Air Toxicity Surveillance across Thirteen Cities Using Rats

Current monitoring methods fail to assess air toxicity
in real
time, which is yet badly desired to better estimate the health impact.
Here, we developed and deployed an automated, low-cost, and time-resolved
system for noninvasive monitoring of air toxicity by detecting eight
breath-borne biomarkers from rats, including VOCs, CO2,
CO, NO, H2S, H2O2, O2,
and NH3. Using this system, two large-scale monitoring
campaigns were conducted across 13 cities in China during the 2023
winter and 2024 spring continuously on a 24-h-a-day basis. In characterizing
overall air pollution health impact, a novel Air Toxic Index (ATI)
was developed using the eight breath-borne biomarkers from the rats.
Significant differences in diurnal patterns of ATI were observed across
13 cities. Among others, time, city, PM2.5, and O3 were identified as the primary influencing factors of ATI, exhibiting
complex nonlinear relationships in real-world environments. The unique
variation patterns of breath-borne NO and H2O2 from rats indicated the time-resolved impacts of ground human activities
on weekends and PM components on air toxicity. Histopathologic changes
in these deployed rats’ lungs further validated the differential
health effects of real-world air pollution from different cities as
detected by the rat system. Here, we pioneer a new air pollution health
effect monitoring system that realizes the in vivo detection of air
toxicity in contrast to the traditional protocol of air sampling,
exposure, and offline toxicity analysis steps. The system can be deployed
easily to any location with minimal support for real-time monitoring
of air pollution health impacts.

现有空气毒性监测技术均无法实现实时检测，而实时监测正是精准评估空气污染健康影响的迫切需求。本研究开发并部署了一套自动化、低成本且具备时间分辨率的无创空气毒性监测系统，通过检测大鼠呼出的8种生物标志物实现空气毒性监测，所检测标志物包括挥发性有机化合物(VOCs)、二氧化碳(CO₂)、一氧化碳(CO)、一氧化氮(NO)、硫化氢(H₂S)、过氧化氢(H₂O₂)、氧气(O₂)与氨气(NH₃)。依托该系统，本研究于2023年冬季与2024年春季在中国13座城市开展了两项大规模监测工作，每日24小时不间断运行。为表征空气污染的整体健康影响，本研究基于大鼠呼出的8种生物标志物，构建了一种新型空气毒性指数(Air Toxic Index, ATI)。13座城市的空气毒性指数日变化模式存在显著差异。研究表明，时间、城市、细颗粒物(PM₂.₅)与臭氧(O₃)是影响空气毒性指数的核心因素，且在真实环境中这些因素与空气毒性指数之间存在复杂的非线性关联。大鼠呼出的一氧化氮(NO)与过氧化氢(H₂O₂)的独特变化模式，揭示了人类地面活动在周末时段对空气毒性的时间分辨影响，以及大气颗粒物组分对空气毒性的调控效应。受试大鼠肺部的组织病理学变化，进一步验证了本大鼠监测系统所检测到的、不同城市真实环境空气污染所引发的差异化健康效应。相较于传统的空气采样、暴露染毒与离线毒性分析流程，本研究首创了一套可实现空气毒性活体(in vivo)检测的空气污染健康效应监测系统。该系统仅需极少配套支撑即可便捷部署至任意地点，实现空气污染健康影响的实时监测。