| In oral fluid, drugs of abuse can be detected for 5-48 hours at a low nanogram per milliliter level. |
| We also know that at one nanogram there is no effect. |
| The North Pacific contains about 1 nanogram of PCBs per litre. |
| He tested positive for the banned substance methamphetamine when a nanogram of the chemical was detected in his urine sample. |
| The sensors can register as little as a nanogram, or one billionth of a gram. |
| We test in nanograms, and one nanogram is a positive test. |
