DISTRIBUTION AND RISK ASSESSMENT OF PERSISTENT ORGANIC POLLUTANTS IN THE SEDIMENTS OF AGBARHO RIVER IN DELTA STATE NIGERIA
Abstract
ABSTRACT
This study investigated the distribution and risk assessment of persistent organic pollutants (POPs) particularly dioxins and furans (PCDD/Fs) in the sediments of the Agbarho River, Delta State, Nigeria. Sediment samples were collected from seven stations along the river and analyzed using high-resolution gas chromatography/mass spectrometry (HRGC/HRMS). Physicochemical parameters such as pH, electrical conductivity (EC), temperature, and total organic carbon (TOC) were also determined to evaluate their influence on contaminant distribution. Results indicated that the sediment pH ranged between 5.90–6.48, EC values were 183–205 µS/cm, and TOC ranged from 0.58–3.51%, suggesting low salinity and slightly acidic to neutral conditions. The total concentration of 17 dioxins and furans (ΣPCDD/Fs) ranged from 4,630 to 6,030 pg/g, with toxicity equivalent (TEQ) values between 57–74 pg TEQ/g. Octachlorodibenzofuran (OCDF) and octachlorodibenzodioxin (OCDD) were the most dominant congeners, indicating that combustion and vehicular emissions were likely major sources. Compared to global datasets, the Agbarho River sediments exhibited moderate to high contamination levels. The findings highlight significant ecological and potential human health risks associated with long-term exposure to POPs, emphasizing the need for environmental monitoring, pollution source control, and remediation strategies. This research provides essential baseline data to support sediment quality management and public health protection in the Niger Delta region.
Full-Text Access Notice
In accordance with the NERD Policy on promoting peer-reviewed publication, public access to the full text of a project, thesis or dissertation is restricted for three years, allowing the author and supervisors sufficient time to pursue peer-reviewed publication.
During this period, researchers with legitimate academic or research purposes may request authorisation directly from the author to enable NERD to release the indexed full texts of the work using the form below.