1. breathe easy:
your guide to
air purifiers
Many air purifiers available claim to relieve
a whole spectrum of respiratory woes, and
while that sounds great, how useful are
they really? With so many types to choose
from, how do you decide which one is right
for you? And even then, what should you
look for? In this guide to air purifiers, all
these questions are answered to help you
start breathing a little bit easier.
by emily white| design by catrina pang
what’s the point?
According to the Environmental Protection Agency,indoor
air pollution is amongthetop5environmentalhealthrisks
in theUnited States.1
It is also estimated that nearly60
million Americanssufferfromallergiesorasthmadueto
airborneparticleslikedust,petdander,pollen,orsmoke.2,1
Although most homes and buildings are equipped with
ventilation systems to combat indoor air pollution, personal air
purifiers can further remove these pollutants (also known as
particulate matter) that may contribute to asthma or allergies.1
By removing floatingtriggersfromindoorair,allergyand
asthmasymptomsmaybemanagedmoreeffectively.3
what kinds are there?
The 2 most common types available are HEPA filters & ionizing
electrostatic devices, which both remove particulate matter
from indoor air.4
high-efficiency particulate air (HEPA) filters: HEPA
filters work by mechanically fanning particles through the
device, trapping them in an internal filter.1
ionizing electrostatic devices: Ionizers work by
charging particles as they enter the filter, causing them to stick
to a metal plate.5
plants: Even plants can remove various harmful compounds
from indoor air. See “Living Air Purifiers” from Issue 4, Volume
13 for more information about these all-natural air purifiers.
what is there to consider?
There are generally 3 critical attributes to keep in mind when
selecting the best purifier:4
efficiency: Can the filter catch a wide range of particle sizes?
capacity: How much can the filter effectively hold?
airflow: What is enough for proper ventilation?
A balance of these 3 traits will help find the device with the
longest life and greatest effect. Other things to consider
include the filter’s size, noise level, cost, and maintenance
level. Many varieties available advertise a range of features
to increase efficiency and safety, so it is important to choose
the best for your particular situation. Moreover, the only
rating system in place for air purifiers was created by the
manufacturers, so there are no independent health ratings
or standards monitored by the FDA that judge a purifier’s
usefulness.2
This makes it difficult to distinguish between more
than just technical aspects of filters, but more effective filters
are likely to improve health the most. Consumer Reports urges
buyers to weigh all features carefully in order to have the most
success purchasing an air purifier.6
left:yinyang/istockphoto;milea/istockphoto;right:jtyler/istockphoto;
karammiri/istockphoto
are they even useful?
Maybe.
Some filters are better than others. HEPAfiltersaregenerally
themostefficientatremovingairbornepollutantsthatmay
contributetoallergiesandasthma. A number of studies
suggest that HEPA filters may relieve asthma symptoms when
placed in the bedroom, combined with air conditioning and
frequent cleaning.5,7
They may also help to manage asthma
symptoms in households with pets by minimizing dander.4
Itisstillunclearastowhetherairfiltersalleviatesymptoms
ofrespiratorydiseases,buttheycouldbeahelpful
componentofindoorairqualityimprovementtominimize
respiratorystress. A number of other studies also suggest that
portable air cleaners (both HEPA or electrostatic) can greatly
reduce indoor pollutants and dust concentration, though
the exact benefit this reduction has on respiratory health is
unclear.3,8
Furthermore, someaircleanersmaybeabletoprotectagainst
certainairbornediseasepathogens like tuberculosis, chicken
pox, and measles.9
how can you use a purifier safely?
follow all maintenance guidelines: Understanding
the filter’s technology and procedures will ensure the purifier’s
safe use as recommended by the Ontario Health Technology
Assessment Series in 2005.9
Be sure to change or clean the filter
often to ensure it is working in top condition.
know the risks: Ionizing purifiers are more likely to release
harmful byproducts like ozone, a reactive relative of oxygen,
which can damage respiratory tissues and make asthma
symptoms worse, as seen in a study by the Journal of Allergy
and Clinical Immunology in 2010.5
According to the Journal
of Toxicological Sciences in 2010, models of air purifiers that
release reactive oxygen species (like ozone) into the air were
specifically linked to DNA damage in the lungs after prolonged
exposure.10
When used correctly and maintained
appropriately, air purifiers are an effective
way to remove pollutants from an indoor
environment. Whether or not the removal
of these pollutants actually helps with
the symptoms of allergies or asthma is
unclear. However, the use of an air purifier
in conjunction with other techniques to
reduce indoor air pollution may be a good
step to alleviate respiratory stress and
allergic symptoms.
References
1.
“Guide to Air Cleaners in the Home.” epa.gov. (2012).
2.
“Allergy Facts and Figures.” aafa.org. (2010).
3.
“Control of asthma triggers in indoor air with air cleaners: a modeling analysis.”
Environ Health. (2008).
4.
“Effectiveness of Air Filters and Air Cleaners in Allergic Respiratory Diseases: A
Review of the Recent Literature.” Curr Allergy Asthma Rep. (2011).
5.
“Air filters and air cleaners: Rostrum by the American Academy of Allergy,
Asthma & Immunology Indoor Allergen Committee.” J Allergy Clin Immunol.
(2010).
6.
“Air purifier buying guide.” consumerreports.org. (2014).
7.
“Environmental Issues in Managing Asthma.” Respir Care. (2008).
8.
“The effects of intervention with local electrostatic air cleaners on airborne dust
and the health of office employees.” Indoor Air. (2005).
9.
“Air cleaning technologies.” Ont Health Technol Assess Ser. (2005).
10.
“Air purifiers that diffuse reactive oxygen species potentially cause DNA
damage in the lung.” J Toxicol Sci. (2010).
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