MANY DIVERSIFIED INTERESTS, INCORPORATED
HOUSTON, HARRIS COUNTY, TEXAS
- The four samples collected from the MDI site indicate that this location is heavily contaminated with metals ofpublic health concern. The soil is likely contaminated from the thousands of corroding barrels of leakingmaterial. The MDI site itself has restricted access via a chain link fence; therefore, it is not expected that childrenwould have direct contact with the metal contaminants on-site.
- The drainage area outside of the fenced area and adjacent to the site is contaminated with heavy metals. This areais very accessible to neighborhood children. Lead and arsenic are of primary public health concern for childrenwho may be exposed to this contaminated soil.
- Thallium was found at elevated levels in the drainage area. This metal can be a significant public health concernfor children or adults who may be exposed to the contaminated soil through incidental ingestion.
- Lead was found at elevated levels in all five of the residential yards analyzed. It also was found at elevated levelsin the drainage area, but was not found to be above background levels on-site. Based on available modelscorrelating blood lead levels with lead in soil, children exposed to contaminated soils in the residential yards anddrainage area could experience elevated blood lead levels.
- Other metals found to be significantly above background levels in the accessible areas of the drainage area andresidential yards include manganese, nickel, antimony, copper, and iron. These metals typically adhere stronglyto soil particles and are not readily bioavailable to humans. The type of exposure leading to adverse health effectsis less likely than those caused by exposure to lead, arsenic, and thallium mentioned above.
- Off-site migration of metals found on or near the MDI site could be responsible for the elevated levels of metalssuch as copper, iron, antimony, and arsenic in the drainage area and residential yards, where these metals werefound to be significantly above background levels.
- Access to the MDI properties should continue to be restricted and clean-up activities should continue.
- Migration of metals off-site via the drainage area or any other potential sources should be eliminated. All visibleslag from the drainage area should be removed and access to this area should be restricted to prevent potential forhuman exposure.
- Children from Bruce Elementary School and/or the neighborhood adjacent to the MDI site should be tested forelevated blood lead levels.
- Residents should be advised to minimize exposure to the soils contaminated with heavy metals near the MDI site,particularly lead in their yards.
- No remedial actions are recommended for the Bruce Elementary schoolyard.
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- Agency for Toxic Substances and Disease Registry. Toxicological profile for arsenic. Atlanta: ATSDR, April 1993
- IRIS, 1996. Integrated Risk Information System. U.S. Environmental Protection Agency, Office of Health andEnvironmental Assessment, Environmental Criteria and Assessment Office. Cincinnati, OH.
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- Agency for Toxic Substances and Disease Registry. Toxicological profile for manganese and compounds. Atlanta: ATSDR, July 1992.
- Agency for Toxic Substances and Disease Registry. Toxicological profile for nickel (draft). Atlanta: ATSDR, Feb.1996.
- Agency for Toxic Substances and Disease Registry. Toxicological profile for antimony and compounds (draft). Atlanta: ATSDR, Feb. 1991.
- Agency for Toxic Substances and Disease Registry. Toxicological profile for copper. Atlanta: ATSDR, Dec. 1990.
- Casarett and Doull, 1986. Toxicology. The Basic Science of Poisons, third edition. Macmillan Publishing Co., NewYork.
- Agency for Toxic Substances and Disease Registry. Toxicological profile for thallium. Atlanta: ATSDR, July 1992.