Jump to main content or area navigation.

Contact Us

Extramural Research

Transcript: Children and Asthma -- Children in Rural Communities: Iowa Children's Center

TIME: 5:00

DR. JOEL KLINE:  Here at the University of Iowa, we have the Childhood Asthma Center, and one of the important studies that I’m involved in is looking at some of the reasons why we think children today are getting more asthma than they were a decade ago or 25 years ago.
And we’re seeing a 50 percent increase over 25 years, which is really not possible from a genetic explanation, so it’s probably an environmental cause for the increased amount of asthma.

DR. GARY HUNNINGHAKE:  Our studies are indicating that as many as a fifth, maybe even as high as a fourth, of the children in the rural communities in Iowa may have asthma, and in over half of the cases, we are estimating that asthma is in the moderate to severe category. The primary problem is exposure to grain dust and endotoxin that contaminates a lot of grain and get into the air.
So, if you travel in the rural communities, you don’t see smog like you see in Los Angeles, but you can see clouds of dust in the air, and these can be very irritating to the air tubes of the lung for the children with asthma.

DR. JAMES MERCHANT:  Kiacut County is a small southeastern Iowa county, typically rural, typically agricultural, and we have been studying this county for about six years.
The first round of 1000 families revealed something surprising to us, which was a rather high rate of childhood asthma.
We’re also looking at what exposures the kids have on the farm. There are a number of organo-phosphate pesticides that have been identified as causes of asthma.
A rite of passage in Iowa and every other rural community in America is that, uh, children begin to work at a very young age, so they’re out there in the barn, around animals, getting exposed to farm chemicals, ammonia, hydrogen sulfide that arises from animal manure. In Iowa, there’s a lot of livestock raised in confinement, so-called concentrated animal feeding operations, or "CAFOs."
We have the organic dusts themselves, which is common to agriculture. The animals are fed grain, primarily corn and soybeans.
And then the detergents that are used to clean these units cause asthma. Then there’s the whole area of endotoxins that live in the guts of the animals and they get aerosolized in these livestock facilities.

KLINE:  Endotoxin is the product of certain kinds of bacteria, and it’s extremely hardy; it stays around for years or decades. It’s difficult to get rid of even in the laboratory situation and we’ve done studies here showing that endotoxin inhalation can cause bronchospasm, or narrowing of the airways, after you inhale it, even in nonasthmatic, normal individuals.

MERCHANT:  Endotoxin is tracked into the homes by farmers. They typically wear their work clothes and their work boots into the homes.

DR. ELIZABETH CHRISCHILLES:  About 30 percent of the families in the parent study live on farms. We are really focusing our efforts to improve the child’s indoor environment, realizing that a lot of exposures out on the farm out in the community get tracked into the home.

WOMAN #1:  We take our shoes off when we walk in the house so it doesn’t track dirt through the carpets to keep the dust down.

CHRISCHILLES:  We meet with the family in their home; we walk around with a checklist identifying particular issues that might be, uh, a problem for a child with asthma.

RESEARCHER:  Hi. Let’s see where the heavy traffic area is and where I can get my sweeper in.
(TITLE:  kqed.org/baywindow – Tips for cleaning your home)

RESEARCHER: I’ll be doing the main sample area right here, one square meter.
What’s in here is could be anything that’s on their feet -- lint from the carpet, tracked in dirt -- whatever they bring in from the outside is on the floor in here. So we’ll go down here and check out the furnace.

CHRISCHILLES:  We have several families who have wood-burning furnaces. Now, smoke is a direct irritant to any child with asthma.
©  Light-Saraf Films 2002

Centers Funded By:
Centers Funded by Epa and NIEHS

Top of page

Jump to main content.