This picture taken on July 23, 2015 shows a sales staff exhaling vapour while demonstrating an electronic cigarette product at the Beijing International Vapor Distribution Alliance Expo, or the Vape China Expo, at the China International Exhibition Center in Beijing. (Photo by AFP Photo)

Exhibitors of e-cigarette and vapor products exhale as they demonstrate using their products to lure customers and visitors at the “Vape China Expo” at an exhibition center in Beijing, China, 23 July 2015. While health benefits of e-cigarettes and vapor products are largely still undetermined and up for argument from many sectors, the market for these products are reportedly growing around the world. (Photo by Rolex Dela Pena/EPA)

A visitor uses an electronic cigarette at Beijing International Vapor Distribution Alliance Expo (VAPE CHINA EXPO) in Beijing, July 24, 2015. According to the organizer, the Expo, which is held in Beijing from July 23 to 25, attracts over 120 companies, including global high-end e-cigarette and e-liquid brands. China’s capital city unrolled ambitious new curbs on smoking in early June. Under the new rules, anyone in Beijing who violates the ban, which includes smoking in restaurants, hotels, schools and hospitals as well as in certain outdoor public places, must pay a 200 yuan ($32.25) fine. (Photo by Jason Lee/Reuters)

Staff members from an exhibitor perform with electronic cigarettes at Beijing International Vapor Distribution Alliance Expo (VAPE CHINA EXPO) in Beijing, July 24, 2015. (Photo by Jason Lee/Reuters)

Children lie in a canal to cool off from summer heat in Urumqi, Xinjiang Uighur Autonomous Region, China, July 22, 2015. The highest temperature in the city reached 40 degrees Celsius (104 degrees Fahrenheit) on Wednesday, local media reported. (Photo by Reuters/Stringer)

A cooling tower of a coal-burning power plant topples during a controlled demolition in Guiyang, Guizhou province, China, July 22, 2015. (Photo by Reuters/Stringer)

Bystanders look on as people dine at a table lifted by a crane to a height of 30 metres mid-air, near a residential construction site, in Kunming, Yunnan province, China, July 23, 2015. According to local media, having a meal at this lifted dining table can cost 8,888 yuan (1,431 USD) for one person. (Photo by Wong Campion/Reuters)

Players battle for the ball during their match at the swamp soccer China tournament in Beijing, China, July 23, 2015. (Photo by Reuters/China Daily)

Players from two opposing teams compete in the 'Swamp Soccer China' tournament at a sports complex in Beijing, China, July 26, 2015. A total of 32 teams is participating in this year's 'Swamp Soccer China' tournament, which is played for 24 minutes on a mud field with a six players per side. (Photo by Rolex Dela Pena/EPA)

Workers clear floating plants and garbage off the surface of the Yangtze River at a section in Chongqing municipality, China, July 22, 2015. (Photo by Reuters/China Daily)

A woman showers a kitten inside a house in Shanghai, China, July 22, 2015. Picture taken on July 22, 2015. (Photo by Aly Song/Reuters)

Men exercise in a park in Shanghai, China, July 23, 2015. (Photo by Aly Song/Reuters)

A nurse (R) leads cataract patients as they walk past a train which serves as a mobile hospital, in Ledu county, Qinghai province, China, July 23, 2015. The train, donated by people from Hong Kong and Macau, came to the county three months ago and has provided free medical treatment to over 900 local cataract patients, local media reported. (Photo by Simon Zo/Reuters)

A man rides a improvised bicycle, which can travel through water, at a flooded street after heavy rainfall hit Wuhan, Hubei province, China, July 23, 2015. Severe downpours hit the city on Thursday, flooding streets and shutting down public transportations, local media reported. (Photo by Reuters/China Daily)

A girl clings to her mother as they travel on a flooded street amid heavy rainfall in Shenzhen, Guangdong province, China, July 24, 2015. Approximately a million people have been affected by severe downpours in several Chinese provinces, causing collapsed houses, decimating crops as well as blocking highways, reported Xinhua News Agency. (Photo by Reuters/Stringer)

A man paddles a makeshift boat along a flooded street after heavy rainfall hit Wuhan, Hubei province, China, July 24, 2015. (Photo by Reuters/Stringer)

Ethnic Yao minority women brush their long hair near a creek, in Huangluo village of Guilin, Guangxi Zhuang Autonomous Region, China, July 23, 2015. The village, known for the long hair of its female residents, attracts about 80,000 tourists a year. More than 80 women in the village have hair longer than 1.4 metres, with the longest reaching 2.2 metres, according to local media. (Photo by Reuters/Stringer)

An ethnic Yao minority woman twines her long hair near a creek, in Huangluo village of Guilin, Guangxi Zhuang Autonomous Region, China, July 23, 2015. (Photo by Reuters/Stringer)

A resident rests on wreckage of houses in Xian village, a slum area in downtown Guangzhou, China July 24, 2015. (Photo by Tyrone Siu/Reuters)

People play with their phones on wreckage of houses in Xian village, a slum area in downtown Guangzhou, China July 24, 2015. (Photo by Tyrone Siu/Reuters)

People fish at an abandoned flat in Xian village, a slum area in downtown Guangzhou, China July 24, 2015. (Photo by Tyrone Siu/Reuters)

Residents rest on wreckage of houses in Xian village, a slum area in downtown Guangzhou, China July 24, 2015. (Photo by Tyrone Siu/Reuters)

A resident talks on mobile phone on wreckage of houses in Xian village, a slum area in downtown Guangzhou, China July 24, 2015. (Photo by Tyrone Siu/Reuters)

Farmers rush to transplant paddy on a flooded field amid heavy rainfall in Zhuzhou, Hunan province, China, July 24, 2015. Approximately a million people have been affected by severe downpours in several Chinese provinces, causing collapsed houses, decimating crops as well as blocking highways, Xinhua News Agency reported. (Photo by Reuters/China Daily)

People play cards as others watch in a cafe on Shengshan island, China July 25, 2015. (Photo by Damir Sagolj/Reuters)

In this Thursday, July 23, 2015 photo, vendors browse mobile phone as they wait for customers near variety of fashion clothes hanging for sale at the Mutianyu section of the Great Wall of China in Beijing. An index shows China's manufacturing slumped to a 15-month low in July, in a fresh sign of deterioration in the world's second biggest economy. (Photo by Andy Wong/AP Photo)

This picture taken on July 22, 2015 shows a man swimming amid algae at a beach in Qingdao, in eastern China's Shandong province. The algal phenomenon, an annual occurrence in Qingdao, is usually caused by an abundance of nutrients in the water, especially phosphorus, although the triggers for the enormous blooms which began to appear in the Yellow Sea in 2007 remain uncertain. (Photo by AFP Photo/Stringer)

This picture taken on July 22, 2015 shows a worker clearing out algae from the water along a beach in Qingdao, in eastern China's Shandong province. (Photo by AFP Photo/Stringer)

Visitors walk across a beach covered by seaweed in Qingdao in eastern China's Shandong province Friday, July 24, 2015. Beaches in Qingdao have been plagued by large recurring seaweed drifts from the Yellow Sea during recent summers. (Photo by Chinatopix/AP Photo)

Children laugh as they swim with floats at the seashore covered by algae, in Qingdao, Shandong province, China, July 24, 2015. (Photo by Reuters/Stringer)

Visitors take a photo on a beach covered by seaweed from the Yellow Sea in Qingdao in eastern China's Shandong province Friday, July 24, 2015. (Photo by Chinatopix/AP Photo)

This photo taken on July 26, 2015 shows a woman clad in her self-made mermaid costume swimming in a pool in China's southwest Chongqing municipality. (Photo by AFP Photo/Stringer)