Qi Xue, Lan Jiacheng, Sun Yuchuan, Wang Shasha, Liu Lei, Wang Junxian, Long Qixia, Huang Mingzhi, Yue Kunqian
School of Karst Science / State Engineering Technology Institute for Karst Desertification control, Guizhou Normal University, Guiyang 550001, China.
School of Karst Science / State Engineering Technology Institute for Karst Desertification control, Guizhou Normal University, Guiyang 550001, China.
Ecotoxicol Environ Saf. 2023 Oct 1;264:115465. doi: 10.1016/j.ecoenv.2023.115465. Epub 2023 Sep 15.
A systematic assessment of the variations in the ecological risk of PAHs and the key emission sources controlling the variations is of great importance to human health and aquatic organisms. PAH concentrations, composition, source, and ecological risk in soils and water in two different periods (2010-2011 and 2019) of three typical epikarst springs in Southwest China were investigated. Results showed that PAH concentrations in soil and water have an overall downward trend (a reduction of 57 % and 93 %, respectively) in the past 10 years, which is consistent with the downward trend in the relative contribution rate of raw coal production (a 66 % reduction). In terms of composition, the proportion of low-ring PAHs decreased, medium-ring and high-ring PAHs increased in the soil profile. The proportion of low-ring PAHs did not change obviously, the proportion of medium-ring PAHs increased, and the proportion of high-ring PAHs decreased in epikarst springs. The source of PAHs changed remarkably over time, the relative contribution of coal combustion to PAHs decreased from 38 % to 20 %, and the vehicle contribution of PAHs increased from 31 % to 44 % in soils. The relative contribution rate of unburned oil and coke oven and biomass combustion change is less. Furthermore, the ecological risk of PAHs in the soils was reduced from moderate risk 2 to moderate risk 1, the risk in epikarst spring was reduced from high risk to moderate risk 2 after 10 years. This study demonstrates that substituting petroleum and coal with green energies can reduce PAH concentrations and risk.
系统评估多环芳烃（PAHs）生态风险的变化以及控制这些变化的关键排放源，对人类健康和水生生物至关重要。对中国西南地区三个典型表层岩溶泉在两个不同时期（2010 - 2011年和2019年）土壤和水中的PAH浓度、组成、来源及生态风险进行了调查。结果表明，过去10年土壤和水中的PAH浓度总体呈下降趋势（分别降低了57%和93%），这与原煤产量相对贡献率的下降趋势（降低了66%）一致。在组成方面，土壤剖面中低环PAHs的比例下降，中环和高环PAHs的比例增加。表层岩溶泉中低环PAHs的比例变化不明显，中环PAHs的比例增加，高环PAHs的比例下降。PAHs的来源随时间发生了显著变化，土壤中煤炭燃烧对PAHs的相对贡献率从38%降至20%，车辆排放对PAHs的贡献率从31%增至44%。未燃烧石油、焦炉和生物质燃烧的相对贡献率变化较小。此外，土壤中PAHs的生态风险从中等风险2降至中等风险1，10年后表层岩溶泉的风险从高风险降至中等风险2。本研究表明，用绿色能源替代石油和煤炭可以降低PAH浓度和风险。
