Levels of Pesticide Residues and Physicochemical Properties of Water in River Taraba, Tella, Gassol Local Government Area, Taraba State, Nigeria

Abstract

This study assessed the physicochemical properties and pesticide residues in water samples collected from six sampling stations (A–F) in Tella, Gassol L.G.A Taraba State to determine their safety based on World Health Organization (WHO) and Standards Organization of Nigeria (SON) guidelines. Parameters analyzed included pH, Total Dissolved Solids (TDS), Electrical Conductivity (EC), Biological Oxygen Demand (BOD), and Dissolved Oxygen (DO) using standard analytical procedures. GC_MS was used for the determination of pesticides concentration. The pH value at all stations was 8.80, slightly exceeding the recommended range (6.50–8.50), indicating potential alkalinity. TDS and EC levels were within acceptable limits, ranging from 53.00–56.00 mg/L and 108.00–112.00 μS/cm respectively, reflecting low mineral content and acceptable conductivity. BOD ranged from 1.03 to 4.33 mg/L, with Station E exceeding the SON limit (3.00 mg/L) but still within WHO’s acceptable range (5.00 mg/L). DO values (1.52–4.60 mg/L) were below the minimum 5.00 mg/L threshold in all stations, suggesting reduced oxygen availability for aquatic life. Pesticide residue analysis revealed the non-detection of several organochlorines including DDT, DDE, DDD, Endrin, Heptachlor, and Heptachlor epoxide, indicating limited contamination from these compounds. However, Aldrin was detected at extremely high levels (38.17–1050 μg/L), far exceeding the WHO permissible limit of 0.001 μg/mL. Dieldrin was also detected at 90 μg/L in Station E, above the allowed limit of 0.07 μg/L. Despite relatively good physicochemical quality, the detection of hazardous pesticide residues renders the water unsafe for domestic or ecological use. Regular monitoring and stricter pesticide regulation are essential to protect public health and the environment.