The First 'Shot': Meuse Valley Fog of Belgium in 1930

When people talk about air pollution disasters, the first incident comes to mind is usually the Great Smog in 1952 that happened in London and led to thousands of death. However, as early as 1930, Industrial air pollution has caused over 60 casualties in Meuse Valley in Belgium during 1st to 5th December. This was the very first scientific evidence that linked air pollution to cause of death and diseases.

fig.1 map of Meuse valley between Liege and Huy in 1930, indicating the fog-covered area and location of fatalities and factories

The incident happened in southeast Belgium, along the 20km of the narrow valley of Meuse river, where located 4 coke ovens, 3 steel mills, 4 glass factories, and 3 zinc smelters. From December 1 to 5, the weather was characterized by anticyclonic conditions with high atmospheric pressure and an easterly wind at 1-3 km/h from the city of Liege down to the valley. These conditions resulted as a persistent fog. Moreover, while the near-ground temperature in the fog was approximate 1-2°C, the higher temperature at around 70 to 80 meters above the ground, where the tallest chimneys in the valley located, formed an inversion and prevented the fog from rising. As a result, the pollutants and impurities accumulated along the valley from Liege to Huy and affected about 6000 residents.

According to Benoit Nemery et al, a professor at Faculty of Medicine, the average age of 48 of the victims listed in newspaper reports, the average age was around 62, ranging from 20 to 89 years. The major symptom was dyspnea (shortness of breath) and was possibly caused by pure carbon dust particles of 0.5 to 1.35 μm diameter floating in the air. The estimated sulfur dioxide concentration was 9.6 to 38.4 ppm, while the actual concentrations of air pollutants were not recorded in this area. There were some argued that fluorides were the one contributed to the mortality and morbidity, instead of sulfur dioxide.

Although there were warning about incidents like the one took place in Meuse Valley might happen again under similar conditions, people at that time were not fully aware of the impact of industrial pollution on human health yet. The loss in Meuse valley did not prevent same events happening in Donora in 1948 and in London in 1952. The global sulfur dioxide emission dropped temporarily in the 1930s, yet kept increasing until 1980 (fig.2).  

fig.2 Global sulfur emission from 1850 to 2000

Air Pollution: A Brief History

With air pollution gaining an increasingly important position on International agenda, surprisingly we would found that it is not newly introduced to our blue planet at all. Long before the industrial revolution, both humans and nature itself have been producing air pollutant.

Air pollution, by definition, is 'a presence of toxic chemicals or compounds in the air that lowers the quality of air and poses a health risk'. While the air pollutant is the substance causing the pollution. The source of air pollutant can be natural, such as volcanic activities, or man-made, for example, due to the burning of fossil fuels.

As early as 16th century, there was already documented record of poor air quality in cities like London. At that time, the air pollution was mainly caused by the usage of coal. During 18th and 19th centuries, the emerging industry increased the coal consumption, and combined with the domestic use of coal for heat, air pollution escalated dramatically in the urban area.  London has even once been called the 'city of fog', while the 'fog' is actually smog, which was a form of air pollution. Nowadays, sources of air pollutant become much more diverse compared with the Middle Age. However, the public and the states are more and more aware of the air pollution around us and are seeking for ways to act on the problem.

 In this blog, I am going to write about the major historical events about air pollution such as the Meuse Valley fog of Belgium in 1930 and London's Great smog in 1952, and effects of worldwide air pollution nowadays. Through the history and present-day examples, we would be able to see how the degraded air quality and the pollutants (such as SO2) influence our lives and our health. Moreover, I would write about those regulations about air pollution in the past, at present and hopefully in the future.