Hmmm you seem to forget the Wally Shirra that had a cold while on one of
the Apollo missions.  If you hydrogen and chlorine theory held true I
would have had a cold continuously for several years as I worked around
HCL(Hydrochloric Acid) daily. The medical profession say it is a virus
that causes a cold, I think I will go along with their opinion rather
than this half cooked scheme.

You're wrong.

I think you're a nut (not to put too fine a point on it).

Uh, no, both the shuttle and the station use approximately the same
atmosphere as here on Earth:  21% oxygen, almost all the rest nitrogen, at
circa 14.7psi.  Only the spacesuits use pure oxygen now.

Some of the trace ingredients are different, e.g. there is not much argon
(nearly 1% of Earth air) in the station air.

The amount of free hydrogen in Earth's atmosphere is tiny -- about half a
part per million -- and it comes from the breakup of water vapor by
various means.  There is just as much water vapor in the shuttle and
station air as in Earth's air.

Minor infections, including colds, actually appear to be more common in
space than on the ground.  Weightlessness causes changes in the immune
system -- just how that happens is unknown -- and that may be part of it,
and more small airborne debris (since it doesn't settle due to gravity)
may also be a factor.

And what price are you asking for the Brooklyn Bridge?

Actually, on the shuttle, the "air supply" is O2 and N2 at sea level mix and
pressure.  CO2 scrubbers keep CO2, generated by the astronauts, at low
levels.  As far as I know, the same is true for ISS and Soyuz.

Jeff

There is hydrogen in the space station, though not as much as in older
spacecraft. People fart, and since the total volume of air in ISS is less
than Earth, the portion of hydrogen is greater. In older spacecraft it was
worse, because the lower pressure encouraged more farting. The fuel cells
also sometimes added hydrogen to the water.

Here is some information on the current tests being done on STS-118
examining the how bacteria grow in space which "will give insight on
what types of bacterial infections may occur during long duration
space missions"

http://www.nasa.gov/pdf/182728main_STS-118_Press_Kit.pdf
STS-118 press kit Page 69
Biological Science Investigations
"Streptococcus pneumoniae Gene Expression and Virulence Potential in
the Space Environment (SPEGIS) will examine the behavior and growth of
bacteria in microgravity. The data collected will give insight on what
types of bacterial infections may occur during long duration space
missions and the risks to crew members."

The Experiments Link
http://www.nasa.gov/mission_pages/station/science/experiments/SPEGIS.html#description
"Streptococcus pneumoniae Expression of Genes in Space (SPEGIS)
08.14.2007
Brief Summary
Streptococcus pneumoniae Expression of Gene in Space (SPEGIS) will
examine the behavior and growth of bacteria in microgravity and
investigate the effects of the space environment on the gene
expression, protein production, and virulence of the bacteria
Streptococcus pneumoniae. The data collected will also provide insight
on what types of bacterial infections may occur during long-duration
space missions and the risks to crew members....
Experiment/Payload Description
Research Summary
During spaceflight, as well as on Earth, humans risk infection that is
caused by bacteria.
This investigation will examine gene and protein expression of
Streptococcus pneumoniae (a bacteria that is normally found living in
the human body) are effected by microgravity.
Data from SPEGIS is anticipated to provide information on the threat
of opportunistic pathogens in the space environment, which will assist
in the development of diagnostic tools to monitor the atmosphere and
surfaces (air, soil, and food) for the presence of these microbes.
Description
The Streptococcus pneumoniae Expression of Genes in Space (SPEGIS)
will investigate S. pneumoniae gene expression and protein production
in the space environment. S. pneumoniae is an important human pathogen
and the leading cause of bacterial pneumonia (inflammation of the
lungs with congestion), meningitis (inflammation of the membrane
covering the brain and spinal cord), and otitis media (ear infection).
Importantly, this pathogen has been isolated previously from the crew
pre-flight and related bacteria are found in the spacecraft
environment. Experiments will be performed to identify and
characterize S. pneumoniae genes and proteins, which are
differentially expressed in response to the space environment and
compare microgravity-induced genes and proteins to those expressed
during post-flight animal infection.

This experimental approach will result in new information about a
significant human pathogen, add to our knowledge about the S.
pneumoniae pathogenic mechanism, and also provide basic information on
the bacterial model system of gene and protein expression in the space
environment.

S. pneumoniae is a respiratory microbe that is normally found in the
upper respiratory tract of approximately 40% of the healthy human
population. The identification of specific S. pneumoniae virulence
factors and cellular and molecular processes may aid scientists in
furthering the understanding of how this bacteria causes infection.
This data may aid in the design and development of new antimicrobial
drugs.

Pre-flight the S. pneumoniae cultures will be grown on the ground in a
laboratory environment and inoculated into Todd Hewitt Yeast extract
(THY) growth medium for the flight experiment. The bacterial cultures
will be loaded into the experiment containers approximately L-72 hours
and will be launched at 4 degrees C in the Microgravity Environment
Research Locker/INcubator (MERLIN)."