The Chiba Municipal Board of Education said a cigarette butt turned up in rice served for lunch Monday at a public elementary school in Inage Ward.
The butt was found by a sixth-grader at Chigusadai Higashi Elementary School who ate it. The boy suffered from red eyes and a nose bleed that night but has since recovered, board officials said Thursday.
A cigarette filter was also found in rice served in a classroom for fifth-graders, they said.
The rice was cooked by a company in Oamishirasato, Chiba Prefecture, the same day. The company delivers rice and bread to 28 schools in the prefecture.
A prefectural organization overseeing school lunches told the company to stop distributing food to schools from Friday and began investigating the incident.