The cities of today are locked in a constant battle to improve air quality. From cycle routes to low emission zones, to banning cars altogether, urban dwellers across the globe are fighting to breathe cleaner air.
But air pollution is not just a modern problem.
The Industrial Revolution brought rapid expansion to Britain’s cities, and none more so than London. Pollution from the industrial and residential burning of coal resulted in notorious noxious winter fogs.
Under certain conditions, known as an air inversion, the polluted smog could become trapped beneath a layer of warm air leading to days of dense, choking haze.
One such event occurred in the winter of 1873 when 1,150 people reportedly died as a result of the poisonous fog and livestock had to be put down to save them from choking to death.
Donora, Pennsylvania, 1948
A similar air inversion led to one of the United States’ worst air pollution events in 1948 in Donora, a mill town southeast of Pittsburgh. Emissions from the US Steel Corporation’s zinc and iron works became trapped creating a thick, acrid smog that appeared on 27th October and lasted for five days.
Firefighters went from house to house offering oxygen to residents suffering from breathing problems.
It was not until the 31st that US Steel agreed to temporarily halt operations at their plants but rain cleared the smog later that day anyway and the plants began operating again the following morning.
Reports stated that 20 people were killed by the smog, with the fluorine gas produced by the zinc works singled out as the likely cause of their deaths.
US Steel refused to accept any responsibility for the event, pointing to additional pollutants from cars and railroads in the area, but settled a large number of lawsuits privately.
The events at Donora led to the establishment of a clean air movement in the United States. Theatre productions were halted and cinemas closed as audiences simply couldn’t see what they were watching.
In 1952 London was forced to address the issue of its air pollution. A temperature inversion again led to the winter fog becoming trapped over the city by a high pressure system. The fog lasted from 5th – 9th December, during which time visibility dropped to below 10 metres.
Theatre productions were halted and cinemas closed as audiences simply couldn’t see what they were watching. Much of the transport system ground to a halt, with only the underground remaining operational.
At street level, conductors armed with torches led London’s buses through hazy streets and pedestrians who dared step outside returned home to find their faces blackened with soot.
By 10th December a westerly wind had dispersed the fog but its impact would be felt long after it had gone. Reports suggested as many as 12,000 people died as a direct result of London’s worst air pollution event, many from chest complaints such as bronchitis and pneumonia.
The impact was worst in central areas, as the image of Nelson’s Column shows.
In 1956 the British Parliament passed the Clean Air Act which banned the burning of coal and wood in urban areas.
Crowds and press attending the Macy’s Thanksgiving Parade on 24th November were distracted by the growing smog covering the city.
New York City, 1966
Following two serious smog events in 1953 and 1963, the first of which lasted for six days and the second for two weeks, New York City was brought to a standstill again in 1966. The smog began to form on 23rd November, coinciding with Thanksgiving Weekend.
Again it was a temperature inversion that caused the pollutants from the city to become trapped beneath unseasonably warm air. Crowds and press attending the Macy’s Thanksgiving Parade on 24th November were distracted by the growing smog covering the city.
In response to the worryingly high rates of carbon monoxide and sulphur dioxide in the air, the city closed its municipal garbage incinerators.
The next day, as the city was further shrouded in filthy air, an appeal was made to the businesses and citizens of New York to do their bit in limiting emissions by not using their cars unless absolutely necessary and turning their heating down.
On 26th November a cold front displaced the warm air and the smog cleared.
The smog had affected around 16 million people and the number of deaths linked to it ranges from 80 to over 100. The city of New York subsequently tightened its limits on pollutant levels.
The event also raised awareness of air pollution at a national level, at a time when only half of the United States’ urban population lived in areas with air pollution regulations.
Ultimately this growing awareness led to the Clean Air Act of 1970.
The widespread burning of plants and woodland in Indonesia through an agricultural method known as “slash-and-burn” contributes to the build up of an annual haze in Southeast Asia.
The problem can become particularly acute during El Nino years, a climate cycle that delays the onset of the monsoon rains to clear the haze. In 2006, with the haze having begun to build up in July, by October Indonesia, Singapore and Malaysia were all reporting record levels of air pollution.
Schools were closed and people were encouraged to remain indoors, especially if they suffered with respiratory problems.
Reports suggested that visibility in the Indonesian region of Borneo was reduced to 50 metres in places, a problem that led to an aircraft skidding off the runway in Tarakan.
The ongoing annual fires in Indonesia continue to frustrate neighbouring nations. The inhabitants of Indonesia have used the “slash-and-burn” method for centuries but population increase and the growth of commercial logging produced a sharp increase in fires.
The practice has been banned by the Indonesian government but they have failed to enforce the ban adequately.
Relations were further strained by Indonesia’s continued reluctance to ratify the 2002 ASEAN Agreement on Transboundary Haze Pollution, which called for cooperation between nations to reduce the impact of the yearly haze.
However in 2014, after twelve years of hesitation, Indonesia finally signed the agreement. Yet the haze continues to be an annual problem, hospitalising millions of people across the region and costing billions of dollars in lost tourism revenue.
How clean is your air?
Check out the links below for further information on air pollution levels around the world
Header image credit: Smog in New York City as viewed from the World Trade Center in 1988. Credit: Commons.