While there's not much scientific data, common sense tells us that masks give us some protection against contagion.
The federal government already stockpiles about 150 million masks in case of a flu epidemic.
The Centers for Disease Control and Prevention released guidelines on Use of Face Masks in Flu Outbreak
If a flu pandemic ever emerges, surgical masks “should be considered” by anyone entering a crowd, and thicker industrial masks “should be considered” for anyone taking care of the sick, federal health officials said yesterday as they finally released guidelines for mask use.
The guidelines released yesterday re-emphasized earlier suggestions that in a pandemic, people should shun crowds, avoid close contact with anyone at work or school, and stay home if they are sick, or anyone in their household is sick.
They should also wash their hands frequently, use hand sanitizers and cover their noses and mouths when coughing or sneezing.
Masks are most useful, said Dr. Julie Gerberding, director of the disease control centers, when placed on people who are already sick — to keep in droplets from their sneezes and coughs. They are also important for health care workers or family members tending anyone with flu, especially during potentially dangerous procedures like giving nebulizer treatment to an asthmatic child or suctioning a patient with a chronic breathing problem.
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Masks come in two types. Surgical masks are the thin disposable or washable cloth or paper ones worn by surgeons and dentists, costing a few cents each. N-95 respirators are thicker fiber masks, often round or duck-billed in shape, worn by construction workers to keep out dust or paint, and by hospital nurses working with infectious patients. They are certified to keep out 95 percent of all particles and usually cost $1 or more.