It was fortunate that so much human evidence linked arsenic to cancer because for over 70 years, researchers were unable to "confirm” the dangers in laboratory animals. Suspicions that arsenic might cause cancer date back to 1809 when its harmful effects in drinking water were first noted.(1) In 1887/88, Sir Jonathon Hutchinson described the earliest cases of cancer resulting from medicinal use of arsenic1 and subsequently, others have reported cancers in chemical, agricultural and metallurgical workers exposed to arsenic.(2)
Animal tests began in 1911 and an historical analysis of the subject, published during 1947, described how dozens of experiments had been performed.(1) However, these had given "only doubtful results.'' The tests continued but still proved negative, and in 1969 researchers at America's National Cancer Institute stated that "arsenic has been suspected by many investigators as a carcinogen in man, though there is no supporting evidence from animal experiments."(3) And in 1977 a further summary of the data concluded that "there is little evidence that arsenic compounds are carcinogenic in experimental animals."(2)
Finally, in the late 1980s, scientists managed to produce cancer in animals. This was 180 years after arsenic was first suggested as a human carcinogen. Despite decades of failure, animal researchers had at least been correct about one thing: in 1962 Heuper and Payne wrote that "With perseverance and some luck arsenicals one day may be shown to cause cancer in animals."(4)
I ) O.Neubauer, British Journal of Cancer, 1947, vol 1. 192-251.
2) F.W.Sunderman Jr. in Advances in Modern Toxicology, vol.2, Eds R.A.Goyer & M.A.Mehlman (Wiley, 1977).
3) A.M.Lee & J.F.Fraumeni Jr. Journal of the National Cancer Institute. 1969, vol.42, 1045-1052.
4) W.C.Heuper & W.W.Payne, Archives of Environmental Health, 1962, vol.5, 459
|<<Previous||Back to 101 Mislead Results Index||Next>>|