During a Capital Improvements walkthrough, the School District’s engineer of record reported suspect mold growth in several areas of the Sandy Run Middle School. Element Environmental Solutions (E2S) was contracted by the School District of Upper Dublin to provide an Indoor Environmental Quality/Indoor Air Quality screening. The objective was to confirm if mold or other irritants were present in these select areas and if they were likely to result in health issues. Our evaluation included visual inspection and basic IAQ/IEQ parameters such as collection and analysis of airborne mold spores, suspect surface mold sampling and identification, and direct read IAQ/IEQ parameters from the same interior locations. Outside samples and direct read results were collected for comparison.
Select parameters were evaluated during the direct read results to have a better understanding of the overall IEQ to include:
- Carbon Dioxide (CO2): an indicator of adequate ventilation (air exchange and fresh air introduction)
- Carbon Monoxide (CO): to evaluate possible intrusion of combustion exhaust (from facility sources or from vehicular sources)
- Temperature (oF): occupant comfort may be affected by temperatures that are either too cold or too warm, and can also indicate issues related to Relative Humidity
- Relative Humidity (%RH): Low humidity can be an “irritating” comfort issue, high humidity can indicate increased potential for microbial growth (mold, bacteria, dust mites, etc.)
- Total Volatile Organic Compounds (TVOC): these most commonly occur in inks, adhesives and air fresheners as well as other fragrances. Most are noticeable as odors but can act as irritants and in much higher concentrations as intoxicants.
- Total Particulate (PM10): evaluate possible concern levels of airborne particulate 10 microns or smaller. Elevated concentrations can indicate HVAC filter failure, additional unfiltered introduction (non-ventilation system sources, etc.). May be an irritant or have other health effects.
All parameters, except for relative humidity, were in the expected ranges for the heating season and for the observed conditions. Relative humidity during the heating season is almost always on the dry side of the recommended range of 30% to 60% RH. In fact, in schools that seldom have humidity control, it is often substantially drier than 30%. This evaluation fit that pattern with % RH values ranging from 19.4% in to 27.0 %, during the sampling performed in mid-February 2014. Dry conditions can lead to some minor irritation from mucus membranes (eyes, sinuses, etc.) and dry skin, but from a mold prevention perspective low % RH is very good. Low humidity is much more likely to produce comfort related issues than higher humidity levels.
Relative humidity in excess of 60% contributes to the potential for increased microbial growth, which in turn may aggravate allergic conditions, or in extreme cases, create biological hazards. Values near the 60% RH level are more common in the cooling season and can easily lead to condensation on cold surfaces such as chilled water pipes, HVAC supply diffusers, surfaces the cold air from the HVAC supply diffusers flows to or over, and carpeted slab on grade floors, as well as any other surface at or below the dew point temperature for the school interior. Interior humidity can shift quickly, depending on the outside conditions (outside humidity) and the operation of HVAC equipment (unit capacity, amount of fresh air introduced, operational mode (On or Auto) and other factors.
Following the IEQ/IAQ evaluation, Bob Pfromm, CIH, E2S’ Certified Industrial Hygienist (CIH) was asked to present the findings of this initial evaluation to the middle school’s teachers. The airborne mold spore counts throughout the evaluated area of the Sandy Run Middle School did not indicate any significant airborne mold spore concerns and no special precautions were recommended. The levels of airborne mold spore concentration were low enough that it is doubtful that the counts would be enough to cause any symptomatic reactions, even in individuals with mold allergies. Bob communicated effectively with teachers, as Michael Pladus the Superintendent of Schools conveyed to Bob:
“I just wanted to let you know how impressed I was with your ability to present complicated data in a way that was so understandable to all, and your ability to not only respond to questions and concerns but to anticipate them as well. What could have been a very difficult meeting was greatly diffused by the instant credibility that you established in the quality and the thoroughness of your responses. You used technical data when it was appropriate, but, again, was also able to supplement the more esoteric facets of the air quality report with more tangible, real life illustrations. Again, I was truly impressed and was very thankful to have you working as part of the District’s efforts to identify and remediate whatever air quality issues might exist. Thanks for all your efforts.”
Shortly after the meeting with the school’s teachers, a follow-up IEQ/IAQ screening evaluation was requested for select areas of the Sandy Run Middle School. The follow up evaluation was planned based on informational discussion from the teachers, which developed at the initial teacher meeting. The E2S follow-up evaluation was similar to the initial IEQ/IAQ inspection; however, a visual inspection and analysis of carpet and surface dust for mold, dust mites, and mouse allergens in specific locations was also included. The findings of the follow-up evaluation indicated likely causes for the IAQ/IEQ concerns voiced during the meeting. Again, Bob communicated the results in a clear and timely manner to the teachers and corrective actions have been implemented in the Sandy Run Middle School.