That’s not the conclusion the study’s authors drew. The particles being airborne for longer means they can float further and contaminate things further away from the toilet, and also are more likely to end up inhaled. That could be a bigger problem than the number of particles initially released, so the study didn’t make a recommendation of whether the lid should be up or down. More research is required before anyone should be issuing definitive commands in bold to strangers on the internet.
Significantly – 30-50%.
So to be clear: close the lid
That’s not the conclusion the study’s authors drew. The particles being airborne for longer means they can float further and contaminate things further away from the toilet, and also are more likely to end up inhaled. That could be a bigger problem than the number of particles initially released, so the study didn’t make a recommendation of whether the lid should be up or down. More research is required before anyone should be issuing definitive commands in bold to strangers on the internet.