The National Institutes of Health today released the results of a report that revealed 90 percent of U.S. homes have three or more detectable allergens from pets, pests and rodents.

The researchers studied eight kinds of common allergens — cat, dog, cockroach, mouse, rat, mold and two types of dust mites — in the bedrooms of 7,000 homes and found that indoor allergens were most common in mobile homes, older and rental homes, rural homes and households with dogs and cats.

The study also revealed which allergens were most prevalent in various regions around the country.

Overall, dust mites were most common in the South and Northeast, and pet allergens seemed to be most common in the West and Midwest regions. Lastly, cat and dust mite allergens were more common in rural homes than in urban homes.

The impact of these allergens varies from person to person, but physician Darryl Zeldin and lead author Paivi Salo, Ph.D., noted that prolonged exposure can cause sensitization, which makes a person’s immune system overreactive to allergens.

Beyond exacerbating asthma and allergy symptoms for homeowners, pets, pests and the allergens they spread can impact a buyer’s decision to purchase a home.

In a 2015 interview, Chicago-based broker, David Scott of Re/Max Valley Realtors told Inman he estimates that for every dollar needed to repair pet damage, a buyer will reduce their offer by 2 to 3 dollars.

“Buyers occasionally are sensitive enough that they ask not to see homes where certain pets, typically cats or dogs, are residents,” Scott added.

Fortunately, there are steps homeowners can take to reduce the number of allergens in a home for themselves and future buyers.

  • Vacuum carpets and upholstered furniture weekly.
  • Thoroughly wash sheets and blankets in hot water each week.
  • Use allergen-impermeable covers to encase mattresses, pillows and box springs.
  • Lower humidity levels inside to below 50 percent.
  • Remove pets or limit their access to bedrooms.
  • Eliminate nesting places for pests, and remove their food and water sources; seal entry points.

These results come from “the nation’s largest indoor allergen study to date,” according to the press release. It was initially published on Nov. 30 in the Journal of Allergy and Clinical Immunology.

Read the full study here.

Email Marian McPherson.

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