Contribution of X-Ray Imaging Microscopy in Metal Bioaccumulation Studies

摘要

Industrialization, urbanization, agriculture and natural resource exploration activities are the main sources of release of pollutants, which contaminate both the aqueous compartment and the sediment. In general, metals are the major pollutant, and 90 % approximately of the heavy metals bind to mineral particles, organic matter and to microbial biofilm. The sufficient bioavailability of contaminants can result in bioaccumulation and, depending on the contaminant level, most marine sedimentary ecosystems can become toxic and/or presumably extinct. The knowledge of the physiological mechanisms and the investigation of how these organisms deal with the bioaccumulation of heavy metals are the key in order to unlock adaptive processes, which contribute to the evolutionary fitness and permanence of the species in the environment. In this context, X-ray fluorescence microscopy with Synchrotron radiation with tomography assessment (3D images) was used in order to mapping the body heavy metal distribution of a high abundant marine worm from Guanabara Bay, which is a chronic heavy metal polluted area located at Rio de Janeiro, Brazil. Cadmium, nickel, chromo and cooper were investigated and the results showed a bioaccumulation in the inner parts and especially at the anterior region of the organism. Therefore, X-ray imaging techniques can be a useful tool in order to investigate bioaccumulation in marine benthic invertebrates.