Who is this guidance intended for?
This guidance is intended for environmental health professionals working in municipalities, as well as healthcare professionals working in municipalities, wellbeing services counties and private healthcare services.
The purpose of this guidance is to provide clear and up-to-date information on the health effects of air pollution and to support professionals in advising the public and communicating health risks.
This guidance is not legally binding.
How does air pollution affect health?
A large proportion of the population may occasionally experience various mild and temporary health effects, whereas serious health effects are less common.
Short-term exposure to poor air quality may cause symptoms such as coughing, a runny nose, irritation of the eyes and throat, and breathing difficulties. It may also exacerbate chronic cardiovascular and respiratory diseases. Even short-term exposure to high concentrations of air pollutants may increase the risk of acute death.
Long-term exposure over several years may increase the risk of cardiovascular diseases, respiratory diseases such as lung cancer and chronic obstructive pulmonary disease (COPD), and premature death.
Air pollutants can increase inflammatory responses, oxidative stress, impairment of immune system function and cellular damage. These effects primarily affect the lungs and the heart, but also the brain, and may increase the risk of a wide range of diseases.
The magnitude of the health risk depends on the concentration of air pollutants, the duration of exposure, and the characteristics of the pollutants, such as particle size distribution and chemical composition. Individual factors, such as a person's age and health status, also influence the health risk. Healthy lifestyle choices may support the body's ability to recover from the physiological stress caused by air pollution.
Who is particularly susceptible to the health effects of air pollution?
The following groups are particularly sensitive to the health effects of air pollution:
- children
- older people
- pregnant people
- people with chronic cardiovascular or respiratory diseases.
These groups may experience adverse health effects at lower concentrations than the general population. Such effects include, for instance, worsening of existing disease and an increased need for medication.
In addition, some population groups are particularly vulnerable, for example because of socioeconomic status. They may have fewer opportunities to reduce their exposure, and factors such as poor diet and underlying health conditions may further increase the risk of adverse health effects.
The main sources of fine particles (PM2.5) are residential wood burning, road traffic and long-range transboundary air pollution from other countries. Fine particulate matter consists of particles with an aerodynamic diameter of less than 2.5 micrometres (µm).
Long-term exposure to fine particles increases mortality, particularly from cardiovascular diseases, respiratory diseases such as chronic obstructive pulmonary disease (COPD) and lung cancer, as well as acute lower respiratory infections.
There is also strong evidence that long-term exposure to fine particles is associated with incidence of childhood asthma, chronic obstructive pulmonary disease (COPD), ischaemic heart disease, stroke, hypertension and lung cancer.
Short-term increases in fine particle concentrations may also cause more serious health effects in addition to mild irritation symptoms, including an increased need for hospital treatment for cardiovascular diseases and an increased risk of death.
Exposure to fine particles during pregnancy may increase the risk of preterm birth and low birth weight.
Recent evidence suggests that exposure to fine particles may also be associated with type 2 diabetes, dementia and autism spectrum disorders. However, the evidence for these health effects remains limited, and further research is needed.
The chemical composition of particles, and therefore their emission source, influences their toxicity. However, it has not yet been possible to establish a clear ranking of the harmfulness of particles from different sources.
No concentration threshold has been identified below which fine particulate matter poses no risk to health. Consequently, even low concentrations may increase the risk of adverse health effects.
A major source of inhalable particle emissions is road dust, particularly in spring. Construction sites, for example, may also generate substantial local particle emissions.
Inhalable particles (PM10) are airborne particles with an aerodynamic diameter of less than 10 micrometres (µm). They include both fine particles (PM2.5) and coarse particles with a diameter of 2.5–10 µm.
Inhalable particles may have long-term health effects similar to fine particles, but it is difficult to distinguish their independent effects from those of fine particles.
Long-term exposure to inhalable particles has been associated with an increased risk of premature death, particularly from respiratory diseases, cardiovascular diseases and lung cancer.
Short-term exposure may cause irritation of the eyes and airways, including a runny nose, coughing, and throat and eye irritation. Even short-term exposure may also increase mortality and hospital admissions related particularly to cardiovascular and respiratory diseases.
Ultrafine particles are mainly generated during combustion processes. The major sources of ultrafine particles are road traffic, residential wood burning, energy production and industry.
Ultrafine particles are the smallest airborne particles. They have a diameter of less than 100 nanometres, or 0.1 µm.
Because of their extremely small size, ultrafine particles can penetrate deep into the lungs, enter the bloodstream, and may also reach the brain directly via the olfactory nerve.
Assessing exposure to ultrafine particles and their associated health effects is challenging as concentrations can vary considerably over short distances, for example near busy roads. In addition, comprehensive monitoring data on ultrafine particles are not yet available because monitoring stations remain limited in number.
Further research is needed to better understand the health effects of ultrafine particles. At present, the strongest evidence for their long-term health effects relates to an increased risk of mortality and their ability to trigger inflammatory responses in the body. In addition, both long-term and short-term exposure may be associated with adverse effects on the cardiovascular and respiratory systems.
The main sources of nitrogen dioxide (NO₂) are road traffic, energy production and industry.
Nitrogen dioxide is a gaseous compound consisting of nitrogen and oxygen. Its health effects primarily affect the respiratory system.
Long-term exposure to nitrogen dioxide may increase respiratory symptoms and respiratory infections, as well as the risk of developing asthma. It may also increase the risk of premature death, particularly from respiratory diseases, chronic obstructive pulmonary disease (COPD) and lower respiratory infections.
Short-term exposure to high concentrations may cause respiratory symptoms, such as coughing and wheezing, worsen respiratory diseases, and increase the risk of mortality.
Ozone (O₃) is a gaseous air pollutant formed in the atmosphere from other gases through photochemical reactions.
Ozone concentrations are highest during sunny weather in spring and summer. Ozone is also transported to Finland from other parts of Europe.
Ozone irritates the airways and may cause coughing, throat irritation and breathing difficulties.
Short-term exposure may worsen asthma and other respiratory diseases, increase hospital admissions, and reduce the lungs' ability to fight infections. In addition, short-term exposure to high ozone concentrations may be associated with increased mortality.
Long-term exposure to ozone may increase the risk of death from chronic obstructive pulmonary disease (COPD) and other respiratory diseases.
Providing advice on protection from air pollution
Professionals can provide advice on protection from air pollution particularly in the following situations:
- the person's exposure to air pollution is higher than usual, for example because of their living environment
- the person belongs to a population group that is particularly susceptible to the health effects of air pollution or is concerned about their exposure to air pollution.
Advice on reducing emissions can also be provided to people whose activities are considered to cause air pollution problems in residential areas.
Our view: Tips for protecting yourself from air pollution and reducing emissions