Air Pollution: A Historical Problem?

Air pollution has been a problem for centuries, with the earliest written accounts of air pollution dating back to 400 BCE by Hippocrates. However, it was during the 19th century that episodes of smog in cities like New York and London resulted in many deaths, and air pollution became a significant problem. The Industrial Revolution accelerated the magnitude of emissions and the spread of pollutants, with highly polluted cities becoming a defining issue. While air pollution has always been a concern, it is only in recent decades that we have seen a more significant focus on addressing and mitigating its negative effects.

Air pollution's ancient origins

Air pollution has been a problem for at least the last 100 years, with industrialization and the burning of fossil fuels contributing to increased air pollution levels. However, its ancient origins go back much further. As early as 400 BCE, Hippocrates wrote about air pollution in 'On Airs, Waters and Places', recognizing it as a threat to human health. Successive written accounts of air pollution occur in different countries over the following two millennia.

During the Middle Ages, diseases such as cholera and typhoid fever broke out across Europe due to unsanitary conditions caused by human and animal waste. In 1347, the bacterium Yersinia pestis, carried by rats and spread by fleas, caused the "Black Death", an outbreak of bubonic plague that was exacerbated by the unsanitary conditions of the time.

In the 19th century, episodes of "smog" (a combination of smoke and fog) in cities like New York and London resulted in many deaths. One of the earliest government regulations related to air quality was England's Smoke Abatement Act of 1273, which attempted to curb localized smoke pollution by prohibiting the burning of soft coal. However, it wasn't until the 20th century that we saw sweeping advances in the identification, regulation, and control of air pollution, alongside some of the most disastrous air pollution events in human history, such as the Great Smog of London in 1952, which caused thousands of deaths.

The industrial revolution accelerated the magnitude of emissions of primary pollutants and the geographical spread of contributing countries, with highly polluted cities becoming a defining issue. Europe and North America dominated emissions and suffered the majority of adverse effects until the latter part of the 20th century when transboundary issues such as acid rain, forest decline, and ground-level ozone became the main environmental and political air quality concerns.

While air pollution and its spread have been exacerbated by modern technologies and practices, it is clear that people have contended with its effects throughout history.

Industrial Revolution's impact

Air pollution has been a problem for centuries, with the earliest accounts of air pollution dating back to the time of Hippocrates, around 400 BC. However, the Industrial Revolution, which began in Britain in the late 18th to early 19th centuries, significantly exacerbated this issue. This period, marked by mechanization and the use of steam power, led to the mass burning of coal, which became the fuel of choice for industrial machinery. As a result, cities like Manchester, the world's first industrial city, experienced severe air pollution, with coal-fired factories and residential heating darkening the skies and causing respiratory illnesses and higher death rates.

The Industrial Revolution's impact on air pollution was twofold. Firstly, it led to a massive increase in emissions of primary pollutants, particularly from coal-powered factories and steam engines. This was evident in Manchester, where a dense forest of smoking chimneys dominated the skyline by 1870. London also experienced similar issues, with its concentration of suspended particulate matter rising dramatically between 1760 and 1830. The burning of fossil fuels, especially coal, pumped large amounts of carbon into the atmosphere, contributing to climate change as early as the 1830s, according to a 2016 study.

Secondly, the Industrial Revolution caused a geographical spread of air pollution beyond the boundaries of individual cities. As highly polluted cities became a defining issue, the great smog of London in 1952 served as a culmination of this trend. Europe and North America dominated emissions and suffered the most adverse effects until the latter part of the 20th century. However, as controls on emissions of sulfur and nitrogen oxides were implemented in these regions, emissions in East and South Asia grew, dominating global emissions by the early 21st century.

The environmental consequences of the Industrial Revolution were severe and long-lasting. In addition to air pollution, industrialization led to deforestation, water pollution, and the depletion of natural resources. Urban areas became overcrowded, with poor sanitation and air quality contributing to serious public health issues such as cholera and typhoid fever. The rapid industrial growth outpaced the ability to manage waste and emissions, resulting in long-term damage to both the environment and public well-being.

While the Industrial Revolution brought about economic growth and new opportunities, it also introduced acute hardships for workers, with squalid living conditions, unsafe working environments, and health hazards becoming prevalent. The negative impacts of industrialization prompted a wave of grassroots activism and federal legislation aimed at addressing air and water pollution, leading to the creation of the Air Pollution Control Act of 1955 and subsequent clean air laws.

20th century's disastrous events

The 20th century witnessed some of the most disastrous air pollution events in human history, alongside significant advancements in the identification, regulation, and control of air pollution. Here are some of the notable events:

The Great Smog of London (1952)

In December 1952, London experienced one of its most severe air pollution events, known as the Great Smog. The smog lasted for nearly a week, causing an estimated 10,000 deaths. This event highlighted the detrimental effects of coal burning and led to the UK's first Clean Air Act in 1956, which aimed to address pollution and smog issues.

Donora Smog Incident (1948)

In October 1948, the town of Donora, Pennsylvania, was enveloped in a deadly smog that asphyxiated 20 people and affected more than 7,000 others. This incident, along with the 1969 Cuyahoga River fire, spurred the creation of the Air Pollution Control Act of 1955, the first federal attempt to control air pollution in the United States.

Cuyahoga River Fire (1969)

The Cuyahoga River in Ohio caught fire on several occasions between 1936 and 1969 due to the accumulation of debris and oil on its surface. The 1969 blaze occurred during a time of increasing environmental awareness and symbolized years of environmental neglect. It sparked grassroots activism that led to a wave of federal legislation aimed at tackling air and water pollution.

Auto Makers' Conspiracy (mid-1950s to 1969)

In the mid-1950s, automakers in the United States conspired to stifle the development of pollution-control devices. This conspiracy was settled by the Justice Department in 1969, around the same time as the Cuyahoga River fire, further emphasizing the need for action against air pollution.

Asia's Megacities and Industrialization (late 20th century)

During the second half of the 20th century, Asia experienced rapid population growth and unprecedented economic expansion, leading to the emergence of "megacities." Countries like India and Pakistan underwent significant industrialization and urbanization, resulting in them becoming some of the world's most polluted countries. Asia's rapid growth contributed to a shift in global emissions, with Central, East, and South Asia dominating global emissions by the early 21st century.

Clean Air Acts

Air pollution has been a problem for centuries, with the ancient Greek physician Hippocrates (c. 400 BC) the first to recognise it as a threat to human health. The burning of coal in factories and homes, industrial processes, and automobile emissions have all contributed to poor air quality. The 19th century saw episodes of "smog" in cities like London and New York, resulting in many deaths.

The Clean Air Act (CAA) is a federal law in the United States that regulates air emissions from stationary and mobile sources. The Act was first enacted in 1963 and has been amended several times since, making it one of the country's most influential modern environmental laws. The Act authorises the Environmental Protection Agency (EPA) to establish National Ambient Air Quality Standards (NAAQS) to protect public health and welfare and to regulate emissions of hazardous air pollutants.

The 1970 and 1990 amendments to the CAA are particularly noteworthy. The 1970 Act is often referred to simply as the "Clean Air Act". The 1990 amendments were designed to curb four major threats to the environment and human health: acid rain, urban air pollution, toxic air emissions, and stratospheric ozone depletion. These amendments also established a national operating permits program and strengthened enforcement to ensure better compliance.

The CAA has substantially reduced air pollution and improved US air quality. It has achieved dramatic reductions in emissions of key air pollutants, with approximately a 50% decline since 1990. The Act has also been instrumental in saving trillions of dollars and thousands of lives each year.

The Clean Air Act continues to be revised and strengthened, with newer programs tackling specific problems such as acid rain, ozone layer protection, and climate change. The Act calls for state, local, tribal, and federal governments to work in partnership with the EPA to address air pollution through programs based on the latest science and technology.

Air pollution today

Air pollution has been a problem for centuries, but it has become an increasingly pressing issue in modern times. While pollution levels in many areas of the United States exceed national air quality standards, great progress has been made in achieving these standards since they were established in 1971. For example, visible air pollution is less frequent and widespread than it was in the 1970s. The Clean Air Act of 1990 sets limits on the discharge of air pollutants from industrial facilities and motor vehicles, and addresses acid rain and ozone depletion.

The industrial revolution accelerated the magnitude of emissions of primary pollutants, and highly polluted cities became the defining issue. The Great Smog of London in 1952, for example, caused thousands of deaths. Atmospheric nuclear testing in the 1950s and 1960s also released radioactive pollutants. More recently, in 2012, Beijing experienced what has been labelled its "airpocalypse", with extremely high levels of particulate matter and sulphur dioxide.

The United States Environmental Protection Agency (EPA) has been successful in achieving large reductions in national emissions of air toxics. As directed by Congress, the EPA has completed emissions standards for all 174 major source categories, and 68 categories of small area sources representing 90% of emissions of 30 priority pollutants for urban areas. The EPA has also reduced the benzene content in gasoline and established stringent emission standards for on-road and non-road diesel and gasoline engine emissions, significantly reducing emissions of mobile source air toxics.

However, air pollution remains a serious problem in many parts of the world, and new challenges are constantly emerging. For example, Asia has emerged as the largest source of sulphur dioxide and nitrogen oxide emissions in the 21st century. In addition, indoor air pollution, which is not regulated under the Clean Air Act, can also cause health problems. Fine particulate matter, or PM2.5, can cause premature death and harmful effects on the cardiovascular system, including increased hospital admissions and emergency department visits for heart attacks and strokes. Scientific evidence also links PM2.5 to harmful respiratory effects, including asthma attacks.

Frequently asked questions