Follow-up metals assays were not conducted. Further assays of fish flesh for heavy metals should be conducted to see if a potential human exposure problem exists, regardless of the contaminant source. According to available blood lead data, workers handling the aggregate and citizens living near the aggregate currently do not show elevated blood lead levels. Occupational studies associated with aggregate exposure use too high a detection limit to make those data useful in estimating blood lead levels in children. Another data gap exists about whether the physical size or structure of fine or crushed aggregate poses a respiratory hazard.
More information is needed to understand the situation.
On-site air and water monitoring programs at MSP are useful and should be continued as a quality control check for possible releases from the plant. The proposed continuous stack gas emissions monitoring and analysis system should provide an extra measure of safety in guarding against poor combustion conditions. Other ongoing quality assurance measures, which include radiation scanning of incoming materials, sampling and analysis of wastes to be processed, and leach testing of produced aggregate, should be continued. That conclusion is based primarily on the data gaps about the safety of the aggregate under conditions of Chronic exposure and its use in areas where dust generation and inhalation could occur. Using the data evaluated, it is not possible to link adverse health outcomes that might be present in the community living near the MSP site with site-related exposures.