Wallpaper, arsenical pigments

Museums and industrial facilities, especially, often have exotic minerals, pigments, and chemicals that release arsenic-bearing dust and vapors. In particular, mold growing on arsenic pigments in old wallpaper has been a potentially dangerous source of trimethylarsine gas in the past (Chapter 5). 

The attractiveness of the bright arsenic colors and the development of cheap arsenic pigments and printing methods led to the widespread use of wallpaper in British and other European homes in the nineteenth century. A square meter of wallpaper would often contain 25-35 g of arsenic and by 1858 some 260 million km2 of arsenic-bearing wallpaper hung in British homes (Meharg, 2005), 67-68. Wallpaper use... 

In the 19th century, the inhabitants of many houses who had wallpaper decorated with green arsenical pigments suffered illness and sometimes death caused by certain fungi that grew on the wallpapers - these fungi formed a toxic, garlic-... 

Arsenic is highly toxic, and indeed much speculation has surrounded arsenic poisoning as the cause of death of Napoleon Bonaparte, on account of the levels of As in the Emperor s hair (perhaps derived from fungal activity on a green pigment present in the wallpaper of his apartments in St. Helena). Arsenic trioxide has been approved by the Food and Drug Administration (FDA) of the USA for the treatment of acute promyelocytic anaemia in adult patients who fail to respond to other chemotherapy, or have relapsed disease. 

The levels of arsenic found, up to 11 ppm, are more consistent with therapeutic use of arsenic, such as in Fowler s solution (see p. 224). An alternative explanation is that the wallpaper and draperies in the house where he lived were coloured with pigments, such as Scheele s green dye (copper arsenite), which contained arsenic. Samples of the wallpaper have been found which do indeed contain arsenic, it is known that in damp conditions, in the presence of mould, this dye wiii reiease a voiatiie organic form of arsenic, methylarsine, which is very toxic. Such a case of poisoning occurred more recently in the US Embassy in Rome in the 1950s. 

The widely used wood preservative chromated copper arsenate is converted to trimethylarsine by the yeast Candida humiculus (Cullen et a/., 1984). Chromated copper arsenate is quite similar to the arsenical wallpaper pigments that had triggered Gosio s work. 

Liquid, bp 105°C. Said to be produced by the mould Penicillium brevicaule growing on wallpaper coloured green with arsenical green pigments. Causes chronic exposure to arsenic. 

Copper(II) hydrogen arsenite (CUHASO3) is a green pigment once used in wallpaper in fact, forensic evidence suggests that Napoleon may have been poisoned by arsenic from his wallpaper. In damp conditions, mold metabolizes this compound to trimethylarsenic [(CH3)3As], a highly toxic gas. 

Arsenic derivatives were used as pesticides and as paint (by artists the bright yellow pigment, royal yellow, which was favoured by seventeenth-century Dutch painters, is known to oxidise slowly to the deadly compound arsenic oxide), and also in wallpapers (during the nineteenth century, most wallpaper was printed with emerald green containing copper arsenate, which could easily be transformed into the deadly gas methylarsine, by a particular mould that developed when the walls became damp, causing arsenic poisoning. 

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