This article reviews and updates data on macro and trace elements and radionuclides in edible wild-grown and cultivated mushrooms. A huge biodiversity of mushrooms and spread of certain species over different continents makes the study on their multi-element constituents highly challenging. A few edible mushrooms are widely cultivated and efforts are on to employ them (largely Agaricus spp., Pleurotus spp., and Lentinula edodes) in the production of selenium-enriched food (mushrooms) or nutraceuticals (by using mycelia) and less on species used by traditional medicine, e.g., Ganoderma lucidum. There are also attempts to enrich mushrooms with other elements than Se and a good example is enrichment with lithium. Since minerals of nutritional value are common constituents of mushrooms collected from natural habitats, the problem is however their co-occurrence with some hazardous elements including Cd, Pb, Hg, Ag, As, and radionuclides. Discussed is also the problem of erroneous data on mineral compounds determined in mushrooms.

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Macro and trace mineral constituents and radionuclides in mushrooms: health benefits and risks.

Contamination of soils with toxic metals is a major problem on military, industrial, and mining sites worldwide. Of particular interest to the field of bioremediation is the selection of biological markers for the end point of remediation. In this microcosm study, we focus on the effect of addition of a mixture of toxic metals (cadmium, cobalt, cesium, and strontium as chlorides) to soil on the population structure and size of the ammonia oxidizers that are members of the beta subgroup of the Proteobacteria (beta-subgroup ammonia oxidizers). In a parallel experiment, the soils were also treated by the addition of five strains of metal-resistant heterotrophic bacteria. Effects on nitrogen cycling were measured by monitoring the NH3 and NH4+ levels in soil samples. The gene encoding the alpha-subunit of ammonia monooxygenase (amoA) was selected as a functional molecular marker for the beta-subgroup ammonia oxidizing bacteria. Community structure comparisons were performed with clone libraries of PCR-amplified fragments of amoA recovered from contaminated and control microcosms for 8 weeks. Analysis was performed by restriction digestion and sequence comparison. The abundance of ammonia oxidizers in these microcosms was also monitored by competitive PCR. All amoA gene fragments recovered grouped with sequences derived from cultured Nitrosospira. These comprised four novel sequence clusters and a single unique clone. Specific changes in the community structure of beta-subgroup ammonia oxidizers were associated with the addition of metals. These changes were not seen in the presence of the inoculated metal-resistant bacteria. Neither treatment significantly altered the total number of beta-subgroup ammonia-oxidizing cells per gram of soil compared to untreated controls. Following an initial decrease in concentration, ammonia began to accumulate in metal-treated soils toward the end of the experiment.

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Effect of Toxic Metals on Indigenous Soil β-Subgroup Proteobacterium Ammonia Oxidizer Community Structure and Protection against Toxicity by Inoculated Metal-Resistant Bacteria

DISCLAIMER The use of company or product name(s) is for identification only and does not imply endorsement by the Agency for Toxic Substances and Disease Registry. A Toxicological Profile for cobalt, Draft for Public Comment was released in July 2001. This edition supersedes any previously released draft or final profile. Toxicological profiles are revised and republished as necessary. For information regarding the update status of previously released profiles, contact ATSDR at: vi Background Information The toxicological profiles are developed by ATSDR pursuant to Section 104(i) (3) and (5) of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA or Superfund) for hazardous substances found at Department of Energy (DOE) waste sites. CERCLA directs ATSDR to prepare toxicological profiles for hazardous substances most commonly found at facilities on the CERCLA National Priorities List (NPL) and that pose the most significant potential threat to human health, as determined by ATSDR and the EPA. ATSDR and DOE entered into a Memorandum of Understanding on November 4, 1992 which provided that ATSDR would prepare toxicological profiles for hazardous substances based upon ATSDR=s or DOE=s identification of need. The current ATSDR priority list of hazardous substances at DOE NPL sites was announced in the Toxicological Profiles are a unique compilation of toxicological information on a given hazardous substance. Each profile reflects a comprehensive and extensive evaluation, summary, and interpretation of available toxicologic and epidemiologic information on a substance. Health care providers treating patients potentially exposed to hazardous substances will find the following information helpful for fast answers to often-asked questions. Chapter 1: Public Health Statement: The Public Health Statement can be a useful tool for educating patients about possible exposure to a hazardous substance. It explains a substance's relevant toxicologic properties in a nontechnical, question-and-answer format, and it includes a review of the general health effects observed following exposure. Chapter 3: Health Effects: Specific health effects of a given hazardous compound are reported by type of health effect (death, systemic, immunologic, reproductive), by route of exposure, and by length of exposure (acute, intermediate, and chronic). In addition, both human and animal studies are reported in this section. NOTE: Not all health effects reported in this section are necessarily observed in the clinical setting. Please refer to the Public Health Statement to identify general health effects observed following exposure. The following additional material can be ordered through the ATSDR Information Center: Case Studies in …

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Toxicological profile for cobalt

Measurement of 240Pu/239Pu isotopic ratios in soils from the Marshall Islands using ICP-MS.

Soil samples collected from three forest sites within the 30-km zone around the Chernobyl reactor were analyzed for 239Pu and 240Pu by ICP-MS. The average 240Pu/239Pu atom ratio in contaminated surface soil samples, values of which are scarce in the literature, was 0.408. There were almost no differences in the 240Pu/239Pu ratios between the individual samples analyzed, although the 239+240Pu levels varied very widely (i.e. from 6.3 to 1430 Bq kg-1 dry weight) depending on the distance from the reactor and on the soil layers investigated. This result corresponded to area-related activities for 239+240Pu between 1.1 kBq m-2 and 13.3 kBq m-2. It was estimated that about half of the Pu migrated from the organic layers to the underlying mineral layers. The 240Pu/239Pu ratio observed in the Chernobyl area was much higher than that attributed to weapons fallout (ca. 0.18). The high ratio was related to the high burn-up grade of the reactor fuel. The 240Pu/239Pu ratio observed might be used as a “fingerprint” in...

W. Rühm

Papers

Migration of 137Cs and 134Cs in different forest soil layers

Cycling of Pu, Sr, Cs, and other longliving radionuclides in forest ecosystems of the 30-km zone around Chernobyl

The ratio in fungi as an indicator of the major mycelium location in forest soil