Brendan McDermid / Reuters A man wears a medical mask during the morning commute in New York City, April 29, 2009.

The surgical face mask has become perhaps the most recognizable symbol of the H1N1 pandemic threat, but if the currently circulating flu virus does in fact reach full-fledged pandemic proportions, U.S. health officials say there won't be enough face masks to go around.

The Department of Health and Human Services (HHS) says the nation would need more than 30 billion masks  27 billion of the simple surgical kind, which can be worn safely for only about two hours before needing replacement, and 5 billion of the sturdier respirator variety, which also requires regular replacement  to protect all Americans adequately in the event of a serious epidemic. But the Centers for Disease Control and Prevention (CDC) Strategic National Stockpile currently contains only 119 million masks  39 million surgical and 80 million respirator. That's less than 1% of the goal health officials set in 2007 following the devastation of Hurricane Katrina, which highlighted the country's shortages of vital medical gear. (See pictures of the swine flu in Mexico.)

The U.S. mask gap stands in stark contrast to what other nations have on hand: the U.S. has one mask for every three Americans (masks are not supposed to be shared), while Australia has 2.5 masks per resident and Great Britain boasts six. "With the recent outbreak of the novel H1N1 influenza virus," warned Representative Kay Granger, a Texas Republican, "it has become clear that we need to purchase more medical supplies and replenish the Strategic National Stockpile." (Read "How to Prepare for a Pandemic.")

Maskmakers are worried too, especially since ramping up production in the midst of a pandemic won't be easy. Most maskmaking operations have moved outside the U.S., and 90% of masks sold in the U.S. now come from Mexico or China. But if the U.S. suddenly put in orders for millions of masks, Mexico and China would be unlikely to export their supplies before making sure their own populations were fully protected. "HHS knows the problem exists and yet they won't tell the health-care industry," says Mike Bowen of Texas-based Prestige Ameritech, the largest and one of the last remaining American mask manufacturers. "If they would only admit the problem exists, American hospitals would buy American masks and the manufacturing infrastructure would return." (Read "Battling Swine Flu: The Lessons from SARS.")

Of course, the more basic question is, How much do masks really help to stem the spread of disease? It's unclear, according to the CDC, which isn't recommending that people wear masks amid the current H1N1 outbreak. The CDC website says that "very little is known about the benefits" of wearing masks during a pandemic, and that the best preventive steps are frequent hand-washing and covering one's mouth when coughing or sneezing. Along with these strategies, the most effective techniques for preventing contagion are so-called social-distancing measures, such as closing schools, churches, theaters and other public gatherings, and generally keeping people apart from one another  efforts that may be further encouraged by the presence of face masks.

Surgical masks by themselves may not do much to prevent transmission within the community in part because they are loose fitting, offering a weak barrier between infected and uninfected people  hence, the government's better advice to wash hands and cover up sneezes and coughs  and masks must be changed frequently to avoid contamination. Respirator masks, which have a tighter fit, filter 95% of airborne particles to give wearers better protection, so long as they wear them consistently  which most people generally fail to do.

Where masks do make a demonstrable difference is in the health-care setting, protecting caregivers from sick patients  both in hospitals and at home  and a national shortage could impact these front-line responders most severely. "Much of what is contained in the Strategic National Stockpile are vaccines and medicines," including 50 million doses of Tamiflu, says CDC spokesperson Von Roebuck, noting that more medical supplies must be purchased.

Meanwhile, as the H1N1 virus continues its rapid spread around the world  as of May 18, 40 countries had officially reported 8,829 cases, including 74 deaths  nervous customers have been snapping up face masks in the U.S. Prestige Ameritech's sales have doubled in recent weeks, forcing the company to maintain a seven-days-a-week production schedule to keep up with demand. Even though Prestige Ameritech is a wholesaler that sells its products to retailers, such as 3M, there have been so many people trying to buy masks directly from the Prestige factory in suburban Fort Worth that the company has had to lock all its doors. Whether or not face masks will protect people from disease, sometimes it helps just to have the illusion of security.

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