Local residents expressed their concerns regarding the tailings from the Iron King Mine and Humboldt Smelter at Dewey-Humboldt, AZ. The purpose of this health consultation is to evaluate the available water and soil sampling results to determine if the detected metal levels pose adverse health effects when residents come into contact with the water or soil. In 2008, EPA initiated the field investigation portion of the Remedial Investigation and Feasibility Study for the Site. The primary objectives of the RI/FS are to determine the nature and extent of contamination and to gather sufficient information so that EPA can select a long-term remedy that eliminates, reduces, or controls risks to human health. The investigation included the collection of airborne particulates, groundwater, surface water, surface soil, subsurface soil, and sediment data across the entire Site. Data from the RI/FS was not available at the time the health consultation was prepared and thus it was not incorporated into this health consultation.

The objective of this health assessment is to provide an evaluation of the health risks that may result from exposure to abandoned mine tailings in Klondyke, Arizona. The tailings are remnants from an earlier flotation mill and mining operation that was in business from the early 1900's until 1950. Environmental data indicate that the 70,000 cubic yards of tailings that remain on the property have contaminated the soil and nearby creeks with heavy metals. This report evaluates the potential pathways of human exposure to the contaminated media. The contaminants of concern further evaluated are lead, arsenic, cadmium, mercury, manganese, and boron. Child health issues and community concerns are also an integral part of the evaluation.

Until recently carbon monoxide poisonings were thought to occur in enclosed, poorly ventilated areas. However, open-air cases of poisoning have recently been reported including exposures from exhaust from various kinds of watercraft including houseboats, cabin cruisers and ski boats. Unlike automobiles, boat engines do not have mechanisms to reduce carbon monoxide emissions. The density of watercraft and the large numbers of people using the channel creates the opportunity for individuals to be exposed to excessive carbon monoxide emissions. This exposure investigation examines the extent of carbon monoxide exposure in recreational boaters in the Rotary Beach area near the London Bridge in Lake Havasu City, Arizona during the Memorial Day Holiday in 2003. The objective of the investigation is to determine whether a public health hazard from carbon monoxide exposure exists in an area heavily used by recreational boaters.

The Arizona Department of Health Services conducted a carbon monoxide exposure survey among recreational boaters at the Maricopa County Lake Pleasant Regional Park during the 2003 Labor Day weekend. To investigate the extent that recreational boaters are exposed to carbon monoxide from a variety of watercraft, ADHS measured exhaled carbon monoxide to determine the amount of carboxyhemoglobin (COHb) present in their blood. To determine whether a widespread public health hazard exists because of carbon monoxide exposure from watercraft, the ADHS health consultation, "Investigation of Carbon Monoxide Exposure, Rotary Beach at the London Bridge, Lake Havasu, Arizona, May 25-26, 2003", recommended conducting further biomonitoring studies at other recreational lakes in Arizona. ADHS asked the Agency for Toxic Substances and Disease Registry (ATSDR), under its Cooperative Agreement Program with ADHS, to interpret data from the Lake Pleasant survey and to determine whether carbon monoxide exposure is a public health hazard among recreational boaters at Lake Pleasant.

Previous studies at Lake Havasu and Lake Powell, combined with other national data indicate that carbon monoxide poisoning from recreational watercraft can create a significant health hazard. The current study was designed not to repeat the 2003 study. Instead, it was designed to explore the potential health effects of carbon monoxide under the conditions of Humbug Cove. Humbug Cove is known for congregating idling boats, higher frequency of alcohol consumption, and being a location that was secluded and sheltered from breezes or wind.