Tianjin deputy mayor He Shushan gave an update on the latest developments on the chemical blast in the city during a news conference on Monday morning.
Currently, a total of 698 people remain in hospital, of which 57 are still in a critical condition.
He Shushan says they have found hydrogen cyanide in a perimeter of one kilometer and therefore they have widened the safety limit area to around 2 and 3 kilometers.
"In this way, the periphery of that is safe. The core area will be problematic if it rains, because of disintegration (of chemicals), but if it does not affect the core area, it should be dispersed quite quickly after coming in touch with water. In this area there is no water now, only one crater left by the explosion. In the crater there is a bit of water. We are currently taking samples, and will process them accordingly."
He also says about 700 tonnes of sodium cyanide were stored at the blast site and they remain intact.
"We can make an approximate calculation of the cyanide currently in this area, and it is about 700 tons. Most of it, after our search, is still in the core area, within the 0.1 square kilometers."
Bao Jingling, chief engineer of the city's bureau of environmental protection, gave an update of the air quality at 17 air monitoring locations around the blast site from August 13 to 14.
"Among the 17 air monitoring locations, four are detected to have excessive volatile organic compounds, 1.2 to 1.62 times higher than the local standard for air condition around factories."
Gao Huaiyou, deputy director of Tianjin's work safety watchdog, says the authorities have mobilized many public and private sources to help prevent the spread of toxic chemicals.
"First we have organized sodium cyanide producers to handle the storage at the disaster site as they are more familiar with the chemical's nature. Secondly, we organized technicians from local chemical engineering companies to help relieve the toxicity. Thirdly, chemical defense corps has arrived to detect the location of sodium cyanide. And we also asked the related departments to build cofferdam at rain and discharge outlets to prevent the outflow of contaminated water."
Hebei Chengxin Co., Ltd., producer of the large amount of sodium cyanide stored at the blast site, has sent over 140 engineers to the site to help dispose of the chemical together with several peer companies.
Zhi Qunshen is the general manager of the firm.
"Most of the storage has been located and checked and will be transported back to our firm after proper treatment. Since it is alkaline, we are using hydrogen peroxide, a strong oxidizer, to oxidize and eliminate the poisonous elements."
Tianjin deputy mayor He Shushan promises the sodium cyanide at the periphery of the Tianjin blast area will mostly be collected and cleared by Monday evening.
For CRI, I'm Qian Shanming.