Small difference in carcinogenic potency between GBP nanomaterials and GBP micromaterials

Safety assessment of nanomaterials using an advanced decision-making framework, the DF4nanoGrouping

“…An extensive meta-analysis of chronic rat inhalation studies with GBPs found the difference in carcinogenic potency between nanosized and micron-sized GBPs to be low (i.e., a factor of 2.0–2.5 referring to mass concentration) (Gebel 2012). However, data are sparse whether nanomaterials, upon long-term low-dose administration, may accumulate to an extent that chronic adverse effects may evolve, just as there are limited data on the chronic effects of inhaled nanomaterials (Becker et al 2011; Gebel et al 2014; Moreno-Horn and Gebel 2014).…”

The toxicology of indium tin oxide

“…The question of human relevance of these induced lung tumors and those induced by an increasing number of non-genotoxic, mostly crystalline and/or poorly soluble, biodurable particles after long-term treatment of rodents at levels causing chronic lung toxicity/inflammation has been intensively been debated in recent years (Federico et al, 2007;Gebel, 2012;Green 2000;Mossman 2000;Warheit et al, 1997;Watson and Valberg 1996). The available mechanistic and epidemiological studies and considerations do not support human relevance of such lung tumors at least at a conceivable human exposure.…”

Commentary to Gebel 2012: a quantitative review should apply meta-analytical methods

“…With interest, I read the quantitative review on the carcinogenic potency of GBP nano-materials and GPP micromaterials (Gebel 2012). GBP is used by the author as an abbreviation for ''granular biopersistent particles.''…”

“…These methods are available in standard statistical software (e.g., Sterne et al 2009). Without re-running the calculations of Gebel (2012) in terms of a meta-analysis, the derived quantitative summary statistics should not be mistaken as reliable input to regulatory discussions.…”