Exposure to polluted air on the day of the exams lowers students’ marks, says new research.

The study of 2,400 central London university students sitting 10,000 papers found high pollution levels equals a drop in scores.

When pollution levels breached World Health organization limits (PM10 – 50 micrograms per cubic metre), students scored 2% less then those in halls in cleaner areas.

Sefi Roth, from the London School of Economics, carried out the research, and said you should limit your outdoor activity on polluted days and even take less polluted routes to the exam venue.