汚染【おせん】
pollution, contamination
感染【かんせん】
infection, contagion, becoming infected, being infected (e.g. with harmful ideas), being influenced (by)
染色【せんしょく】
dyeing, staining, dyed colour (color)
染める【そめる】
to dye, to colour, to color
染まる【そまる】
to be dyed, to be tainted, to be infected, to be stained, to be steeped
染みる【しみる】
to pierce, to penetrate, to soak in, to permeate, to sting (wound or sensitive area, etc.), to smart, to twinge, to be infected (with vice), to be steeped (with prejudice), to be influenced, to feel keenly, to make a deep impression
染み【しみ】
stain, spot, smudge, blot, smear, blotch, spot (on one's skin, e.g. chloasma, liver spot), blemish, discoloration, freckle