"We want to be sure that people understand what risk factors are real and what are not real," Stein said.

The report appears in the September 1 issue of Cancer.

In the study, Stein's team asked 957 adults whether or not they agreed with 12 common cancer myths.

About two-thirds (67.7 percent) said the risk of dying from cancer was increasing -- even though statistics show that the five-year cancer survival rate has been steadily improving for the last 30 years.

Almost 39 percent agreed with the myth that living in a polluted city puts a person at a higher risk of developing lung cancer than smoking a pack of cigarettes a day would.

"If people believe that the risk of cancer is higher from pollution than from smoking they may be more likely to engage in risky behavior," Stein said.

Many people also believed that low-tar cigarettes are less likely to cause lung cancer than regular cigarettes, Stein noted.

"Really, there is no evidence for that," he said.

In addition, almost 30 percent of the respondents thought electronic devices, such a cell phones, can cause cancer (studies have shown there is no effect).

Among other myths explored: Close to 15 percent thought products such as shampoo, deodorant and antiperspirants can cause cancer. And 6.2 percent believed underwire bras could trigger breast cancer.

Stein's team found that education and money was directly related to the belief in such myths.

"Related to these misconceptions were people who were underserved in terms of socioeconomic status and education," he said. "People who don't have the opportunities to hear public health messages are more likely to hold these beliefs," he added.

"We need to do a better job of providing reliable accurate health information to these groups," Stein said. He also believes that misconceptions about other medical conditions are likely to be seen among the same groups.

Some people may hold these misconceptions to justify their own behavior, Stein said, noting also that studies show people who engage in risky behaviors like smoking tend to underestimate the risks.

One expert said that better education can help dispel the myths.

"The public understanding of cancer risk suffers from important gaps and misconceptions," said Dr. David Katz, director of the Prevention Research Center at Yale University School of Medicine.

"In some cases, cancer risk is exaggerated; American women believe breast cancer is the leading cause of death among them, but heart disease kills fully 10 times as many women," Katz said.

He added, "Some potential risk factors, such as pesticide residues on foods, are exaggerated, while others, such as cigarette smoking or excessive sun exposure, don't get the full respect they deserve."

This study confirms that the misconceptions are greatest in socioeconomically challenged populations, Katz said. "The population at greatest risk of cancer seems to know the least about the disease, and how to prevent it," he said.

"Among the important disparities in our country is access to reliable, understandable health information," Katz added. "To empower people to protect themselves from cancer, we must arm them with accurate information."

More information

For more information on cancer, visit the American Cancer Society.