Amid all those burning cities and plague-ridden ruins, catching a breath of fresh air might prove a challenge in the post-apocalyptic world.
If the chance arises on the forsaken Earth, loot yourself a gas mask or two. A simple painting respirator should filter out ammonia, chlorine or swirling toxic dust. Just remember that any gas mask you grab from an adult lingerie store or detach from a bong might not provide that much protection.
Even the mutants know better than to pass up a good gas mask, so you might find supplies rather limited. Don't be afraid to create your own out of household items. The first personal air filters from the early 20th century mimicked the body's mucous membranes -- by forcing incoming air through a wet sponge.
In the wake of the Occupy Wall Street movement and the Arab Spring, various do-it-yourself gas mask plans made the rounds on the Internet. These crude devices followed a similar approach, using a soda bottle and a clinical face mask soaked in vinegar [source: Stone].
Other designs incorporate charcoal-based filters made with canisters and mesh flyswatters. The task is still the same: adsorption of harmful chemicals [source: Anderson]. Try to score some activated charcoal when building one of these filters. Treated with oxygen, this really porous form of charcoal traps even more harmful organic chemicals you don't want to fill your lungs with.
If the air's loaded with particularly heinous inorganic compounds, however, you might be out of luck. But hey, even a failing gas mask will make you look like a fearsome, rubber aardvark man.