Largest Cell Phone StudyBy George Grow
This is the VOA Special English SCIENCE REPORT.
Scientists have completed the largest study yet on the safety of cellular telephones. The study involved more than four-hundred-twenty-thousand people in Denmark.
The researchers found that cell phone users are no more likely than other people to develop cancer. However, the study failed to end the debate over cell phone safety. Critics say it will be years before evidence of cancers linked to cell phone use is confirmed.
Cellular telephones may be the best-selling electronic devices in the world. Cell phones are small, wireless devices. They are held close to the user's head during normal use. Their widespread use has led to increased concerns about possible health risks.
The antennas on these phones produce low levels of radio wave radiation while in use. Most of the debate about the phones involves the amount of radiation they release. Scientists know that intense electromagnetic radiation can harm human tissue. But they are not sure if the radiation from cell phone antennas could cause serious damage.
The Danish Cancer Society and the International Epidemiology Institute near Washington, D-C organized the new study. Researchers identified Danes who began using cell phones between Nineteen-Eighty-Two and Nineteen-Ninety-Five.
The researchers compared this information with Danish health records. The researchers found that the cell phone users developed the expected numbers of cancers. They found no increased risk for cancers of the brain, nervous system, mouth or blood.
The Journal of the National Cancer Institute published a commentary with the study. Robert Park of the American Physical Society wrote that cell phones are dangerous - when people use them while driving cars. He said the large number of people in the study makes it difficult to question the findings that cell phones do not cause cancer. Recently, two smaller American studies also found no increased cancer risk.
Not everyone agrees, however. For example, researcher George Carlo has written books about cell phone safety. He says other studies suggest that cell phone use may damage genes. He warns that cancers of the brain develop over many years.
This VOA Special English SCIENCE REPORT was written by George Grow.