I think it's related to this news about London:
Great Fog of 1952 in London
The Great Fog of 1952 in London was a period of environmental contamination, between December 5 and 9, 1952, which covered the city of London. The phenomenon was considered one of the worst environmental impacts until then, which was caused by the uncontrolled growth of the burning of fossil fuels in industry and transport. It is believed that the phenomenon caused the death of 12,000 Londoners, and left another 100,000 sick.
History
In December of 1952 a strong cold arrived in London and caused the population to burn much more coal than usual in winter. The increase in air pollution was aggravated by a greater thermal inversion, caused by the dense mass of cold air. The accumulation of pollutants was increasing, especially from smoke and particles of coal that was burned.
Due to the economic problems of the postwar period, the best quality coal had been exported. As a result, Londoners used low-quality, sulfur-rich coal, which greatly aggravated the problem.
The resulting fog, a mixture of natural fog with a lot of black smoke, became denser, making it impossible to traffic cars in the streets. Many cinemas closed and the concerts were canceled, as it reached the point where the audience could not see the stage or the screen, as the smoke easily invaded the closed environments.
Public health
Initially, there was no panic, because the mists in London are common and famous. Even so, in the following weeks the statistics collected by the medical services discovered that the fog had already killed 4,000 people.
The majority of the victims were very young children and people with previous respiratory problems. The deaths, in the majority of cases, occurred as a consequence of respiratory tract infections, causing hypoxia and also due to mechanical obstruction of the upper respiratory tract by secretions, a consequence of black smoke and the affections.
The lung infections were mainly bronchopneumonia or acute bronchitis.
A total of 12,000 people died in the following weeks and months.
The precise number of deaths that occurred during the Great Fog of 1952 (Great Fog or Great Smog) is very difficult to establish and has been controversial.
Environment
The large number of deaths gave an important boost to environmental movements and led to a reflection on air pollution, since the smoke had shown great lethal potential. Then new legal measures were taken, restricting the use of fossil fuels in the industry. In the following years, a series of legal regulations such as the Clean Air Act 1956 and the Clean Air Act 1968, restricted air pollution.
Carbon, in addition to sulfur, can contain potentially toxic heavy metals such as mercury, cadmium, nickel, arsenic, among others.
(From wiki)
FULL ARTICLE HERE.
es.wikipedia.org