Elemental mapping of lung tissue sections. A: Representative elemental map obtained by X-ray micro-fluorescence (μXRF) in a Control and a Welder. Signal of sulphur: green. Signal of iron: blue. Signal of manganese: red. Scale bar: 100 μm. For each element, fluorescence intensities are proportional to the total amount of element. B: Quantification of the signal obtained for each element, given as a ratio to that of sulphur. *: p < 0.05 vs Control, **: p <0.01 vs Control, n = 6-8 per group. Open circles: Controls (grey horizontal bar: mean value). Black squares: Welders (black horizontal bar: mean value).