# Anthracene Absorption and Concentration Dynamics in Radishes [PERSON]
## 4 Discussion  
### Relationship between Anthracene Concentration in Soil and Concentration in Radishes  
Figure 4 shows the relationship between the AN concentration in the soil and the concentration in radishes. In the figure, \"\(\bullet\)\" indicates the common logarithmic value of the detected concentration in both soil and radishes in P1, P2, and P3, and \"\(\Circarrow\)\" indicates the value in P4. While P1, P2, and P3 were used in an experiment to grow plants from sowing onward in AN-contaminated soil and P4 was used in a methodologically different experiment to grow plants after maturity in AN-contaminated soil, positive correlations were observed in each experiment. It is inferred that the greater the degree of soil contamination, the greater the effect will be on the amount of AN assimilated by the radishes.  
Figure 5 shows the relationship between the number of days that elapsed after exposure to AN and Cr/Cs and the ratio of the concentration in radishes to the concentration in the soil. A higher Cr/Cs ratio indicates that the chemical is more likely to be absorbed or concentrated in living organisms from the soil. The relationship between the number of days that elapsed after the application of AN (x) and the concentration ratio (y) was expressed as y = 0.201e\({}^{-0.113\text{x}}\). The correlation coefficient was 0.856, and the concentration ratio decreased exponentially. It was interpreted that AN was significantly absorbed in the early stages of radish growth, and some of the AN returned to the soil as the growth period progressed. For diazinon, the relationship y = 0.395e\({}^{-0.151\text{x}}\) has been reported [28]. The Cr/Cs ratio for AN was lower than the ratio for diazinon. The lower Cr/Cs ratio for AN probably indicates that the lower solubility of AN makes movement between the radish plant and the soil difficult.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \multirow{2}{*}{**Planet No.**} & \multirow{2}{*}{**Sample Type**} & \multicolumn{5}{c}{**Day (after Seeding)**} \\ \cline{3-8}  & & **0 * (27)** & **1 * (28)** & **4 * (31)** & **11 * (38)** & **19 * (46)** & **24 * (51)** \\ \hline \multirow{6}{*}{P4} & Soil & N.D. & 17,900 & 22,100 & 5670 & 14,400 & 9560 \\  & Radish & N.D. & 2180 & 2270 & 879 & 967 & 342 \\  & & (17.1 g) & (13.9 g) & (34.1 g) & (35.6 g) & (52.8 g) \\ \cline{1-1} \cline{2-8}  & \multirow{2}{*}{Root} & N.D. & 3470 & 228 & 2230 & 1820 & 742 \\  & & (4.9 g) & (4.0 g) & (11.0 g) & (16.3 g) & (22.4 g) \\ \cline{1-1} \cline{2-8}  & \multirow{2}{*}{Stem} & N.D. & 230 & 52.2 & 182 & 143 & 39.5 \\ \cline{1-1}  & & Stem & (5.80 g) & (4.55 g) & (10.2 g) & (9.87 g) & (15.7 g) \\ \cline{1-1} \cline{2-8}  & \multirow{2}{*}{Leaf} & N.D. & 2960 & 5750 & 283 & 356 & 55.9 \\ \cline{1-1}  & & (6.34 g) & (5.28 g) & (13.0 g) & (9.46 g) & (14.7 g) \\ \hline \end{tabular} Note: Units are ng/g-ww, unless otherwise noted. N.D. indicates ‘not detected’. Asterisks (*) show the number of days after AN was buried; the values in parentheses denote the number of days after seeding. AN concentrations and weights were measured for each part of a plant for root, stem, and leaf samples. “Radish” denotes measured AN data for the whole plant; the concentration was multiplied by the weight for each part, the products added together, and the total divided by the sum of the weight. The upper values in each cell are concentrations (ng/g-ww); the lower values in the parentheses are masses (g).  
\end{table}
Table 3: AN concentration in soil and radishes under late exposure experiments.