INDOOR AIR QUALITY
“Quality” Indoor Air
Good Indoor Air Quality (IAQ) depends upon...
Proper circulation Age of the building Regular maintenance Filtration Humidity levels
Indoor air in schools
One out of every thirteen school-aged children suffer from asthma
Every year, more than 10 million absentee days are accumulated on account of airborne related illnesses
EPA study in 2000 determined 50% of nation’s schools had improperly maintained equipment
Student test performance
Effect of outdoor air supply rate and filtration Speed of 4 of 7 tests performed improved
significantly when outdoor air supply rate increased
No sig. effect on test scores Effect of moderately raised temperatures
When temps reduced from 25 to 20 degrees Celsius, performance (speed) improved in 2 numerical and 2 language based tests
Effect of particle filtration So significant effects on performanceWargocki and Lyon, 2006. Wargocki et al., 2007.
Indoor Air Pollutants
Radon Carbon Monoxide Ozone Tobacco Smoke Volatile Organic Compounds (VOC’s) Toxic Materials – Asbestos, Lead Biological Aerosols (Bioaerosols)
Bioaerosols
Defined as... - Any airborne molecule that is biological in
origin
can be in the form of gases, vapor, or large particulates.
can also be microorganisms themselves- Fungi, bacteria, viruses, protozoans
Bioaerosols
SOURCE EXAMPLES OF BIOAEROSOLS
Bacteria Legionella, Actinomycetes
Fungi Histoplasma, Alternaria, Pencillium, Aspergillus, Stachybotrys, aflatoxins, aldehydes, alcohol
Protozoans Naegleria, Acanthamoeba
Viruses Influenza
Algae Chlorococus
Green Plants Ambrosia (ragweed) pollen
Arthropods Dermatophagoides (dust mites) feces, Cockroaches
Mammals Dog or cat danderSource: http://www.state.nj.us/health/eoh/peoshweb/bioaero.htm
Aerial Microbiological Contamination
Study conducted in Italy, Daccarro et al. 2003, looking at airborne microbial communities in gyms
Found a higher abundance of “Staph” in the gym compared with outdoors
Also, 38 fungi taxa in gyms and 30 outdoors
Classroom activities
Growing Airborne Microbes Comparing different areas of the scholastic
environment Petri dishes Agar medium
Particulate traps Wire hangers, nylon, and petroleum jelly
Legionella
Genus of bacteria
Legionnaires disease
Flu-like symptoms
Domestic hot-water systems and cooling towers
Staphlococcus
Most species harmless
Food poisoning
More recently, human infections
Actinomycetes
Very common: 1-20 million/ g of soil
Look much like fungi but are bacteria
Tuberculosis
Histoplasma
Histoplasmosis
Primarily effects lungs
Common in immunodeficent individuals
Alternaria
Mostly plant pathogens
Allergen to humans
Pencillium
Commonly known as moulds
Main cause of food spoilage
Produce mycotoxins
Many practical applications
Aspergillus
Another common mould
Some species produce aflatoxins
Also, many practical applications
Stachybotrys
Black mold
Moist areas
Wide range of symptoms
Extended exposure: very severe symptoms
Dermatophagoides (dust mites)
One of the main causes of asthma
Fecal matter higher allergenic
Unfortunately, no way to avoid...FOUND EVERYWHERE