Indelible pencils were the cause of significant health risks due to the presence of
aniline dyes. Exposure to aniline dyes could lead to
eczema, acne and
carcinoma. Penetration of the pencil lead into the body commonly leads to severe and debilitating effects such as fever,
anaemia, elevated white cell count, gastro-intestinal upset, kidney and liver damage,
anorexia and
necrosis of the tissue surrounding the wound. Such risks are not associated with ordinary graphite pencils. While these symptoms may appear after a couple of days they often develop only after weeks have passed since the injury was sustained. Surgery is required to remove the lead and the infected tissue and "the necrotizing action may be so severe and extensive amputation is necessary".
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