FRIDAY, March 11 (HealthDay News) -- Brandon Smith started a radon inspection company of his own when the company for which he made heat-resistant wire closed down after 100 years in business.

Smith and his wife, who live in Battle Creek, Mich., opened their mom-and-pop business, Michigan Radon Agency, in 2005 and now test about 15 houses a week for radon.

"It's not an easy business to get into," Smith said. "You have to get trained, certified and licensed, and have all your business connections in place." And that includes real estate agents. "They're the ones recommending you, so you've got to know a lot of them," he said.

For his testing, which Smith said ranges from $75 to $150, electronic monitors are placed around a house and left for two weeks. He also takes an instant hour-by-hour readout for the homeowners. "It's always done in the basement, if it's livable," he said.

The tests are so accurate that there's usually little need to run a second test to confirm the findings, Smith said. "Sometimes I'll offer to retest if it's close to the threshold…but that's usually it," he said.

Clients usually are surprised if their home has a high radon level and come at him with dozens of questions, Smith said. In part that's because radon is a mystery to much of the general public, he said, "but the awareness is growing."

Smith said he offers reassurance that while a radon problem does need to be mitigated, it's not an immediate danger.

"One thing about radon, it's a long-term exposure," he said. "However, that means different things to different people."

Few people shrug off a high radon level, he said: "Pretty much everybody mitigates these days." And if a problem is discovered during an inspection that's part of a real estate transaction, "it's negotiable, like everything," Smith said. "The buyers try to get the homeowners to put in a system."

High radon levels are found in "quite a few" homes, Smith said. "The big reason is the U.S. has some pretty high standards, so there are going to be a lot of homes that don't meet the standards," he said. "The whole point is to make sure everyone's got low levels."

The most pervasive myth about radon that Smith said he has to knock down is that homes without basements and homes with basements that have doors leading outside are not susceptible to high radon levels.

"If a house doesn't have a basement, it still has the same vacuum tendencies to draw in and collect radon," he said. "Anything attached to the ground has the potential, even if it's on a slab. Just because there's no basement doesn't change anything."

More information

A companion article on radon offers more on its health risks.