The dangers of toxic mercury exposure are well known. However, the exact mechanism of mercury’s toxicity and how it infiltrates cells remains unclear.  Using synchrotron X-ray fluorescence (XRF) mapping at HXMA (Microprobe), University of Saskatchewan researchers observed high concentrations of mercury in tissues made up of rapidly dividing cells – specifically the epithelial cells that grow the eye lens in newly hatched zebrafish. This finding has important implications for understanding the effect of mercury exposure in developing animals, including humans.