Pan Shiyi, chairman of Soho China, uses a PM2.5 density monitor a Shanghai subway on Jan 9, 2014. Pan arrived in Shanghai on Thursday, and took a 15-minute ride on Subway Line 2 from Hongqiao Airport to Jing'ansi station. He said his tests showed the PM2.5 concentrations in the subway cabins is 50 micrograms per cubic meter on average, and that in subway platforms is around 80 micrograms per cubic meter. Guo Xiang, a member of the political consultative conference in Shanghai, at the invitation of Pan, visited the real estate tycoon's Beijing office on Wednesday to test an indoor PM2.5 filtration device designed by Pan's company, just weeks before Shanghai's political consultative conference, a sign of Pan's ambition to tap into the Shanghai market if the conference suggests benchmarks for indoor air quality.