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.