Beginning in March 2001, The Health Effects Group, Inc., under the direction of Dr. John B. Sullivan, Jr., M.D., University of Arizona Health Sciences Center, and a team of 10 consulting physicians, conducted an extensive assessment, or monitoring, of individuals in the areas of Globe, Claypool, Miami, and Wheatfields. The purpose of this medical monitoring was to determine whether any of these individuals may have suffered adverse health effects due to potential manganese exposure from drinking groundwater. The assessment was conducted with complete independence from the Pinal Creek Group. Qualified participants were self-selected and testing was conducted as a part of the Wilkes Settlement Agreement, which is on file at the Miami Public Library.

This monitoring program tested 343 individuals and was implemented in three stages, or tiers, conducted at The Holiday Hills Mobile Home Park (Tier I), the Cobre Valley Hospital (Tier II) and the University Medical Center in Tucson (Tier III). At each tier of the monitoring, the physicians conducted more specific testing. Tier I testing enrolled 343 individuals, 73 individuals were invited to continue to Tier II testing, and 25 individuals were invited to continue to Tier III testing.

After completing Tier III testing, The Health Effects Group concluded: “No subject who completed all three tiers had neuroimaging evidence of adverse manganese effects on the basal ganglia of their brains.” The medical monitoring program was concluded in October 2001, and the Health Effects Group issued a final report entitled Environmental Manganese Exposure, Medical Examination of a Class of Subjects, dated July 15, 2002. The report states: “At the conclusion of the medical screening program, no subject tested had evidence of neurological adverse effects that could be attributed to manganese.” A copy of the report is available at the Miami Memorial Library. The medical monitoring program is now concluded.