RISK ASSESSMENT APPROACH TO EVALUATING POTENTIAL REMEDIAL ACTIONS AT THE DIEMERZEEDIJK HAZARDOUS-WASTE SITE

As a result of the former burning of hazardous chemical wastes in the open air along the border of lake IJmeer, located southeast of Amsterd am, the surrounding environment was contaminated with a variety of org anic substances. The major contaminants detected were solvents, volati le aromatics, organochlorine pesticides, arsenic, PCBs, PAHs and PCDDs /PCDFs. For the purpose of risk assessment, several pathways for the m igration of hazardous substances were identified. Both site-specific t otal-lifetime cancer risk and total acceptable daily intake were calcu lated. The relative contribution of the PCDDs/PCDFs to the total accep table daily intake was 50.1%. In addition, their contribution to the t otal-lifetime cancer risk amounted to more than 98%. It is concluded t hat without remedial action neither the total-lifetime carcinogenic ri sk nor the total acceptable daily intake would satisfy the minimum hea lth protection goals of 10(-6) and 300%, respectively. Complete remova l of the residues from burning and of the adjacent lake sediments turn ed out to be the remedial action plan offering the greatest degree of public health protection.