A study led by researchers at IDIBAPS-Hospital Clínic Barcelona has reanalysed all the meta-analyses done worldwide on the effects of climate change and air pollution on mental health and has found strong links between rising temperatures and an increase in mortality due to suicide or mental disorders. Exposure to various pollutants has also been linked to a higher incidence of dementia or cognitive impairment.
The direct effects of climate change and pollution on people’s physical health, such as cardiorespiratory problems and carcinogenic effects, are widely known. There is also great concern about the impact they have on mental health, but no complete analysis of the existing evidence had been conducted until now.
For the study, published in the journal World Psychiatry, all meta-analyses published thus far that related climate change or air pollution to mental health were reviewed and all the results obtained were grouped in a large meta-analysis (“umbrella review”) from which to draw solid conclusions. The meta-analysis was led by the group Imaging of mood- and anxiety-related disorders (IMARD), led by Joaquim Raduà, and the Bipolar and depressive disorders group, headed by Eduard Vieta, the head of the Psychiatry and Psychology Department at Hospital Clínic Barcelona. Both are also members of the University of Barcelona and the Mental Health area of CIBER (CIBERSAM).
Climate change and pollution have a negative impact on mental health
One of the most important results is the link that has been found between rising temperatures and an increase in suicide. Specifically, it has been estimated that global warming may have caused a 5% increase in suicide and it is expected to rise to 7% by 2050. There has also been an increase in suicidal behaviour and hospital admissions due to this problem.
“These data on the impact of climate change on mental health add to what we already knew about its impact on physical health, forcing us with capital letters to urgently push global initiatives to fight climate change”, says Joaquim Raduà, the first author of the article.
Joaquim Raduà and his team have also found that long-term exposure to solvents is related to a higher incidence of cases of dementia or cognitive impairment. Specifically, exposure to high levels of products such as toluene (used in paints, enamels, vanishes and adhesives) increase the likelihood of developing one of these disorders.
“The use of these solvents poses serious health risks, especially in low- and middle-income countries, where alternatives to these inexpensive materials are difficult to find for construction and manufacturing”, says Michele De Prisco, an IDIBAPS researcher and the co-first author of the study. “Since they are products that are used globally, emissions of these pollutants are expected to double by 2030. This is alarming because we now know that they not only pose an environmental risk, but also seriously affect mental health”.
The study also indicates that exposure during the second trimester of pregnancy to polluting particles, which may contain various substances such as benzopyrenes, furans or heavy metals coming from fossil fuels and industrial activities, can increase the incidence of postnatal depression. Finally, it has also been found that exposure to high levels of sulphur dioxide (from the combustion of oil and other solid fuels used in industry) may increase the risk of relapse in patients with schizophrenia.
“Thanks to this study, we now have robust evidence of the negative impact that climate change and pollution are having on mental health around the world. These results can be used to inform the authorities and raise public awareness about the impact of air pollution and the risks of climate change on mental health and thereby seek and take action to prevent it”, says Joaquim Raduà.
Study reference:
Radua, J., De Prisco, M., Oliva, V., Fico, G., Vieta, E. and Fusar-Poli, P. (2024), Impact of air pollution and climate change on mental health outcomes: an umbrella review of global evidence. World Psychiatry, 23: 244-256.
