By Mariana Llamas-Cendon
MEXICO CITY — Surgical masks and respirators have become a popular shield against the swine flu or H1N1 virus pandemic but they are not almighty. According to a story published on Esmas.com, the news website from Noticieros Televisa â€” one of the two main broadcasting companies in Mexico â€” experts at Mexicoâ€™s Autonomous National University (UNAM) said the masks prevent the transmission of swine flu by inhibiting the discharge of saliva drops when sneezing, coughing or even talking. Also, the masks help avoid direct contact between hands and mouth, which seems to be the most common form of infection with the H1N1 virus.
Mexican family sports surgical masks to ward off the H1N1 virus.
Surgical masks, although useful, also have a dark side. The most common type â€“ one that usually comes in a blue color â€” offers protection for only about two to six hours, depending on the level of exposure to the virus.
â€œMasks should not be used longer than that (six hours) because they get moist and therefore, will not be able to protect as intended,â€ said Dr. Ricardo C. Armendariz, a renowned Mexican oncologist. â€œThe virus (H1N1) is transmitted through microscopic particles known as fomite, which are present every time we breathe, and greater when we sneeze or cough.â€
For Dr. Jaime Morales, vice director of the Department of Pulmonary Circulation in Latin America and a pneumologist for the National Institute of Medical Sciences and Nutrition Salvador Zubiran in Mexico City, a surgical mask has to be replaced every two hours, this being especially important for healthcare professionals.
â€œAt the moment, due to the emergency situation that prevails, common surgical masks are being replaced every two hours; medium-efficiency ones that are not as thin, every eight hours, and the hard, rounded ones, every seven days,â€ Morales said.
Once replaced, masks are not reusable under any circumstances.
Even though one size fits all, not all surgical masks are the same. The level of performance â€” simple, medium or high â€” and the life of a mask depend mostly on the porosity of the material it is made of. Basically, the fabric should have a compact hard-to-see-through texture, but not necessarily thick.
For instance, a simple efficiency mask, such as the surgical blue one, lasts two to six hours; whereas, the medium-efficiency mask has a life of about eight hours and generally comes in a white plasticized fabric. The high-efficiency one, better known as a respirator, is made out of a hard material.
â€œThe characteristic of surgical masks is the small pore (of fabric), that makes them efficient,â€ said Dr. Morales.
So, the protection offered by those made of lyocell fabric â€” commonly used as a household cleaning rag â€” is certainly not sufficient to avoid spreading or becoming infected.
â€œI do not think those made of lyocell work because the fabric has a very open pore. (Lyocell) is very soft, hence the protection dispensed by them is not great,â€ said Dr. Morales.
Regarding doubling the masks, Dr. Armendariz said: â€œSomeone may use two masks at one time, but no matter what, the first mask will have to be replaced once it is moist, and the second one will not last much longer after that.â€
Since the World Health Organization (WHO) raised the alert to level 5 pandemic, the biggest problem is not the protection that masks offer, itâ€™s the shortage of masks due to overwhelming demand in Mexicoâ€™s drugstores, big supermarket chains like WalMart, Comercial Mexicana and Soriana, and even hardware stores such as Home Depot.
â€œThe problem is that there are none in stock. Yesterday I had surgery and the mask was given to me,” Dr. Armendariz said. â€œBefore, they were up for grabs.â€
â€œSince Sunday night, we noticed that the regular stock of masks for construction (industry) in our 75 stores in the country had decreased dramatically. This stock was reduced to zero in almost half of the stores and obviously clientsâ€™ demand for the product increased during the following hours,â€ said Roberto Vazquez Carlo, manager of Public Relations and Social Responsibility of Home Depot Mexico, who also pointed out that the masks Home Depot sells are intended for a different use such as construction.
He also declared that Home Depot is in the process of restocking the masks in the next 48 hours.
WalMart of Mexico was also contacted for this story, but no information was received from them.
Whether or not the task of finding a mask is difficult at the moment, Dr. Morales recommended: â€œInfected or ill people, as well as those close to them, have to use it.â€
Dr. Armendariz said that even handkerchiefs and scarves can be used when masks are not available as long as the same provisions of those of a mask are followed.
Mariana Llamas-Cendon is a Mexico City-based freelance journalist.