Hong Kong CNN  —  A case in which more than 200 kindergarten students in northwestern China were found to have abnormal blood lead levels is revealing a deep distrust in local government, as members of the public question the findings of an official investigation. Authorities in the city of Tianshui in China’s Gansu province earlier this week said eight people, including the principal of the Heshi Peixin Kindergarten, had been detained after an investigation found 233 students had been exposed