Shi Tingming, Schins Roel P F, Knaapen Ad M, Kuhlbusch Thomas, Pitz Mike, Heinrich Joachim, Borm Paul J A
Particle Research, Institut für Umweltmedizinische Forschung (IUF) at the University of Düsseldorf PO Box 10 30 45, 40021 Düsseldorf, Germany.
J Environ Monit. 2003 Aug;5(4):550-6. doi: 10.1039/b303928p.
Epidemiological studies have demonstrated the relationship between exposure to ambient particulate matter (PM) and health effects in those with cardiopulmonary diseases. The free radical generating activity of particles has been suggested as a unifying factor in the biological activity of PM in toxicological studies but so far has not been applied as a method for environmental monitoring of PM. The purpose of this study was to characterize hydroxyl radical (OH*) production by different size fractions of PM, to use as an alternative method for monitoring of PM composition and activity. We have developed a method, using electron paramagnetic resonance (EPR), to measure OH* radical formation in suspensions of particles in the presence of hydrogen peroxide and 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a specific spin-trap. Samples of ambient particulate matter (PM) of different size fractions were collected from various sites on various filters. PM deposited on filters as well as suspensions in water retain its ability to generate OH* and this generation is determined by concentration of hydrogen peroxide and soluble metals. However, large variations in OH* radical formation and kinetics were found with different soluble metals and within metals (Fe, V) with different valencies. The method was applied to environmental monitoring in Hettstedt-Zerbst, situated in South-Eastern Germany, where it showed a relation to Cu-content of PM. The method was also applied in Duisburg, where the PMI fraction showed the highest DMPO-OH* generation but was not linked to particle counts. The method integrates metal bioavailability and reactivity and can provide a better understanding of the effect of small variations in mass concentrations on health.
流行病学研究已证明，暴露于环境颗粒物（PM）与心肺疾病患者的健康影响之间存在关联。在毒理学研究中，颗粒物产生自由基的活性被认为是PM生物活性的一个统一因素，但迄今为止尚未作为一种PM环境监测方法应用。本研究的目的是表征不同粒径分数的PM产生羟基自由基（OH*）的情况，用作监测PM组成和活性的替代方法。我们开发了一种使用电子顺磁共振（EPR）的方法，在过氧化氢和作为特定自旋捕获剂的5,5-二甲基-1-吡咯啉-N-氧化物（DMPO）存在下，测量颗粒悬浮液中OH自由基的形成。从不同地点的各种滤膜上采集不同粒径分数的环境颗粒物（PM）样本。沉积在滤膜上的PM以及水中的悬浮液都保留了其产生OH的能力，并且这种产生由过氧化氢和可溶性金属的浓度决定。然而，发现不同可溶性金属以及不同价态的金属（铁、钒）之间OH自由基形成和动力学存在很大差异。该方法应用于德国东南部的赫特施泰特 - 策尔布斯特的环境监测，结果表明它与PM的铜含量有关。该方法也应用于杜伊斯堡，在那里PMI部分显示出最高的DMPO - OH生成量，但与颗粒计数无关。该方法整合了金属的生物可利用性和反应性，能够更好地理解质量浓度的微小变化对健康的影响。
