Exposure to benzene and nitrobenzene from the toxic chemical spill into the Song Tùng Hoa River in China may lead to cancer and bone marrow diseases among residents. This is the warning from environmental experts.
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More than 3.5 million people in Harbin lack drinking water after the city stopped drawing water from the Song Tùng Hoa River for 4 days. |
On November 13, approximately 100 tons of toxic chemicals spilled into the Song Tùng Hoa River. The incident occurred following an explosion at a chemical plant owned by Jilin Petrochemical Company in Jilin City. The chemical spill forced cities located on both banks of the Song Tùng Hoa River to cease water intake. The 4 million residents of Harbin, a city 320 kilometers downstream from Jilin, have also taken similar measures. Water intake could potentially resume on November 26 if the pollution is washed away by the current.
According to Zhang Lijun, Deputy Director of the National Environmental Protection Bureau, one week after the incident, the nitrobenzene levels in the section of the river flowing through Harbin were 30 times higher than the national standard in China. Meanwhile, benzene levels were only 2.6 times higher. As the polluted water flows downstream, the concentration of pollutants is gradually decreasing, although some residue remains along the way. The pollution levels from this 80-kilometer chemical spill are expected to further decline in Harbin due to the confluence of several large tributaries with the Song Tùng Hoa River in the city.
On the afternoon of November 25, 13 days after the incident, the nitrobenzene concentration in the river water in Harbin was still 18 times higher than China’s standard. However, the benzene level had fallen below the regulatory limit. Alan Boobis, a toxicology expert at the Royal College of London, stated that benzene is a molecule that can persist in animal and plant tissues for some 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 may also cause a type of anemia that affects white blood cells. However, the risk of developing leukemia from benzene is very low, applicable only to those with several years of exposure. The risk of exposure to compounds like asbestos is significantly higher.
Nevertheless, nitrobenzene can be transformed into other toxic compounds. For example, bacteria can convert it into an aniline compound. The U.S. Environmental Protection Agency has classified aniline as highly toxic to humans and as a potential carcinogen.
