Ozone or trivalent oxygen is perhaps the most misunderstood, hated
and loved element in the air we breathe. On one hand we are told
that it is a harmful, poisonous gas capable of doing great harm
to our lungs. On the
other hand we are told that it has the potential of being
the greatest natural purification element we have available
to deal with man-made pollutants The truth lies in the understanding
of the nature of ozone itself, the mechanisms of ozone formation,
the nature of the pollution problem that requires a solution and
finally any adverse health effects involved with ozone as compared
with other health risks encountered in our modern indoor environments.
ozone is commonly accepted to be a pollutant associated with large
urban areas typified by Los Angles. it is true that ozone is a part
of smog, but it is also true that ozone exists outside of the smog
environments in even the purest of outdoor environments.
How the Ozone is created?
In unpolluted areas ozone is created by the action of nitrogen
oxides and ultraviolet light from the sun with the natural agricultural
and animal husbandry sources of methane and even the hydrocarbon
compounds of isoprene and terpene emitted from trees of the forest.
In fact, anywhere in nature that hydrocarbons exist with strong
sunlight and moisture, ozone will occur in some quantities. Areas
that are considered the most healthy vacation spots in the country
have some of the highest levels of naturally occurring ozone. Ozone
is also created electrically in nature during active thunderstorms.
The electrical discharge creates that positive sweet smell that
we understand as clean fresh air and that we can recall as the fresh
smell of laundry hung outside in the sun to dry. Who can deny the
positive values associated with sleeping on sheets exposed to and
purified by sunlight? In urban areas ozone is also created in two
other important ways. First there is the direct breakdown of chemicals
that are spewed into the environment in industrial processes. Formaldehyde,
xylem, and olefin also combine with nitrogen oxides and ultraviolet
light to create ozone while at the same time reducing the feed stock
of these harmful industrial chemicals. The second is related to
the photochemical production of ozone from automobile emissions
and mass burners. It can be seen that in the last case ozone is
being created by the breakdown of the hydrocarbons but that it is
also aiding in the breakdown of these same chemicals. It is, therefore,
natural that the highest concentrations of ozone will be found in
areas with the highest concentration of un-oxidized or unburned
hydrocarbons. it is this confusion with cause and effect that have
given rise to the notion that ozone itself is the source of the
problems related to smog rather than just one of the chemicals present
in the process. The additional problem in the air quality of urban
areas is related to the magnitude of the feed stocks of unburned
hydrocarbons. With heavy industries and the associated heavy automobile
traffic, the amount of chemical involved with this process is immense.
While the ozone and the hydrocarbons are eliminating each other
there are enough of both in the air to be a problem. As the noted
toxicologist Dr. Robert Olcerst wrote in his paper Ozone Monograph:
Toxicity and Evaluation, "Toxicology is the science of poisons.
Every chemical substance has a range of effects on biological systems
that range from no effect to levels of lethality."
In effect, every chemical has the capacity to be toxic, and
it is dosage that becomes significant. Too much of any substance
will upset and become harmful to a biological system. ozone is no
exception. At extremely high concentrations there are indications
that ozone itself is harmful. However, in the case of smog, studies
show that its other ingredients, the nitrogen oxides, sulfur oxides,
suspended sulfuric acid, nitric acid particles and suspended hydrocarbons
are the real health risks. It is unfortunate that smog and ozone
have been interchanged in the discussion of air pollution because
it has masked the positive characteristics of ozone as the natural
way of dealing with air quality problems. The focus on smog as "air
pollution" has prevented us from seeing the even greater problem
of indoor air quality problems. The same chemical soup exists in
our indoor environment as exists in smog. The only variant is the
concentration of the pollutant and the total lack of any means of
reconditioning that air to natural standards.
What are the sources of indoor air pollution?
The most common sources are:
a) The building itself and the furnishings in the building emit
hazardous chemicals such as formaldehyde and styrene. Sources range
from particle board to ceiling tile to carpets and furniture to
paints and finishes. b) Chemicals inadvertently brought into the
home such as the residue in dry cleaned clothing, the hydrocarbons
collected on our clothing while driving home, the small amount of
chemical residue on the food from the grocer. c) Cleaning products
of all types d) Tobacco smoke and the 3600 chemicals resulting from
smoke e) organic residue from insects, rodents, roaches, pets, f)
Mold, mildew and fungus that etc. It is interesting to note that
most of the pollutants are organic in nature and that the chemicals
which we consider to be problems exist all around us in nature where
they are not considered problems. To become a problem, as noted
earlier, the dosage must be such that adverse effects result. Dosage
is, of course, a function of both concentration and time of exposure.
Even small amounts of pollutants will cause adverse effects if the
time of exposure is long enough. These adverse effects occur so
gradually that they are not associated with their true cause. The
gradually increasing frequency of headaches may never be associated
with the move to a new home or the acquisition of new furniture,
or a child's allergy problem may not be associated with an exposure
to pollutants in the bedroom that began at birth, or the hyperactivity
of a child may not be connected to the fact that it began with a
subtle change in the environment. These changes have accelerated
since the date of the first oil embargoes when the cost of energy
for heating and cooling our environments. soared. From that date
we have attempted to eliminate all outdoor air from our indoor environment.
By doing so we have also trapped all of the pollutants indoors and
have eliminated the one chemical that has the capacity to restore
the air to its pure state-ozone.