spatial distribution of organochlorine pesticides contamination in the galma river sediment, nigeria

This study investigated chlorinated pesticide contamination in galma river sediments, zaria, nigeria, focusing on its spatial distribution and ecological risks. despite global bans on many organochlorine pesticides (ocps), residues persist in nigerian rivers, posing significant environmental and public health threats. sediment samples from 10 locations along the river were analyzed using gas chromatography-mass spectrometry (gc-ms), revealing widespread contamination by 18 ocps. among these, hexachlorobenzene (hcb), α-hch, and heptachlor epoxide were found in the highest concentrations, with hcb ranging from 46.29 to 167.21 ng/g, α-hch from 31.56 to 159.4 ng/g, and heptachlor epoxide peaking at 142.03 ng/g. ecological risk assessments identified major contamination hotspots at locations p5, p6, and p8, where heptachlor epoxide concentrations exceeded safe limits, indicating severe risks to aquatic life. historical pesticide use was evident in p10, where elevated levels of p, p'-ddd and p,p'-ddt were found. clustering analysis revealed three distinct contamination patterns, highlighting areas requiring urgent remediation. this study highlights the need for better regulation, continuous monitoring, and targeted remediation efforts to mitigate the ongoing risks posed by pesticide contamination in northern nigeria's agricultural regions.