Many people in China are accustomed to boiling
tap water before drinking it because they think this can make it clean,
but that may not be the case, according to an investigative report.
Beijing-based
Century Weekly reported this week that the quality of water from at
least 1,000 tap water providers in Chinese cities was below standard,
citing Song Lanhe, chief engineer of the Urban Water Quality Monitoring
Center under the Ministry of Housing and Urban-Rural Development.
Song's comment was based on a drinking water survey conducted by the center in 2009.
"Among
more than 4,000 water plants we surveyed, we found the water provided
by over 1,000 plants was disqualified," said Song, who added that the
quality of urban tap water had not improved much since the survey.
The
ministry has not yet released the survey results. The report said this
indicated that the underlying truth might be much worse.
"I am not authorized to tell you the exact figure (of tap water's qualification rate)," Song said.
The report went further, saying that the figure might be around 50 percent.
Online
comments on sina.com.cn yesterday criticized the country's inability to
provide safe water, with many people saying they were worried about
disqualified tap water that could lead to serious diseases due to high
CODmn and untreated remnants of heavy metals.
CODmn is an index used to gauge the amount of organic compounds in water.
One
comment claimed that tap water in parts of China could cause serious
diseases because of the chemical companies along the upper reaches of
major rivers.
Wang Zhansheng, a Tsinghua University professor,
said the accumulation of organic compounds in the human body could lead
to cancer and other diseases.
At the end of 2009, 98 percent of
the plants surveyed were still treating water using conventional methods
including coagulation, sedimentation, filtration and disinfection, but
experts argue these simple steps can not treat heavy metals and organic
compounds.
Boiling water can't get rid of heavy metals and may even
concentrate the pollution.
Song said outdated water pipes were
also likely to cause pollution. "Old pipes are easy to corrupt and
become encrusted with scale, which will produce microbial bacteria and
cause pollution," said Liu Wenjun, a researcher with Tsinghua.
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