Page 5 - Indoor Air Quality 3Roda

walked on — the same way microbes are launched pollutants that persist in the environment. An
airborne at hospitals when curtains are drawn or example is windowless classrooms, the result of
bedding is changed. In other cases, germs are a design trend that began with the 1973 energy
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propelled directly into the air when an infected crisis.” 22
student or teacher coughs, talks, even breathes.
Another example: portable classrooms, in use
Germs are propelled by 36% of U.S. school districts. Compared to
permanent classrooms, the country’s 385,000
directly into the air when an portable rooms have reduced ventilation, so they are
infected student or teacher more susceptible to mould growth, and are more

coughs, talks, even breathes. likely to contain pressed-wood products that emit
formaldehyde and other VOCs.
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Infectious microbes can hover
for hours and travel long Older buildings are particularly susceptible to

distances. excess moisture — no small problem in an era
when climate change is triggering more extreme
snowstorms, hurricanes, and heavy rains. Snow
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Infectious microbes can hover for hours and travel build-up on school roofs can lead to ice dams and
long distances before landing on surfaces that kids water dripping into classrooms. The massive
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touch. flooding brought by Hurricane Harvey in Texas and
Before long, a quarter of the class may be out with Irma in Louisiana left behind bacteria, pollutants, and
the flu, while custodians scramble to change air mould that inevitably penetrated school buildings. 26
filters, examine exhaust fans, and clean carpets.
As a World Health Organization report on indoor
While viral crises are often seasonal and garner air quality states, “Excess moisture on almost all
headlines (“More Schools Closed for Norovirus indoor materials leads to growth of microbes, such
Outbreak,” “Flu Epidemic Closes in at Least 14 as mould, fungi and bacteria, which subsequently
States”), absences linked to pollutants tend to occur emit spores, cells, fragments and volatile organic
continually and with less fanfare. compounds into indoor air.” Dampness, the
report notes, also triggers “chemical or biological
Year-round, school building conditions may degradation of materials,” further polluting indoor
expose students (and staff) to substances that air. 27
trigger asthma, allergies, headaches, nausea,
and other symptoms that make it difficult, if not Even schools without moisture problems, design
impossible, to learn or teach. flaws, or decaying structures can emit enough VOCs
to trigger respiratory symptoms in susceptible
In some cases, the culprit is a school building in students and staff. Cleaning chemicals, copier ink,
disrepair. As the Harvard report notes: “Children adhesives, carpet backing, particle board, dry-erase
regularly face adverse environmental exposures markers, and newly painted surfaces are all known
associated with building decay, such as water sources of VOCs and allergens.
damage, mould growth, poor plumbing, and legacy

small infectious droplets released by breathing and
talking travel large distances on air currents

large infectious droplets released by coughing
and sneezing fall to surfaces and hands

METRES 1 m 45+ m

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