A third runway at Heathrow Airport would be 'very detrimental' to the health of west Londoners, the new head of the Environment Agency has claimed.
Lord Smith of Finsbury said the evidence was weighted against expansion and a new runway would fail EU air pollution limits.
"All the studies we've done in the Environment Agency of the likely impact of air quality on west London are very detrimental," he added.
"If the third runway goes ahead, if we get that extra both air and ground traffic that will arise out of that, then it is absolutely certain that nitrogen dioxide levels will go way beyond what they ought to be for the sake of human health."
But ministers have always insisted any expansion would have to meet strict local environment conditions.
A government decision on a third runway is due by the end of the year.
