## 3 Results and Discussions
### VAs Accumulation and Bio-Concentration
In carrot roots, the concentration of VAs was higher in the peel/skin in comparison to the flesh. A similar observation where _Solanum tuberosum_ tubers accumulated a higher percentage of sulfamethazine in their peels [26]. The calculated BCF values for root and shoots of lettuce, carrot, and pepper plants grown in VAs amended soil presented in Table 5. BCF values increased with increasing concentration of VAs in the soil-manure mixture. Among the three test plants, the highest BCF was reported in carrot plants, followed by lettuce and pepper. The BCF values for lettuce plants ranged from \(0.065\pm 0.001\) to \(2.307\pm 0.008\) and \(0.227\pm 0.004\) to \(6.103\pm 0.005\)\(\upmu\) kg kg\({}^{-1}\) for OTC and SDZ, respectively. In carrot, BCF for OTC and SDZ ranged from \(0.010\pm 0.054\) to \(2.132\pm 0.003\) and \(0.018\pm 0.023\) to \(8.859\pm 0.002\)\(\upmu\) kg kg\({}^{-1}\), respectively. On the other hand, BCF in pepper ranged from \(0.033\pm 0.010\) to \(0.474\pm 0.118\), and \(0.066\pm 0.005\) to \(3.361\pm 0.099\)\(\upmu\) kg kg\({}^{-1}\) for OTC and SDZ, respectively. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Veterinary Antibiotics (mg kg\({}^{-1}\))**} & \multicolumn{4}{c}{**Bio-Concentration Factor (ug kg\({}^{-1}\))**} \\ \cline{3-6}  & & \multicolumn{2}{c}{**Lettuce**} & \multicolumn{2}{c}{**Carrot**} & \multicolumn{1}{c}{**Pepper**} \\ \hline \multirow{6}{*}{SHOOT} & \multirow{3}{*}{OTC} & 10 & \(0.069\pm 0.003\) & \(0.010\pm 0.054\) & \(0.033\pm 0.010\) \\  & & 50 & \(0.240\pm 0.008\) & \(0.043\pm 0.013\) & \(0.109\pm 0.003\) \\  & & 100 & \(2.307\pm 0.008\) & \(0.610\pm 0.009\) & \(0.102\pm 0.003\) \\ \cline{2-6}  & \multirow{3}{*}{SDZ} & 10 & \(0.286\pm 0.002\) & \(0.018\pm 0.023\) & \(0.066\pm 0.005\) \\  & & 50 & \(2.373\pm 0.006\) & \(1.069\pm 0.006\) & \(0.727\pm 0.002\) \\  & & 100 & \(6.103\pm 0.005\) & \(3.088\pm 0.004\) & \(1.227\pm 0.001\) \\ \cline{2-6}  & \multirow{3}{*}{STR} & 10 & - & - & - \\  & & 50 & - & - & - \\  & & 100 & - & - & - \\ \hline \multirow{6}{*}{ROOT} & \multirow{3}{*}{OTC} & 10 & \(0.065\pm 0.013\) & \(0.515\pm 0.009\) & \(0.134\pm 0.091\) \\  & & 50 & \(0.177\pm 0.004\) & \(1.517\pm 0.005\) & \(0.374\pm 0.094\) \\  & & 100 & \(0.243\pm 0.003\) & \(2.132\pm 0.003\) & \(0.474\pm 0.118\) \\ \cline{2-6}  & \multirow{3}{*}{SDZ} & 10 & \(0.227\pm 0.004\) & \(1.250\pm 0.003\) & \(0.513\pm 0.016\) \\  & & 50 & \(1.485\pm 0.021\) & \(5.003\pm 0.003\) & \(1.016\pm 0.057\) \\  & & 100 & \(4.671\pm 0.041\) & \(8.859\pm 0.002\) & \(3.361\pm 0.099\) \\ \cline{2-6}  & \multirow{3}{*}{STR} & 10 & - & - & - \\ \cline{1-1}  & & 50 & - & - & - \\ \cline{1-1}  & & 100 & - & - & - \\ \hline \hline \end{tabular} \(\pm\) represents standard error. SDZ = Sulfadimethooxine; OTC = Oxytteracycline; STR = Streptomycin.  
\end{table} 
Table 5: _Bioconcentration factor_ (BCF) values of lettuce, carrot and pepper plants grown in soil treated with VAs. Figure 1: _Cont._  
The level of VAs sensitivity and eventual bio-accumulation was greatly affected by plant type. For instance, carrot is a root vegetable and significantly affected by VAs. Since roots are the first plant organ to come in contact with soil and its contaminants, carrot a root vegetable was more sensitive to VAs. As a result, there was a higher accumulation of VAs by carrot roots that functions as its primary storage organ. A study funded by the United States Department of Agriculture showed that root crops such as carrots and radiashes, that directly come in direct contact with soil, may be particularly vulnerable to VAs contamination [27]. Some of the staples enjoyed worldwide are root vegetables, and the uncontrolled introduction of VAs in the agriculture ecosystem can jeopardize food security. Alternately, lettuce plants accumulated VAs mostly in the shoot (leaves), and the BCF values for VAs in the shoot were in the order: lettuce > pepper > carrot. Lettuce is a leafy vegetable; therefore, VAs were accumulated mostly in the leaf, its primary storage organ.