Soil samples taken from an area near last week's explosions are placed on a table at a monitoring station to check for environmental pollution located within a 3-km (2-mile) exclusion zone from the explosion site in Binhai new district in Tianjin, China, August 18, 2015. The explosions late last Wednesday in Tianjin, the world's 10th-busiest port in China's industrial northeast, forced the evacuation of thousands of people after toxic chemicals were detected in the air. More than 700 people were injured and another 70, mostly fire fighters, are still missing. REUTERS/Kim Kyung-Hoon