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 study, Assessment of Airborne Fine Particulate Matter and Particle Size Distribution in Settled Chalk Dust During Writing and Dusting Exercises in a Classroom, was done by Deepanjan Majumdar [pictured here], DG Gajghate, Pradeep Pipalatkar and CV Chalapati Rao of the National Environmental Engineering Research Institute in Nehru Marg, India.
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”: