Conclusions
With the available information, a risk analysis approach was applied to assess environmental risk of heavy
metals in Bohai sea water. The RQ-based technique takes on-site concentrations of heavy metals as MEC and the
national sea water quality standard as environmentally accepted values. Risk uncertainty was analyzed based on
Monte Carlo simulation. Hg and Pb were priorities in risk management. Almost ¾ of the sea area was under risk of
Pb. Metal pollution near estuaries and big cities were worse than other areas. Pollution in Bohai Bay was the worst
among the four parts of Bohai Sea. In some area of Bohai Bay concentration of Pb has reached 10 folds of the
threshold value. An exceedance of those two metals over critical values in the next year approves the result from
Monte Carlo analysis. Data cited shows sediment and biota in Baohai Sea have been contaminated by metals also.
And anthropogenic activities have greatly contributed to the risk increase for heavy metals in Bohai Sea.