The Risks of a Manned Mission to Mars, Part IV

If the astronauts can somehow reach Mars safely, there will be some major hazards that await them on the surface of Mars. One of these hazards is the Martian dust. The dust on Mars is probably 50 times finer than on Earth. With a prolonged stay on Mars, the dust can potentially become hazardous. It can get into the equipments, cause airlocks to malfunction, or even get into the astronauts’ lungs. Russell Kerschmann, a pathologist at the NASA Ames Research Center, believes that the Martian dust could be dangerous due to its fineness and unknown chemical makeup. According to him, if the dust particles are small enough, they could penetrate deeply into the astronauts’ lungs and cause many health-related problems.

http://www.space.com/businesstechnology/070711_tw_mars_spaceflight.html