Dust, The health effects - danger to humans from both Moon and Mars

Grypd · 2005-04-22 05:59:49

We have discussed the Long term health effects of Mars and Moon lower gravities but we have only ever touched on that the actual landscape is probably dangerous to long term occupation. And in this Mars is more dangerous apparently than the Moon.

http://science.nasa.gov/headlines/y2005 … e.htm]Nasa wonders about breathing in dust

SpaceNut · 2005-04-22 07:37:59

Just one more reason to give a fully thought out plan for the habitats crew entrance to have some sort of dust removal system. One type for mars we have discused was the Co2 compressed gas system. But any source of a gas of any type might do the job just as well.

Palomar · 2005-04-22 15:31:47

*Just now read the version at universetoday.com. I do recall the "gunpowder smell" reference ala Apollo astronauts Schmidt and Cernan.

Astronauts on several Apollo missions found that it clung to everything and was almost impossible to remove; once tracked inside the Lunar Module, some of it easily became airborne, irritating lungs and eyes.

Geez.

Martian dust could be even worse. It's not only a mechanical irritant but also perhaps a chemical poison. Mars is red because its surface is largely composed of iron oxide (rust) and oxides of other minerals. Some scientists suspect that the dusty soil on Mars may be such a strong oxidizer that it burns any organic compound such as plastics, rubber or human skin as viciously as undiluted lye or laundry bleach.
"If you get Martian soil on your skin, it will leave burn marks," believes University of Colorado engineering professor Stein Sture, who studies granular materials like Moon- and Mars-dirt for NASA. Because no soil samples have ever been returned from Mars, "we don't know for sure how strong it is, but it could be pretty vicious."
Moreover, according to data from the Pathfinder mission, Martian dust may also contain trace amounts of toxic metals, including arsenic and hexavalent chromium--a carcinogenic toxic waste

Apparently one scientist is optimistic ensuing troubles/obstacles in this regard can be surmounted.

http://www.newmars.com/forums/viewtopic.php?t=2925]This old thread might be of additional interest.

--Cindy

RobertDyck · 2005-04-22 18:30:30

I have pointed out that the planet-wide average mineral composition reported by the team studying MGS data included serpentine and actinolite. On Earth these minerals are crushed to release fibrous crystals within the mineral, the fibres are asbestos. Serpentine is white, actinolite is green. Mars surface has been pulverized by meteors and sand blasted by wind, resulting in fines. That could mean the dust and fines include micro-fibrous asbestos.

To avoid asbestosis as well as silicosis described in the article Cindy found, astronauts will have to carefully ensure all dirt is left in the EVA prep room, and that room is cleaned frequently. Perhaps vacuum the suits and the floor after each EVA before entering the hab. Air circulation from that room will require a HEPA filter. It would make most sense if the suits were machine washable, and a washing machine was in the EVA prep room.

Viking found Mars soil reacts quickly on contact with water, and released oxygen. I don't expect it will burn human skin, although it may tingle a little. Years ago when I etched a printed circuit board for a modem, I got a few drops of ferric chloride on my skin. That's the corrosive that dissolves copper. Years later when I was making some silver jewellery I cleaned the solder points by bathing it in acid. Both times it slightly tingled but didn't hurt; I washed my hands right away. A cloth that I used to clean the acid was left in the workshop with acid on it. A year later the cloth had disintegrated. It takes time for a corrosive to do real damage. Extremely strong industrial corrosive can react quickly, but I expect Mars soil won't be any stronger than ferric chloride or jeweller's acid.

That said, I suppose it is worth studying. At the Lunar and Planetary Sciences Conference this year I heard the Opportunity team found cyanogen; that's two molecules of cyanide bound together. I haven't heard of cyanide anywhere but Meridiani Planum, it was probably created by the evaporite plane, but you have to be very careful with that. When cyanogen powder is mixed with water it forms hydrogen cyanide, the poison gas used for execution in a gas chamber. Meridiani has sedimentary rock so it probably doesn't have silica fines or asbestos, unless they were blown in.

MarsDog · 2005-04-22 22:12:17

In high humidity conditions dust settles out.

People will be in humid greenhouse environments.

Just like on Earth, don't eat the dust that you sweep from under your bed.

Grypd · 2005-04-23 15:12:05

The problem is that we will need to ensure that we manage to clean a very high percentage of the Dust that will be on the suits/equipment. The problem is that we have to deal with dust which is highly charged and as such reacts strangely. We will also have to ensure that we can do it in a small space which does not use air or water as these are precious.

One thing to note our skin is tough but certainly in the case of certain areas of our anatomy Mars dust will be very bad. Imagine blind Mars astronauts and you see or not the problem.

Mars dust will react strongly with the moisture that is prescent in our eyes to form acids.

RobS · 2005-04-23 15:53:11

One solution would be high humidity and rapid air filtration. The peroxides and other strongly oxidizing compounds will break down in the presence of water, and electrostatic charges will dissipate. Washing the outsides of the spacesuits will remove dust fairly well.

One NASA web page mentioned a liquid carbon dioxide washing facility. I'm not sure how it would work. If you sprayed a person wearing a space suit with liquid CO2, the liquid would immediately flash into gas and would probably cool off surfaces extremely. It would blow dust off, for sure, but the sudden cooling would fatigue fibers, and it might dissolve some things as well.

-- RobS

Shaun Barrett · 2005-04-23 22:25:02

"If you get Martian soil on your skin, it will leave burn marks," believes University of Colorado engineering professor Stein Sture, who studies granular materials like Moon- and Mars-dirt for NASA. Because no soil samples have ever been returned from Mars, "we don't know for sure how strong it is, but it could be pretty vicious."

The analog Martian soil being discussed here is presumably based on the Viking-era paradigm(?). In other words, I suppose we're talking about bone-dry soil, rich in hydrogen peroxide and other superoxide compounds, which was hypothesized to explain the life-search experimental results obtained on Mars at the time.

But now we know there's sufficient reasonable doubt about the Viking results to question the rationale behind the creation of these soil analogs. It's now known that Martian soil commonly contains greater amounts of water (or at least water-ice which probably melts frequently, close to the surface, in the middle of the day, in summer) than we assumed possible back in 1976.

In addition, we know the Gas Chromatograph Mass Spectrometer used on Viking, and pivotal in denying the possibility of microbial life in Martian soil, was fatally flawed and its results patently unreliable. We also have a greater respect for the toughness, tenacity and 'ingenuity' of bacterial life as we find it in more and more inhospitable places here on Earth. [Check http://www.sfgate.com/cgi-bin/article.c … 1.DTL]THIS SITE for more on bacterial survival capabilities.] And we're finding high concentrations of methane in places on Mars known to be water-rich, which has many scientists intrigued by the possibility, or even probability, that the gas may well be biogenic.

If Mars is wetter than we used to think, and if bacteria do indeed inhabit the regolith (and were discovered by Viking, despite the denials since), then the entire basis upon which we produce our Mars soil analogs could be quite wrong.

If so, I think it's premature to form opinions about how corrosive or carcinogenic real Martian soil actually is. My personal hunch, for what it's worth, is that it will turn out to be far more benign than we think.

Palomar · 2005-04-24 09:36:51

If Mars is wetter than we used to think, and if bacteria do indeed inhabit the regolith (and were discovered by Viking, despite the denials since), then the entire basis upon which we produce our Mars soil analogs could be quite wrong.
If so, I think it's premature to form opinions about how corrosive or carcinogenic real Martian soil actually is. My personal hunch, for what it's worth, is that it will turn out to be far more benign than we think.

*Hi Shaun. Glad to see you back at New Mars.

Certainly do hope you are right. Your general optimism is always so welcome, at least to me.

Hopefully this'll go in the way of the A. C. Clarke quote:

New fears pass through three periods:
*It's highly inimical! Run for the hills!
*It's likely dangerous, but we'll do our best to try and tackle it.
*We -knew all along- that the fears were completely overblown !

-laugh-

--Cindy

Shaun Barrett · 2005-04-24 18:02:18

New fears pass through three periods:
*It's highly inimical! Run for the hills!
*It's likely dangerous, but we'll do our best to try and tackle it.
*We -knew all along- that the fears were completely overblown !

I hadn't heard this 'Clarkeism' before but it's very appropriate, I feel. As I think I've mentioned before, there were all sorts of fears about space travel before the first human went into orbit:-
1) Zero-g would cause disorientation and total incapacity. (Not so.)
2) Radiation would fry us. (Not so.)
Then later:-
3) When orbiting Earth failed to produce the predicted disastrous effects, some peole were sure leaving Earth-orbit probably would. They reasoned that a human on the way to the Moon, seeing mother-Earth receding in the distance, would suffer a kind of primeval separation anxiety and lapse into madness. (Didn't happen.)
4) The Van Allen radiation belts would be lethal. (Not true if you pass through them quickly.)
5) The Moon would be covered in a sea of fine dust, perhaps many metres thick, into which a crewed landing craft would sink without trace - as though in a dry form of quicksand. (Not so.)
6) Incredibly hardy organisms in the Lunar regolith would find humans very tasty and devour them on contact, or hitch a ride back to Earth and eat the rest of us too! (Didn't happen.)
7) Lunar dust itself would be chemically dangerous to humans. (It turned out to be a minor irritant. No big drama.)

These fears are typical of our general tendency to imagine the worst about unexplored territory and probably reflect a survival instinct which has served us well in the past. If you don't know what to expect; expect the worst and plan for that ... then you're more likely to avoid disaster.
Before space became the 'final frontier', explorers thought they'd sail off the edge of the world if they went too far. Unexplored seas were assumed to be filled with monsters and early maps were marked accordingly. Strange and dangerous animals inhabited distant shores, ready and waiting to pounce on the unwary.

I see much of the present-day anxiety about Mars in the same light. The soil will be poisonous or voracious pathogenic organisms are awaiting our arrival, smacking their lips and slavering at the thought of all that lovely human meat! :;):
By all means, let's be careful and think things through. But let's see our primitive fears in the context of history and stop telling one another scary stories around the campfire.
Most human fears are either completely unfounded or turn out to be unnecessarily exaggerated.

[Thanks for the kind comments, Cindy. It's good to be back. ]

Grypd · 2005-04-24 19:04:13

Hi Shaun, Glad to see you back

The Lunar soil was found to be a danger to us but like Mars its a long term risk that we should develop systems to ensure that it is removed. As previously stated traditional ways of removing the charged dust is inefective as we really dont have the water or air to spare and who wants to constantly carry a large supply of well...Nappy wipes.

We have seen with the probes on Mars now that the Martian fines are very small and easily transportable and also they accumalate to the point they interfered in power supplies. It does not matter that Mars has water to these as the Martian water is basically a frozen permafrost as far as we can see and well covered by soil. What makes the danger to us is the highly oxidising rust partickles of micro nature that can do serious damage to lung capacity and the damage takes many years to come out.

I know a couple of shipbuilders who since there exposure to asbestos in there early working lifes has resulted in there lifes being very blighted and very shortened. Actually a week ago I was at one of there funerals.

Palomar · 2005-04-24 19:15:42

I see much of the present-day anxiety about Mars in the same light. The soil will be poisonous or voracious pathogenic organisms are awaiting our arrival, smacking their lips and slavering at the thought of all that lovely human meat! :;):

*Bwa-ha-ha-ha! That was hilarious! :laugh:

I needed that laugh. :;):

You make really good points.

Hmmm...I guess I could add the fear that all of Earth's atmosphere would catch on fire with the detonation of the first nuclear bomb (which of course didn't happen)...but then I don't like bombs anyway, so bad analogy. :-\

--Cindy

Shaun Barrett · 2005-04-24 22:29:56

I'm delighted to think my fanciful portrait of ravenous Martian microbes tickled your sense of humour, Cindy.
It's a long day without a laugh, isn't it?!

Thanks for the welcome back and for the response to my post, Grypd. Your points are well taken and I agree with you that we can't allow complacency to dull our sense of danger when it comes to exploration. As in most things in life, I think it's a case of balance; plan carefully for various contingencies and take precautions, but let's not "distress ourselves with imaginings".
(Sorry to hear about the loss of your shipbuilder friend. )

Grypd · 2005-04-26 03:55:57

Of course the lack of knowledge of the properties of the Moon and Mars dust and its probable health effcts is something that must be studied. If the Colorado school of mines is doing the project this is for the good is it not. At least then we will know what we are dealing with.

Still there is the likehood that any means designed to stop Lunar dust will work just as well on Mars. This is a good example of a direct technology transfer that helps both programs.

RobS · 2005-04-26 19:20:40

I'm not sure dust removal systems on the moon and Mars will be the same. In Mars we can used compressed Martian air to blow dust off. We won't have that option on the moon.

-- RobS

Commodore · 2005-04-26 20:57:01

I'm not sure dust removal systems on the moon and Mars will be the same. In Mars we can used compressed Martian air to blow dust off. We won't have that option on the moon.
-- RobS

If we bake enough oxygen out of the soil, we could use that.

Just not in a confined area, or near sparks.

Grypd · 2005-04-27 03:50:11

I was hoping for a more efficient system than to just blast it with compressed CO2. Especially as we are going to have to spend a lot of energy to compress that CO2 in the first place and the equipment needed to process the gas and to store it weighs heavily on the tight Hab weight budget. And CO2 blasting would need a lot of compressed gas.

The best way forward in my belief would be to use the science of suit design to ensure that the least amount of dust sticks to the suit. And a means to automatically remove the dust of a human entering a lock either by the Martian exploration equivalent of a non water using car wash, all spinning brushes and sponges or to actually have the suits dock to a port and the astronaut comes from the shirt sleeve enviroment into the equivalent of a very deep sea hard suit.

There are lots of little things that can be done to reduce dust taken into the airlock as well. Since most fines will be attached to the astronauts feet like super clingy mud we simply issue them with wrap around boots that they wear while on the surface but leave outside when they come in.

SpaceNut · 2005-04-27 06:41:35

So now they are stepping into an uncleaned area only to track it in any ways.
As for the moon there will be other gasses other than o2 to use and if anything use a water wash and air to clean the suit. Just keep these in a closed loop system within the airlock.

Grypd · 2005-04-27 18:36:35

You mean to create a car wash idea but with the water...Hmmmm.

Still a hard type suit design unlike the cloth types would benefit dust removal as there would be a shortage of spaces ie folds for the dust to accumalate.

The water system would hopefully allow a rapid cycle of people through a lock and as long as you dont plan to use the water for anything else should not be a problem. The reason I dont think the water will be of much use is the likehood of its reaction to some of the materials to form alkilis and acids and to be very highly toxic shortly afterwards from heavy element poisoning.

Still how good can we make a closed loop system.

SpaceNut · 2005-04-27 20:44:18

These same alkilis and acids that might get made could be re-used in the tool making or smelting processes for mining or even for rocket fuel creation.

Grypd · 2005-04-28 05:14:25

Still finding a way to have the water treated and purified should also be looked into if only so we can treat the water that is on Mars. I know it is in the form of ice but this does not necassarily make it pure as Ice usually captures and forms over the smallest dust particles.

SpaceNut · 2005-04-28 05:18:58

Well in these types of soils to change there ph one would add lime and calcium to them to nuetralize before trying to process them.

Grypd · 2005-04-28 05:50:05

Well in these types of soils to change there ph one would add lime and calcium to them to nuetralize before trying to process them.

It does not get rid of the heavy mineral content that makes them poisonous and the trouble with this stuff is that it works over time slowly building a concentration in Humans. And limestone will be rare on Mars unless there has been long standing seas or life. And the life has to be above the bacteria stage.

Still using distillation and condensation techniques with a filtering should provide most of the techniques we need to clear most of the water. Just a bit big for anything like a first mission unless we can make it smaller.

Grypd · 2006-05-03 11:52:45

Moondaily: Lunar Dust Buster

By using the very simple process of alternating current it is possible to design a means to clean off Lunar and Martian dust. Though it is a very simple idea it does not lend itself to being used on Spacesuits.

JonClarke · 2006-05-10 04:35:43

I was hoping for a more efficient system than to just blast it with compressed CO2. Especially as we are going to have to spend a lot of energy to compress that CO2 in the first place and the equipment needed to process the gas and to store it weighs heavily on the tight Hab weight budget. And CO2 blasting would need a lot of compressed gas.

ISPP plants will, by their very design, collect and compres large amounts of CO2. In the main ISPP scenarios, the plant will be largely ideling once the crew arrives. So a supply of compressed gas should not be a problem.

As I have said before, the risk of dust is exaggerated. There are many environments on earth which generate large amounts of hazardous dusts, as as asbestos, toxic metals, and corrosive agents, which are managed routinely. The trick is to remove as much as possible before people doff their suits and then vacuum up and filter out material that gets through.

I don't have the amounts here, but the actual amounts of peroxide in Martian dust is actually quite small, certainly not enough to burn the fingers.

Jon

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