Army friends who have used laptops in Afghanistan and Iraq report serious problems with the fine dust that infiltrates everything and damages moving parts. Somehow even the contacts for keys in the keyboards become disabled. Covering the keyboards with membranes slowed the damaged, but didn't stop it. Users considered the equipment expendable because of dust damage and no solution was suggested. I have no idea how to cope with such a problem, but can see how it could pose a major problem for many areas where laptops will be distributed.
- This is a redundant question. The Hardware specification page says that the keyboard is a sealed membrane type keyboard. You could have discovered this by searching for dust using the search button at the right. And Google would have told you, on its first search page, that sealed membrane keyboards are both dust and water resistant.