Thursday, September 11, 2008

EPA BASE study suggests HVAC plays a role in Sick Building Syndrome

A newly released analysis of the US EPA BASE study shows that improperly maintained HVAC systems may cause symptoms associated with Sick Building Syndrome (SBS). The study's authors (representing Lawrence Berkeley, Harvard University, Helsinki University and the US EPA) assessed data collected from 97 representative US office buildings that use air conditioning.
The findings that interested us most dealt with SBS symptoms that may be attributed to moisture with the HVAC systems. From the study's abstract (text emphasis added by me):
"Humidification systems with poor condition/maintenance were associated with significantly increased upper respiratory symptoms, eye symptoms, fatigue/difficulty concentrating, and skin symptoms, with OR = 1.5, 1.5, 1.7, and 1.6. Less frequent cleaning of cooling coils and drain pans was associated with significantly increased eye symptoms and headache, with OR = 1.7 and 1.6. Symptoms may be due to microbial exposures from poorly maintained ventilation systems and to greater levels of vehicular pollutants at air intakes nearer the ground level. Replication and explanation of these findings is needed."
Also from the study's Discussion section:
"These findings support current beliefs that moisture-related HVAC components such as cooling coils and humidification systems, when poorly maintained, may be sources of contaminants that cause adverse health effects in occupants, even if we cannot yet identify or measure the causal exposures."
The authors caution that these findings need replication before suggestions or guidelines are advocated. While researchers were able to quantify the risks associated with poorly maintained humidification systems, they were unable to "...identify important (symptom) benefits from well-maintained humidification systems."

The study's findings are important because they demonstrate and elevate the need for Ultraviolet Germicidal Irradiation (UVGI) in all air conditioned buildings. Our experience has shown that if you have dirty or inefficient cooling coils, your HVAC is likely a reservoir for microorganisms. These microorganisms can cause symptoms associated with SBS, in hospitals these pathogens can promote Hospital Acquired Infections (HAI).

This study is a small but important piece in the puzzle that surrounds Indoor Air Quality. Its importance lies in the fact that yet another credible group of scientists have found evidence that HVAC systems can be linked to airborne pathogens that cause health problems.