Risk of cancer from chemical plant explosion

Exposure to benzene and nitrobenzene from the toxic chemical spill into Songhua River in China can cause residents to suffer from cancer and bone marrow diseases. This is a warning from environmental experts.

More than 3.5 million people in Harbin have no running water when the city stops sucking water from the Songhua River for 4 days

On November 13, about 100 tons of toxic chemicals spilled onto the Songhua River. The incident occurred after an explosion at a chemical plant of Jilin Petrochemical Company, in Jilin City. The chemical spill has forced cities located on the banks of the Songhua River to stop taking water. 4 million people in Harbin, a city 320km from Jilin in the downstream, does the same. This activity can be resumed on November 26 if pollution is swept away by the flow.

According to Zhang Lijun, deputy director of the National Environmental Protection Agency, a week after the accident, the nitrobenzene level in the river section passing through Harbin is 30 times higher than China's national standard. Meanwhile benzene levels are only 2.6 times higher. When polluted water flows downstream, the concentration of pollutants in the water is decreasing and a little settles on the way. The level of pollution in this 80km chemical spill will definitely fall further in Harbin because of the many large branches joining Songhua in the city.

At noon on November 25, 13 days after the accident, the nitrobenzene content in river water in Harbin is still 18 times higher than the Chinese standard. However, benzene levels have fallen below the prescribed level. Alan Boobis, a toxin expert at the Royal College of London, said benzene is a molecule that can exist in plants and animals for a while. It is also very volatile and can evaporate into the atmosphere.

Epidemiological evidence suggests that long-term exposure to benzene can damage the bone marrow and cause leukemia. It can also cause anemia, affecting white blood cells. However, the risk of benzene leukemia is very low, only for those who have been exposed for many years. Exposure to compounds such as asbestos is much higher.

Even so, nitrobenzene can be turned into other toxic compounds. For example, bacteria can turn it into an aniline compound. The US Environmental Protection Agency has classified aniline as a very toxic substance in humans as well as a substance that can cause cancer in humans.

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Minh Son