Health hazard evaluation report, HETA-2004-0417-2987, El Dorado County Health Department, Placerville, CA and South Lake Tahoe, CA.
On September 30, 2004, the National Institute for Occupational Safety and Health (NIOSH) received a request for technical assistance from a management official at the El Dorado County Health Department in Placerville, California concerning the potential for airborne transmission of infectious diseases within health department clinics. At the time of the request, no health effects had been reported. NIOSH representatives visited the El Dorado County Health Departments in Placerville, California and in South Lake Tahoe, California during March 7-10, 2005, to conduct a hazard evaluation. During the evaluation, indoor environmental quality (IEQ) parameters and the heating, ventilation, and air conditioning (HVAC) systems were evaluated. The IEQ measurements did not indicate a problem with temperature, relative humidity, or carbon dioxide levels. However, many supply and return air diffusers were discovered to be either non-functioning, obstructed, or functioning at a capacity other than intended. None of the exam rooms at either clinic met the criteria for airborne infection isolation. Airborne infection isolation rooms should be used when providing care for patients with airborne infections such as tuberculosis and chickenpox. The results of the IEQ measurements confirmed that the indoor environmental quality is within acceptable ranges. However, the air flow measurements indicated problems with the function of diffusers, thus affecting the supply of outdoor air and reducing the potential for dilution of normal room contaminants and potentially infectious aerosols. This report provides recommendations to address these issues and advises the designation of an airborne isolation infection room at both clinics.