China mulls using human-like fish to test for water quality

In its efforts to tackle water pollution the Chinese government may soon use a tiny tropical fish to test water quality. The zebra fish, which has a genetic code similar to humans, could well be the most “stringent” test for all possible water pollutants.

Due to its genetic peculiarities, the fish was for a long time used for drug testing. But now China is to be first country to use it for water pollution tests, the South China Morning Post reports. Professor Chen Feng, a biological researcher with the Chinese Academy of Sciences' South China Botanical Garden in Guangzhou, told the newspaper that she had been consulted by the Ministry of Environmental Protection, which has spent several years drafting a national standard water quality test using zebra fish.

"Today most technical issues have been solved. I think the standard will be launched soon," she said.

The tiny fish, originating from India’s River Ganges, has more than 90 percent of its genes identical to those of a human being.

The water quality test described by Chen involves 20 healthy zebra fish embryos being placed in various samples of water and examined with a microscope in a laboratory-controlled environment for between four and seven days. As the zebra fish embryos are extremely sensitive to any amount of pollutants, mutations or deaths will mean the water is unsafe for humans.

"The zebra fish test is the most stringent test ever. Even the death or mutation of a single embryo can rate an entire water source unsafe for drinking," Chen said.

"We can see directly and vividly the impact of polluted water on the embryos. Some may die, some experience mutations in critical organs such as brain, heart or blood lines. If the fish can die or get sick” the same may happen to us.

The current central government’s water quality test covers only 106 pollutants, and excludes many chemical and biological pollutants. Also some authorities carry out checks only for eight pollutants on a regular basis, the SCMP points out.

The rapid development of industry and mining has caused serious problems in air and water pollution in China. Many of these pollutants are unique to China and their impact on human health is still unknown.