Blame it on the buses.
Emissions scientists from King's College London released a report this week showing that London's Oxford Street has the highest levels of nitrogen dioxide — a toxic pollutant — in the world, reports The Independent.
The street's average pollutant levels — produced by fumes from diesel-fueled buses and London's classic black cabs — have hovered at nearly three times the EU's safety limit since scientists installed a monitor at the beginning of 2014. Businesses in the bustling shopping district blame the excessive levels on a constant "wall of buses."
So maybe cross Oxford Street off your "tourist spots to see" list if you have a trip coming up (NO2 is linked to asthma and even heart attacks) — at least until the city figures out some greener public transit options.