Analysis of Zebrafish contamination with heavy metals using a FF-XRF imaging system based on a MPGD

Heavy metals have been extensively used by humans and are still present in many aspects of modern-day life. Such elements tend to accumulate, degrading the quality of air, soil, and water, negatively affecting the living organisms. As such, it is of paramount importance to understand the environmental risks of heavy metals, including their bioaccumulation capacity in organisms, since they are associated with several harmful health effects, such as neurological damages. The Zebrafish (Danio rerio) has been shown to be an excellent animal model to understand physiological responses in mammals and consequently to perform toxicological studies due to characteristics such as the high genetic and physiological similarity with humans. In this work, a Full-Field Energy Dispersive X-ray Fluorescence (FF-XRF) imaging system, based on the 2D-THCOBRA micropattern gas detector, was used to monitor heavy metal accumulation in Zebrafish during a water borne exposure bioassay. The distributions of Mn, Se, and Pb in Zebrafish, exposed to different concentrations of the heavy metal compounds during different time intervals, were mapped. The results show a preferential accumulation of Mn, Se, and Pb in the Zebrafish's visceral region and highlight the suitability of the FF-XRF imaging system for quick screening of metal accumulation in fish bioassays.