SALT LAKE CITY (AP) - Neighbors of two plants that made products containing asbestos were about 50 percent more likely to get lung cancer than residents living elsewhere in the state, a new study indicated.

Using data from the U.S. census and the Utah Cancer Registry, a Utah Department of Health study identified about 70,000 people who lived in the 2-mile radius around both vermiculite processing plants and traced their cancer incidence over 28 years.

The number of cases of respiratory cancer in the area was significantly higher than other areas of the state, but cases of the specific cancer directly linked to asbestos - mesothelioma - were significantly lower, said Wayne Ball, lead epidemiologist with the state Department of Health.

The plants on the city's southwest side closed in the 1980s. One facility made a popular insulation and the other a soil additive.

Data for the people most at risk - the workers at the plants - was not available.

"All we were able to do was just a population study and basically draw a circle around these sites," Ball said Friday.

Other factors, like smoking, could have also caused the cancers, Ball said.

State, local and federal health officials are trying to find former employees of the plants, to make sure they are aware of the health risks and learn more about the safety and working conditions at the plants.

There is no public health hazard at either site, which were both part of Superfund cleanups, according to the study.

Residents in the 2-mile radius of the plants had 1,057 cases of respiratory cancer during the years of the study. The number of cases in the state outside the area over the same time frame was about 715, the study said.