Summary of DNA damage and responses in A549 cells to particles in relation to relevant physicochemical properties and constituents
| Particle | SSB | DSB | Cell cycle | p-ser15-p53 at 1–2 h | p-H2A.X at 1–6 h | p-BRCA1 at 6 h | 53BP1 at 1 h |
| Carbon black | − | − | − | − | − | − | − |
| Tert-butyl-hyperperoxide | +++ | − | G0/G1 | +++ | + | + | + |
| Urban dust | +++ | +++ | G0/G1 | + | + | + | ++ |
| Nanoparticulate carbon black | +++ | − | G2/M | ++ | + | + | ++ |
| Nanoparticulate carbon black + benzopyrene | +++ | − | − | + | + | + | ++ |
| Benzopyrene | +++ | − | G2/M | + | + | + | ++ |
SSB: single-strand breaks; DSB: double-strand breaks; p-ser15-p53: p53 phosphorylated at ser15; p-H2A.X: phospho-histone H2A.X; p-BRCA1: phospho-BRCA1; 53BP1: p53 binding protein 1. -: no effect; +: small response; ++: moderate response; +++: large response.