Audouin's gulls (Ichthyaetus audouinii, AG) are highly susceptible to plastic additives, due to their distribution, trophic position, and behaviour. In this study, we assessed PBDEs and MeO-BDEs uptake in different tissues and their effects on physiological and reproductive parameters. Findings indicate that, apart from annual differences, adult AG accumulated more MeO-BDEs than YLG in a natural breeding habitat (Deserta), while the latter had lower PBDE levels than YLG breeding in the city of Porto. In relation to chicks, only YLG from Deserta showed higher PBDE concentrations than AG chicks. Individual analysis of each physiological parameter revealed impacts only for adult YLG from Deserta, with neurofunction and immune system inhibition at higher MeO-BDE concentrations. For chicks, AG showed impaired neurofunction, while YLG chicks from Porto exhibited potential genotoxicity effects triggered by higher MeO-BDE levels. Overall health analysis showed activation of antioxidant defences and compromised immune system in YLG adults from Porto due to high values of PBDEs, while chicks from Deserta exhibited inflammation and oxidative stress with high concentrations of MeO-BDEs in the same species. Fertility parameters showed significant differences for sperm counts though suggesting individuals may be able to compensate any exposure effects. This study confirms the widespread presence of plastic-associated compounds and their harmful effects on gulls, particularly on neurofunction, immune system, oxidative balance and fertility, especially due to the presence of MeO-BDEs.

Black Vulture (Coragyps atratus) feathers as bioindicators of exposure to metals and metalloids contamination in urban, semi-urban, and rural areas from Campeche state, Mexico

Landfills are sources of soil, water, and air pollution due to the release of toxic compounds such as metals and metalloids. In both tropical and temperate environments, scavenger birds such as the Black Vulture (Coragyps atratus) that have learned to use these sites as a feeding area are probably exposed to metals, metalloids and other "persistent bioaccumulative toxic substances (PBTs)" released in open dumpsite (OD) and sanitary landfill (SL). The objective of this study is to evaluate the presence and distribution of toxic metals (Al, Sn, Hg, Cu, Pb, Cd, Cr) and As in OD and SL from urban, semi-urban and rural localities in Campeche, México, using molting feathers of C. atratus as bioindicators. A total of 125 Black Vulture primary and secondary wing feathers were collected from OD and SL. Metals were determined by voltammetry through acid digestion. The highest levels of metals occurred in landfills in urban, semi-urban, and rural localities. The elements with the highest concentrations were Al, with an average of 35.67 ± 33.51 μg g-1 from rural environments, and As, with 16.20 ± 30.06 μg g-1 from the urban localities. Mercury was the only element that had a very homogeneous distribution between the three environments we studied. In general, Pb, Hg, Cu and Cd were the elements that presented the lowest concentrations with 0.32 ± 0.35, 0.16 ± 0.22, 0.14 ± 0.31 and 0.06 ± 0.10 μg g-1, respectively regardless of any particular location or environment. Black Vultures from dumpsites are good bioindicators of what humans consume in urban, semi-urban, and rural environments. However, the conservation of vultures is of great importance since these scavenger birds perform ecosystem services by feeding on decomposing organic material.