Robert Reid trudges around a grimy and polluted Salford in 1955 to remind us just how much of a profound effect on the nation's health the NHS had. The disastrous effects of smog on the nation's lungs continued to be a major healthcare issue until the arrival of the Clean Air Act of 1956. This legislation followed the severe London smog of 1952, during which 4,000 people died. The Act allowed local authorities to create smokeless zones, with householders encouraged to burn smokeless fuels.