Researchers are getting to the bottom of what exactly is behind the increase in air pollution. A new study revealed that burning garbage is throwing more toxic particles in the air than what governments are reporting.
Published Tuesday in the Environmental Science and Technology journal, researchers estimate that more than 40 percent of the world's garbage is burned.
"Doing this study made me realize how little information we really have about garbage burning and waste management," says lead researcher Christine Wiedinmyer of the government-funded National Center for Atmospheric Research, in Boulder, Colorado. "What's really interesting is all the toxins. We need to look further at that."
The study is the first comprehensive assessment of trash burning worldwide and includes data on carbon dioxide, carbon monoxide, mercury and other tiny matter that clogs the lungs or dims the rays of the sun. It features the first index of carbon dioxide emissions presented by country. The index also includes other toxic pollutants. But researchers state that the emission data is a "first draft" and estimates could be off anywhere from 20 to 50 percent.
"There is a lot of room for improvement in the index," says Wiedinmyer.
To calculate how much garbage is burned globally, the researchers analyzed population data, per capita production of garbage and official reports on garbage disposal. They concluded that 41 percent of the 2 billion-ton of global garbage is burned each year.
Burning garbage that includes plastics and electronics is the cause of most of air pollution. 29 percent of toxic, lung-affecting particles called PM 2.5 comes from burning garbage. Five percent of man-made carbon dioxide and 10 percent of mercury emissions comes from lighting trash on fire.
The study found that China, Brazil and Mexico burn the most at garbage dumps, but residents of China and India are both to blame for burning the most trash individually. It is illegal to burn garbage in India, but thousands of residents have no other choice. A lack of garbage pickup and cold winters are the cause behind burning whatever trash is left behind.
The study found that small developing countries in Asia and Africa could possibly be releasing more toxic emissions through burning than reported.
It is hard to estimate the amount of emission in developing countries, but the research raises attention to the significant role garbage plays in the global pollution crisis.