Health hazard evaluation report: HETA-98-0235-2836, North View Elementary School, Clarksburg, West Virginia.
In May of 1999, the National Institute for Occupational Safety and Health (NIOSH) received a request to conduct a health hazard evaluation (HHE) at the North View Elementary School in Clarksburg, WV. The request, submitted by the West Virginia Education Association (WVEA), cited indoor air quality associated health complaints such as asthma, sinus infections, allergies, respiratory problems and increased absenteeism. On May 27 and June 6, 1999, NIOSH investigators conducted initial investigations of the environmental conditions and health concerns. The investigation involved interviews with workers, a questionnaire survey, lung function testing, inspection of the building and the air handling unit (AHU), and measurements of temperature, relative humidity, carbon dioxide, and microbial volatile organic compounds in air. On July 22, 1999, NIOSH investigators made a site visit with officials from the Environmental Protection Agency (EPA) to further inspect the school AHU. On August 11 and 12, 1999, during the summer recess, NIOSH investigators took additional environmental measurements to assess the potential for fungal growth and other indoor environmental conditions when the school was unoccupied. Following these surveys, an interim report with recommendations was presented to the school management and employees. On August 14, 1999, further questionnaire survey and lung function testing were done to determine the baseline respiratory health status following a summer recess. On February 11 and 17, 2000, NIOSH investigators conducted additional environmental and medical assessment at the school during the winter season. This survey also evaluated progress made on recommendations provided in the interim report and their impact on employee health. The results of the investigation are summarized below. At the initial investigation on May 1999, employees who worked in the basement area of the school reported higher occurrence of upper and lower respiratory symptoms than those who worked on the first or second floor of the school. Almost all employees from the basement area (89%) reported wheezing and shortness of breath with wheezing during the last 12 months, and 66% reported taking medication for breathing problems. The employees working on the second floor had the lowest prevalence of respiratory symptoms. The prevalence of nonspecific symptoms (these include a stuffy/runny nose, irritation of the eyes, throat, headache and sinus problems) was also high. There was a noticeable decrease in the prevalence of respiratory symptoms during the summer recess. However, during the winter months the frequency of reported symptoms increased, in particular in the basement and on the first floor. Cross-sectional spirometry testing determined that 8% of the adult school occupants had mild obstructive impairment. Serial lung function tests performed by nine occupants who complained of asthma-like respiratory symptoms did not show visible variability in lung function in response to being in the school environment. On inspection of the school, we observed water incursions and fungal growth on interior ceiling tiles in basement areas. Bioaerosol concentrations in building air, measured during the school break with the AHU in operation, were below ambient levels for fungi, bacteria, spores, and endotoxin. Some of the fungal and bacterial organisms identified in the building, especially in basement areas, were different from those identified in ambient samples suggesting amplification of these organisms within the building. Five unique microbial volatile organic compounds (MVOCs) were detected in the basement area; none of these compounds were detected on the sample collected on the second floor. The airborne dust concentrations measured in building air were below those measured in ambient air. Samples for carbon dioxide, obtained when school was in session, suggest inadequate outside air intake and distribution. Inspection of the AHU indicated too small a filter surface area and other operational problems that would impact system operation and indoor environmental quality.