In one of the world's fastest growing industrial regions, a study finding that a class of pollutants exist at levels four times that of U.S. air quality standards has prompted a Hong Kong public policy group to call for government standards on fine particulate matter. The finding was released by Civic Exchange, a non-profit public policy think tank comprised of scientists as well as representatives from the power and oil industries, government and civic organizations.
The study measured levels of fine particulate matter and ozone, a major component of smog, across Hong Kong and its northern neighbor Guangdong Province. Fine particulate matter is made up of chemical particles less than 2.5 microns in diameter. The main sources of these particles are the burning of coal for energy, emissions from gasoline and diesel vehicles and the burning of other organic material such as vegetation and trash.
"By far the highest levels in the region were found in Guangdong where measurement sites showed levels of particulates as high as four times the U.S. National Ambient Air Quality Standard," said Michael Bergin, principal investigator for the fine particulate segment of the study and associate professor in the School of Earth and Atmospheric Sciences and the School of Civil and Environmental Engineering at the Georgia Institute of Technology. According to the U.S. Environmental Protection Agency (EPA), the class of pollutants has been proven to be harmful to human health and long-term exposure can lead to reduced lung function, chronic bronchitis and premature death.
"Sites in Hong Kong were roughly twice the U.S. standards," said Bergin. "Overall it appears to us that, with regard to particulate matter, Hong Kong air quality is being seriously impacted by Guangdong province in mainland China just to the north". By comparison, Atlanta, which has some of the highest concentrations of fine particulate matter of any city in the United States, slightly exceeds the EPA standard. China does not have air quality standards for fine particulate matter.
Much of the pollution can be tied to the Chinese export market, which manufactures goods such as electronics and clothing to the United States, Europe and other markets. "About 20 to 30 percent of the pollution in the region is due to manufacturing goods for export," said David Streets, a senior scientist at Argonne National Laboratory who has studied pollution controls in China. "This includes not only manufacturing facilities, but generating the electricity that goes into the factories and the trucks that transport goods to the ports. This contributes significantly to some of the high concentrations of pollutants to the region."
Reducing those pollutants wouldn't add much to the cost of export goods, said Streets. Upgrading motor vehicle emission standards and placing emission controls on power plants and industrial smokestacks among other measures could lower the amount of fine particles and ozone precursors in the region by about 20 to 30 percent. And it would add only three-tenths of a percent to the cost of each good. A $100 DVD player, for instance, would only cost 30 cents more after emissions standards were put in place.
Lead was one chemical particle that researchers found in extremely high concentrations in Guangdong. "The lead levels were much higher in Guangdong than what we find in the U.S.," said Bergin.
According to the U.S. Environmental Protection Agency, lead is very damaging to neurological development in children and can lead to behavior problems and learning disabilities.
"We're not sure where the lead is coming from," said Bergin. "We suspect that most of it is coming from burning leaded gasoline, but we can't rule out other sources related to the intense industrial activity going on in the region."
Another source of fine particulate matter is biomass from a variety of sources including crop residue and trash.
"Biomass burning seems to take place nearly anywhere and everywhere in China," said Bergin. "We really have to find out the timing and location of biomass burning in the region, in addition to what is being burned."
While the report found that particulate matter in Hong Kong is largely originating in Guangdong, that wasn't entirely the case with ozone levels. While much of the ozone found in Hong Kong is believed to have originated in mainland China, volatile organic compounds from industrial activities in Hong Kong were found to be contributing to ozone formation. Ground-level ozone is formed when volatile organic compounds react with nitrogen oxides in the presence of sunlight. Repeated exposure to ozone can lead to reduced lung capacity and permanent lung damage according to the EPA.
"Many in Hong Kong thought almost all the ozone in the area was coming from mainland China," said Bergin. "Our results suggest organic compounds that lead to ozone formation may have sources in and around Hong Kong. Hence solving the ozone problem in Hong Kong indicates a combination of local control strategies as well as collaboration with Guangdong.
In addition to recommending that both the governments of Hong Kong and Guangdong establish standards for fine particulate matter, the report called for more study to pinpoint the exact sources of the pollutants and their chemical precursors.
Contributing to the study, "Hong Kong and Pearl River Delta Pilot Air Monitoring Project", were scientists from Georgia Institute of Technology, Peking University, the University of Science and Technology and Polytechnic University in Hong Kong. The Hong Kong Environmental Protection Department (EPD) was also integral to the study, contributing resources, data and expertise.
The project was funded by the Hong Kong Jockey Club Charities Trust, Castle Peak Power, the Hong Kong Environmental Protection Department and Shell Hong Kong.