I started working as a volunteer in Beijing in 2009 after I retired from my post as a designer for a furniture company in Beijing.

In 2011, I joined Beijing Green Woodpecker, a nonprofit organization that promotes environmental protection. I mostly worked in public squares near the Beijing West Railway Station, such as helping the traffic police and giving directions to passengers.

When Beijing adopted the new tobacco control regulations in June last year, I began a new assignment - persuading people not to smoke in public places.

In addition to the railway station, I have also been working at other places such as the Shichahai area, which is home to a large number of restaurants and bars. Usually we work in groups of three, checking public places such as hotels and subway stations and advising smokers to quit.

Nowadays, we find that most smokers are cooperative and put out their cigarettes if we ask them to, but in the early days, few people had heard of the regulation so they wouldn't listen to us.

We still encounter obstacles sometimes. I remember a man pushing me violently when I asked him not to smoke, saying it was none of my business. I almost fell to the ground.

I find that smokers congregate at internet cafes. In most cases, I talk to people in an indirect manner to avoid clashing with them.

I like being a tobacco-control volunteer because tobacco is harmful to health and people should not harm others with second-hand smoke. Last year, my brother, a smoker, died of a lung disease, and that has made me more determined. Another reason I continue to work as volunteer is that I walk a lot during each session, and that prevents me from sitting idle at home.

Voluntary work is exciting and it makes me feel young. It could even be classed as an addiction - once you start, it's difficult to stop.

Chen Yingyi spoke with Wang Xiaodong.