Abstract A166: Bioremediation of river sediment used in crop production for sustainable reduction in soil contamination and cancer risk

Abstract Bioremediation, the use of biological materials and agents to degrade pollutants, has been applied extensively in the remediation of contaminated river sediments. Recent studies have highlighted the potential of bioremediation byproducts to exhibit anti-cancer properties. The present study employed mechanisms such as microbial degradation and immobilization by soil fungal isolates, for reduction of cancer risk. This was aimed at breaking down organic pollutants and heavy metals in Asa River sediment, reducing their availability for uptake by plant roots and potential buildup of toxic metabolites in the human body. The bioremediation studies of Asa River sediment using agricultural wastes such as rice husk and abattoir effluent involved characterization of the river sediment and agricultural wastes. The physicochemical characteristics of the sediment were evaluated using standard analytical methods. Using the ten-fold serial dilution method on potato dextrose agar (PDA), various fungi were isolated from the river sediment as well as the organic amendments. Fungi isolated from the river sediments were characterized and evaluated for their potentials to degrade heavy metals (lead, arsenic and mercury etc). Biological activities such as basal respiration, dehydrogenase activity, phytotoxicity, and microbial biomass were evaluated during the remediation process. The byproducts of bioremediation were analyzed for their chemical properties and bioactive compounds, which may exhibit anti-proliferative, pro-apoptotic, or immunomodulatory effects on cancer cells. The results showed that sediments contain high concentrations of organic matter and heavy metals, which were attributed to influx of industrial wastes and agricultural run-off into the river. These higher amounts of heavy metal contamination in the sediment were significantly (p ≤ 0.05) phytotoxic and prevented seed germination. A total of 21 fungal isolates were obtained from the sediment and agricultural wastes which significantly (p ≤ 0.05) degraded the heavy metals in the sediment. Among the fungal isolates, Aspergillus niger was the most effective in degrading most of the heavy metals, except for nickel, where Fusarium solani had the highest degradation. It was concluded that the reduction in heavy metal contamination through bioremediation will contribute to the development of sustainable and eco-friendly strategies for cancer risk reduction. Hence, it is recommended that this innovative approach be adopted in the development of novel cancer risk reduction strategies by leveraging on the potential of bioremediation processes. Citation Format: Oluyemisi Bolajoko. Fawole, James Ukwumonu. Yahaya, Wonsebolatan Samuel. Omoleye. Bioremediation of river sediment used in crop production for sustainable reduction in soil contamination and cancer risk [abstract]. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr A166.