In response to the Letter to the Editor by Kevin Driscoll et al., we certainly agree that particle clearance halftimes are increased with increasing lung burden in rats, hamsters and mice, whereas complete inhibition of particle clearance has only been observed in rats, and only at high particle concentrations (50 mg/m3). Where we disagree with Kevin Driscoll and colleagues, is on the implications of the increased clearance halftimes observed at higher lung burden. We argue that it does not hamper the extrapolations from relatively high dose levels to lower dose levels. Furthermore, we highlight, again, the challenges of detecting particle-induced lung cancer in epidemiological studies where occupational, particle-induced lung cancer has to be detected on top of the background lung cancer incidence. Almost all available epidemiological studies on carbon black and titanium dioxide suffer from a number of limitations, including lack of control for smoking, the use of background population cancer rates as reference in the US studies, lack of information regarding particle size of the exposure, and incomplete follow-up for cause of death of the study population.

中文翻译：

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Driscoll等人给编辑的信的回应。

在回应Kevin Driscoll等人写给编辑的信中，我们当然同意，随着大鼠，仓鼠和小鼠肺部负担的增加，颗粒清除的半衰期会增加，而仅在大鼠中观察到完全清除了颗粒清除，并且只有在高颗粒浓度（50 mg / m3）下。我们不同意Kevin Driscoll及其同事的观点是，在较高的肺部负担下观察到的清除半衰期增加。我们认为，这不会妨碍从相对较高剂量水平到较低剂量水平的推断。此外，我们再次强调，在流行病学研究中检测颗粒诱导的肺癌所面临的挑战，在这些研究中，必须在背景肺癌发生率之上检测职业性颗粒诱导的肺癌。