The actual smoking rate among women is likely to be nearly triple the official count of 6.4 percent, due to women's underreporting, a health professor said in a report Monday.

The smoking rate was measured at 40.7 percent for men and 6.4 percent for women in 2016.

According to Jeong Geum-ji of Yonsei University's graduate school of public health, the difference between men and women in the incidence rate for lung cancer was narrower than the gap in the smoking rate. In 2015, for example, 17,015 men were newly diagnosed with lung cancer, a disease closely affiliated with smoking, compared with 7,252 women, a difference of 2.4 times, according to Jeong.

"If the smoking rate for men is 6.4 times higher than that for women, then it would be reasonable for the lung cancer incidence rate to also be 6.4 times higher. However, the difference stopped at 2.4 times," Jeong said in the report, submitted at a parliamentary forum Thursday.

On the assumption that there are no genetic conditions at play in the occurrence of lung cancer, given the incidence rate, the smoking rate for women is probably more like 17.3 percent, the report said.

The official smoking rate for women rose from 5.3 percent in 1999 to 6.4 percent in 2016. The number of lung cancer patients among women increased from 3,466 in 1999 to 7,252 in 2015, up 2.1 times.(Yonhap)