By Mary Hearty

Evidence from World Health Organization’s (WHO) New Global Air Quality Guidelines (AQGs) shows that polluted air is a major risk factor for cardiovascular, acute and chronic respiratory diseases.

Therefore, when people who are living in locations with worse air quality get affected with COVID-19, they are likely to develop severe outcomes, according to The United Nations Environment Programme (UNEP).

Although current studies and data show unprecedented reduction in air pollution in countries affected by reduced economic activity as a result of measures to reduce the spread of COVID-19.

Dr Maria Neira, Director of the Department of Public Health and Environment at WHO during WHO ‘Science in 5’ interview on air pollution and COVID-19, urged governments to come up with interventions that would help lower the recommended levels of exposure to air pollutants in order to protect people’s health.

Like building on the enhanced awareness and on the changes in behaviour which emerged during the pandemic such as enhanced teleworking, reduced travel, and preference for certain forms of transport, may have long lasting positive effects on air quality in a post pandemic world – to the extent that they are retained.

Also, promoting further research into the linkages between air pollution exposure and COVID-19 impacts on health; and strengthening research on how changes in behaviour and lifestyles impact our environment with a focus on: teleworking, changes in mobility patterns, social distancing measures, and reduced consumption, among others.

According to Dr Neira, 90% of the global population breathe in air that is not respecting the WHO’s recommended standards of protecting human health.

The revised WHO’s air quality guidelines recommend air quality levels for six pollutants. They include: particulate matter (PM), ozone (O₃), nitrogen dioxide (NO₂) sulfur dioxide (SO₂) and carbon monoxide (CO).

Regarding PM, it is primarily generated by fuel combustion in different sectors, including transport, energy, households, industry, and from agriculture. In 2013, outdoor air pollution and particulate matter were classified as carcinogenic by WHO’s International Agency for Research on Cancer (IARC).

The health risks associated with particulate matter equal or smaller than 10 and 2.5 microns (µm) in diameter (PM₁₀ and PM₂.₅, respectively) are of particular public health relevance.

Both PM₂.₅ and PM₁₀ are capable of penetrating deep into the lungs but PM₂.₅ can even enter the bloodstream, primarily resulting in cardiovascular and respiratory impacts, and also affecting other organs.

Dr Neira said: “If those recommendations of WHO are implemented, particularly for PM₂.₅, which is one of the most dangerous for our health, we could save 80% of the total number of deaths that we have every year due to air pollution, and that number is 7 million premature deaths caused by exposure to air pollution.”

Every year, exposure to air pollution is estimated to cause 7 million premature deaths and result in the loss of millions of healthy life years. In children, this could include reduced lung growth and function, respiratory infections and aggravated asthma.

In adults, ischaemic heart disease and stroke are the most common causes of premature death attributable to outdoor air pollution, and evidence is also emerging of other effects such as diabetes and neurodegenerative conditions.

Consequently, this puts the burden of disease attributable to air pollution on a par with other major global health risks such as unhealthy diet and tobacco smoking.

The guideline also highlights good practices for the management of certain types of particulate matter such as black carbon or elemental carbon, ultrafine particles, particles originating from sand and dust storms for which there is currently insufficient quantitative evidence to set air quality guideline levels. They are applicable to both outdoor and indoor environments globally, and cover all settings.

Dr Neira advised that we need to reimagine a greener world with clean sources of energy, so that we can breathe air that is not killing us.