To the Editor As a toxicologist and consultant to the Juice Products Association, I write to correct errors in the Viewpoint titled “Public Health Responses to Arsenic in Rice and Other Foods.”1 The Food and Drug Administration (FDA) has an established, enforceable limit for levels of arsenic in juice, 23 parts per billion (ppb). This “level of concern” was determined from juice consumption data and the reference dose for arsenic determined by the Environmental Protection Agency (EPA). A reference dose is the amount of a substance that can be consumed daily for a lifetime that is unlikely to produce adverse effects, even in sensitive people. The reference dose for arsenic was calculated from epidemiologic studies in southeast Taiwan, where people are exposed throughout their lives—in utero, as infants and children, and as adults—to naturally high levels of arsenic in drinking water.2 The reference dose was based on the level of exposure in those studies that did not produce precancerous lesions and dividing it by an uncertainty factor to ensure that it would protect health. To set its limit on arsenic in juice, the FDA divided the EPA’s reference dose for arsenic by the amount of juice that the 90th percentile of juice consumers drink daily over a lifetime, including childhood. Juice consumption data came from the 2003-2004 National Health and Nutrition Examination Survey by the US Centers for Disease Control and Prevention.
Charnley G. Arsenic in Rice and Other Foods. JAMA Intern Med. 2014;174(2):298. doi:10.1001/jamainternmed.2013.11994