Carbon black nanoparticles, Biosensor, Endothelial cell activation, Mediation effect, Toxicology. Poisons, RA1190-1270, Industrial hygiene. Industrial welfare, HD7260-7780.8

Abstract Background Among manufactured or engineered nanoparticles, carbon black (CB) has largest production worldwide and is also an occupational respiratory hazard commonly seen in rubber industry. Few studies have assessed the risk for cardiovascular disease in carbon black exposed populations. An endothelial biosensor assay was used to quantify the capacity of sera from 82 carbon black packers (CBP) and 106 non-CBPs to induce endothelial cell activation ex vivo. The mediation effect of circulatory proinflammatory factors on the association between carbon black exposure and endothelial cell activation was assessed and further validated using in vitro intervention experiments. Results The average elemental carbon level inside carbon black bagging facilities was 657.0 μg/m3, which was 164-fold higher than that seen in reference areas (4.0 μg/m3). A global index was extracted from mRNA expression of seven candidate biosensor genes using principal component analysis and used to quantify the magnitude of endothelial cell activation. This global index was found to be significantly altered in CBPs compared to non-CBPs (P