Q) I was riding my bike the other morning and accidentally inhaled a bug. Is there a big pile of assorted bug parts in my lungs?
Jeff Eisken, Fort Smith, Arkansas
A) IF INDEED YOU are worried, don't be. Your lungs, while prone to harboring an insect or two, have a built-in bug-removal process. Assuming the critter isn't a 2.5-ounce giant weta from New Zealand (considered by many to be the world's largest insect), rest assured that the hairlike structures in your airway, called cilia, will work in sequence to brush microscopic bug bits up the trachea so you can cough them out. It's unlikely that the little corpse will make it all the way down your windpipe, but if it does, your lungs will activate an emergency backup plan. "Your body recognizes the bug as foreign," explains Armando Huaringa, a pulmonologist and member of the American Association for Bronchology. "Your lungs encapsulate the bug with mucus, and over time the proteins get broken down by chemical processes." This pulmonary entombment leaves a small tumor on the lung, called a granulomabut fear not, it's benign, more granola than melanoma. On the other hand, aspirant pneumonia is a remote possibility if the bug carried bacteria. Ideally, though, the pharynxa trapdoor at the back of the mouthhas already diverted the errant bit of vermin down your esophagus and into your belly, away from your windpipe. "Your stomach is better equipped than your lungs for this kind of work," says Huaringa.
Q) Why is lichen put into natural deodorant?
Sarah Bovey, Sunderland, Vermont
A) PRESS YOUR NOSE against a lichen-covered rock, and you might detect a pleasant herbal smell. But the reason the crusty plant is used in deodorant has more to do with science and folklore than with its subtle perfume. First, the science: Every lichen is actually two organismsa fungus and an algaliving in symbiosis and exchanging food, water, and minerals with each other. Among the dozens of chemicals that lichens produce (from naturally occurring sugars) are acids designed to kill invading microbes that might be harmful to the relationshiphence the theory, among some scientists, that these same acids are capable of killing the odor-causing bacteria that flourish around your sweat glands during a long trail run. It's not a new notion: For 2,000-plus years, lichens have been thought to wield curative powers. The lichen known as old-man's beard, which drapes the branches of oak and pine trees from North America to China, was used to treat whooping cough, cataracts, dropsy, and epilepsy, in addition to being considered an astringent, a tonic, a diuretic, a remedy for baldness, and a salve that could heal battle wounds. Today, you'll find this once-ubiquitous cure-all in homeopathic prescriptions for headachesand as a key ingredient in Tom's of Maine deodorant.
Q) If lightning strikes the water while I'm scuba diving, how far away do I need to be to avoid getting hit?
Chris Wojcik, Point Pleasant, New Jersey
A) SINCE SALT- AND MINERAL-RICH H2O IS a shockingly good conductor of electricity, it's wise to stay completely dry during an electrical storm. But if circumstances demand otherwise, you're better off scuba diving than, say, swimming, boating, or practicing your belly flop off the high dive. According to a law of physics commonly known as the skin effect, most of the electricity in lightning travels on the surface of an objectbe it a copper wire, a metal mast, or a bay off the coast of Belizeas opposed to within it. Some of the lightning's zap will penetrate the water, perhaps ten feet directly below the strike, but otherwise the charge spreads out along the surface, dissipating by various degrees (depending on things like salinity and pollution levels) as it radiates from the point of contact. Since it takes only a few amps to fry a human's circuits and a bolt of lightning is about 25,000 amps, snorkelers and swimmers need to be at least 1,500 feet away from the point of impact to have a decent shot at survival. Scuba divers, as long as they're not surfacing at the strike zone, will be spared entirely.
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