- Full (HTML) - Related EHP Articles - Purchase This Issue

Paul Mushak¹ and Annemarie F. Crocetti²

¹PB Associates, Durham, NC 27705 USA
²Consultant in Nutrition Epidemiology, New York, NY 10003 USA

Abstract
Oral exposures of nonoccupational populations to environmental inorganic arsenic are associated with skin and internal cancers as well as various noncarcinogenic effects. Cancer risk assessments have been based largely on epidemiological studies of a large population exposed to inorganic arsenic in well water in Taiwan. Criticisms and skepticism of the use of the Taiwanese data for estimating arsenic cancer risks outside of Taiwan, including potential use by the U.S. Environmental Protection Agency for regulatory purposes, have been expressed on various grounds. The nature and extent of such criticisms have sharpened with recent findings in the exposed Taiwanese of increased incidence of internal cancers (bladder, kidney, liver, and lung) , in addition to already-observed skin cancer, coupled with a good likelihood that these findings will produce more stringent arsenic regulation in the United States and elsewhere. These criticisms collectively posit a revisionist view that: 1) cancer incidence among the Taiwanese was amplified by a number of host and environmental factors not applicable elsewhere, 2) the cancer dose-response curve may not be linear at the lower exposures elsewhere, and 3) there is a toxicokinetic and metabolic threshold to cancer risk that was exceeded by the Taiwanese. However, a number of the arguments against wide use of the Taiwanese data are flawed and subject to challenge. We explore some of these arguments and their critical evaluation, particularly as they concern certain exposure, metabolic, and nutritional determinants of the cancer risk of inorganic arsenic in the Taiwanese. Key words: arsenic, arsenic epidemiology, cancer risk. Environ Health Perspect 103:684-689 (1995)

Address correspondence to P. Mushak, PB Associates, Suite G-3, 714 Ninth Street, Durham, NC 27705 USA.

Received 23 February 1995 ; accepted 10 April 1995.