December on the calendar signals most of us to pull out the winter clothes, shop, cook and clean for the upcoming holidays, and fit in those last-minute doctor visits to use up the money in our flexible spending accounts.
Amid all those activities, we may skimp on exercise time, spend more of that time indoors and find a cold, sore throat or other ailment settling in occasionally. One simple thing to do to keep ourselves healthy during this hectic time is to check the humidity in our homes and workplaces.
Not only do most homeowners and employers tend to keep indoor humidity low to prevent the growth of mold and bacteria, but winter indoor temperatures are often cranked up high, especially in high-ceilinged areas, and those higher temps lead to lower humidity, sometimes under 20 percent relative humidity (RH). What does that mean for you? Less comfort, more susceptibility to germs and disease.
In a room with low humidity, moisture from your skin will evaporate at a faster rate, causing you to feel cooler—the same thing that happens when we sweat in hot weather to cool down. If you'd like to feel warmer this winter and save money on heating bills, buy a humidifier or two."Cool mist" or ultrasonic humidifiers put an impressively large amount of moisture into the air in a fairly limited amount of time, and are energy efficient. Investing the $25-75 for a humidifier can result in savings on your heating bill by not cranking the furnace up for comfort. Place one in every bedroom (most are very quiet, but if you can't fall asleep with one running, run it during the day with the door closed to humdify the room, then turn it off when you go to bed).
A simple bowl of water near the vents which push warm air into a room will help humidify the air as well. Just make sure it's placed where it can't easily be knocked over; a wide windowsill or shoulder-height shelf works well. (At work, you may have to find an out-of-the-way spot underneath your desk). If you have an older home with radiators (common in many Baltimore neighborhoods), simply set the bowl on top of the radiator. You may need to use a tray, cutting board or platter for support on the radiator's ribs.
In addition to helping you feel warmer and saving you money on heating costs, keeping the humidity in your home at a higher level in the winter can also be beneficial to your health. Breathing dry air can lead to such ailments as bronchitis, sinusitis, asthma, nosebleeds, colds, flu and dehydration. Dry air can also cause dry skin and eye irritation.
Flu viruses survive longer and are more easily transmitted when humidity levels are low, such as in the peak flu months of January and February, Oregon State University researchers say. "Outbreaks of influenza typically occur in winter when low absolute humidity conditions strongly favor influenza survival and transmission," said study author Jeffrey Shaman, an atmospheric scientist at OSU who specializes in ties between climate and disease transmission.
Interestingly, in Baltimore, relative humidity (which varies with temperature), is relatively stable throughout the year, but varies dramatically between morning and afternoon. Humidity in the morning ranges from an average high of 85 percent in September to a low of 72 percent in February, March and April. But in the afternoon, that number drops to a high of 57 percent in December and January; it dips as low as 49 percent in April. The problem, of course, is that we tend to air condition our homes in summer to remove excess humidity and overheat in winter, drying the indoor air to levels well below the outdoors.
If you Google “ideal indoor humidity”, you’ll find most sources advise trying to keep it right about 45%. Below 30%, you get increased risk of dry skin, respiratory infections, static electricity, and ozone. Above 55% you have increased risk of condensation, fungus and mites. Bacteria and viruses allegedly become more prevalent both above and below this range, as do risks of allergies and asthma. Here’s a nice chart, based on this complex report from the Technical Resource Center of Finland:
So do yourself a favor: step outside more often and humidify your indoor air for better health.