gam@amdahl.UUCP (Gordon A. Moffett) (11/18/84)
This article is in response to some questions raised about the
effects of negative ion generating air cleaners. It is reputed
that in addition to cleaning the air, the negative ions produce
at least a subjective effect of well-being.
I collected excerpts from medical abstracts on the effect of
negative ions under different conditions and on different people.
They are herein summarized.
Note that some abstracts conflict with the results of others;
science is like that. Read on, and draw your own conclusions.
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[ Effect of negative air ions on adult asthmatics ]
"... Thus moderately long exposure to
positive or negative small air ions did not influence the
clinical condition of these patients, many of whom reported
exacerbations with weather changes. The findings do not support
a significant role of small air ions in exacerbations or
treatment of bronchial asthma."
[ ... on adolescent asthmatics ]
"... It is concluded that negative
ionisation of inspired air can modulate the bronchial response
to exercise but the effect on the response to histamine is much
more variable."
[ Air Force study on subjective effects on males ]
"... The tests used
were the Taylor Manifest Anxiety Scale (TMAS) and a self-report
mood index. The analysis of TMAS change scores clearly showed no
effect of negative ion exposure on anxiety. Analysis of mood
index data showed significant changes in the subjective
perception of both physiological state (relaxation increased)
and psychological state (irritability, depression, and tenseness
decreased while calmness and stimulation increased."
[ Effects on males (24-35yrs) doing aerobic exercise; reaction
time ]
"... The
intake of oxygen, which is a gross indicator for the entire
aerobic metabolism, is not influenced by negative air ions.
Given a constant environment, the presence or absence of ions
does not have any effect. Sudden introduction or removal of
negative air ions induces changes in control that tend to be of
a negative nature: there is an increase in breathing frequency,
breathing equivalent, and cardiac frequency at constant oxygen
intake (p less than 0.025). In testing reaction time, only the
sudden introduction of negative air ions produced a
statistically significant effect, i.e. prolongation of reaction
time. This effect, too, is of a more negative nature (p less
than 0.05)."
[ Effects on mental abilities ]
"... 16 subjects, only half
of whom were informed of the ion level in each session,
performed reasoning, psychomotor, and memory-search tasks.
Despite adequate control of confounding variables, no clear
evidence was obtained in support of the view that negative ions
in the air influence performance."
[ Effects on respiration ]
"Ergometrical investigations with standard stress show that
negatively charged air increases carbon dioxide exhalation.
Thereby work-acidosis is decreased and the centers of the
circulatory system are relieved."
[ Another asthma study, this one positive ]
"The influence of artificially generated atmospheric ions is
studied in 15 patients with bronchial asthma. A slight but
significant (at 5% level) improvement in the lung function was
demonstrated in nine patients during positive as well as
negative ion exposure, but the patients' subjective votings of
the air quality did not show any changes due to ion exposure. No
change in the histamine threshold of the airways in six patients
with bronchial asthma was demonstrated during exposure to ions.
Further controlled studies with electro-aerosols are needed."
[ ions and work in a hot envirionment ]
"... Although not
statistically significant, being exposed to negative air-ions seems
also to reduce total sweat rate and minute ventilation (.ovrhdot.VE),
and to increase O2 pulse. Under the conditions of this study
negative air ions can improve various cardiovascular and thermoregulatory
functions as well as subjective feelings during physical effort.
Such positive influences may be augmented by increasing the exposure
time to negative ionized air and/or prolonging the stressful
conditions."
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[ If you would like the full text of these abstracts, drop me a line. ]
--
Gordon A. Moffett ...!{ihnp4,hplabs,amd,nsc}!amdahl!gam
37 22'50" N / 122 59'12" W [ This is just me talking. ]norm@ariel.UUCP (N.ANDREWS) (11/20/84)
Thanks and some questions for Gordon Moffett: Thanks for the references re psychobiological effects of negative ions. Some of the negative ion generators being marketed are producers of ozone, while others produce the ions without producing significant ozone. I have read that ozone isn't good for people. What have youn found out about that? What is the difference in ion generation techniques that determines whether ozone is generated or not? --Norm Andrews
gam@amdahl.UUCP (Gordon A. Moffett) (11/25/84)
> Thanks and some questions for Gordon Moffett: > Thanks for the references re psychobiological effects of negative ions. Some > of the negative ion generators being marketed are producers of ozone, while > others produce the ions without producing significant ozone. I have read that > ozone isn't good for people. What have youn found out about that? What > is the difference in ion generation techniques that determines whether ozone > is generated or not? --Norm Andrews I didn't research ozone effects specifically but the general area of air ions. How does one know if their ion generators are ozone-producing? -- Gordon A. Moffett ...!{ihnp4,hplabs,amd,nsc}!amdahl!gam 37 22'50" N / 122 59'12" W [ This is just me talking. ]
ron@brl-tgr.ARPA (Ron Natalie <ron>) (11/26/84)
> Thanks and some questions for Gordon Moffett: > Thanks for the references re psychobiological effects of negative ions. Some > of the negative ion generators being marketed are producers of ozone, while > others produce the ions without producing significant ozone. I have read that > ozone isn't good for people. What have youn found out about that? What > is the difference in ion generation techniques that determines whether ozone > is generated or not? --Norm Andrews Ozone is detrimental. Users of air cleaners in warehouses found that the tires stored there decomposes and begins to crumble. Even moderate but repeated ozone exposure to plants causes black spots to appear on them and eventual death (now you know what they are). There was an article about this in the Smithsonian Magazine about ten years ago. In addition, I researched all this for a science fair project back in high school, but I've forgotten the rest of the details. -Ron