Table 4.
Classical and benchmark concentration modelling to derive points of departure (µg/mL) based upon percentage DNA in tail measurements after 2–4 h exposure to NPs, MPs, and metal chlorides. For all BMC modelling, the benchmark response was set to 1.0 (100% extra risk). NOEC: no-observed-effect-concentration. LOEC: lowest-observed-effect-concentration. BMC: benchmark concentration. BMCL: the lower 95% confidence interval of the BMC. BMCU: the upper 95% confidence interval of the BMC. No Covariate: All BMC analyses were computed for each individual particle and timepoint. Covariate: BMC modelling conducted using covariate approach.
| Timepoint | Metal Oxide | Particle Type | Classical | BMC Modelling (No Covariate) | BMC Modelling (Covariate) | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| NOEC a | LOEC b | BMCL | BMC | BMCU | BMCL | BMC | BMCU | |||
| 2 h | ZnO | US3580 | 20 | 30 | 18.9 | 23.7 | 28.2 | 18.4 c | 22.3 c | 26.3 c |
| US1003M | 20 | 30 | 29.9 | 33.5 | 36.5 | 25.9 c | 30.9 c | 37 c | ||
| ZnCl2 | 67 | >67 | 59.2 | 78.7 | 141 | 64.2 c | 79.1 c | 103 c | ||
| CuO | SA544868 | 10 | 25 | 9.16 | 12.7 | 16.7 | 12.2 c | 15.7 c | 19.8 c | |
| US1140M | 50 | >50 | - | - | - | - | - | - | ||
| CuCl2 | 108 | >108 | - | - | - | - | - | - | ||
| TiO2 | NIST1898 | 100 | >100 | - | - | - | - | - | - | |
| 5422HT | 100 | >100 | - | - | - | - | - | - | ||
| 5423HT | 50 | 100 | 77.1 | 91.4 | 105 | 73.9 c | 90.4 c | 112 c | ||
| 5424HT | 100 | >100 | - | - | - | - | - | - | ||
| 5425HT | 100 | >100 | - | - | - | - | - | - | ||
| A050 | 100 | >100 | - | - | - | - | - | - | ||
| R050P | 100 | >100 | 99 | 145 | 318 | 107 c | 134 c | 176 c | ||
| A005 | 100 | >100 | - | - | - | - | - | - | ||
| Nano Wires | 100 | >100 | - | - | - | - | - | - | ||
| US1017M | 100 | >100 | - | - | - | - | - | - | ||
| 4 h | ZnO | US3580 | 5 | 10 | 7.32 | 8.48 | 9.6 | 6.94 d | 8.24 d | 9.77 d |
| US1140M | 10 | 20 | 10.5 | 12.1 | 13.8 | 8.87 d | 10.6 d | 12.5 d | ||
| ZnCl2 | 16.5 | 33.5 | 18.7 | 22.3 | 26.2 | 20.5 d | 24.9 d | 29.6 d | ||
| CuO | SA544868 | 1 | 5 | 3.56 | 4.04 | 4.55 | - | - | - | |
| US1003M | 50 | >50 | - | - | - | - | - | - | ||
| CuCl2 | 108 | >108 | - | - | - | - | - | - | ||
| TiO2 | NIST1898 | 100 | >100 | - | - | - | - | - | - | |
| 5422HT | 100 | >100 | 61.1 | 184 | 832 | 70.4 e | 91.5 e | 121 e | ||
| 5423HT | 50 | 100 | 72.3 | 91.8 | 115 | 70.4 e | 91.5 e | 121 e | ||
| 5424HT | 100 | >100 | - | - | - | - | - | - | ||
| 5425HT | 100 | >100 | - | - | - | - | - | - | ||
| A050 | 100 | >100 | - | - | - | - | - | - | ||
| R050P | 50 | 100 | 47.7 | 75.4 | 118 | 70.4 e | 91.5 e | 121 e | ||
| A005 | 100 | >100 | - | - | - | - | - | - | ||
| Nano Wires | 100 | >100 | - | - | - | - | - | - | ||
| US1017M | 100 | >100 | - | - | - | - | - | - | ||
a NOEC is defined as the first dose preceding the LOEC. b LOEC is defined as the first dose where there is a statistically significant (p < 0.05) increase in percentage DNA in the tail of at least 2-fold as compared to the media control. c Exposure type set as covariate. d Zn exposure type set as covariate. e TiO2 particle type set as covariate.