Exposure to benzene and nitrobenzene from the toxic chemical spill into the Songhua River in China could lead to cancer and bone marrow diseases among residents. This is the warning from environmental experts.
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Over 3.5 million people in Harbin are without drinking water as the city has stopped drawing water from the Songhua River for 4 days |
On November 13, approximately 100 tons of toxic chemicals were spilled into the Songhua River. The incident occurred following an explosion at a chemical plant of Jilin Petrochemical Company in Jilin City. The chemical spill forced cities along the banks of the Songhua River to halt their water intake. The 4 million residents of Harbin, located 320 km downstream from Jilin, are also taking similar measures. Water intake may resume on November 26 if the pollution is flushed away by the current.
According to Zhang Lijun, Deputy Director of the National Environmental Protection Bureau, one week after the accident, nitrobenzene levels in the section of the river flowing through Harbin were 30 times higher than China’s national standards. Meanwhile, benzene levels were only 2.6 times above the limit. As the contaminated water flows downstream, the levels of pollutants are gradually decreasing, with some settling along the way. The extent of pollution from this 80 km chemical spill will certainly decrease further in Harbin due to the convergence of many large tributaries with the Songhua River in the city.
On the afternoon of November 25, 13 days after the incident, nitrobenzene levels in the river water in Harbin were still 18 times higher than China’s standards. However, benzene levels had dropped below the regulated limit. Alan Boobis, a toxicology expert at Royal London University, stated that benzene is a molecule that can persist in animal and plant bodies for a time. It is also highly volatile and can evaporate into the atmosphere.
Epidemiological evidence suggests that long-term exposure to benzene can damage bone marrow and lead to leukemia. It can also cause a form of anemia, affecting white blood cells. However, the risk of developing leukemia from benzene exposure is very low, particularly for those exposed over many years. Exposure to compounds like asbestos carries a much higher risk.
Nonetheless, nitrobenzene can be transformed into other toxic compounds. For example, bacteria can convert it into aniline, which the Environmental Protection Agency has classified as highly toxic to humans and a potential carcinogen.
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Minh Sơn
