Impact of air pollution on mental health (Signal)

The burden of mental health in Europe

The link between physical health and exposure to pollution is well known. A significant proportion of the burden of disease in Europe is attributed to environmental pollution (EEA, 2019).

However, the impact of pollution on mental health is not as well understood. According to data from the European Health Interview Survey (Eurostat, 2024), which was conducted in 2019, mental health problems affect one in six people in the EU, with 7.2% of EU citizens suffering from chronic depression (Eurostat, 2021).

In this context, the Commission’s communication on a comprehensive approach to mental health pointed out the importance of addressing the environmental determinants that promote good mental health (EC, 2023) along with the biological and socio-economic determinants, which historically have been studied in relation to mental health. Measures to reduce exposure to some relevant pollutants, such as lead, have delivered health benefits, as explained in the signal on Progress in regulating lead, however, the potential mental health impacts of other environmental stressors, such as air pollutants, noise and chemicals, requires further investigation and action.

Emerging evidence on the impact of air pollutants on mental health

The possible causal pathways between air pollution and the risk of mental disorders are currently not fully understood. However, research increasingly points out that inflammation and oxidative stress are key factors influencing the observed association between air pollutants and mental health outcomes (King et al., 2022).

Numerous studies have already highlighted the association between long-term exposure to air pollution and various psychiatric disorders, including depression, anxiety and bipolar disorder (Pun et al., 2017; Braithwaite et al., 2019; Khan et al., 2019; Newbury et al., 2021; Borronia et al., 2022; Forastiere et al., 2024), as well as suicide risk (Davoudi et al., 2021, Liu et al., 2021). Long-term exposure to air pollution has also been correlated to a progressive decline in mental function (Kulick et al., 2020), increasing the risk of dementia in the elderly (Power et al., 2016; Chen et al., 2017; Wang et al., 2022) and exacerbating the development of other diseases, including Alzheimer’s (Fu and Yung, 2020). Children and young people are particularly exposed to air pollution due to their higher air intakes and exposure levels (EEA, 2022) and also because their organs, including the nervous system, are more sensitive to pollution than adults.

A growing body of studies shows moderate evidence of an association between air pollution and adverse neurodevelopmental outcomes. There are indications that children exposed to ambient air pollution are restricted in their cognitive development, might show structural changes in the brain and are more likely to be diagnosed with autism (Castro et al., 2023). However, the association between cognitive function and traffic-related PM_2.5 is thus far inconclusive (Castro et al., 2023).

Traffic-related air pollution exposure during childhood and adolescence appears to result in higher generalised anxiety rates in teenagers (Brunst et al., 2019), while NO₂ and NO_x concentration are associated with adolescent mood disorders (Newbury et al., 2021) and PM_2.5 and NO₂ concentrations with depressive disorders (Roberts et al., 2019). Another study also found a strong association between post-natal exposure to PM_2.5 in the first year of life and a moderate association in the second year with autism spectrum disorder (Castro et al., 2023).

Second-hand smoke, a type of air pollution, is also linked to an increase in the risk of a variety of mental health and cognitive impairments. These include depressive mood and suicidal ideation, with a dose-response relation (Kim et al., 2016; Bang et al., 2017; Park, 2017), and anxiety, aggression, conduct disorder symptoms and lower cognitive function ( Khorasanchi et al., 2019).

The potential risks of air pollution on mental health seem unevenly distributed across the population. Markedly, the likelihood of developing mental disorders is highly related to socioeconomic status: children and adolescents from disadvantaged backgrounds are reportedly two to three times more likely to suffer from mental illness (Reiss, 2013). On top of that, lower socio-economic groups are more exposed to air pollution and thus more susceptible to related health effects (Fairburn et al., 2019). It is therefore likely that the impact of air pollution is accentuated in poorer populations.

Further research is needed to reveal the impact of children’s uneven exposure to pollution and mental health in relation to socioeconomic inequalities and environmental justice (Rauh and Margolis, 2016).

Please consult the relevant indicators and signals below for a more comprehensive overview on the topic.