TY - JOUR
T1 - Air Pollution and Suicide in 10 Cities in Northeast Asia
T2 - A Time-Stratified Case-Crossover Analysis
AU - Kim, Yoonhee
AU - Ng, Chris Fook Sheng
AU - Chung, Yeonseung
AU - Kim, Ho
AU - Honda, Yasushi
AU - Guo, Yue Leon
AU - Lim, Youn-Hee
AU - Chen, Bing-Yu
AU - Page, Lisa A
AU - Hashizume, Masahiro
PY - 2018/3
Y1 - 2018/3
N2 - 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 ≤10 lm (PM10), aerodynamic diameter ≤2:5 lm (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.
AB - 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 ≤10 lm (PM10), aerodynamic diameter ≤2:5 lm (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.
KW - Air Pollutants/toxicity
KW - Air Pollution/adverse effects
KW - Environmental Exposure
KW - Humans
KW - Nitrogen Dioxide/toxicity
KW - Particulate Matter/toxicity
KW - Republic of Korea
KW - Suicide/statistics & numerical data
KW - Sulfur Dioxide/toxicity
U2 - 10.1289/EHP2223
DO - 10.1289/EHP2223
M3 - Journal article
C2 - 29529596
SN - 0091-6765
VL - 126
JO - Environmental Health Perspectives
JF - Environmental Health Perspectives
IS - 3
M1 - 037002
ER -
