Evaluation of an Engineering Control to Prevent Carbon Monoxide Poisonings of Individuals on Houseboats at Wahweap Marina, Lake Powell, Arizona.

摘要

During the period of 1990 to 2000, 111 carbon monoxide (CO) poisoning cases occurred on Lake Powell near the border of Arizona and Utah. Seventy-four of the poisonings occurred on houseboats, and 64 of these poisonings were attributable to generator exhaust alone. Seven of the 74 houseboat-related CO poisonings resulted in death. Many of the CO poisonings that have been reported occurred to the general public; however, some poisoning incidents and relatively high CO exposures have involved workers performing maintenance activities on houseboats. The National Institute for Occupational Safety and Health (NIOSH) conducted an evaluation of an engineering control retrofitted onto a gasoline-powered, generator on a houseboat to reduce the hazard of CO poisonings from the exhaust. The control consisted of a water separator and 17 foot long exhaust stack that extended 9 feet above the upper deck of the houseboat. When compared to no engineering control, results of the evaluation indicated that use of an exhaust stack provides a dramatically safer environment to individuals on or near the houseboat. CO concentrations were reduced by ten times or more at numerous locations on the houseboat. Average CO* concentrations near the rear swim deck of the houseboat, an area where occupants frequently congregate, were reduced from an average of 606.0 ppm to 2.85 ppm, a reduction greater than 99%. CO concentrations were also reduced on the upper deck of the houseboat. Based upon the results of this study, NIOSH investigators recommend that all U.S. houseboats, using gasoline-powered generators, should be retrofitted with an exhaust stack that extends well above the upper deck in order to reduce the hazard of CO poisoning and death to individual on or near the houseboat.