The purpose of this study was to investigate the toxic effects of zinc in collembolan Paronychiurus kimi at the individual (survival and juvenile production) and population (population growth and age structure) levels after 28 days of exposure in artificially spiked soil. These toxic effects were interpreted in conjunction with the internal zinc concentrations in P. kimi. The EC50 value for juvenile production based on the total zinc concentration was 457 mg Zn kg-1 dry soil, while the LC50 value for adult survival and ri=0 value for population growth were within the same order of magnitude (2,623 and 1,637 mg Zn kg-1 dry soil, respectively). Significant differences in adult survival, juvenile production, and population growth compared with the control group were found at concentrations of 1,500, 375, and 375 mg Zn kg-1 dry or higher, respectively, whereas significant differences in the age structure, determined by the proportion of each age group in the population, were observed in all treatment groups. It appeared that the internal zinc level in P. kimi was regulated to some extent at soil zinc concentrations of ≤375 mg Zn kg-1 dry soil, but not at high soil zinc concentrations. These results indicate that, despite zinc being regulated by P. kimi, excess zinc exceeding the regulatory capacity of P. kimi can trigger changes in the responses at the individual and population levels. Given that population dynamics are affected not only by individual level but also by population level endpoints, it is concluded that the toxic effects of pollutants should be assessed at various levels.

Abstract
Introduction
Materials and Methods
    1. Test species
    2. Test soil and spiking
    3. Toxicity test
    4. Head capsule width measurement
    5. Internal zinc concentration inParonychiurus kimi
    6. Chemical analysis
    7. Data analysis
Results and Discussion
    1. Zinc concentrations and its adsorption toartificial soil
    2. Internal zinc concentration andbioaccumulation factor (BAF)
    3. T oxic effects of zinc on Paronychiuruskimi at individual and population levels
Conclusions
References

• Jino Son(Ojeong Eco-Resilience Institute, Korea University)
• Yun-Sik Lee(Ojeong Eco-Resilience Institute, Korea University)
• Yongeun Kim(Ojeong Eco-Resilience Institute, Korea University/Institute of Environment and Ecology, Korea University)
• June Wee(Department of Environmental Science and Ecological Engineering, Korea University)
• Euna Ko(Department of Environmental Science and Ecological Engineering, Korea University)
• Kijong Cho(Department of Environmental Science and Ecological Engineering, Korea University) Corresponding author