Concentrations, Sources, and Associated Risks of Polychlorinated Biphenyls Measured in Soil Profiles from Selected Telecom-masts in the Niger Delta, Nigeria

ABSTRACT

This study determined the concentrations, origin, and associated ecological and human health risks of Ʃ₂₈PCBs in soil profiles from selected telecom-masts in the Niger Delta, Nigeria. A total of 18 soil samples were quantified for Ʃ₂₈PCBs with gas chromatography-mass spectrometry after soxhlet extraction with n-hexane/dichloromethane and purified with florisil and silica gel column. The occurrence of the ∑₂₈PCBs varied widely, and ranged from 88.0 to 293 mg kg^-1, with pollution load in the order of subsoil > topsoil, and SS 3 > SS 2 > SS 1 > SS 6 > SS 7 > SS 9 > SS 4 > SS 8 > SS 5. The compositional pattern of the ∑₂₈PCBs were in the order of deca-PCB > tetra-PCBs > di-PCBs > penta-PCBs > hexa-PCBs > hepta-PCBs > tri-PCBs > octa-PCBs > nona-PCBs. Also, the LC-PCBs are the dominant PCBs with a composition of 50 to 91.8%, while the HC-PCBs accounted for 34.8 to 78.8%. The levels of the ∑₂₈PCBs from the telecom-masts were significantly higher than the recommended standards for urban and agricultural soils. The ecological risk index, toxic equivalence, hazard index, and total cancer risk suggest ecological risk to soil-dwelling organisms and on-site human occupational risk to soils around the telecom-masts. The source identification depicts that PCBs originated from the use of Aroclor1254 mixtures, cable and wire insulators, lubricants, paints, transformer oils, pesticides, and power capacitors in the telecom masts. Standard guidelines for the operations of telecom-masts should be carried out to mitigate the potential ecological and on-site human occupational risks in soil profiles around the telecom-masts, and similar land use somewhere else around the world.

KEYWORDS:

• Soil pollution
• PCBs occurrence
• risks assessment
• telecom masts
• Niger Delta

Acknowledgments

Thanks to Apex Analytics Ltd, Rumuomasi, Port Harcourt, Nigeria and laboratory personnel, department of chemistry, Delta State University, Abraka for the laboratory and technical support.

Availability of data and materials

All data generated during this study are included in this article and its supplementary information files.

Competing Interest

The authors declare that they have no competing interests.

Author Contributions

All authors contributed to the study’s development and completion. Onoriode Onos Emoyan conceptualize and design the study. Onoriode O. Emoyan, Beatrice O. Peretiemo-Clarke, Godswill O. Tesi, Efe Ohwo and Wilson Adjerese carried out samples collection, materials preparation, and analysis of samples for the determination of PCBs. Onoriode O. Emoyan and Godswill O. Tesi compiled and the statistical analyzed the results. The first draft of the manuscript was written by Beatrice O. Peretiemo-Clarke and Godswill O.Tesi, and all authors commented on previous versions of the manuscript. Onoriode O. Emoyan reviewed and edited the final manuscript. All authors read and approved the final manuscript.

Additional information

Funding

This study was funded by the authors.