| S/N | Location of collection centers | Number of scrap center sampled | Number of questionnaire administered |
| 1 | Choba | 3 | 36 |
| 2 | Rumuokoro | 3 | 36 |
| 3 | Rumuodumaya | 3 | 36 |
| 4 | Eliozu | 3 | 36 |
| 5 | Rumuolumeni | 3 | 36 |
| Total | 15 | 180 | |