气态污染物浓度对流感暴发风险的影响

The Influence of Gaseous Pollutants Concentration on Influenza Outbreak Risk

摘要: 为探究深圳市气态污染物浓度对流感暴发疫情的潜在影响，为流感的防控提供参考依据。本研究收集了2013年5月1日至2015年12月31日的深圳市流感暴发疫情逐日监测数据，以及该时间段内气象要素与大气污染物浓度数据，区分两种流感病毒亚型(甲流、乙流)，通过建立分布–滞后模型(Distributed-Lag Nonlinear Model, DLNM)研究流感暴发风险与三种气态污染物(NO₂、SO₂和O₃)浓度的关联性。结果表明，冷季(11月4日至次年4月20日)两种病毒亚型的暴发高峰基本与NO₂、SO₂的浓度高峰相对应；而暖季(4月19日至11月3日)大气中高浓度的O₃常伴随着流感的暴发。冷季高浓度的NO₂和SO₂对甲流疫情存在显著的短期滞后影响。暴发当天68.51 µg/m³ (P₉₅)的NO₂和21.77 µg/m³ (P₉₅)的SO₂相关联的相对危险度(Relative Risk, RR)分别为3.04 (95% CI: 2.07~4.48)和1.76 (95% CI: 1.08~2.88)。然而，NO₂对乙流疫情的影响不显著，SO₂在滞后3~5 d时对乙流有微弱影响，例如，滞后4 d时21.77 µg/m³ (P₉₅) SO₂相关联的RR = 1.45 (95% CI: 1.12~1.80)。在暖季，高浓度的O₃对流感暴发存在显著影响。对甲流而言，在滞后3 d时效应最为显著，162.12 µg/m³ (P₉₅) O₃的RR = 2.42 (95% CI: 1.12~5.42)；对乙流而言，暴发当日影响最强烈，162.12 µg/m³ O₃的RR = 3.50 (95% CI: 1.54~7.96)。此外，冷季O₃浓度本身较低，且对流感的影响不甚显著。综上，NO₂、SO₂在冷季对甲流疫情的影响更为显著，而高浓度O₃在暖季也会增加流感风险。

Abstract: To explore the potential impact of gaseous pollutant concentration on influenza outbreak epidemics in Shenzhen, and provide a scientific reference for influenza prevention and control, in this study, we collect the daily monitoring data of influenza outbreak in Shenzhen from May 1, 2013 to December 31, 2015, as well as local meteorological factors and atmospheric pollutant concentration during the same period. We differentiated two influenza virus subtypes, i.e., influenza A and influenza B, to research the risk of influenza outbreak and lag effects of three gaseous pollutants (NO₂, SO₂, and O₃), through establishing the Distributed-Lag Nonlinear Model (DLNM). The results show that, the peaks of two subtypes’ outbreak in the cool season (November 4 to April 20 of the following year) basically corresponded to the high peaks of NO₂ and SO₂, while high concentration of O₃ in the warm season (April 19 to November 3) was accompanied by influenza epidemic. There was a significant short-term lag effect of NO₂ and SO₂ during the cold season on the influenza A outbreak. The Relative Risk (RR) associated with 68.51 µg/m³ (P₉₅) of NO₂ and 21.77 µg/m³ (P₉₅) of SO₂ on the current day was 3.04 (95% CI: 2.07~4.48) and 1.76 (95% CI: 1.08~2.88), respectively. However, NO₂ did not show a significant influence on influenza B, while SO₂ had a weak effect at a lag of 3~5 d. For example, the RR of a 21.77 µg/m³ (P₉₅) SO₂ on lag 4 d was 1.45 (95% CI: 1.12~1.80). High concentration of O₃ had a significant effect on influenza during the warm season. For influenza A, the effect was strongest on lag 3 d, RR was 2.42 (95% CI: 1.12~5.42) for a 162.12 µg/m³ (P₉₅) of O₃. With regard for influenza B, the strongest effect was on the day of outbreak, the RR at a concentration of 162.12 µg/m³ was 3.50 (95% CI: 1.54~7.96). In addition, in the cool season, the concentration of O₃ was lower and had minor effect on influenza. In conclusion, NO₂ and SO₂ have more significant effects on influenza A epidemic in the cold season, while high concentration of O₃ increases the risk of influenza in the warm season.