BOSTON ( MainStreet) -- Here's a look at five U.S. cities that have big problems with congestion -- and we aren't talking about traffic. We're talking about the presence of mold, pollen and other things that make the communities below America's worst places for nasal congestion, according to a recent study by Sperling's Best Places and Breathe Right Nasal Strips. "Allergy sufferers should consider the findings of our study as a starting place in their search to find a place which may be more comfortable for them," researcher Bert Sperling says. "We wouldn't suggest anyone make a life-changing decision based solely on our research, but our findings do a great job of providing some insights so people can make their own best decisions." Sperling's analysis is nothing to sneeze at. He compiled his list by looking at such things as rates of smoking, influenza and use of prescription and over-the-counter allergy medicines. He also studied humidity, rainfall, wind speed and other climate conditions that can promote the growth of mold spores, ragweed and other allergens. Here's a look at the five cities at the top of his list, along with a rundown of each community's local economy and housing market. Home-price figures refer to properties listed on Realtor.com inside a given city or within approximately 20 miles of the community's borders.