Some interesting facets of the role of arsenical pigments in poisoning those exposed to them in ancient surroundings are mentioned in a letter in the Lancet for July 8 from Martin E. Gordon of Yale.
The dangers of exposure to toxic concentrations of arsenic derived from the pigments incorporated into fabrics and wall-hangings were understood in the 18th century, he writes. Moreover, there is documentation of arsenical intoxication after contact with traditional Chinese herbal balls, Korean herbal remedies intended to treat haemorrhoids, kelp supplements, pesticides, rodenticides and industrial wastes, all attributed to arsenical pigments. Even cot deaths have been put down to the arsine liberated by fungi from the plasticisers and fire retardants used in damp and deteriorating cot mattresses.
In the 1890s, writes Gordon, attention in the United States was turned to the hazards posed by arsenical pigments popular in wallpapers, and which in damp conditions produced arsine through the activity of the fungus Penicillium brevicaule. The addition of arsenious oxide to the sizes used to hang wallpapers, though it deterred rodent pests, also contributed to the poisoning of humans. The renovation of ancient houses is a well documented cause of both lead and arsenic poisoning. When an arsenical wallpaper is removed, both the dust and the gas evolved through fungal action on the pigments constitute a hazard.
The signs and symptoms which indicate arsenical poisoning have included torsade de pointes, circulatory collapse, polyneuropathy, encephalopathy, enteritis, myelodysplastic syndrome, vasospastic attacks, skin neoplasia, renal failure, liver necrosis and veno-occlusive fibrosis. It makes a sorry tale, but fortunately one which is unlikely to be repeated with modern pigments used to decorate the home and workplace.