After days of urgent pollution alerts and under pressure from environmental groups, French authorities took definite steps on this day two years ago to help reduce the emission of toxic fumes by imposing obligatory emergency regulations:

  • cars with even number plates had to alternate daily with those having uneven number plates in staying put, the exception being electric or hybrid cars, or those carrying more than three passengers;
  • public transport was free of charge (implying a loss of ca. € 4 million per day);
  • a speed limit of 20 km was compulsory for all vehicles;
  • people were to stay indoors, if possible.

The “City of Light” had become a “City of Haze”, and this not for the first time. In 1997 and 2007 Paris and surrounding regions had been engulfed by similarly polluting smog. Meteorological conditions such as the lack of wind and rain, and a layer of cold air held at ground level by a layer of stagnant warmer air above trap the pollutants from vehicle and industrial emissions in the air. During the day, sunlight creates further toxic substances by acting on the exhaust gases in the air, thus producing what is called photochemical smog. The capital’s geographic position in the basin of the Seine is a further factor favouring smog formation.

In March 2014 maximum pollution alerts were sounded not only for the capital region, but also for 30 other departments in France, and included the cities of Caen, Grenoble, Reims and Rouen, all of which followed the example set by the capital in dealing with the crisis.

Smog – a combination of ‘smoke’ and ‘fog’ – had been coined at the turn of the 19th to the 20th century as an alternative expression for what Londoners knew as the ‘pea soupers’. These were frequent spells of dense fog in London as a result of certain weather conditions combined with emissions from coal-heated houses and coal fires used in industrial production.

Source: Encyclopedia of Earth, N. T. Stobbs

How deadly this kind of pollution can be became evident during the rather cold winter of 1952, when heavy coal combustion from both private homes and industry combined with cold and humid ground-level air (trapped by a layer of warmer air) to produce very thick, smoke-polluted fog in the night of December 5. For five days, life in the metropolis came to a near standstill. As an increasing number of people began to die of pneumonia, bronchitis, tuberculosis, and heart failure, medical authorities established the connection. All in all, over 4,000 deaths came to be officially linked to the smog. At last, the British government passed Clean Air Acts (1956 / 1968) that provided for subsidies for replacing coal heaters with cleaner heating systems, and proscribed taller industrial chimneys, respectively. More in the article by Laura De Angelo, or here.

A few decades later, air pollution from traffic emission and the industry were such that toxic smog would, under certain meteorological condition, once more invade major cities worldwide. Especially smog-plagued are the Chinese cities of Shanghai and Beijing. Among other major cities with smog problems are Mexico City (Mexico), Santiago (Chile), Tehran (Iran), Seoul (South Korea), Singapore [smog here is also due to forest fires], Los Angeles and other American cities, London (UK), Rome (Italy), and Athens (Greece).

A comparison:

Source: World Culture Pictorial

For more details about the measures taken in 2014, see for example:

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