Effects of China's Songhua River Chemical Spill Still Emerging

BEIJING, China, January 13, 2006 (ENS) - Two months after the Songhua River transboundary chemical spill, one of the largest in a river system anywhere in the world in recent years, more study is needed to determine its environmental and human health effects, a United Nations team has concluded. The team issued its report Thursday, after studying the effects of an explosion that occurred on November 13, 2005 at a petrochemical plant of the Jilin Petrochemical Corporation in China's northern Jilin Province.

The explosion resulted in spill of an estimated 100 metric tons of the toxic chemicals benzene, aniline and nitrobenzene into the Songhua River, with surface water concentrations exceeding the surface water levels permissible in China.

The four person team from the United Nations Environment Programme (UNEP) visited China from December 10 to 16, 2005 at the invitation of the Chinese State Environmental Protection Administration (SEPA) to help with assessment and mitigation of the spill.

The mission team was informed that at the central government level, the State Council - consisting of all Ministers - established a task force for handling the Songhua River Water Pollution Incident. The task force coordinates a number of working groups. SEPA heads the working group on monitoring and prevention.

On November 18, five days after the accident, the State Environmental Protection Administration issued emergency monitoring instructions to its provincial counterpart, Heilongjiang Environmental Protection Bureau. The instructions focused on the location and speed of the pollution plume, the concentrations of benzene and nitrobenzene in the river water, and the length of the pollutant plume.

"These three factors enabled authorities at different levels to take timely and appropriate mitigation measures," the UNEP team said. "Unfortunately, this effective effort of SEPA had not been communicated with the public sufficiently. Had this communication been adequately provided, the level of uncertainty and fear by public would have been lower."

In its recommendations, the UNEP team says environmental impacts on the site of the accident, including any potential sources of groundwater, surface water and soil contamination and air pollution should be identified and mitigation and decontamination measures implemented as a matter of urgency.

Overall the team said it was "impressed" by the Chinese commitment to regular and systematic pollution monitoring, the sharing of results and other information, and their cooperation with Russian experts and the UNEP team itself.


Marked off with warning tape, the polluted Songhua River is frozen over. (Photo courtesy UNEP)
The ratio of the substances spilled is not known at this time and investigations on the accident site are ongoing, the team said. The pollution entered the Songhua River and a plume of contamination started flowing downstream. The Songhua River joins the Heilongjiang River and forms a natural border with the Russian Federation. The river continues into the Russian Federation where it is called the Amur River and flows into the Sea of Okhotsk.

The pollution plume reached Harbin, a city of four million people, on November 25, 2005. The city's water supply obtained from the Songhua River was shut down from November 23 through 27 as a safety measure.

The peak concentration of nitrobenzene tested at 33 times the permissible level at Harbin, yet on the same day, the concentration of benzene was below the permissible level and aniline was not detected.

The plume of contamination stretched for 80 kilometers (50 miles) when passing through Harbin and it extended to 150 kilometers when it passed through Jiamusi on December 10, 2005.

The surface of the Songhua River is currently frozen, and some of the nitrobenzene is captured in the ice. Preliminary tests by the China Academy of Environmental Sciences indicate that the concentration of nitrobenzene in tested ice sample is one fourth of that in water.

The sampling of the river water proved to be a challenging task especially right after the accident, the UNEP team said. The regular monitoring of the water quality at Songhua river water is carried out monthly from April to October. During the winter months, the river quality is not monitored except for research proposes due to the difficulties in taking samples.

During the field mission, the temperatures in Jiamusi and Harbin ranged between -10 and -14 degrees Celsius during daytime, and between -21 and -23 degrees Celsius at night.

In November when the river was in the process of icing, no proper means and methodologies were available for taking samples and the monitoring experts had to develop temporary means for sampling, said the UNEP team.

No air monitoring on nitrobenzene and benzene was carried out as response to the spill. Nitrobenzene has a higher density relative to air and its vapor may settle. This has a potential to impact living organisms.

The UNEP mission team believes that further impact studies would be important to determine what additional support is required by the population directly and indirectly affected by the pollution incident.

As the substances involved are carcinogenic and have various vectors, epidemiological studies on acute, short, medium and long-term impacts on human health should be conducted. This should investigate all routes of human exposure including river water, ground water, drinking water, air and soil.

The team recommends that this should be done in close working collaboration with internationally recognized organizations, such as the World Health Organization.


Scientists from UNEP and SEPA take samples from the polluted Songhua River. (Photo courtesy UNEP)
The UNEP team suggests that air monitoring be undertaken to determine if any response is required. Since much of the river is covered by ice, this problem is limited during the winter but it has a potential to be of concern during the spring when the ice melts, the team said.

Aquatic toxicity studies of organisms found in the Songhua River should be undertaken using the range of chemicals that were introduced to the river through this accident, the UNEP team recommends. Long term studies on bioconcentration and bioaccumulation in aquatic organisms of the substances released by the accident is necessary in order to take appropriate measures to protect the population.

The report further recommends the consideration of a risk assessment of a random sample of Chinese chemical factories in order to strengthen safety related procedures, to minimize the risk of accidents and the improved handling of accidents if they do occur.

As a preparedness measure, aquatic toxicity research should be promoted for other chemicals that are produced in a large scale close to the Songhua River and along other rivers along where there are chemical production facilities. "The private sector involved with the production of such chemicals may be interested in supporting such work," the UNEP team suggests.

The cooperation and coordination between China and Russia over the incident has reached the highest level of both governments. Both China's President and the Prime Minister extended their apologies to the Russian government.

Chinese President Hu Jintao said, “We will take all necessary and effective measures and do our utmost to minimize the pollution and reduce the damage to the Russian side.”

The Russian government provided a list of chemicals to China and requested that they be monitored. SEPA experts undertook the tests and reported back to Russian side.

China and Russia agreed on a joint monitoring team, and joint sampling at the pollution plume position is carried out twice a day. On the basis of the Joint Emergency Response Monitoring Plan on Water Quality of the Songhua River signed between China and Russia, both countries will strengthen joint monitoring.

At Russia's request, Heilongjiang Province began the construction of a diversion dam on the Fuyuan waterway on December 16, closing the diversion dam five days later. The dam prevents the polluted water from flowing through the intakes of drinking water in Khabarovsk City and effectively reduced the pressure on the city to prevent and control the water pollution. The dam will also protect the Russian residents along the lower reaches of the Ussuri River from being affected by the pollution.

Endorsed by both UNEP and the Chinese government, the UNEP team's report notes that lessons learned from the incident should be incorporated into policy, legislation and enforcement. China and UNEP have agreed to share this report with Russian authorities.