| Site | Mean/variety (units in µg/l) | P-value | |
| Par Artemis | Mutant Artemis | ||
| UoE | 21.788 ± 2.583 | 24.925 ± 2.583 | 0.227 |
| Njoro | 22.355 ± 5.754 | 43.166 ± 5.754 | <0.001 |
| Par Anamed | Mutant Anamed |
| |
| UoE | 22.665 ± 3.636 | 25.908 ± 3.636 | 0.375 |
| Njoro | 22.805 ± 6.323 | 45.484 ± 6.323 | <0.001 |