Bioaccumulation

About: Bioaccumulation is a research topic. Over the lifetime, 7112 publications have been published within this topic receiving 208953 citations. The topic is also known as: bioakumulace.

Microplastics as Vehicles of Environmental PAHs to Marine Organisms: Combined Chemical and Physical Hazards to the Mediterranean Mussels, Mytilus galloprovincialis

Abstract: The ubiquitous occurrence of microplastics (MPs) in the marine environment is raising concern for interactions with marine organisms. These particles efficiently adsorb persistent organic pollutants from surrounding environment and, due to the small size, they are easily available for ingestion at all trophic levels. Once ingested, MPs can induce mechanical damage, sub- lethal effects and various cellular responses, further modulated by possible release of adsorbed chemicals or additives. In this study, ecotoxicological effects of MPs and their interactions with benzo(a)pyrene (BaP), chosen as a model compound for polycyclic aromatic hydrocarbons (PAHs) were investigated in Mediterranean mussels, Mytilus galloprovincialis. Organisms were exposed for four weeks to 10 mg/L of low-density polyethylene (LD-PE) microparticles (2.34x107 particles/L, size range 20-25 µm), both virgin and pre-contaminated with BaP (15µg/g). Organisms were also exposed for comparison to BaP dosed alone at 150 ng/L, corresponding to the amount adsorbed on microplastics. Tissue localization of microplastics was histologically evaluated; chemical analyses and a wide battery of biomarkers covering molecular, biochemical and cellular levels allowed to evaluate BaP bioaccumulation, alterations of immune system, antioxidant defenses, onset of oxidative stress, peroxisomal proliferation, genotoxicity and neurotoxicity. Obtained data were elaborated within a quantitative weight of evidence (WOE) model which, using weighted criteria, provided synthetic hazard indices, for both chemical and cellular results, before their integration in a combined index. Microplastics were localized in haemolymph, gills and especially digestive tissues where a potential transfer of BaP from MPs was also observed. Significant alterations were measured on the immune system, while more limited effects occurred on the oxidative status, neurotoxicity and genotoxicity, with a different susceptibility of analyzed pathways, depending on tissue, time and typology of exposure. Molecular analyses confirmed the general lack of significant variations on transcriptional activity of antioxidant and stress genes. The overall results suggest that microplastics induce a slight cellular toxicity under short-term (28 days) exposure conditions. However, modulation of immune responses, along with bioaccumulation of BaP, pose the still unexplored risk that these particles, under conditions of more chronic exposure (months to years) or interacting with other stressors, may provoke long-term, subtle effects on organisms’ health status.

Biological uptake and depuration of carbon nanotubes by Daphnia magna.

Abstract: It is inevitable that carbon nanotubes (CNTs) will be released to and widely dispersed in environmental ecosystems, given their numerous expected applications. Determination of their potential for bioaccumulation by ecological receptors is thus critical. Previous research involving several different terrestrial and benthic organisms has indicated that CNTs spiked to soils or sediments do not bioaccumulate. Conversely, we report here distinctly different uptake and depuration behaviors for an aquatic organism, Daphnia magna, in a water-only system. After 48 h of exposure of this organism to a 0.4 μg/mL solution of dispersed nanotubes, the CNTs comprised 6.3 ± 1.5% of the residual organism dry mass. Moreover, these organisms were unable to excrete the nanotubes to either clean artificial freshwater or filtered Lake Kontiolampi water after 24 h depuration periods, even though the lake water had a substantial concentration of natural organic matter. Addition of algae to the water during the depuration period ...

Bioaccumulation of marine pollutants.

Abstract: Bioaccumulation of pollutants can occur from sea water, from suspended particles, from sediments and through food chains. The rate at which accumulation occurs in an organism depends not only on the availability of the pollutant but also on a whole range of biological, chemical and environmental factors. The ultimate level which is reached is governed by the ability of the organism to excrete the pollutant or, alternatively, store it. This latter course often leads to the attainment of very high concentrations and sometimes no equilibrium level is ever reached. Two particular topics which are considered are the biological amplification of pollutants along food chains and the development of tolerance which sometimes occurs.