Health hazard evaluation report: HETA-2000-0091-2803, Horry County Assessor's Office, Conway, South Carolina.
In December 1999, the National Institute for Occupational Safety and Health (NIOSH) received health hazard evaluation (HHE) requests from employees working in a Horry County Administrative Building, Conway, South Carolina. These workers described a prior incident in 1999, which involved carbon monoxide (CO) exposures, as well as ongoing concerns with mold in the building. The employees believed that their symptoms, which included headache, sinus problems, and upper respiratory problems, were work related. A walk-through of the entire building was conducted March 27, 2000. Measurements of carbon dioxide (CO2), CO, temperature, and relative humidity (RH) were made and the ventilation systems were visually examined, including the condition of the air filters, coils, drain pan, and other interior components of two randomly selected heat pump units. Five bulk dust samples were collected by micro-vacuuming sections of carpet. Ten "sticky" tape samples were collected of suspect fungal colonies by using the adhesive side of the tape to pull spore structures and hyphae from the growth surface. Areas suspected of water damage (both exterior walls and carpeted floors near these walls) were probed with a moisture meter to qualitatively assess water content. Twelve of the approximately 115 employees volunteered for informal interviews. The highest CO2 concentrations ranged from 1030 to 1190 parts per million (ppm), suggesting that parts of the two story building may be receiving insufficient amounts of outside air. Temperature and RH levels ranged from 69 to 75 degrees F, and 35 to 53%, respectively, which were within the thermal comfort parameters recommended by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. CO concentrations were very low, ranging from none-detected to 2 ppm. A new exhaust ventilation system in the boiler room, along with repairing cracks in the walls of the boiler room, were made to prevent CO from re-entering the building. Of the 12 employees interviewed, most reported respiratory problems (sinus problems or allergies), congestion, fatigue, and headache while working in the building. Several of the interviewed employees were also concerned with hair loss, high blood pressure, digestive problems, and joint pain which they believed were work-related. Many of those interviewed had been experiencing these symptoms since they first began working in this building. NIOSH investigators conclude that various indoor environmental quality deficiencies exist in this building, including inadequate amounts of outside air (OA) to some offices, localized microbial reservoirs, and numerous ongoing moisture incursion or moist conditions. It is unclear, however, how these conditions relate to the health complaints described by the interviewed employees. Recommendations are provided to further improve ventilation and eliminate the wet conditions conducive to microbial growth.