Driving, prolonged exposure to gasoline, vehicle exhaust and kitchen smoke, as well as an unhealthy diet, may all cause lung cancer, Chinese scientists have warned.

A group of researchers, headed by Prof. He Yumin, of the Shanghai University of Traditional Chinese Medicine, reached the conclusion after a five-year survey of 2,276 lung cancer patients.

Of 343 patients aged 50 or below, 98, or 28.6 percent, were full-time drivers, the research team found.

"The percentage is even higher among the younger group of patients," said He. "As 33.3 percent of those under 40 years old had been driving for ten years or more before they were diagnosed with lung cancer."

The professor warned lung cancer occurred equally in men and women, as the male-female ratio was almost 1:1 for patients aged under 50, counter to the traditional assumption that male sufferers normally outnumbered females.

Smoking remained the biggest cause of lung cancer in men, but not for women, He said.

"About 70 percent of the male lung cancer patients are smokers, but only 18 percent of the women suffered secondary smoking or were smokers themselves," he said.

Among the 82 percent non-smoking female patients, 60 percent reported long exposure to oily kitchen smoke, 32 percent liked to fry food in hot oil and 25 percent had bedrooms next to the kitchen, the research team found.

"The oily smoke impaired the cellular tissues in their respiratory system and subsequently caused cancer," said He.

While fried food has long been recognized as unhealthy, experts say eating fried food on the street -- the way many urbanites have breakfast in the morning rush hour -- triples the likelihood of developing lung cancer.

A lack of green vegetables in the diet, excessive exposure to certain chemicals and x-rays, and chronic respiratory diseases such as tuberculosis and bronchitis could also lead to lung cancer.

The best way to prevent lung cancer was to not smoke, to stay away from pollution and seek medical treatment for chronic diseases.

A balanced diet with plenty of fruit and vegetables and a low intake of fried and smoked food was also beneficial.

(Xinhua News Agency March 9, 2004)