不是神經兮兮的，看這文章

https://medium.com/@Drug_Justice/is-the-colorful-powder-used-in-the-color-run-actually-safe-d043045834ca

Lung specialist Dr. Brian Christman currently serves on the American Lung Association’s Scientific Advisory Board. Last year, he told the NewsChannel5 reporters that breathing in even small amounts of cornstarch could pose a health hazard. After watching the Color Run, Dr. Christman said, “You’d be hard-pressed to find a lung doctor who would advocate that.” He also stated that respiratory exposure to hazardous particles can have long-term lung effects, especially on young children and babies.