Abstract:
Antibiotic pharmaceuticals are used to treat bacterial diseases in both humans and livestock. In poultry farming,
they are used not only to treat and prevent diseases but also to promote growth. However, their overuse increases
antibiotic resistance, posing significant global concerns for both humans and the environment. In Kenya,
humans’ exposure levels to antibiotic residues from consuming animal products has been scarcely explored. This
study determined the occurrence of penicillins and cephalosporins in chicken meat and evaluated the associated
human health risks. A total of 100 chicken meat samples were collected from chicken farmers and vendors in
Kiambu County, including 56 broilers, 24 ex-layers, and 18 indigenous samples. The samples were prepared for
antibiotic analysis using the Quick-Easy-Cheap-Effective-Rugged-Safe (QuEChERS) method and quantified by Ultra-
Performance Liquid Chromatography-Mass Spectrometry. Recoveries ranged from ‘72.5–98.9 %’. Among the
penicillins, ampicillin residues were the most predominant, particularly, in broiler breast tissues, with concen-
trations of up to 263.76 μg kg− 1
. Ampicillin also showed the highest frequency of residues above the recom-
mended maximum residue limits. Detected cephalosporins were below 100 μg kg− 1 and showed their highest
residue concentrations in broiler tissue samples. Calculated daily intake (CDI) and the hazard quotients (HQ)
were used to assess human health risks. The CDI of ampicillin in broilers’ breast muscles exceeded the Acceptable
Daily Intake (ADI) and posed a medium risk (1 < HQ < 5) to adults. Meanwhile, the levels of ampicillin in both
the thigh and breast muscles of broilers and ex-layer breast muscles exceeded the ADI for children indicating
medium (1< HQ < 5) to high health risk (HQ > 5) to the youngsters. The study underscores the need for the
continuous monitoring of antibiotics in chicken meat and addresses significant knowledge gaps on exposure
levels and risks. This is valuable for policymaking to ensure food safety.
