An anonymous reader writes: 32.9 percent of the 2,103 underground wells tested in China received grade 4 for water quality -- meaning they're only fit for industrial use and are not safe for drinking water. Another 47.3 percent received a grade 5 for water quality. "These latest statistics are an indicator of how bad the underground water quality is. The sources of pollution are widespread and include a lot of agricultures. I think that would be the main source of pollution," Dabo Guan, professor at the University of East Anglia in Britain, told the New York Times. "From my point of view, this shows how water is the biggest environmental issue in China. People in the cities, they see air pollution every day, so it creates huge pressure from the public. But in the cities, people don't see how bad the water pollution is," said Guan. According to statistics from the country's Ministry of Water Resources, 70 percent of lakes used as a water source, 60 percent of underground water, and 11 percent of water in reservoirs did not meet the country's safety standards. Even though the study measured water sources close to the surface, the results are shocking and depict the adverse effects air pollution has in China currently and in years to come.