Impact of Air Pollution on Human Health

Why in news?

Recently, the State of Global Air (SoGA) 2024 was released which offers a stark reminder of the significant impacts air pollution has on human health.

What is air pollution?

• Air pollution – It is contamination of the indoor or outdoor environment by any chemical, physical or biological agent that modifies the natural characteristics of the atmosphere.
• Common sources – Household combustion devices, motor vehicles, industrial facilities and forest fires are common sources of air pollution.
• The major outdoor pollution sources include residential energy for cooking and heating, vehicles, power generation, agriculture/waste incineration, and industry.
• Pollutants - Pollutants of major public health concern include particulate matter, carbon monoxide, ozone, nitrogen dioxide and sulfur dioxide.
• Impact on climate – Many of the drivers of air pollution (i.e. combustion of fossil fuels) are also sources of greenhouse gas emissions.
• Impact on human health - Outdoor and indoor air pollution cause respiratory and other diseases and are important sources of morbidity and mortality.
• Polluted air is a big trigger for pneumonia and other respiratory infections and allergic diseases in children.
• There is a strong connection between long-term exposure to traffic-related air pollution and early death due to cardiovascular diseases and lung cancer, asthma onset in children and adults, and acute lower-respiratory-tract infections in children.

WHO data show that almost all of the global population (99%) breathe air that exceeds WHO guideline limits and contains high levels of pollutants, with low- and middle-income countries suffering from the highest exposures.

What are the key findings of the report?

• During the pre-pandemic phase (1990 to 2019) – The order of the leading global causes of death were ischemic heart disease, stroke, chronic obstructive pulmonary disorder (COPD), and lower respiratory disease. 
• Post pandemic in 2021 – Covid-19 changed the order with age-standardised mortality from COVID ranking second after ischemic heart disease, and stroke and COPD dropping to third and fourth place, respectively. 
• Impacts of air pollution on human – It become the second largest killer globally after blood pressure, recording a dubious tally of 8.1 million deaths in 2021.

• Impact on children under five years - With more than 700,000 deaths, air pollution become the second leading risk factor after malnutrition globally.
• As many as 500,000 of these child deaths are linked to household air pollution from cooking indoors using dirty fuels in Africa and Asia.
• Polluted air is a big trigger for pneumonia and other respiratory infections and allergic diseases in children.

• Impact of Climate Change – It can exacerbate the health burden of non-communicable diseases, including heart and lung diseases, during heatwaves.

What is the status of pollutants causing air pollution?

• Even though PM2.5 (both ambient and household together) account for more than 90% of the total air pollution disease burden, NO2 and ozone are the growing risk factors globally.

What lies ahead?

• Emulate the successful policy decisions – There has been a 61% reduction in the age-standardised death rate from household air pollution.
• This improvement has been possible due to growing access to clean energy for cooking, grid electricity, cleaner-burning cookstoves, and cleaner fuels.
• Tackle air pollution – It can be done by reducing toxic emissions and greenhouse gases, which will improve public health and combat climate change. 

References

1. Down To Earth| Air Pollution is 2^nd Leading Risk Factor for Children
2. WHO| Air Pollution
3. State of Global Air| State of Global Air 2024 Report