Pollution and mental health: current scientific evidence

Mental health emerges from a complex interplay between intrinsic factors. These include genetics, social and economic determinants, as well as psychological, lifestyle and other factors.

Many of these factors and their interactions are not well understood. Emerging evidence suggests that pollution — specifically certain air pollutants, environmental noise and some toxic chemicals — may trigger mental disorders, aggravate their symptoms or contribute to the aetiology of diseases through long-term exposure (Cao et al., 2024; Hahad et al., 2025; Rückle et al., 2025).

This briefing explores the currently available evidence on the associations between pollution and mental health in Europe. It is based on a comprehensive review of the literature, with a particular focus on systematic reviews and meta-analyses carried out by the European Topic Centre on Human Health and the Environment (ETC HE, 2026).

Mental health conditions covered in this briefing include:depressive and bipolar disorders, anxiety and fear-related disorders, schizophrenia and other primary psychotic disorders (WHO, 2024). Although suicide is not a mental disorder per se, in some cases it can be regarded as an outcome indicator of underlying mental illness. The scope of this briefing does not include neurological or neurodevelopmental disorders.

In the EU, more than 11 million disability-adjusted life years were lost in 2023 due to mental health disorders, according to the Global Burden of Disease Study. As such, mental health disorders accounted for the sixth largest burden of disease in the EU out of all the categories included in the study (IHME, 2025) and represented the eighth most common cause of death (Eurostat, 2026). Multiple studies show a significant increase in the prevalence and incidence of mental health disorders across Europe, particularly since the late 2000s (Lozano-Sánchez et al., 2024; Momen et al., 2025; Ten Have et al., 2023).

Environmental determinants can be risk factors, but they can also have a protective effect on health. Studies have shown that exposure to nature, such as a walk in a forest, provides some degree of protection against some mental disorders and/or symptoms. Regular exposure to nature can reduce stress and symptoms as well as facilitate mental recovery. Thus, alongside research on the links between environmental pollution and mental health, studies on environmental interventions are also of interest for public health policymakers as inputs for reducing the mental health burden on society (Bratman et al., 2012; Coventry et al., 2021).

Pollution and mental health

A summary of relevant evidence on the key types of pollution in Europe and their confirmed or probable association with mental health disorders is given below. It is based on a comprehensive review of the literature, with a particular focus on systematic reviews and meta-analyses carried out by the ETC HE (2026).

It is important to note that an association between pollution and adverse mental health outcomes does not automatically imply causation. Demonstrating the latter requires a lot of long-term, comprehensive studies addressing known influences and potential confounders. These influences and confounders are explored below in the sub-section ‘Addressing research gaps’ under ‘Opportunities for action’. Most of the evidence on the links between pollution and mental health is at a relatively early stage.

Air pollution

Neurological studies indicate that exposure to outdoor air pollution during critical stages of brain development — for example in utero, childhood and early adolescence — is associated with structural and functional brain changes (Morrel et al., 2025; Zundel et al., 2022). Additionally, evidence suggests that outdoor air pollution can cause changes to neurotransmitters, neuromodulators and their metabolites (Bhui et al., 2023).

In parallel with these studies on biological mechanisms, several studies, reviews and meta-analyses have investigated the epidemiological association between various air pollutants and several mental health disorders. An expert assessment of the current scientific evidence for links between exposure to the main air pollutants and mental health disorders is summarised in Table 1. The findings are presented as exposure-outcome pairs and are based on the literature, taking into account the consistency of the results available and their statistical significance. More detailed results are available in the ETC HE report Mental health impacts of air pollution, chemicals, and noise (2026).

All systematic or narrative reviews investigating the effects of air pollution on depression or depressive symptoms show a statistically significant association between long-term exposure to poor air quality (with the most evidence available for PM_2.5 and NO₂) and increased prevalence or risk of new onset depression and acute high pollution episodes during which depressive symptoms are exacerbated (Bhui et al., 2023; Buoli et al., 2018; Chauhan et al., 2025; Cuijpers et al., 2023; King et al., 2022; Ragguett et al., 2017; Tota et al., 2024; Xie et al., 2023; Zhao et al., 2018; Zundel et al., 2022). The few studies that include noise as a co-pollutant point to independent effects from air pollution.

Evidence for the association of long-term air pollution on the development of other mental health problems is more limited or inconsistent. However, it has been shown that short-term peaks of exposure are consistently and statistically significantly associated with worsening schizophrenia symptoms (Radua et al., 2024; Song et al., 2023; Xu et al., 2023; Tota et al., 2024; King et al., 2022; Pignon et al., 2022).

Some evidence also indicates that short-term air pollution can result in exacerbation of symptoms of anxiety and can trigger bipolar episodes (Chauhan et al., 2025; Lu, 2020; Tota et al., 2024; Braithwaite et al., 2019).

Despite the uncertainty in the associations between air pollution and mental health diseases, the existing evidence suggests that even small reductions in pollution could result in some decreases in depressive symptoms or improved outcomes for other mental health issues. This suggests that reducing pollution could contribute to decreasing the current mental health burden at the population level.

Table 1. Summary of the strength of evidence linking exposure to air pollution and mental health disorders

Environmental noise

Most studies and reviews on the association between environmental noise and mental health focus on transportation noise from road traffic, railways and aircraft. Transportation noise may affect mental health through multiple, interconnected biological and psychological pathways. Chronic exposure to low-level noise activates the body's stress response and can also cause sleep disturbances. These effects can lead to inflammation and oxidative stress, which may contribute to mental health issues.

The main evidence to date on the associations between transportation noise and mental health is summarised in Table 2. This gives an overview of the expert assessment of the scientific evidence for links between exposure to the main sources of environmental noise and mental health disorders. The findings are presented as exposure-outcome pairs and are based on the literature, taking into account the consistency of the results available and their statistical significance. More detailed results are available in the ETC HE report Mental health impacts of air pollution, chemicals, and noise (2026).

Road traffic noise is the most extensively studied source of transportation noise in relation to mental health. Evidence from a systematic review and meta-analyses suggests that for every 10-decibel (dB) increase in noise day-evening-night-level (L_den) there is a small increase in the risk of depression (3%) and anxiety (2%) (Hegewald et al., 2020). It should be noted, however, that the overall quality of evidence is low due to the dominance of cross-sectional studies, heterogeneity in exposure and outcome assessment, as well as potential confounding.

Recent large cohort studies that adjust for sociodemographic and environmental confounders confirm these earlier results and also report small, non-significant risk increases for depression and anxiety (Nobile et al., 2023; Eze et al., 2020; Motoc et al., 2023). Additionally, Wicki et al. (2023) found a significant 4.0% increase in suicide rates per 10dB increase in road traffic noise at the place of residence.

As reported in the European Environment Agency’s (EEA’s) recent briefing on children and environmental noise, exposure to environmental noise is associated with a higher prevalence of behavioural issues in children; this in turn affects their mental well-being (EEA, 2025). Specifically, the evidence suggests that road traffic noise, particularly when experienced at home (i.e. residential exposure), is linked to higher total behavioural difficulties (ETC HE, 2025). The findings for adolescents and the findings relating to aircraft noise exposure remain inconsistent (Clark et al., 2021; Thompson et al., 2024; Dėdelė et al., 2025).

The evidence for railway noise is more limited and less consistent than for road traffic noise. Hegewald et al. (2020) report a small (2%) and non-significant increase in depression risk per 10dB L_den. Meanwhile, Wicki et al. (2023) found a significant 2.2% increase in suicide rates per 10dB increase in railway noise.

Evidence for the effect of transportation noise on anxiety and other mental health disorders remains insufficient. To date, only a few studies have been undertaken in these areas and their findings are inconsistent. Residential exposure to railway noise is generally less prevalent than exposure to road traffic noise, which may partly explain why fewer studies have been conducted. Additionally, in the analyses in existing studies, railway noise may be masked by other sources, particularly road traffic noise, contributing to less consistent findings.

Aircraft noise is linked to mental health disorders, particularly depression. A meta-analysis by Hegewald et al. (2020) found a 12% increase in depression risk per 10dB L_den increase in aircraft noise. This represents a stronger association than for road or rail noise. More recent studies (Wright et al., 2018; Eze et al., 2020) suggest that aircraft noise is associated with elevated depression risk, though their findings are not statistically significant.

Evidence for other mental health issues is limited. Aircraft noise does, however, cause greater annoyance than other transport sources at similar levels (Brink et al., 2019; Fenech et al., 2022) and annoyance is strongly tied to depression and anxiety (Gong et al., 2022). According to Wicki et al. (2023), suicide risk begins to increase at aircraft noise levels of 50dB.

Overall, it is important to consider the mediating effect of annoyance in the causal pathway between environmental noise and poor mental health. People reporting extreme annoyance have nearly double the prevalence of these conditions, with aircraft noise being the top source and social vulnerability amplifying these effects (Baudin et al., 2018, 2021; Beutel et al., 2020). In fact, psychological factors such as noise annoyance and sensitivity to noise often have a stronger association with mental health symptoms than measured noise exposure itself (Baudin et al., 2018).

Table 2. Summary of the strength of evidence linking noise exposure and mental health disorders

Chemicals

Exposure to a wide variety of environmental chemicals is known or suspected to be associated with adverse mental health outcomes. The biological mechanisms underlying such associations are specific to the substances studied and are explored elsewhere (James and O´Shaughnessy, 2023). Although they remain poorly understood, they frequently involve interferences with neurotransmitter systems and receptor functions.

The reviewed evidence on associations between selected environmental chemicals and mental health is summarised in Table 3 below. This gives an overview of the expert assessment of the scientific evidence for links between the main types of chemical exposure and mental health disorders. The findings are presented as risk-outcome pairs and are based on the literature, taking into account the consistency of the results available and their statistical significance. More detailed results are available in the ETC HE report Mental health impacts of air pollution, chemicals, and noise (2026).

Metals: Most of the literature on the association between chemicals and mental health focuses on heavy metals, especially Pb. The most consistent findings relate to links between prenatal or childhood Pb exposure and both depression and schizophrenia. There is evidence that there is an increased risk of developing a major depressive disorder in young adulthood following childhood exposure (Neuwirth et al., 2020). There is also evidence of an association between prenatal Pb exposure and schizophrenia (Opler et al., 2004, 2008). For other heavy metals such as cadmium (Cd), mercury (Hg) or tin (Sn), the evidence is less conclusive.

SHS: Exposure to SHS is consistently linked to depression and schizophrenia, especially in vulnerable groups like children and pregnant women (Han et al., 2019; Jacobson et al., 2022; Modabbernia et al., 2016; Suzuki et al., 2019). Research indicates that SHS results in a significantly increased risk of antenatal depression (Padhani et al., 2024).

Schizophrenia is also associated with prenatal SHS exposure (Hunter et al., 2020). Among children, several reviews point to a consistent link between prenatal or home SHS exposure and increased depressive symptoms (Theron et al., 2022; van der Eijk and Woh, 2023), though some studies report no association or gender-specific effects (Christian and Kim, 2022).

In contrast, evidence linking SHS exposure and anxiety is inconsistent, with no clear pattern of significant associations.

Endocrine-disrupting chemicals: Most of the published studies and reviews focus on Bisphenol A (BPA) and phthalates.

All the identified studies found a positive association between prenatal BPA exposure and depression as well as anxiety in childhood (Raja et al., 2022; Van Den Bosch and Meyer-Lindenberg, 2019; Mesnil et al., 2020). Additionally, there is substantial evidence suggesting sex-specific effects of BPA; however, these effects are not consistent across reviews. For example, Mustieles et al. (2015) suggest that anxiety and depressive symptoms linked to BPA have a greater effect on girls, whereas Van Den Bosch and Meyer-Lindenberg (2019) and Mesnil et al. (2020) suggest that it is mainly boys who are affected. Meanwhile, Mikołajewska et al. (2015) report non-sex-specific positive associations between BPA exposure and depressive symptoms in children.

Authors hypothesise that these differences may result from BPA-induced disruption of brain development, leading to altered formation of sex-specific brain structures and behaviours. This in turn could produce sex-specific effects.

For phthalates, the evidence is more inconsistent; the directions of association are mixed and the strength of evidence varies. A few reviews report a positive association between phthalate exposure and depressive symptoms (Van Den Bosch and Meyer-Lindenberg, 2019; Mesnil et al., 2020), whereas others identify evidence suggesting negative associations (Raja et al., 2022).

Findings for postpartum depressive symptoms are similarly inconsistent: some studies report significant associations, while others suggest there is no evidence for a relationship (Jacobson et al., 2022).

Pesticides: Across the scientific reviews focusing on pesticide exposure, a generally consistent link is reported between exposure and various mental health disorders, primarily depression but also schizophrenia and anxiety. Both Ventriglio et al. (2021) and Wu et al. (2023) examine suicide risk as an outcome and they identify some significant associations.

Several reviews investigate the relationship between prenatal pesticide exposure and depressive symptoms later in life, identifying positive associations in the studies they report on (Van Den Bosch and Meyer-Lindenberg, 2019; Mesnil et al., 2020).

Jacobson et al. (2022) focus on mental health disorders among women postpartum. They point to a positive association between the pesticide heptachlor epoxide and depression and anxiety.

While only a minority of the findings reach statistical significance, multiple reviews nonetheless report that there are positive associations between pesticide exposure and mental health disorders; others describe indicative, though nonsignificant, trends.

Table 3. Summary of the strength of evidence linking chemical exposure and mental health disorders

Opportunities for action

Reducing pollution for mental health

More research is needed to establish conclusively the links and causality between pollution and mental health outcomes. However, the current levels of evidence strengthen the already solid case for urgent and drastic action on pollution, through a variety of means:

• Air pollution: Effective implementation of the revised Ambient Air Quality Directive (EU) 2024/2881 and other legislative mechanisms that reduce the emission of pollutants will help lower air pollution levels and bring them closer to World Health Organization (WHO) recommendations. This will be safer for health and have a range of benefits in terms of reducing non-communicable diseases, including mental health disorders. In addition, the actions required to reduce air pollution have clear co-benefits in terms of climate change mitigation as well as noise reduction (EEA, 2020).
• Environmental noise: Stronger regulatory action and improved urban planning are required to reduce transport noise to achieve the objectives of the ZPAP. Some measures that reduce noise, such as increasing access to green and quiet areas, can also offer co-benefits for mental health (see Box 1 on NbS) as well as climate change adaptation. Others, like improved traffic management, also have co-benefits in terms of reducing air pollution and improving road safety.
• Chemicals: To reduce the risks to mental health from chemicals, it is important for the EU to strengthen its knowledge base on the effects on mental health and underlying mechanisms. Additionally, there is an urgent need to enforce chemicals regulations, accelerate the phase-out of neurotoxic substances and promote safer alternatives. In the case of Pb, the recently adopted Directive (EU) 2024/869 significantly strengthens protections for workers exposed to Pb and its inorganic compounds, lowering the occupational exposure limit. The European Commission has also proposed a ban on Pb in ammunition and fishing weights under the REACH Regulation.

The One Health approach recognises the interconnectedness of human, animal and environmental health. The approach can help to reduce stressors like outbreaks of zoonotic diseases and environmental degradation that contribute to mental health problems. Using environmental assets to prevent and treat mental health disorders (as featured in Box 1) is in line with this integrative approach. However, NbS cannot be a substitute for reducing pollution. The two approaches must be complementary.

The One Health approach recognises the interconnectedness of human, animal and environmental health. The approach can help to reduce stressors like outbreaks of zoonotic diseases and environmental degradation that contribute to mental health problems. Using environmental assets to prevent and treat mental health disorders (as featured in Box 1) is in line with this integrative approach. However, NbS cannot be a substitute for reducing pollution. The two approaches must be complementary.

Addressing research gaps

More research is needed to establish conclusively the actual links between certain environmental exposures and mental health disorders. Key research gaps include:

• Lack of integration across disciplines: Research often remains siloed between environmental science and psychiatry. This hinders an understanding of how environmental exposures interact with neurobiological pathways  (National Academies of Sciences, Engineering, and Medicine, 2021).
• Lack of longitudinal and causal evidence: Most studies are cross-sectional. This limits the extent to which causation can be inferred. Separating out the effects also remains a particular challenge for the research on air pollution, noise and chemicals. Interpreting the effects of the different types of exposure is complicated further by sociodemographic factors such as housing conditions or neighbourhood social capital. This makes it hard to paint a clear picture of causation. Future research should focus on strengthening causal understanding, improving the consistency of measurements and exploring long-term effects. Long-term studies with rigorous assessments of outcome and exposure — which take a developmental approach to examine windows of susceptibility — are crucial to determine both the significance and magnitude of the associations (Zundel et al., 2022).
• Lack of focus on built and natural environments: While there has been research on the social determinants of mental health outcomes, there has been less focus on the roles of natural (e.g. climate, biodiversity) and built environments (e.g. housing quality, urban design) (Ratjen et al., 2025).
• Measurement challenges: Inconsistent definitions and metrics for both environmental exposures and mental health outcomes mean that it is hard to compare studies (Garavito et al., 2024). This is a problem across most research on certain environmental factors, such as the availability of green space.
• Mechanistic pathways: There is limited understanding of the biological mechanisms linking environmental exposures to psychiatric disorders, such as inflammation, neurotoxicity or epigenetic changes (Zundel et al., 2022).

Conclusions

A growing body of evidence linking pollution to mental health issues underscores the urgency of integrating environmental and public health policies as well as fostering cooperation and collaboration between relevant sectors and disciplines. It points to the need for a One Health approach, which recognises the interdependence between human, animal and environmental health to better prevent, detect and respond to complex global threats like pandemics and antimicrobial resistance.

Scientific studies indicate that air pollution, environmental noise and chemical exposures — particularly during sensitive developmental phases of human life — are associated with increased risks of a range of mental health disorders. These include depression, anxiety, schizophrenia and behavioural disorders. While some associations are increasingly established, others remain indicative but inconclusive. This highlights the complexity of disentangling environmental influences from other social and biological determinants.

Nonetheless, even modest reductions in pollution levels could yield meaningful improvements in mental health across the population. This understanding reinforces the importance of proactively implementing EU directives and strategies to reduce pollution.

NbS cannot replace exposure-reduction policies but may be beneficial as complementary interventions targeted at the individual to support mental well-being. Structured engagement with green and blue spaces — through activities like forest bathing, gardening and nature-based social prescribing — can reduce stress, enhance mood and foster social connectedness. These approaches align with a One Health perspective, promoting both human and environmental health.

Overall, further research is needed to strengthen causal understanding, improve the consistency of measurements and explore long-term effects. Bridging the gaps between environmental science and psychiatry is key to developing effective, equitable and sustainable responses to the mental health burden linked to pollution.