Open Dumpsites as Reservoirs of Antibiotic Contamination: Assessing Pharmaceutical Residues in Hilly Dumpsite Ash, Nakuru Town, Kenya

Abstract

The purpose of this article is to analyse dumpsite ashes from Hilly Dumpsite in Nakuru Town, Kenya, for the presence of Metronidazole, Benzyl penicillin, and Ceftriaxone as potential environmental contaminants. The study adopted a longitudinal research design, with ash samples collected weekly from the dumpsite for three weeks. A total of nine ash samples were gathered, with three composite ash samples collected each week by scooping small quantities from different points of the ash heap using a stainless steel spade and combining them into a composite sample. The samples were analysed using High-Performance Liquid Chromatography (HPLC) with a UV detector, following sample pre-treatment through Solid Phase Extraction (SPE). A two-way Analysis of Variance (ANOVA) was applied to examine differences in antibiotic concentrations across sampling sites and antibiotic types. The assumptions of independence of observations were assessed before conducting ANOVA. From the study results, the mean concentrations of Benzyl penicillin and Ceftriaxone detected at Hilly dumpsite were 11,624.08 µg/ml and 12,816.96 µg/ml, respectively, both substantially exceeding the resistant breakpoints for these antibiotics. On the other hand, metronidazole was absent in the dumpsite ash. The CLSI breakpoints for Benzyl penicillin are susceptible at ?0.06 µg/ml, intermediate at 0.12-1 µg/ml, and resistant at ?2 µg/ml. For Ceftriaxone, the breakpoints are susceptible at ?1 µg/ml, intermediate at 2 µg/ml, and resistant at ?4 µg/ml. The findings indicate significant potential for environmental contamination and the development of antimicrobial resistance. This study contributes to the body of knowledge by providing evidence of pharmaceutical contamination at open dumpsites in Kenya. Thus, the study recommends strengthening regulations on waste disposal to include testing for pharmaceutical contaminants before disposal at open dumpsites and enhancing collaboration among regulatory bodies.