[Risk assessment of soil contamination in a residential area: the importance and role of human biological monitoring--a case report]. / Gefährdungsabschätzung von Bodenverunreinigungen in einem belasteten Wohngebiet: Bedeutung und Funktion des Human-Biomonitoring -- ein Fallbeispiel.

BACKGROUND AND PURPOSE: High levels of arsenic, cadmium, mercury and polychlorinated dibenzodioxins and dibenzofuranes (PCDD/PCDF) were detected in the soil of a residential area located at the river Elbe near Hamburg (Germany). Soil contamination resulted from sediments from the Hamburg harbour and from the Elbe that were deposited in this area up to the late 1950ies. The objective of this study was to evaluate whether the soil contamination in this area is associated with increased levels of arsenic, heavy metals and PCCD/PCDF in the blood and urine of selected residents living on highly contaminated grounds. RESULTS: The blood levels of lead and PCDD/PCDF and the urine levels of arsenic, cadmium and mercury that were measured in 29 residents living on highly contaminated grounds were not elevated in relation to a control group. All individual values were in the range of the background exposure levels of the general population. There were no signs of an increased additional exposure related to soil contamination. CONCLUSIONS: Based on the results of this study it was agreed to refrain from an expensive redevelopment of this area. As a preventive measure some recommendations were given to the residents to minimize possible exposure to soil contaminants. Human biological monitoring studies should be an essential part of exposure and risk assessment of soil contaminations in residential areas in future studies and as a basis for adequate risk management.

Ecological effects, transport, and fate of mercury: a general review.

Mercury at low concentrations represents a major hazard to microorganisms. Inorganic mercury has been reported to produce harmful effects at 5 microg/l in a culture medium. Organomercury compounds can exert the same effect at concentrations 10 times lower than this. The organic forms of mercury are generally more toxic to aquatic organisms and birds than the inorganic forms. Aquatic plants are affected by mercury in water at concentrations of 1 mg/l for inorganic mercury and at much lower concentrations of organic mercury. Aquatic invertebrates widely vary in their susceptibility to mercury. In general, organisms in the larval stage are most sensitive. Methyl mercury in fish is caused by bacterial methylation of inorganic mercury, either in the environment or in bacteria associated with fish gills or gut. In aquatic matrices, mercury toxicity is affected by temperature, salinity, dissolved oxygen and water hardness. A wide variety of physiological, reproductive and biochemical abnormalities have been reported in fish exposed to sublethal concentrations of mercury. Birds fed inorganic mercury show a reduction in food intake and consequent poor growth. Other (more subtle) effects in avian receptors have been reported (i.e., increased enzyme production, decreased cardiovascular function, blood parameter changes, immune response, kidney function and structure, and behavioral changes). The form of retained mercury in birds is more variable and depends on species, target organ and geographical site. With few exceptions, terrestrial plants (woody plants in particular) are generally insensitive to the harmful effects of mercury compounds.

Toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to several ecological receptor groups: a short review.

Toxicity among TCDD isomers can vary significantly. Isomers containing four to six chlorine atoms possess the greatest potential for biological activity, as well as the highest acute toxicity. Information available in the literature focuses largely on fish and terrestrial mammal studies. Toxicity data for aquatic invertebrates and plants is wanting, and essentially no studies pertaining to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) accumulation in these organisms could be found. No data were procurable regarding TCDD toxicity in marine mammals or reptiles. Current knowledge is not sufficient to accurately characterize TCDD toxicity in ecological receptors, with quantification of uncertainty being particularly difficult given the limited base of knowledge.