The smog pollution that hit China's capital in Beijing, so massive that it even crossed borders over to Japan, has been found to contain cancer causing photochemicals.

Experts from the Chinese Academy of Sciences (CAS), without citing statistical data, claimed they found toxic chemicals in the pollution that hit the capital, over Tianjin as well as its surrounding areas.

"Nitrogen compounds that appear in smog are usually nitrogen dioxide. This and sulfur dioxide usually come from car emissions. If the weather is bad and humidity is high, these will turn into larger particles, and is can cause cancer if inhaled," according to Li Xinshu, professor of Pharmaceutical Sciences in Sun Yat-sen University.

CAS said the chemicals were the same elements or major components that killed more than 800 people in the Los Angeles photochemical smog in the 1950s and the Great Smog in London.

"Nitrogen compounds, when reaching a higher density, could cause acute respiratory symptoms such as coughing and shortness of breath. It's a stressor for asthma. And our clinical records show an appreciable increase in respiratory patients last month," Prof. Pan Xiaochuan of School Of Public Health, Peking University, said.

The severity of the China smog pollution was so much that it gripped the country for about 17 days. Although the Chinese government has been running all around to combat the menace, it could only control the effects of the toxic air within the home front. Suffice to say, smog travels with the movement of the wind. As what has happened to Japan.

The Chinese pollution can even reach the U.S. on the Pacific jet stream, according to research made by experts located in as far away as Oregon in the United States. The Pacific jet stream a large, high-altitude current of air that connects the circles the world from east to west.