At long last, after millions of students in thousands of classrooms have freely and incautiously breathed trillions of breaths, there’s a report about the question: How much chalk dust enters the air when a teacher uses a blackboard?
The team weighed each piece of chalk before and after using it. They collected chalk dust from the air, and also the dust that fell on to a long sheet of paper laid over the base of the blackboard….
So begins this week’s Improbable Research column in The Guardian.
BONUS: Two unrelated videos, “Blackboard War” and “Blackboard War 2”: