China tries to measure how safe Tianjin’s air, earth and water are

More than a week after two massive explosions at a chemical warehouse tore into the northeastern Chinese port of Tianjin, officials are still trying to work out how safe is the city's air, its earth and its water.

The Tianjin Binhai New Area is still smouldering with combustible chemicals, the official Xinhua news agency reported. The death toll from the blasts stands at 116 and another 60 people are missing. About 700 were hospitalised. The focus now is on seeing how things develop at the site.

Some 40 different kinds of chemical were said to be in the warehouse. These included about 1,300 tons of oxide compounds, mainly potassium nitrate and ammonium nitrate; 500 tons of flammable materials, consisting of metallic sodium and magnesium; and 700 tonnes of highly toxic substances, mainly sodium cyanide, according to Xinhua.

Apparently only a fraction of the sodium cyanide has been accounted for. Locals wonder where the remainder is. Has it entered the water supply?

Cyanide compounds

Deng Xiaowen, head of the Tianjin Environment Monitoring Centre, was quoted by Xinhua as saying eight of 26 water monitoring stations in the core blast zone have detected concentrations of highly toxic cyanide compounds exceeding the national standard, with the highest being 356 times the standard.

Thousands of dead fish washed up on the banks of the Haihe River in the same Binhai district were the explosion took place, sparking concerns of mass contamination. Officials insist the fish did not show traces of cyanide, but a lack of oxygen was the problem.

Poor water quality

Mr Deng said it was not uncommon for fish to die en masse in local rivers during summer, due to poor water quality.

There were four new fires at the site yesterday, one of them at the area emergency workers call the “tomb of cars”, where thousands of cars lie burned to a crisp. The fire was probably caused by fuel in the tanks.

Nearly 4,500 troops are collecting the thousands of tons of dangerous chemicals and cleaning the area damaged by the blasts, said Liao Keduo, top military commander of the search and clean-up operation.