Air Pollution and Suicide in 10 Cities in Northeast Asia: A Time-Stratified Case-Crossover Analysis

Abstract

Background:There is growing evidence suggesting an association between air pollution and suicide. However, previous findings varied depending on the type of air pollutant and study location.Objectives:We examined the association between air pollutants and suicide in 10 large cities in South Korea, Japan, and Taiwan.Methods:We used a two-stage meta-analysis. First, we conducted a time-stratified case-crossover analysis to estimate the short-term association between nitrogen dioxide (NO2), sulfur dioxide (SO2), and particulate matter [aerodynamic diameter ≤10μm (PM10), aerodynamic diameter ≤2.5μm (PM2.5), and PM10−2.5] and suicide, adjusted for weather factors, day-of-week, long-term time trends, and season. Then, we conducted a meta-analysis to combine the city-specific effect estimates for NO2, SO2, and PM10 across 10 cities and for PM2.5 and PM10−2.5 across 3 cities. We first fitted single-pollutant models, followed by two-pollutant models to examine the robustness of the associations.Results:Higher risk of suicide was associated with higher levels of NO2, SO2, PM10, and PM10−2.5 over multiple days. The combined relative risks (RRs) were 1.019 for NO2 (95% confidence interval [CI]: 0.999, 1.039), 1.020 for SO2 (95% CI: 1.005, 1.036), 1.016 for PM10 (95% CI: 1.004, 1.029), and 1.019 for PM10−2.5 (95% CI: 1.005, 1.033) per interquartile range (IQR) increase in the 0–1 d average level of each pollutant. We found no evidence of an association for PM2.5. Some of the associations, particularly for SO2 and NO2, were attenuated after adjusting for a second pollutant.Conclusions:Our findings suggest that higher levels of air pollution may be associated with suicide, and further research is merited to understand the underlying mechanisms. https://doi.org/10.1289/EHP2223

Hourly Exposure to Ultrafine Particle Metrics and the Onset of Myocardial Infarction in Augsburg, Germany

“…We conducted several sensitivity analyses to assess the robustness of our results: a) we increased the population age limit from 74 y to 84 y by including additional patients 75-84 years of age from 2009 to 2015 (1,377 MI cases); b) we used an alternative 5-d average lag for temperature as reported in a previous analysis (Wolf et al 2009); c) we used two temperature terms to account for both the current temperature and lagged temperature (1-24 h, 1-48 h, or 1-72 h), as well as the concurrent temperature with the same lag as particle metrics and lagged temperature at the previous 2-3 d (25-72 h); d) we redefined the control periods by changing the fixed time strata from calendar month to a recurring 3-week period (e.g., first to third week of the year) to assess the influence of time strata (Kim et al 2018); e) we redefined the high and low levels of copollutants and air temperature, using the 50th percentile as the cut off value in the effect modification analyses; and f) we explored the exposure-response relationships between particle metrics and MI by applying a natural cubic spline with 4 df to the pollutant term (rather than a linear term). Akaike information criteria (AIC) values were used to compare the model fits between model with this nonlinear pollutant term and the main model with a linear pollutant term.…”

Air Pollution, Stress, and Allostatic Load: Linking Systemic and Central Nervous System Impacts

“…Despite their differing properties and potential routes of exposure, both particulate matter and ozone have been associated with a variety of CNS impacts. These include impaired cognitive performance [27][28][29], dementia [30,31], anxiety and depression [32][33][34][35], and suicide [36][37][38]. It should be noted that there is considerable variability in the epidemiologic literature; a more comprehensive overview of associations between particulate matter or ozone and neurological/mental health outcomes is provided in several recent reviews [5,6,20,39,40].…”

Numerical simulation on flow and evaporation characteristics of desulfurization wastewater in a bypass flue

“…Sulfur dioxide (SO 2 ) has a prominent impact on air quality, which is closely related to human health. At present, the SO 2 emissions from coal-fired power plants, which are a traditional energy source still used to support the economic needs in many countries, have become a serious problem which must be considered and solved by the government of each country (Akiko, Yoshiki, & Kazuaki, 2015;Alessandra et al, 2019;Kim et al, 2018;Lin et al, 2018). Under these circumstances, the emission standards for SO 2 have been continuously improved worldwide.…”