Suicide and Associations with Air Pollution and Ambient Temperature: A Systematic Review and Meta-Analysis

Abstract

Given health threats of climate change, a comprehensive review of the impacts of ambient temperature and ar pollution on suicide is needed. We performed systematic literature review and meta-analysis of suicide risks associated with short-term exposure to ambient temperature and air pollution. Pubmed, Scopus, and Web of Science were searched for English-language publications using relevant keywords. Observational studies assessing risks of daily suicide and suicide attempts associated with temperature, particulate matter with aerodynamic diameter ≤10 μm (PM10) and ≤2.5 mm (PM2.5), ozone (O3), sulfur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO) were included. Data extraction was independently performed in duplicate. Random-effect meta-analysis was applied to pool risk ratios (RRs) for increases in daily suicide per interquartile range (IQR) increase in exposure. Meta-regression analysis was applied to examine effect modification by income level based on gross national income (GNI) per capita, national suicide rates, and average level of exposure factors. In total 2274 articles were screened, with 18 studies meeting inclusion criteria for air pollution and 32 studies for temperature. RRs of suicide per 7.1 °C temperature was 1.09 (95% CI: 1.06, 1.13). RRs of suicide per IQR increase in PM2.5, PM10, and NO2 were 1.02 (95% CI: 1.00, 1.05), 1.01 (95% CI: 1.00, 1.03), and 1.03 (95% CI: 1.00, 1.07). O3, SO2, and CO were not associated with suicide. RR of suicide was significantly higher in higher-income than lower-income countries (1.09, 95% CI: 1.07, 1.11 and 1.20, 95% CI: 1.14, 1.26 per 7.1 °C increased temperature, respectively). Suicide risks associated with air pollution did not significantly differ by income level, national suicide rates, or average exposure levels. Research gaps were found for interactions between air pollution and temperature on suicide risks.

Climate change anxiety and mental health: Environmental activism as buffer

“…Increasing evidence indicates that climate change will have far-reaching impacts on human health, including mental health (Doherty & Clayton, 2011 ; Hayes et al, 2018 ). A large body of literature has investigated the mental health consequences of one marker of climate change, weather-related disasters, showing elevated rates of common psychiatric conditions like Major Depressive Disorder (MDD) and Generalized Anxiety Disorder (GAD) (Goldmann & Galea, 2014 ; Hrabok et al, 2020 ), and a growing number of studies also suggest that rising temperatures can impair mental health and increase risk for suicidal behavior (Burke et al, 2018 ; Cianconi et al, 2020 ; Heo et al, 2021 ). However, a focus on weather-related disasters and temperature misses the full range of climate change exposures, including its subtler indicators, and their mental health consequences.…”

The Impact of Foehn Wind on Mental Distress among Patients in a Swiss Psychiatric Hospital

“…The biological mechanisms underlying the influence of meteorological factors on mental health remain largely unknown. Regarding heatwave-related exacerbations, several postulations have been put forth regarding the failure of thermoregulation, leading to an imbalance of serotonin levels, neuroinflammation in the brain, neurotoxicity, and alterations in metabolic functions [ 56 , 57 , 58 ]. Additionally, the dysfunctional effects of certain psychiatric medicines inhibiting adaptive thermoregulation of the body, a deficit of weather-dependent behavioral adaptations by people suffering from mental disorders, and disrupted sleep have been proposed [ 10 , 21 , 22 , 58 , 59 ].…”

The Impact of Foehn Wind on Mental Distress among Patients in a Swiss Psychiatric Hospital

“…The biological mechanisms underlying the influence of meteorological factors on mental health remain largely unknown. Regarding heatwave-related exacerbations, several postulations have been put forth regarding the failure of thermoregulation, leading to an imbalance of serotonin levels, neuroinflammation in the brain, neurotoxicity, and alterations in metabolic functions [55][56][57]. Additionally, the dysfunctional effects of certain psychiatric medicines inhibiting adaptive thermoregulation of the body, a deficit of weather dependent behavioral adaptations by people suffering from mental disorders, and disrupted sleep have been proposed [10,21,22,57,58].…”