Arsenic in Food
Until the mid-nineteenth century, few were very aware of arsenic in their food, although there were increasing incidents of arsenic adulteration and accidental poisonings. The accidental presence of arsenic in British beer around 1900 made thousands very ill and prompted an inquiry by a Royal Commission that led to the first laws governing food contamination, including a 1 ppm limit for arsenic. This Commission knew nothing about the existence of different arsenic compounds and their toxicities, but it was becoming apparent that some foods, especially seafood, greatly exceeded the 1 ppm limit but could be eaten without causing arsenic poisoning. Scientists began to realize that the arsenic in seafood was not the same as the arsenic in rat poison. It was not until the 1970s that analytical methods allowed the identification of arsenobetaine, the only non-toxic form of arsenic and one commonly found in seafood. Further developments revealed a wide variety of arsenic compounds in food, but the main focus has been on inorganic arsenic because we know more about its toxicity. The first paper to show that food can be a significant contributor of inorganic arsenic appeared in 1999. Since then, dietary surveys have been conducted around the world, and results suggest that, for some, health risks caused dietary exposure to inorganic arsenic cannot be discounted. This chapter examines this topic from a global perspective.