PDF(Pubmed)
Abstract：
Baoji is a typical heavy industrial city in northwest China. Its air quality is greatly impacted by the emission from the factories. Elements in fine particulate matter (PM2.5) that are greatly emitted from anthropogenic sources could pose diverse health impacts on humans. In this study, an online AMMS-100 atmospheric heavy metal analyzer was used to quantify 30 elements in PM2.5 under the weak and strong anthropogenic disturbance scenarios before the city lockdown period (from January 9th to 23rd) and the lockdown period (from January 26th to February 9th) due to the outbreak of COVID-19 in 2020. During the lockdown period, the average total concentration of total quantified elements was 3475.0 ng/m3, which was 28% and 33% lower than that of the week and strong anthropogenic disturbance scenarios during the pre-lockdown period. The greatest reductions were found for the elements of chromium (Cr), titanium (Ti), manganese (Mn), and Zinc (Zn), consistent with the industrial structure of Baoji. The mass concentrations of most elements showed obvious reductions when the government post-alerted the industries to reduce the operations and production. Dust, traffic sources, combustion, non-ferrous metal processing, and Ti-related industrial processing that are the contributors of the elements in the pre-lockdown period were apportioned by the positive matrix factorization (PMF) model. Substantial changes in the quantified elements\' compositions and sources were found in the lockdown period. Health assessment was conducted and characterized by apportioned sources. The highest non-carcinogenic risk (HQ) was seen for Zn, demonstrating the high emissions from the related industrial activities. The concentration level of arsenic (As) exceeded the incremental lifetime carcinogenic risk (ILCR) in the lockdown period. This could be attributed to the traditional firework activities for the celebration of the Chinese New Year within the lockdown period.
摘要：
宝鸡是中国西北地区典型的重工业城市。它的空气质量受到工厂排放的极大影响。从人为来源大量排放的细颗粒物（PM2.5）中的元素可能会对人类造成多种健康影响。在这项研究中,由于2020年COVID-19的爆发，在城市封锁期（1月9日至23日）和封锁期（1月26日至2月9日）之前的弱和强人为干扰情景下，使用在线AMMS-100大气重金属分析仪量化PM2.5中的30种元素。在封锁期间，总量化元素的平均总浓度为3475.0ng/m3，比封锁前的一周和强烈人为干扰情景分别低28%和33%。铬（Cr）元素的减少量最大，钛(Ti),锰(Mn),和锌（Zn），与宝鸡的产业结构相一致。当政府对行业发出警告以减少运营和生产时，大多数元素的质量浓度显着降低。灰尘,交通来源,燃烧,有色金属加工，与钛相关的工业加工是封锁前阶段元素的贡献者，由正矩阵分解(PMF)模型进行分配。在封锁期间，定量元素的组成和来源发生了重大变化。进行了健康评估，并以分配的来源为特征。锌的非致癌风险（HQ）最高，展示了相关工业活动的高排放。在封锁期间，砷（As）的浓度水平超过了寿命增加的致癌风险（ILCR）。这可以归因于在封锁期内庆祝农历新年的传统烟花活动。
