American Industrial Hygiene Conference and Exposition, May 8-13, 2004, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 2004 May; :73
NIOSH was asked for assistance in evaluating carbon monoxide (CO) concentrations in the Bridgewater Channel in Lake Havasu City (LHC), Arizona, over the Memorial Day weekend, May 23-26, 2003. The request expressed concern about CO overexposures among LHC police and Emergency Medical Service (EMS) personnel who patrol the waterway during holidays for as much as 10 hours per workshift. Real-time CO monitoring was conducted on podium and EMS personnel with additional general area sampling in and around the channel. Daily pre-shift, mid-shift, and post-shift questionnaires in conjunction with exhaled breath CO measurements were also conducted. Questionnaires included information on work duties and location, tobacco use, and surveys of potential CO exposure symptoms. There were 78 total workshifts where real-time CO monitoring was performed. Of those 78 workshifts, 54 exceeded the NIOSH ceiling limit of 200 ppm, 64 exceeded the ACGIH excursion limit of 125 ppm, 7 exceeded the OSHA PEL of 50 ppm, 17 exceeded the NIOSH REL of 35 ppm, and 33 exceeded the ACGIH TLV of 25 ppm. There were 81 total workshifts where exhaled breath analysis and questionnaires were conducted. Of those 81 workshifts, 63 were with nonsmoking participants. Among the 63 nonsmoking participants, 42 had a post-shift percent carboxyhemoglobin (% COHb) at or above the ACGIH BEI of 3.5%, with some levels approaching 15%. For 40 of the 81 workshifts with pre- and post-shift measurements, the cross-shift difference was at or above 3.5%. The questionnaires indicated that the most frequently reported symptom was headache, followed by fatigue or weakness, visual disturbances, and dizziness. NIOSH investigators concluded podium and EMS personnel working in the canal are exposed to CO concentrations approaching and/or exceeding relevant evaluation criteria.
American Industrial Hygiene Conference and Exposition, May 8-13, 2004, Atlanta, Georgia