Micro scale WC-Co particles were observed in macrophages and nano-scale particles in different vertebrate cell lines ^[1,2].

Literatur:

1. Lison, D. & Lauwerys, R. (1990), Environ Res 52, 187-198.
   
2. Busch, W. et al. (2010), BMC Genomics /// 11, 65.

For hard metal particles investigations on micro-size particles have been conducted for comparison. According to investigations conducted up to now, the assumption of differing modes of actions of nanoparticles compared to micro-sized material due to their small size has not been confirmed. The comparison of the biological effects showed merely differences in the effect strength ^[1]. WC-Co particles are likewise toxic, but exposure is nearly exclusively occupational and can be avoided by suitable protection clothes.

Literature:

Ding, M. et al. (2009), Toxicol Appl Pharmacol 241, 260-268.