The Arizona Department of Health Services Cancer Registry has identified 7 cases of childhood leukemia in the Sierra Vista, Arizona area since 1995. Five of the childhood leukemia cases were identified as a class of lymphoid leukemia and 2 of the cases were a class of myeloid leukemia. Based on random variation, a total of 6 or fewer cases of leukemia would have been expected over those seven years. An analysis of the data suggests that the number of cases is statistically elevated for the time period 1995 to 2001. The objective of this report is to determine whether there are any documented environmental exposures from drinking water, ambient air or waste sites that may have placed residents of the Sierra Vista, Arizona area at greater risk of developing childhood leukemia.

This report evaluates the potential exposure pathways associated with vermiculite concentrate processing activities at the Ari-Zonolite facility. The site is located in the near downtown area of Glendale, approximately ½ mile from the city hall, downtown shops, and other buildings. The former Ari-Zonolite facility received vermiculite from the Libby, Montana, mine. From 1951 to 1964, the site was leased the site to the Ari-Zonolite Company. Following the removal of the vermiculite concentrate processing equipment in 1964, several businesses have occupied the site. None of these businesses were involved in vermiculite processing activities. The last occupant of the former vermiculite processing building was an automotive restoration business, which vacated the site in 2002.