Economic Observer Online 
By Liu Jinsong (刘金松)
Mar12, 2013
Translated by Chen Anqi
Original article:[Chinese]

During the “Two Sessions,” environmental issues have been a major topic of discussion.

NPC delegate and medical scientist Zhong Nanshan has drawn attention by warning of the hazards of air pollution. He says it can harm the human respiratory system, brain, cardiovascular system and will increase the risk of lung cancer. 

“If this continues, the chances of lung cancer will increase, so we need to predict the future situation and take action,” he said in an interview.

However, writer and “science-cop” Fang Zhouzi has challenged Zhong’s assertions. "A prominent medical scientist should always be cautious,” Fang said on his blog. “He cannot bring up a topic just because it attracts attention."

Fang has listed "three mistakes" Zhong made in saying air pollution causes cancer. Firstly, he says claims that lung cancer cases in Beijing have increased 2.42 percent over the past decade are misleading due to a non-scientific calculation method used by Zhong. 

Secondly, he challenged the actual role air pollution plays in causing cancer. “There’s still no conclusive evidence about the relationship between particulate matter and lung cancer,” Fang said. “Some studies suggest it matters and some suggest it’s irrelevant. But if it is relevant, it’s not a major cause." 

He says that smoking leads to 90 percent of lung cancer cases. Compared to direct or second-hand cigarette smoke, air pollution is negligible.

Finally, he argued that even if there is a relationship between air pollution and lung cancer, developing cancer is a very long-term process that takes many years. Therefore, data showing increasing rates over the past decade isn’t relevant.

Zhong Nanshan responded in an interview saying, “My data is based on facts and there are a huge number of references. The relevant data is from the Beijing Cancer Prevention & Control Research Office.” 

He went on to say, "Lung cancer and smoking are related, but regarding how much is caused by smoke and how much is caused by air pollution, there’s no reliable data."