The impact of short-term exposure to air pollutants on the onset of out-of-hospital cardiac arrest: A systematic review and meta-analysis.
BACKGROUND
Acute exposure to outdoor air pollution was considered to be associated with the incidence of out-of-hospital cardiac arrest (OHCA). But the relation between specific air pollutants and OHCA remains controversial. We conducted a systematic review and meta-analysis to quantitatively assess the acute effects of air pollutants, including particulate matter (PM10and PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO) and ozone (O3) on OHCA onset.


METHODS
Six databases were searched to identify studies analyzing the association between OHCA and the main air pollutants. We summarized the pooled estimates using random-effect models. Heterogeneity within studies was assessed using Cochran's Q and I2statistics. Funnel plots, Egger's regression test and Begg's rank correlation method were constructed to evaluate publication bias. Subgroup analyses and sensitivity analyses were also conducted to evaluate the potential sources of heterogeneity.


RESULTS
A total of 15 studies met the inclusion criteria. PM10, PM2.5, NO2and O3were found to be significantly associated with increase in OHCA risk (PM101.021, 95%CI: 1.006-1.037; PM2.51.041, 95%CI: 1.012-1.071; NO21.015, 95%CI: 1.001-1.030 and O31.016, 95%CI: 1.008-1.024). The acute exposure to SO2and CO was not associated with the incidence of OHCA. Additional analyses verified the findings in the overall analyses except SO2and NO2. Population attributable fractions for PM10, PM2.5, and O3were 2.1%, 3.9% and 1.6%, respectively.


CONCLUSIONS
The current evidence confirmed the associations between short-term exposure to PM2.5, PM10and O3and a high risk of OHCA, with the strongest association being observed for PM2.5.
Department of Epidemiology and Biostatistics, Ministry of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical college, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China.
Rongxian
R
Zhao
Department of Epidemiology and Biostatistics, Ministry of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical college, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China.
Shi
S
Chen
Department of Epidemiology and Biostatistics, Ministry of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical college, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China.
Weiye
W
Wang
Department of Epidemiology and Biostatistics, Ministry of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical college, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China.
Jiao
J
Huang
Department of Epidemiology and Biostatistics, Ministry of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical college, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China.
Ke
K
Wang
Department of Epidemiology and Biostatistics, Ministry of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical college, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China.
Li
L
Liu
Department of Epidemiology and Biostatistics, Ministry of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical college, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China. Electronic address: ws2008cn@gmail.com.
Sheng
S
Wei
D000393:Air Pollutants / Q000009:adverse effects* / Q000032:analysis; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D016208:Databases, Factual; D004781:Environmental Exposure / Q000009:adverse effects* / Q000032:analysis; D006801:Humans; D058687:Out-of-Hospital Cardiac Arrest / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology*; D052638:Particulate Matter / Q000009:adverse effects* / Q000032:analysis
D000393:Air Pollutants; D052638:Particulate Matter
Air pollutant; Meta-analysis; Out-of-hospital cardiac arrests