Figure 3.

Histopathological evaluation with repeated oral administration of two sizes of polypropylene microplastics for four weeks. Representative picture of histopathological evaluation. Compared to organs of the control group (first line), there were no specific changes in organs of the approximately 5 μm sized PP microplastic–treated group (second line) and the 10~50 μm treated group (third line). (a,g,m) The hippocampus (hpc) of the brain, (b,h,n) myocardium (mc) and valve (vv) of the heart, (c,i,o) bronchiole (br) and alveolar (av) of the lung, (d,j,p) central vein (CV) and portal triad (PT) of the liver, (e,k,q) white (wp) and red (rp) pulp of the spleen, and (f,l,r) glomerulus (gr) and tubules (tb) of the kidney and other organs were evaluated. Scale bar: 200 μm.