Ozone Generators (Air Purifiers) harmful for asthma?

Dear Doc.

i bought my brother an air purifier the really popular you see on tv all the time. not sure if we can mention brand names on this site. anyway i know it works by making ozone. at first i thought it would be beneficial to him to use it. but now i've been reading that it can actually worsen his asthma. what are your thoughts?   thank you in advance

mike

[National Jewish Health]

You are right to be concerned about ozone (03) and the harmful effect it can have on asthma and other respiratory diseases.  Since it is a respiratory irritant, it can worsen asthma.  It is a side product of many air purifiers and a deliberately produced product of others.  The following abstract is illustrative.  You should seriously consider removing the purifier from your brother's environment.

Authors
Full Name Britigan, Nicole. Alshawa, Ahmad. Nizkorodov, Sergey A.
Institution Department of Chemistry, University of California, Irvine 92697,
USA.
Title Quantification of ozone levels in indoor environments generated by
ionization and ozonolysis air purifiers.
Source Journal of the Air & Waste Management Association. 56(5):601-10,
2006 May.
Abstract Indoor air purifiers are advertised as safe household products for
health-conscious individuals, especially for those suffering from
allergies and asthma.  However, certain air purifiers produce ozone
(O3) during operation, either intentionally or as a byproduct of air
ionization.  This is a serious concern, because O3 is a criteria air
pollutant regulated by health-related federal and state standards.  
Several types of air purifiers were tested for their ability to produce
ozone in various indoor environments at 40-50% relative humidity,
including office rooms, bathrooms, bedrooms, and cars.  O3 levels
generated by personal wearable air purifiers were also tested.  In
many cases, O3 concentrations were well in excess of public
and/or industrial safety levels established by U.S. Environmental
Protection Agency, California Air Resources Board, and
Occupational Safety and Health Administration.  Simple kinetic
equations were obtained that can predict the steady-state level of
O3 in a room from the O3 emission rate of the air purifier and the
first-order decay rate of O3 in the room.  The additivity of O3 levels
generated by independent O3 generators was experimentally
demonstrated.