| Type of sample | Concentrations range | Country | Place of study | Reference |
| Dumpsite and Landfill | ≤MDL - 1200 µg/kg | Kenya | Nzoia catchment area | This study |
| 0.85 - 1.47 mg/L | Nigeria | Lagos | [45] | |
| 1475 μg∙kg−1 dw | Greece | Nothern Greece | [46] | |
| 9.9 - 575.6 ng/g dw | Malaysia | Taman Beringin | [47] | |
| Soil | ≤MDL - 8 µg/kg | Kenya | Nzoia catchment area | This study |
| 0.01 - 3.884 µg/kg | China | Sub urban soils | [43] | |
| 3.1 - 28.5 µg/kg | India | Industrial sites | [44] | |
| 2.0 - 6 µg/kg | France | Highway soils | [48] | |
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| 0.94 - 2.79 mg/kg | Nigeria | Lagos | [45] | |
| 11.2 - 28.1 μg/kg | Greece | Nothern Greece | [46] | |
| Sediment | ≤MDL - 80 µg/kg | Kenya | Nzoia catchment area | This study |
| 37.7 - 11.78 µg/kg | Brazil | Patos Lagoon | [49] | |
| 464 - 2.621 μg/kg | China | Industrial facilities | [42] | |
| 0.3 - 13.5 µg/kg | Kenya | Car wash, Kisat, Kisumu | [50] | |
| 0.04 to 31.95 µg/kg | Kenya | Winam Gulf | [21] | |
| 1.5 × 10−5 ng/g | Malaysia | Taman Beringin | [47] | |
| 1107 - 22,310 μg/kg | South Africa | Buffalo River Estuary | [51] | |
| Water | ≤MDL - 38.4 µg/L | Kenya | Nzoia catchment area | This study |
| 0.989 - 9.663 µg/L | China | Hangzhou city surface waters | [39] | |
| 0.0 - 14.58 µg/L | Ghana | Surface water | [41] | |
| 10 - 20 ng/l | Poland | IDLz river | [52] | |
| 1.95 - 10.5 µg/L | Nigeria | Niger Delta | [40] | |
| 14.91 - 206 μg/L | South Africa | Buffalo River Estuary | [51] | |
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| 3.32 -55.8 µg/L | Kenya | Winam Gulf | [21] |