This week the United Kingdom has experienced a toxic smog that has caused 1.6 million people to suffer an asthma attack. A survey by Asthma UK conducted yesterday found 30% of the country’s 5.4 million asthmatics had suffered an asthma attack as a direct result of the toxic cloud hanging over the U.K. Dr. Keith Prowse, honorary medical adviser to the British Lung Foundation, said symptoms brought on by the smog could last several days: “The people who are most vulnerable are people with chest diseases and heart disease, the very young and very old because their immune systems cannot cope as well.” Ambulance services saw a 14% spike in 999 calls and hospitals are braced for an 
increase in admissions. Mike McKevitt, head of patient services at the British Lung Foundation, said: “It would be surprising if we didn’t see an overall increase in the number of hospital admissions as a result of the pollution, certainly among people with respiratory condition such as asthma and chronic obstructive pulmonary disease.”
A combination of dust from the Sahara Desert, emissions from the European continent, low south-easterly winds, and domestic pollution has caused air quality to plummet across the UK and the smog-like conditions are not expected to clear until Friday night.
In addition to warnings aimed at asthmatics, public health officials urge others experiencing sore eyes, cough, or sore throat to reduce outdoor activity. Some schools in London have banned students from outdoor playgrounds to reduce their exposure to the fog. Frank Kelly, a professor of environmental health at King’s College London and a member of the Department of Health’s Committee on the Medical Effects of Air Pollution, said that doing so would help reduce long-term harm to children. Meanwhile, officials of the London Marathon reported that its doctors were monitoring the smog ahead of next weekend’s race.
All of which reminds me of London’s Great Smog of 1952, an event, along with the Donora, Pennsylvania smog a few years earlier, that is described in every environmental health text as leading to air pollution laws. The Met Office describes the Great Smog as “a fog so thick and polluted it left thousands dead [and] wreaked havoc on London in 1952. The smoke-like pollution was so toxic it was even reported to have choked cows to death in the fields. It was so thick it brought road, air and rail transport to a virtual standstill.” This smog resulted from an inversion, which occurs when air close to the ground is cooler than the air higher above it. When warm smoke emitted from home heating chimneys (it was a particularly cold and wet winter), as well as from (at that time, unregulated) factory chimneys, the particles and gases in it were trapped. And like this week’s toxic smog, winds from the east added industrial pollution from the continent in 1952. All told, 1,000 tons of smoke particles, 2,000 tons of carbon dioxide, 140 tons of hydrochloric acid, and 14 tons of fluorine compounds infused the Great Smog of 1952. In addition, 370 tons of sulphur dioxide were converted into 800 tons of sulphuric acid. As a result, when the fog cleared a few days later, some 4,000 people were dead, many more suffered breathing problems, and even cattle were claimed to have been asphyxiated by the smog.