Poor air may be the cause of skin problems, according to a new study. [Photo provided to China Daily]

Zhou Yuan has had sensitive skin all her life, she says. But living in Hangzhou, capital of eastern China's Zhejiang province, has made it worse.

She suffers from scruffy, itchy and reddish skin, because of the smog in her city.

"When the air gets really bad, I try not to cycle or go out as often as I do on better days," the 30-year-old real estate consultant says.

The situation only gets better when she visits the United Kingdom or Japan, where the air is cleaner than in many Chinese cities and not as humid as Hangzhou.

Air pollution is not just a health concern in the country－it is fast becoming a beauty issue.

While the effects of air pollution on general health have been widely studied and discussed, its impact on skin remains less explored.

Poor air has become the No 1"beauty enemy" for women in China today, according to a L'Oreal study.

The company's China office released its findings during an Air Pollution and Skin Protection seminar in Shanghai on Monday.

Based on more than a decade of research in China and Mexico, the report blames air pollution for causing oiliness, dryness and oversensitivity－situations that may accelerate the aging of skin.

In addition, it says, harm caused by exposure to UV rays is heightened by bad air.

A group of 80 people living in downtown Shanghai and another group in nearby Chongming Island participated in the study.

The residents of downtown Shanghai were found to be low on sebum, a natural substance that protects the skin from aging, but high on lactic acid, which makes skin oily.

Similar results were found in a study done by L'Oreal in Mexico.