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Why clean air matters

Breathing in particulate matter damages the body in two ways:

  • Inflammation: Particulate matter is believed to be mistaken by the body for an infection, triggering an inflammatory response. This causes shortness of breath and exacerbates pre-existing respiratory symptoms, particularly asthma and COPD. That inflammation can spread to other parts of the body, risking heart attacks, stroke and cardiovascular disease. For pregnant women, this inflammation can reach the uterus (see below)
  • Bloodstream: small particles can reach the bloodstream where it can enter other areas of the body and impact the health of all organs, and even get through the placenta to the baby

Particulate matter has been associated with health impacts even at very low concentrations. No threshold has been identified below which no damage to health is observed.

Gaseous pollutants like NO2 or ozone irritate the airways, exacerbating lung related diseases. SO2 has also been linked to increased hospital admissions to cardiac disease and mortality.

What diseases are caused by air pollution?

Outdoor air pollution accounts for:

  • 29% of all deaths and disease from lung cancer
  • 17% of all deaths and disease from acute lower respiratory infection
  • 24% of all deaths from stroke
  • 25% of all deaths and disease from ischaemic heart disease
  • 43% of all deaths and disease from chronic obstructive pulmonary disease

Pollutants can affect cardiovascular health by hardening the arteries and increase the risk of heart attack and strokes

There is emerging evidence that air pollution may be linked to mental health conditions and degenerative brain diseases such as Alzheimer’s disease, Parkinson’s disease and schizophrenia.

Who is most affected?

Children and babies

  • Globally, 93% of all children under 18 breathe polluted air. 98% of children under 5 in low- and middle-income countries are exposed to particulate matter above WHO guidelines
  • Even extremely low exposure to pollutants during pregnancy and in early infancy increases the risk of infant mortality, triggers asthma attacks and, over time, can lead to chronic deficits in lung function, reduced lung growth and reduced cognitive development

The Elderly

  • Exposure to air pollution can be fatal for the elderly as they are more likely to have other illnesses, reducing their resilience to pollution.
  • The elderly are particularly vulnerable to particulate matter, which increases hospitalisations and causes heart and respiratory disease.

The Poor

  • 91% of deaths from ambient air pollution occur in low- and middle- income countries.
  • In all parts of the world, those living in poverty are more likely to live in areas of high pollution, such as near busy roads and industrial sites.

Why are children more vulnerable?

  • Globally, 93% of all children live in environments with air pollution levels above the WHO guidelines
  • Of the 4.2m deaths from ambient air pollution in 2016, 300,000 were in children under 5
  • Exposure to high levels of air pollution during pregnancy has been linked to miscarriages as well as premature birth, autism spectrum disorder, low birth weight and pre-term birth
  • Air pollution can cause pneumonia which kills almost 1 million children under the age of 5 every year
  • Because children’s lungs and brains are still developing, air pollution can interfere with this biological process and affect their cognitive development
  • Children are closer to the ground and breathe more quickly than adults, increasing their exposure

How does air pollution impact the economy?  How much does it cost the economy?

Direct economic impacts of air pollution include:

  • Increased health expenditure: $21 billion of healthcare costs globally in 2015
  • Reduced labour productivity: 2 billion lost working days in 2010, forecast to increase to 3.8 billion by 2060
  • Food system affected: up to 15% of crop yields lost to ozone pollution
  • Chronic exposure is linked to decreased cognitive ability, equivalent to a year of lost education
  • The global indirect cost of ambient PM2.5 emissions was $5.7 trillion in 2016, or 4.4% of global GDP
  • By contrast, actions to meet the Paris commitment of keeping warming to below 2 degrees Celsius, would cost around 1 % of global GDP, says the World Health Organization WHO

How does air pollution impact productivity?

  • The market impacts of outdoor air pollution, which include impacts on labour productivity, health expenditures and agricultural crop yields, are projected to lead to global economic costs that gradually increase to 1% of global GDP by 2060
  • Studies have shown that all sectors are impacted by loss of worker productivity due to high air pollution. In return, it was found that improving air quality generates substantial output and productivity benefits
  • It has been found that exposure to air pollution also impacts cognitive performance in verbal and mathematical tests, with the effect of air pollution on verbal tests becomes more pronounced as people age, especially for men and the less educated