A study by the US-based Johns Hopkins Bloomberg School of Public Health has found people with asthma who live near bigger or larger numbers of active unconventional natural gas wells operated by the fracking industry in Pennsylvania are 1.5 to four times likelier to have asthma attacks than those who live farther away.
The statistics, released by mayor of London Sadiq Khan, also shows that 86 secondary schools were above legal levels, exposing young people to dangerous levels of air pollution.