Exhaust fumes from trains and taxis, coupled with toxic dust kicked up by construction works, are endangering the health of commuters, tourists and workers, experts say - particular people with asthma, lung or heart conditions.
Politicians have reacted with shock and horror to the revelations, and are demanding urgent action to protect the 25 million people who use the station annually. Network Rail, the company the runs Waverley, says it is doing what it can to cut the pollution.
Waverley, situated in a low, glass-roofed hollow in the centre of the capital, is one of the busiest stations in the UK outside London. It now seems it may also be one of the most polluted.
It is the only British mainline railway station that still allows vehicles to drive right inside it, including taxis, private cars and delivery trucks. And it is three-quarters of the way through a four-year, £100 million overhaul, which means almost continual cutting, drilling and pounding confining passengers under scaffolding and awnings.
To help assess the risks of air pollution, Network Rail commissioned consultants to monitor the station continually for three weeks in October and November. Their report was released to the Sunday Herald last week, after repeated requests.