The Health Risks of Ozone

[nicholson]

[Admin Note: This is a new thread containing a bunch of posts on the health effects of ozone, previously posted on this EXERCISE thread. --Dean]

 

Hi Sirtuin:

 

Regarding your:  "I wonder if there's any sort of off-gasing concerns with putting a big treadmill desk in the office and running that motor / belt for hours daily" I think the most serious threat to health from that would be ozone from the electric motor.

 

If you do not know what ozone smells like please find out.  Exposure to ozone, even in very low concentrations, causes irreversible lung damage.  Fortunately, most people can smell ozone in very low concentrations.  I would describe it as a somewhat acrid, musty smell.  It is caused by the very high temperature in electric sparks converting atmospheric oxygen (O₂) to ozone (O₃).

 

Some kitchen blenders emit considerable amounts of ozone, and when I use them I make sure the ozone is dissipated away from me.  If you have a blender, or some similar piece of equipment with an electric motor handy, get it running and sniff around it trying to find a musty/acrid smell.  You must avoid it at all costs, imo.

 

I once visited an Air Force experimental radar station, full of electrical apparatus (but mostly not electric motors).  When I entered the main room the smell of ozone was overpowering.  The people in there very likely all died eventually from emphysema, never understanding the reason.  I have also often detected it in specific subway (train) stations, in Toronto in particular.

 

Rodney.

[Michael R]

I've read a standing desk might be hard on the body.

 

That article largely indicates all the foolish ways one can misuse a standing desk.

 

Hi Sirtuin:

 

Regarding your:  "I wonder if there's any sort of off-gasing concerns with putting a big treadmill desk in the office and running that motor / belt for hours daily" I think the most serious threat to health from that would be ozone from the electric motor.

 

If you do not know what ozone smells like please find out.  Exposure to ozone, even in very low concentrations, causes irreversible lung damage.  Fortunately, most people can smell ozone in very low concentrations.  I would describe it as a somewhat acrid, musty smell.

Ozone is frequently present in significant concentrations — in traffic ("ground-level ozone") and before and after a rainstorm, and most people find the smell to be fresh, pleasant, and clean:

 

http://www.scientificamerican.com/article/storm-scents-smell-rain/

 

http://www.npr.org/templates/story/story.php?storyId=12716163

 

I see on the interwebs claim of it being produced by the running of older photocopiers and other electric devices with motors, and associated with the unpleasant smell of same; I can't comment on this, but I'm not aware of any public health campaigns to eliminate its production if it is indeed responsible for that not-subtle smell and is toxic at detectable concentrations.

[nicholson]

"A statistical study of 95 large urban communities in the United States found significant association between ozone levels and premature death. The study estimated that a one-third reduction in urban ozone concentrations would save roughly 4000 lives per year (Bell et al., 2004). Tropospheric Ozone causes approximately 22,000 premature deaths per year in 25 countries in the European Union. (WHO, 2008)"

 

Source:  Wikipedia  https://en.wikipedia.org/wiki/Tropospheric_ozone#Health_effects

 

Based on my experience with the smell of ozone, in several places all involving electrical equipment, I am rather confident that if what you smell is "clean and fresh", it is not ozone you are smelling  : ^ )))

 

If you have a regular stand up blender, and especially if you can find an old one, plug it in and DON'T turn it on.  Smell all around it and hopefully you will smell next to nothing.  Then turn it on and wait several seconds, THEN smell all around it again.  If the electric motor inside is producing sparks you will smell a pronounced odour of ozone.  It is certainly not a pleasant smell (but not totally repugnant either - "musty, somewhat acrid" is the best description I can come up with), and it is very well worth avoiding once you know what it is  : ^ )))

 

Rodney.

[Michael R]

"A statistical study of 95 large urban communities in the United States found significant association between ozone levels and premature death. The study estimated that a one-third reduction in urban ozone concentrations would save roughly 4000 lives per year (Bell et al., 2004). Tropospheric Ozone causes approximately 22,000 premature deaths per year in 25 countries in the European Union. (WHO, 2008)"

 

Source:  Wikipedia  https://en.wikipedia.org/wiki/Tropospheric_ozone#Health_effects

I don't dispute that ground-level ozone ("smog") kills people, but that the presence or absence of ozone as detected by smell is a good indicator that it has risen to deadly/toxic levels to an average person. Ground-level ozone does kill some people at levels high enough to trigger asthma attacks and other lung distress amongst children and some adults with asthma or other chronic respiratory disease; the elderly; adults who are exercising or working vigorously outdoors respiratory diseases, and people with unusual susceptibility to ozone. Such levels are formed from  nitrogen oxides (NOx) and volatile organic compounds (VOC) breaking down in the presence of sunlight, released in emissions from electric (mostly coal-burning) power plants, industrial facilities, and car exhaust; simply being detectable by smell doesn't mean it poses a danger (viz, again, the buildup to a rainstorm). See EPA's Smog - Who Does it Hurt? (PDF)

 

Based on my experience with the smell of ozone, in several places all involving electrical equipment, I am rather confident that if what you smell is "clean and fresh", it is not ozone you are smelling  : ^ )))

On the one hand, the smell you are detecting could also be a secondary unpleasant byproduct of electrical equipment, caused eg. by overheating wiring. See my reasonably authoritative links above. OTOH:

 

 

Ozone has a very characteristic pungent odor. You can sometimes detect it after lightning strikes or during electrical discharges. Individual humans vary in their ability to smell ozone. Some can smell it at levels as low as 0.05 ppm.

Ozone and Health - Air Resources Board - State of California

[nicholson]

Anyone who really wants to satisfy themselves about what ozone smells like, could try this:

 

http://mattson.creighton.edu/Ozone/Ozone1.html

 

Then tell us if they found it to smell sweet and fresh (!)

 

Rodney.

 

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"The unverified conventional wisdom is almost invariably mistaken."

[nicholson]

An additional point on this:  I had not realized that arcing is not necessary for ozone to be created by electric circuits.  As the following wikipedia link shows: https://en.wikipedia.org/wiki/Corona_discharge the air around a conductor can become ionized and then be converted into ozone as well as other unhealthy gases, simply by induction, especially around smaller diameter wires because of the high curvature of their surfaces:

 

"Corona discharge usually forms at highly curved regions on electrodes, such as sharp corners, projecting points, edges of metal surfaces, or small diameter wires. The high curvature causes a high potential gradient at these locations, so that the air breaks down and forms plasma there first. In order to suppress corona formation, terminals on high voltage equipment are frequently designed with smooth large diameter rounded shapes like balls or toruses".  (my bold face)

 

Arcing also creates ozone, of course, but even moderate voltages in small diameter wires will create ozone even without arcing.

 

Further, the following link shows that oxidation/corrosion or other imperfections in the wire can increase the rate of ozone production by a factor of 50 compared with that of a perfect wire:  http://www.academia.edu/2451530/Corona_emission_and_ozone_production_by_carbonized_and_oxidized_high-voltage_wires

 

"High-voltage wires exhibit corona discharges that cause emission of ozone.  Precipitation, dirt, and wire imperfections have been shown in earlier works to increase both processes by a factor of up to 50".

 

This discussion of ozone originated in response to a question as to whether there might be risks associated with running a treadmill all day.  In my view, if there is a strange smell from a treadmill within a few minutes of being turned on, then I would not wish to use it for extended periods without very good ventilation.  And do not forget the nose's (or, more probably, the brain's) ability at attenuation.  After a relatively short time the ozone may still be there but your nose may no longer detect it.  As an example of this:  people who live for a few days in a town with a pulp and paper mill emitting an unbelievably disgusting stench no longer notice it after a few days residence.  But anyone new to the town cannot believe anyone could tolerate such an awful smell.  This phenomenon is not confined to the smell of pulp and paper mills.

 

Rodney.

 

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"The unverified conventional wisdom is almost invariably mistaken."