Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
Centre for Occupational and Environmental Medicine, Region Stockholm, Stockholm, Sweden.
JAMA Netw Open. 2022 Apr 1;5(4):e228109. doi: 10.1001/jamanetworkopen.2022.8109.
Mounting ecological evidence shows an association between short-term air pollution exposure and COVID-19, yet no study has examined this association on an individual level.
To estimate the association between short-term exposure to ambient air pollution and SARS-CoV-2 infection among Swedish young adults.
DESIGN, SETTING, AND PARTICIPANTS: This time-stratified case-crossover study linked the prospective BAMSE (Children, Allergy Milieu, Stockholm, Epidemiology [in Swedish]) birth cohort to the Swedish national infectious disease registry to identify cases with positive results for SARS-CoV-2 polymerase chain reaction (PCR) testing from May 5, 2020, to March 31, 2021. Case day was defined as the date of the PCR test, whereas the dates with the same day of the week within the same calendar month and year were selected as control days. Data analysis was conducted from September 1 to December 31, 2021.
Daily air pollutant levels (particulate matter with diameter ≤2.5 μm [PM2.5], particulate matter with diameter ≤10 μm [PM10], black carbon [BC], and nitrogen oxides [NOx]) at residential addresses were estimated using dispersion models with high spatiotemporal resolution.
Confirmed SARS-CoV-2 infection among participants within the BAMSE cohort. Distributed-lag models combined with conditional logistic regression models were used to estimate the association.
A total of 425 cases were identified, of whom 229 (53.9%) were women, and the median age was 25.6 (IQR, 24.9-26.3) years. The median exposure level for PM2.5 was 4.4 [IQR, 2.6-6.8] μg/m3 on case days; for PM10, 7.7 [IQR, 4.6-11.3] μg/m3 on case days; for BC, 0.3 [IQR, 0.2-0.5] μg/m3 on case days; and for NOx, 8.2 [5.6-14.1] μg/m3 on case days. Median exposure levels on control days were 3.8 [IQR, 2.4-5.9] μg/m3 for PM2.5, 6.6 [IQR, 4.5-10.4] μg/m3 for PM10, 0.2 [IQR, 0.2-0.4] μg/m3 for BC, and 7.7 [IQR, 5.3-12.8] μg/m3 for NOx. Each IQR increase in short-term exposure to PM2.5 on lag 2 was associated with a relative increase in positive results of SARS-CoV-2 PCR testing of 6.8% (95% CI, 2.1%-11.8%); exposure to PM10 on lag 2, 6.9% (95% CI, 2.0%-12.1%); and exposure to BC on lag 1, 5.8% (95% CI, 0.3%-11.6%). These findings were not associated with NOx, nor were they modified by sex, smoking, or having asthma, overweight, or self-reported COVID-19 respiratory symptoms.
The findings of this case-crossover study of Swedish young adults suggest that short-term exposure to particulate matter and BC was associated with increased risk of positive PRC test results for SARS-CoV-2, supporting the broad public health benefits of reducing ambient air pollution levels.
越来越多的生态证据表明，短期暴露于空气污染与 COVID-19 之间存在关联，但尚无研究在个体水平上对此关联进行检验。
估计短期暴露于环境空气中的污染物与瑞典年轻成年人中 SARS-CoV-2 感染之间的关联。
设计、地点和参与者：这项时间分层病例交叉研究将前瞻性的 BAMSE（儿童、过敏环境、斯德哥尔摩、流行病学）出生队列与瑞典国家传染病登记处联系起来，以确定 2020 年 5 月 5 日至 2021 年 3 月 31 日期间 SARS-CoV-2 聚合酶链反应（PCR）检测结果为阳性的病例。病例日定义为 PCR 检测日期，而同一日历月和年份中相同星期几的日期则被选为对照日。数据分析于 2021 年 9 月 1 日至 12 月 31 日进行。
使用具有高时空分辨率的扩散模型来估计住宅地址处的每日空气污染物水平（直径≤2.5μm 的颗粒物[PM2.5]、直径≤10μm 的颗粒物[PM10]、黑碳[BC]和氮氧化物[NOx]）。
在 BAMSE 队列中，确定了参与者中经证实的 SARS-CoV-2 感染病例。分布滞后模型结合条件逻辑回归模型用于估计关联。
共确定了 425 例病例，其中 229 例（53.9%）为女性，中位年龄为 25.6（四分位距，24.9-26.3）岁。病例日 PM2.5 的中位暴露水平为 4.4[四分位距，2.6-6.8]μg/m3；PM10 为 7.7[四分位距，4.6-11.3]μg/m3；BC 为 0.3[四分位距，0.2-0.5]μg/m3；NOx 为 8.2[四分位距，5.6-14.1]μg/m3。对照日 PM2.5 的中位暴露水平为 3.8[四分位距，2.4-5.9]μg/m3，PM10 为 6.6[四分位距，4.5-10.4]μg/m3，BC 为 0.2[四分位距，0.2-0.4]μg/m3，NOx 为 7.7[四分位距，5.3-12.8]μg/m3。短期暴露于 PM2.5 的每个 IQR 增加与 SARS-CoV-2 PCR 检测结果阳性的相对增加相关，增幅为 6.8%（95%CI，2.1%-11.8%）；PM10 暴露的增幅为 6.9%（95%CI，2.0%-12.1%）；BC 暴露的增幅为 5.8%（95%CI，0.3%-11.6%）。这些发现与 NOx 无关，也不受性别、吸烟、超重或自我报告的 COVID-19 呼吸道症状的影响。
这项对瑞典年轻成年人的病例交叉研究的结果表明，短期暴露于颗粒物和 BC 与 SARS-CoV-2 聚合酶链反应检测结果阳性的风险增加相关，支持减少环境空气污染水平带来的广泛公共卫生效益。
