Prof Whitty told the summit the UK has “concentrated too little on air pollution for quite a while now”.
“What we need to do is get the information from people who can say where and when air pollution is going to be most high risk,” he said.
He called air pollution “a solvable problem”.
“Many of the things that drive pollution where people live and work and study are entirely amenable to us engineering out of the problem, for example on transport,” he said.
“Regulating out the problem” has been “very successfully over many decades,” he added, pointing to the Clean Air Act in 1956 cutting pollution.
Campaigner Rosamund Adoo-Kissi-Debrah, whose daughter Ella became the first person in the UK to have air pollution listed as a cause of death, also spoke at the summit.
An estimated 40,000 people a year die prematurely due to pollution, according to the Royal Colleges of Physicians and of Paediatrics and Child Health.
City Hall has committed to publishing updated air quality guides for local officials.
Sadiq Khan has called on health workers to play a greater role in informing patients of the risk of air pollution and how to protect themselves.