Breathing Safe: Where Can We Escape Pollution?

Air pollution is a major threat to health and climate, causing an estimated 4.2 million premature deaths worldwide in 2019. The World Health Organization (WHO) has been working to combat this issue by supporting policies and investments that promote cleaner transport, energy-efficient homes, and better waste management. Despite these efforts, it is difficult to find a place that is completely safe from air pollution. Natural sources of air pollution, such as volcanic activity, wildfires, and dust storms, can have a significant impact on local environments. Additionally, indoor air quality is not immune to outdoor pollution and can be further affected by household activities such as cooking and heating. To protect oneself from air pollution, individuals can use air quality indexes, air purifiers, masks, and air conditioning settings to reduce exposure and limit the negative health impacts of air pollution.

Natural air pollution sources

Air pollution is a significant environmental health hazard that affects people in low-, middle-, and high-income countries. Outdoor air pollution in cities and rural areas is estimated to cause 4.2 million premature deaths worldwide per year. This mortality is due to exposure to fine particulate matter, which causes cardiovascular and respiratory disease, cancers, and neurological disorders. While human-generated sources of air pollution, such as cars, power plants, and industrial processes, are significant contributors, natural sources also play a role in degrading air quality.

Natural sources of air pollution include wind-blown dust, wildfires, and volcanoes. While these sources may not create ongoing air pollution issues like human-generated sources, they can sometimes be significant. For example, volcanic eruptions can release massive amounts of sulphur dioxide into the atmosphere, and wildfires can increase background pollution levels for years, even in areas far from the original source. Wind can carry pollutants over short or long distances, affecting air quality in areas downwind of pollution sources.

Organic compounds from plants, sea salt, suspended soils, and dust (such as from the Sahara) are also natural sources of air pollution. These pollutants can create haze, reducing visibility and having biological impacts. Additionally, animals like cows and sheep release methane, a potent greenhouse gas, through their digestive processes. Livestock is the largest source of methane globally, contributing to climate change.

Some natural sources of air pollution, such as wildfires and volcanic eruptions, release large amounts of harmful gases and smoke, affecting air quality and human health. While natural sources may not be the primary drivers of ongoing air pollution, their impacts can be significant, particularly when combined with human-generated pollution. It is essential to consider all sources of air pollution to implement effective policies and interventions to improve air quality and protect public health.

Indoor air quality

We often think of air pollution as a risk faced outdoors, but the air we breathe indoors can also be polluted. Spending time indoors accounts for 90% of our time, and indoor air quality affects everyone, especially those who are more vulnerable, such as children, the elderly, and people with health conditions like asthma and heart disease.

The health effects of indoor air pollutants can be significant. Exposure to indoor air pollutants has been linked to respiratory diseases, heart disease, and cancer. For example, radon, the second leading cause of lung cancer, is often present in indoor environments. Additionally, indoor air pollution during pregnancy has been associated with impaired lung function in infants, increasing the risk of pneumonia in the first year of life.

To improve indoor air quality, it is essential to focus on source control, ventilation, and filtration. Ensuring adequate ventilation and air conditioning can help control indoor moisture and mould growth. Additionally, the "green building" design concept aims to achieve energy efficiency while enhancing indoor air quality through careful design, construction, operation, and maintenance. By addressing the sources of indoor air pollution and implementing effective ventilation and filtration strategies, it is possible to reduce exposure to indoor pollutants and create healthier indoor environments.

Air quality monitoring tools

• Handheld and Portable Monitors: These devices offer real-time air quality measurements and are designed to be compact, portable, and easy to use. They can simultaneously measure various parameters, including particulate matter (PM2.5, PM10), volatile organic compounds (VOCs), and multiple gaseous pollutants. Handheld monitors are ideal for on-the-go monitoring and can provide hyperlocal data.
• Fixed Indoor Air Quality (IAQ) Monitors: IAQ monitors are designed to assess indoor air quality by measuring parameters such as PM, VOCs, carbon dioxide (CO2), temperature, and humidity. These monitors help ensure healthier indoor environments in homes, offices, schools, and other spaces. They can identify pollutants and potential health hazards, enabling better ventilation, pollution source control, and maintenance of HVAC systems.
• Outdoor Air Quality Stations: These are stationary monitoring stations that provide real-time air quality data for specific locations. They are often equipped with laser particle sensors to measure PM2.5 and PM10 particle pollution, which are considered some of the most harmful air pollutants. The data from these stations is typically presented on maps, providing a comprehensive view of air quality across different regions.
• Online Air Quality Index (AQI) Maps: Websites like WAQI.info provide real-time Air Quality Index (AQI) maps that show air quality data from thousands of stations worldwide. The AQI is based on the measurement of particulate matter (PM2.5 and PM10), ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO) emissions. These maps offer a visual representation of air quality, helping users understand the pollution levels in their areas.
• Government and Organization Initiatives: Various governments and organizations, such as AirNow.gov, provide air quality monitoring services and resources. These initiatives often include interactive maps, air quality alerts, and educational materials to help the public understand and respond to air pollution. They also work closely with health professionals and researchers to address the health impacts of air pollution.

By utilizing these air quality monitoring tools, individuals, communities, and policymakers can make informed decisions to improve air quality, reduce pollution sources, and ultimately protect public health and the environment.

Reducing air pollution

Air pollution is a major environmental health problem affecting people in low-, middle-, and high-income countries. In 2019, 99% of the world’s population was living in places where the WHO air quality guidelines levels were not met. The combined effects of ambient air pollution and household air pollution are associated with 6.7 million premature deaths annually.

Reduce Energy Consumption

Turn off electrical items when you are not using them. Replace energy-hungry incandescent lights with compact fluorescent light bulbs. Opt for a fan instead of air conditioning. Use a programmable thermostat and set it to 78°F in the summer and 68°F in the winter. Install low-flow showerheads. Wash laundry in cold water and line dry.

Choose Sustainable Products

Buy energy-efficient appliances and heating systems. Choose efficient, low-polluting vehicles, or even zero-emission electric cars.

Reduce Exposure to Chemicals

Eliminate the use of toxic chemicals at home and opt for natural substitutes. Avoid products that emit smog-forming chemicals, such as volatile organic compounds (VOCs) and particulate matter (PM).

Support Cleaner Industries

Reduce toxic emissions from industrial sources. Support policies and investments that promote cleaner transport, energy-efficient homes, power generation, and industry.

Plant Trees

Trees filter pollutants and absorb carbon dioxide, helping to improve air quality.

Air pollution and health

Air pollution is a major threat to global health and prosperity. In 2019, 99% of the world's population was living in places where air quality fell below the standards set by the World Health Organization (WHO). Outdoor air pollution is estimated to have caused 4.2 million premature deaths worldwide in 2019, with 68% of those deaths caused by ischaemic heart disease and stroke. The combined effects of ambient and household air pollution are associated with 6.7 million premature deaths annually.

Air pollution is the presence of one or more contaminants in the atmosphere, such as dust, fumes, gas, mist, odour, smoke, or vapour, in quantities and durations that can be harmful to human health. The main pathway of exposure to air pollution is through the respiratory tract. Breathing in these pollutants leads to inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout the body, impacting the lungs, heart, and brain, among other organs, and ultimately leading to disease.

Particulate matter (PM) is composed of chemicals such as sulfates, nitrates, carbon, or mineral dust. Vehicle and industrial emissions from fossil fuel combustion, cigarette smoke, and burning organic matter, such as wildfires, all contain PM. A subset of PM, fine particulate matter (PM2.5), is 30 times thinner than a human hair and can be inhaled deeply into the lung tissue, contributing to serious health problems. Other harmful pollutants include carbon monoxide (CO), ozone (O3), nitrogen dioxide (NO2), and sulphur dioxide (SO2).

Short-term exposure to high levels of particulate matter can lead to reduced lung function, respiratory infections, and aggravated asthma. Long-term exposure increases the risk of stroke, heart disease, chronic obstructive pulmonary disease, and cancer. Children, the elderly, pregnant women, and people with pre-existing health conditions are more susceptible to air pollution-related diseases.

To protect populations from the health risks of air pollution, the WHO's Air Quality and Health Unit works in three cross-cutting areas: knowledge, evidence, and measuring progress; institutional capacity building and technical support; and leadership and coordination. Member States are typically responsible for implementing and monitoring policies to promote air quality for health.

Frequently asked questions