On Sunday, World Environment Day, Guangdong officials announced 21 prefecture-level cities would begin issuing regular air quality warnings and forecasts 2-3 days in advance. The statement came just in time for summer, when higher temperatures will increase ozone pollution throughout the province.
In October 2014, Guangzhou became the first city in Guangdong to issue regular air quality reports. Now, as of June 5, more than 20 cities are required to do the same and forecasts will be reported on local television networks, the web and via mobile apps, according to Guangzhou Daily.
Due to its steamy climate, South China’s major pollutant is ozone (produced in part by the sun), which primarily affects the cities of Shanwei, Zhanjiang, Dongguan, Chaozhou, Shantou and Huizhou.
In Guangzhou, the highest ozone concentrations are surprisingly not found in the city center but in surrounding suburbs, such as Panyu, Liwan, Huadu and Zengcheng, where ozone precursors (NOx and VOCs) settle after being carried downwind.
Between January and May of this year, the concentration of major pollutants, including PM2.5, has decreased in Guangdong, while ozone concentration has increased 3.4 percent to an average of 122 micrograms/cubic meter (0.122 ppm or 122 ppb).
Ozone arises when oxygen, nitrogen oxides (NOx) and volatile organic compounds (VOCs) combine to form a photochemical reaction under the sun. Though ozone does not affect air visibility, it can irritate the eyes, nose and throat, and can exacerbate symptoms of respiratory diseases, such as asthma.
Even ‘safe’ ozone levels can be hard on the lungs. The results of a 10-year study by the US Environmental Protection Agency show that exercisers’ lung function deteriorated after several hours of exposure to ozone levels of 70 ppb. By comparison, ozone concentration levels in Guangzhou and Shenzhen are regularly above 100 ppb.
According to a follow-up article published by Reuters:
The findings [of the EPA study] suggest that if healthy young adults exercise outside at ozone levels of 70 ppb for several hours – taking a long hike, for example – about half will suffer respiratory symptoms like coughing or pain during deep breathing.
This summer, take precaution when exercising outdoors and be sure to check your city’s ozone levels daily, because, well, now you can!
[Image via Best in World]