Introduction
Vortex Inc. was contracted by Beth Perrin, Director of Facilities
Management of the Middletown Public Schools to provide Indoor Air Quality (IAQ)
testing at the six (6) school buildings occupied by students, faculty, staff
and maintenance personnel. The six
schools included: High School, Gaudet Middle School, Kennedy, Forest and
Aquidneck Elementary Schools and the Oliphant Administration Building.
The IAQ testing was conducted on November 21, 2002 from 8:30 a.m.
to 12:30 p.m. with the assistance from David Rodrigues, Maintenance Foreperson
for the Facilities Management Team.
Random air sampling/testing locations included
classrooms; offices and hallway areas, along with several pre-selected areas of
concern throughout the six school buildings were performed. Refer to the attached INDOOR AIR QUALITY MAINTENANCE CHART per school
building.
Testing was performed to capture readings for temperature/relative humidity, carbon dioxide (CO2),
carbon monoxide (CO) and moisture content. These measurements were chosen
because of the direct contributions they could have with common health related
problems, such as, mold allergies, headaches, itchy eyes, tiredness, etc.
The continuous read digital meter was rented through Response
Rentals/Ashtead Technologies and was calibrated on 11/19/01 through the
supplier.
EXPLANATION OF
TEMPERATURE AND HUMIDITY
The current ASHRAE recommended temperature
for optimum comfort is 68 - 75 degrees Fahrenheit (oF). However, this component is very dependent on
occupant sensitivity. ASHRAE also
recommends that the relative humidity be maintained between 30% and 60%. Levels below 30% may lead to symptoms such
as eye irritation, and drying of the mucous membranes. Levels in excess of 60% are conducive to microbial
growth.
Temperature results revealed interior levels ranging from 65.6
degrees Fahrenheit to 76.7. Exterior
temperatures were approximately 50 - 57 degrees throughout the testing
period. Only 6% of the classroom areas
tested was found to be higher than a recommended temperature high of 75
degrees.
Humidity results revealed interior levels ranging from 40.8% to
59.8%. Exterior relative humidity was
between 58 – 66.5% on a damp, foggy day. Results were within acceptable indoor
air quality levels.
EXPLANATION OF CARBON
DIOXIDE
Carbon dioxide is a
product of human respiration and, in itself is not likely to pose a health
hazard. The reason CO2 is measured is
because elevated levels of carbon dioxide may serve as an indicator of
insufficient intake of fresh air into a building, or an insufficient number of
air changes in the working environment.
OSHA currently sets 5,000 parts per million (ppm) as their Permissible Exposure
Limit (PEL) for occupational exposure to CO2. The American Society of Heating,
Refrigeration and Air Conditioning Engineers (ASHRAE) currently recommends that
CO2 levels be maintained below 1,000 ppm. CO2 levels will typically increase over the course of
a normal day as human exhalation buildings up.
These levels usually decrease when a given area is unoccupied, such as,
during lunch breaks and at the end of a school day.
Carbon Dioxide
Carbon dioxide levels within the areas revealed
interior levels ranging from 610 ppm to 1,585 ppm. Exterior levels were in the 350 ppm range. 100% of the areas
sampled were within OSHA permissible ranges.
70% of the areas sampled were within the acceptable range per ASHRAE
Standards. Of the 30% found in the unacceptable range per ASHRAE Standards, most
could be corrected with the opening of a window.
Carbon monoxide (CO) is
a colorless, odorless, and tasteless gas that is a product of incomplete
combustion of any carbon-containing fuel.
It is a chemical asphyxiate that prevents oxygen from reaching the
body's tissues. The Environmental
Protection Agency (EPA), in the National Ambient Air Quality Standards (NAAQS),
sets 9 ppm over a 24-hour time weighted average (TWA) as their standard for
acceptable levels of carbon monoxide in outdoor (ambient) air. The OSHA PEL for carbon monoxide is 35 ppm
over an eight (8) hour TWA, and 50 ppm over one hour. The outdoor ambient air
quality level for CO is 9 ppm for 8 hours and 5 ppm for one hour. ASHRAE has
suggested these outdoors levels as targets for indoor limits in its ventilation
standard (ASHRAE 62-89). Outdoor levels are usually between 1-10 ppm with
indoor levels usually tracking outdoor levels.
Carbon monoxide results revealed interior levels
ranging from
0 ppm to 2 ppm in most areas. Exterior levels were 1 ppm.
Results were within acceptable indoor air quality levels.
Moisture Levels
Moisture levels of
building components (walls, doors, ceilings and floors) were within acceptable
levels of less than 15%. Low moisture
levels aids in the prevention of mold and mildew growth.
Recommendations
None of the six school
buildings tested appear to have any serious Indoor Air Quality issues at the
time of sampling.
It appears that various
classrooms (carbon dioxide levels of >1,000 ppm) should increase ventilation
in order to lower these levels. This
may be obtained by opening windows, lowering the temperature in the classroom
or a combination of both. If a window is not available then the heating and
ventilation system can be evaluated and/or balanced by a Mechanical Engineering
Company.
Middletown Public Schools will be doing IAQ sampling/testing with
follow-up reports on an annual basis. They will be using these reports as part
of an IAQ Preventative Maintenance Program.
_____________________________________
John Carbone (Industrial
Hygienist)