Abstract:
The anthropogenic load of antibiotics in Morogoro Municipality water bodies was estimated using the ELISA
technique. Commercially available enzyme-linked immunosorbent assay (ELISA) kits commonly used for detection
of tetracyclines, sulfonamides and quinolones residues in meat, milk, eggs and honey were adopted for analysis of
these antibiotics in surface waters. Thirty-three sampling points were selected, including two rivers, one dam and
one wastewater treatment plant. Results showed that there were detectable levels of the selected antibiotics in all the
sampling sites. In rivers there were slightly higher mean concentration of antibiotics in the downstream rivers in
close vicinity to high human activities. High mean concentrations of antibiotics were also found in wastewater
treatment plant. In rivers, the maximum mean concentrations detected were 7.74±2.45, 8.76±2.65 and 8.94±3.83μg/l
quinolones, tetracyclines and sulfonamides, respectively. At Mindu Dam, mean concentrations were, 1.61±0.17,
4.84±1.23 and 3.65±1.37μg/l, quinolones, tetracyclines and sulfonamides, respectively, while at Wastewater
Treatment Plant mean concentrations were 31.55±11.23, 48.89±21.82 and 37.94±14.05μg/l quinolones, tetracyclines
and sulfonamides, respectively. Differences in mean concentrations in Rivers, Dam and Wastewater Plant were
attributed to the fact that in wastewater treatment plant antibiotic residues are continuously poured through human
domestic and hospital waste, while at Mindu Dam and Rivers antibiotic residues are poured mainly through run-off
during rainy season, hence high mean concentrations in Wastewater Treatment Plant than in rivers and dam. The
presence of antibiotics residues in rivers, Mindu Dam and Wastewater Treatment Plant although in very low
concentrations poses risks to population who take antibiotics at low doses. This can be through drinking water and
consumption of crops produced through irrigation using water from these sources; this can lead to acceleration of
antibiotic resistance through selection pressure; also can harm organisms in water ecosystem in long time exposure
