But there's been little study of heavy-metal pollution in the sediments of this lake – and it took place more than 10 years ago on just a few sampling sites. In contrast, our team from the Nanjing Institute of Geography and Limnology carried out detailed sampling experiments in eight separate areas according to the morphology of the lake to prioritize sites and metals of concern. A multivariate statistical-analysis technique was used to differentiate the sources and distribution of heavy metals.
Potential ecological risk indexes indicated that most of the sediments were moderately polluted while a comparison of metal levels with effects range low (ERL) and effects range median (ERM) showed that arsenic, mercury and lead should be given more consideration.
We believe that biota toxicity experiments and sequential extraction should now be carried out to examine the actual toxicity of these metals.