Prof: Control environment to control allergies
It's the lull before the storm for people with allergies.
In Wisconsin, spring allergies are behind us, but ragweed blooms in August and is a major contributor to the fall hay fever season.
More than 50 million Americans suffer from allergies, and the numbers continue to grow despite advances in antihistamines and other drugs.
So why have we failed to reverse this trend?
"It's time to look at the underlying causes of asthma and hay fever instead of only treating the symptoms,'' says Gregg Mitman, a professor of medical history and history of science at the University of Wisconsin-Madison.
Following his own advice, Mitman wrote the book "Breathing Space: How Allergies Shape Our Lives and Landscapes." In it, he traces the impact allergic disease has had on American life, culture and landscape since the 19th century.
Understanding the ecology of allergies and the complexity of environmental interactions, he says, will help us tackle issues of land use and building construction -- along with structural inequities in housing and health care -- that affect illness in the modern world.
"When it comes to global warming, for example, we know that certain allergenic plants, including ragweed, are carbon-limited, so as carbon dioxide concentrations in the atmosphere increase -- as has been the case since the Industrial Revolution -- it's predicted that pollen production from ragweed also will increase dramatically," Mitman warns.
Similarly, it's predicted that global warming and rising temperatures will lead to changes in mosquito populations and the spread of malaria in places never before affected by the disease.
"In the case of the inner city, it's estimated that 25 percent of African-American children in Harlem have asthma," Mitman says. Contributing factors include increased air pollution, cockroach allergens and use of pesticides.
"In fact, because of cockroaches, there are actually more pesticides sprayed in Manhattan than all of New York state's agricultural counties," Mitman says.
Another piece of the puzzle is that inner-city kids often have inadequate access to medical care so they're unable to properly manage their asthma. Plus, ragweed flourishes in the disturbed soil of vacant lots in urban settings.
One of the arguments in Mitman's book is that we need to think about allergies and other diseases more ecologically in terms of how economics and physical and social factors affect illnesses.
This fall, the UW's Nelson Institute for Environmental Studies will open a new Center for Culture, History and Environment, and Mitman will be its first director. The center's big kickoff will be "Tales from Planet Earth,'' an international environmental film festival Nov. 2-4 on the UW campus.
"We're starting to see a lot of concern and interest in the relationships between environment and health, and it needs to continue," Mitman says.
Historically, allergies have significantly shaped the development of Western cities, such as Tucson, Ariz., and Denver.
"It's estimated that about 30 percent of Denver's original population went there to get relief from respiratory problems, particularly TB and asthma,'' Mitman says.
Unfortunately, cities that were once ecological havens for allergy sufferers became ecological nightmares by the 1970s because Easterners brought along Bermuda grass for their lawns, as well as ornamental trees, such as mulberry and olive trees that are highly allergenic, and much of the desert culture was lost.
"By the 1970s, pollen loads increased tenfold in Tucson, making the incidence of asthma twice the national average and the incidence of hay fever six to nine times greater," Mitman said.
Popular hay fever escape destinations traditionally included Mackinac Island as well as Petoskey, Mich., and along the northeastern shore of Lake Michigan.
"Ashland was another place in Wisconsin where people went to escape hay fever, and a lot of the tourist industry that developed in the late 19th century in those areas continues to this day, and it was all driven by the hay fever tourist trade," Mitman says.
Efforts to escape the hay fever season, in part, have been replaced with the development of better antihistamines and inhaled steroids, he adds, but we still can't ignore environmental factors that contribute to the rise in allergies.
"What's needed is an approach to medicine that integrates urban planning and public health," Mitman says.
In Tucson, for example, a city ordinance was established in the 1980s to ban the sale of pollen-producing mulberry and olive trees.
Another example that things are headed in that direction is a Harlem Children's Zone Initiative that takes a holistic approach to asthma by addressing issues of health, employment, environmental changes and access to medical care.
"We really need to start seeing the larger picture," Mitman says.
E-mail: dcarrelsing@madison.com
Mike DeVries
Allergies and hay fever are affected by our ever-changing environment, says Gregg Mitman, a professor of medical history and history of science at the University of Wisconsin-Madison.
