An aerial photo shows residents in Tianjin take nuclear acid tests late at night on Monday. (Photos: VCG)

Medical staff and volunteers help locals from Meihongyuan community in Tianjin take nuclear acid tests late at night on Monday.

Medical staff and volunteers in Tianjin help students and teachers from Tianjin University take nuclear acid tests late at night.

Medical staff and volunteers in Tianjin help students and teachers from Tianjin University take nuclear acid tests late at night.

Medical staff and volunteers in Tianjin help students and teachers from Tianjin University take nuclear acid tests late at night.