Rural residents are less sensitive to allergens than those of metropolitan areas, study finds

Ragweed is a common allergen.

Rural residents are less sensitive to allergens than people in metropolitan areas, according to a study by the National Institute of Environmental Health Sciences. The study found that in metro areas, "50 percent of the population was sensitized to at least one allergen, but only 40 percent in rural areas," Nicholas Bakalar reports for The New York Times. "Outdoor allergens like grass and ragweed affected 37.8 percent of the urban population, but less than a quarter of people in non-metropolitan areas, possibly because respiratory allergies are associated with air pollution."

"Researchers gave blood tests to 8,124 people, 856 of them children under 6, to detect immunoglobulin E antibodies, or IgEs," Bakalar writes. "The presence of an IgE antibody that reacts to a specific substance increases the risk of having an allergy-related illness ike allergic asthma, hay fever or rash." (Read more)