Feld-Cook Elisabeth E, Bovenkamp-Langlois Lisa, Lomnicki Slawo M
Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States.
Center for Advanced Microstructures & Devices (CAMD), Louisiana State University , Baton Rouge, Louisiana 70803, United States.
Environ Sci Technol. 2017 Sep 19;51(18):10396-10402. doi: 10.1021/acs.est.7b01521. Epub 2017 Aug 30.
Environmentally Persistent Free Radicals (EPFRs) are newly discovered, long-lived surface bound radicals that form on particulate matter and combustion borne particulates, such as fly ash. Human exposure to such particulates lead to translocation into the lungs and heart resulting in cardio-vascular and respiratory disease through the production of reactive oxygen species. Analysis of some waste incinerator fly ashes revealed a significant difference between their EPFR contents. Although EPFR formation occurs on the metal domains, these differences were correlated with the altering concentration of calcium and sulfur. To analyze these phenomena, surrogate fly ashes were synthesized to mimic the presence of their major mineral components, including metal oxides, calcium, and sulfur. The results of this study led to the conclusion that the presence of sulfates limits formation of EPFRs due to inhibition or poisoning of the transition metal active sites necessary for their formation. These findings provide a pathway toward understanding differences in EPFR presence on particulate matter and uncover the possibility of remediating EPFRs from incineration and hazardous waste sites.
环境持久性自由基（EPFRs）是新发现的、寿命长的表面结合自由基，它们形成于颗粒物和燃烧产生的颗粒物质（如飞灰）上。人类接触此类颗粒物会导致其转移至肺部和心脏，通过产生活性氧而引发心血管和呼吸系统疾病。对一些垃圾焚烧炉飞灰的分析显示，它们的EPFR含量存在显著差异。尽管EPFR的形成发生在金属域上，但这些差异与钙和硫浓度的变化相关。为分析这些现象，合成了替代飞灰以模拟其主要矿物成分（包括金属氧化物、钙和硫）的存在。本研究结果得出结论，由于抑制或毒害了EPFR形成所需的过渡金属活性位点，硫酸盐的存在限制了EPFR的形成。这些发现为理解颗粒物上EPFR存在差异提供了一条途径，并揭示了从焚烧和危险废物场地修复EPFR的可能性。
