Influence of soil acidification in southern Norway on the 137Cs exposure of moose?

The mean (137)Cs activity concentration in 278 liver samples of moose (Alces alces) from 16 municipalities located in different parts of Norway varied within the range 43-752 Bq kg(-1) among the municipalities. In general the geographical variation corresponded to the fallout pattern produced by the Chernobyl accident. In three communities in the southernmost part of the country however the transfer factor, defined as the activity in moose liver divided by the corresponding level in surface soil, was 6.5 times higher on average than elsewhere in Norway. Possible reasons for this highly significant difference are discussed, and it is hypothesized that the apparently much higher plant uptake in the south may be related to extensive soil acidification in this area from transboundary pollution.

Concentrations of trace elements in human blood serum from different places in Norway determined by neutron activation analysis

The concentrations of As, Fe, Hg, Sb, Se and Zn in 281 serum samples from people living in nine municipalities in Norway were determined by radiochemical neutron activation analysis. The concentrations of Br, Cl, Cs, Na, Rb, Se and Zn were determined in another set of 157 serum samples from four of the municipalities by instrumental neutron activation analysis. Higher arsenic concentrations were found in the coastal districts than in inland municipalities; otherwise no significant difference in mean values was observed between the districts. Except for Na-Cl and Rb-Cs, none of the elements was significantly correlated with any other element studied.

Comparison of epigeic moss (Hypnum cupressiforme) and lichen (Cladonia rangiformis) as biomonitor species of atmospheric metal deposition

In the present work epigeic moss (Hypnum cupressiforme Hedw.) and epigeic lichen (Cladonia rangiformis Hoffm.) samples were collected simultaneously in the Thrace region, Turkey according to a regular sampling grid. Whereas the moss was found at all 68 sampling sites, the lichen could be collected only at 25 of the sites, presumably because lichens are more sensitive than mosses with respect to air pollution and climatic variations. All elements showed higher accumulation in the moss than in the lichen whereas element inter-correlations were generally higher in the lichen. All considered the moss was judged to be a better choice than the lichen for biomonitoring of atmospheric deposition of metals in this case, and it is argued that mosses may be generally more suited than lichens for this purpose.

Painted surfaces--important sources of polychlorinated biphenyls (PCBs) contamination to the urban and marine environment

A study of a large number of samples of flaking old paint from various buildings in Bergen, Norway (N=68) suggests that paint may be the most important contemporary source of PCBs in this urban environment with concentrations of PCB(7) up to 3.39 g/kg. Twenty-three of the samples were collected from a single building, and the concentrations were found to vary over 3 orders of magnitude. In addition, 16 concrete samples from a large bridge previously coated with PCB-containing paint were collected and separated into outer- and inner samples indicating that PCBs are still present in high concentrations subsequent to renovation. PCBs were found in several categories of paint from wooden and concrete buildings, potentially introduced to the environment by natural weathering, renovation, and volatilization. Consequently, this dispersion may lead to increased levels of PCBs in urban atmospheres, soils, and harbor sediments where high concentrations have resulted in Governmental advice against consumption of certain seafood.

Relationships between organic matter, black carbon and persistent organic pollutants in European background soils: Implications for sources and environmental fate

Black carbon (BC) and total organic carbon (TOC) contents of UK and Norwegian background soils were determined and their relationships with persistent organic pollutants (HCB, PAHs, PCBs, co-planar PCBs, PBDEs and PCDD/Fs) investigated by correlation and regression analyses, to assess their roles in influencing compound partitioning/retention in soils. The 52 soils used were high in TOC (range 54-460 mg/g (mean 256)), while BC only constituted 0.24-1.8% (0.88%) of the TOC. TOC was strongly correlated (p<0.001) with HCB, PCBs, co-PCBs and PBDEs, but less so with PCDD/Fs (p<0.05) and PAHs. TOC explained variability in soil content, as follows: HCB, 80%; PCBs, 44%; co-PCBs, 40%; PBDEs, 27%. BC also gave statistically significant correlations with PBDEs (p<0.001), co-PCBs (p<0.01) and PCBs, HCB, PCDD/F (p<0.05); TOC and BC were correlated with each other (p<0.01). Inferences are made about possible combustion-derived sources, atmospheric transport and air-surface exchange processes for these compounds.

Persistent organic pollutants in boreal and montane soil profiles: distribution, evidence of processes and implications for global cycling

The distribution of persistent organic pollutants (POPs) within background soil profiles was investigated in boreal (Norway) and montane (Italy) areas. The typical build-up of slowly mineralizing humus layers, containing high amounts of soil organic matter (SOM) makes soils of such ecosystems an important global sink for POPs released to the environment. The study focused on evidence and implications of processes influencing the fate of POPs in soil. POP deposition, interaction with SOM, volatilization, leaching, degradation, and bioturbation are discussed. Results indicate that the less volatile POPs such as hexa- and higher chlorinated biphenyls (CBs) or polybrominated diphenyl ethers are very stable in soil profiles, undergoing little translocation or (re)transfer to other environmental compartments. In contrast, more volatile compounds (e.g., tri- and tetra-CBs) were found in soil layers below those formed from vegetation ever directly exposed to airborne POPs. This suggests the occurrence of downward transport and hence limited surface-air exchange of more volatile POPs as they are removed from the top layers. Such soils may therefore be able to retain higher amounts of these compounds than just addressed by the capacity of their surface layers.

Spatial patterns of polybrominated diphenyl ethers (PBDEs) in mosses, herbivores and a carnivore from the Norwegian terrestrial biota

The widespread occurrence of polybrominated diphenyl ethers (PBDEs) in the environment has attracted considerable attention, leading to concerns about the extent and magnitude of wildlife and human exposure. In this work, we focus on the occurrence and fate of PBDEs in a Norwegian air-plant-herbivore-carnivore system. Specifically, we have analysed for PBDEs in moss, livers from various terrestrial herbivores (moose, grouse, and European roe deer) and, for the first time, livers from the top predator lynx. The samples were collected from different sites and time periods (1990-2004) to identify possible spatial and temporal trends in contaminant levels and patterns. The general finding was that PBDEs were found in all (biotic) samples, although at lower concentrations than previously observed in mammals from the marine environment. The PBDE levels in the herbivores ranged from less than 0.5 ng/g lipid weight to 9.4 ng/g lipid weight as the highest. The median PBDE concentration in lynx was approximately one order of magnitude higher than in the herbivores. In the lynx samples there was a predominance of BDE-153 whereas BDE-47 and 99 dominated in the herbivores. This probably reflects different bioaccumulation properties or metabolic transformation processes of the BDE-congeners, and food choice. Levels of PBDEs in both moss and herbivores showed a general decline towards the northern parts of Norway. No clear temporal trends were observed. The PBDE levels observed in this study were low and are probably of limited toxicological significance.

Runoff of particle bound pollutants from urban impervious surfaces studied by analysis of sediments from stormwater traps

Runoff sediments from 68 small stormwater traps around the harbor of urban Bergen, Norway, were sampled and the concentrations of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), heavy metals, and total organic carbon (TOC) were determined in addition to grain size. Our study provides empirical data from a large area in the interface between the urban and marine environment, studying the active transport of pollutants from land-based sources. The results of the analyses clearly demonstrate the importance of the urban environment representing a variety of contamination sources, and that stormwater runoff is an important dispersion mechanism of toxic pollutants. The concentrations of different pollutants in urban runoff sediments show that there are several active pollution sources supplying the sewage systems with PCBs, PAHs and heavy metals such as lead (Pb), zinc (Zn) and cadmium (Cd). The concentration of PCB7 in the urban runoff sediments ranged between < 0.0004 and 0.704 mg/kg. For PAH16, the concentration range was < 0.2-80 mg/kg, whereas the concentration ranges of Pb, Zn and Cd were 9-675, 51.3-4670 and 0.02-11.1 mg/kg respectively. Grain size distribution in 21 selected samples varied from a median particle diameter of 13 to 646 microm. However, several samples had very fine-grained particles even up to the 90 percentile of the samples, making them available for stormwater dispersion in suspended form. The sampling approach proposed in this paper will provide environmental authorities with a useful tool to examine ongoing urban contamination of harbors and similar recipients.

Trace elements in cerebrospinal fluid and blood from patients with a rare progressive central and peripheral demyelinating disease

A hereditary neurological disease in a family in Norway has been reported recently. The disease, which we refer to as Skogholt's disease, is a demyelinating disorder of both the central and the peripheral nervous system with adult onset. We investigated whether changes in trace element concentrations could play a role in Skogholt's disease. Using high resolution inductively coupled plasma mass spectrometry, we determined 31 elements in cerebrospinal fluid (CSF), blood plasma and whole blood from these patients, multiple sclerosis patients and a control group. More than threefold increased levels of Cu and Fe, and a twofold increase in Zn were found in the CSF of Skogholt patients compared to controls. Several other significant differences in trace element levels were also found. The increased levels of Cu and Fe in CSF may indicate an active role of these metals in the pathogenesis of Skogholt's disease. Apparently, these metal ions are transferred into the CSF through their protein chelation, as raised protein levels were also seen. We suggest that redistribution of metals from transport proteins into vulnerable sites in the central (and peripheral) nervous system may initiate critical lesions.

Atmospheric deposition of trace element pollutants in Macedonia studied by the moss biomonitoring technique

For the first time the atmospheric deposition of trace metals was studied over the entire territory of the Republic of Macedonia. Samples of the terrestrial mosses Hypnum cupressiforme, Camptothecium lutescens, and Homalothecium sericeum were collected in September-October 2002 at 73 sites evenly distributed over the country, and a total of 43 elements were determined by instrumental neutron activation analysis and atomic absorption spectrometry. Principal component factor analysis was used to identify the most polluted areas and characterize different pollution sources. The most important sources of trace metal deposition are ferrous and non-ferrous smelters, oil refineries, fertilizer production plants, and central heating stations. Four areas appear to be particularly exposed to metal pollution: Veles, Skopje, Tetovo, and Kavadarci-Negotino, whereas the predominantly agricultural regions in the south, southwest, and southeast show levels closer to European median values for most elements of mainly pollution origin.

Elevated levels of polybrominated diphenyl ethers (PBDEs) in fish from Lake Mjøsa, Norway

Surprisingly high levels of PBDEs (polybrominated diphenyl ethers) in fish from Lake Mjøsa watercourse initialized a more detailed study of PBDE contamination in the Lake Mjøsa region as well as fish from other lakes in southeast Norway. With exception of the fish from Lake Mjøsa, the sum concentration of PBDEs in trout was, on a wet weight (ww) basis, in the range of 0.3-40 ng/g (21-1215 ng/g lipid weight (lw)) in fish fillet and 39-446 ng/g (125-915 ng/g lw) in burbot liver. The PBDE levels in fish from Lake Mjøsa, was found in the range of 72-1120 ng/g ww (2348-16,753 ng/g lw) in trout and 156-2265 ng/g ww (4201-45,144 ng/g lw) in burbot. It was later confirmed that the elevated levels in Lake Mjøsa were mainly caused by the release of PBDEs to the water from a textile manufacturer in the town of Lillehammer. In addition to PBDE levels in fish we also present information on the spatial distribution of PBDEs in air around the Mjøsa watercourse, based on the complementary use of passive air samples and analysis of moss, including data on measured air concentrations. The results confirm the presence of an active source of atmospheric PBDEs in the region of Lillehammer. Although this source appears to have a limited impact on atmospheric levels towards the southern reaches of the lake, it could still be a significant source of PBDEs to the lake as a whole. However, more research is needed to better understand and quantify the relative importance of various sources and pathways for which PBDEs enter Lake Mjøsa in order to support the development of future control strategies.

PAHs in background soils from Western Europe: influence of atmospheric deposition and soil organic matter

The levels and distribution of polynuclear aromatic hydrocarbons (PAHs) were determined in soil samples from background locations in the UK and Norway, to investigate their spatial distribution and the controlling environmental factors. Concentrations ranged between 42 and 11200 microg kg(-1) (geometric mean 640 microg kg(-1)) and 8.6 and 1050 microg kg(-1) (150 microg kg(-1)) dry weight in the UK and Norwegian soil, respectively. Proximity to sources and locations susceptible to high atmospheric depositional inputs resulted in higher concentrations. Statistically significant relationships were observed between PAH and total organic carbon (TOC) in the Norwegian samples. High molecular weight PAHs correlated with black carbon (BC) in UK-woodland soil. These observations support the hypothesis that TOC plays an important role in the retention of PAHs in soil and that PAHs are often combined with BC during combustion emissions. PAHs with 4 and more rings comprised approximately 90% of total PAHs in the UK soil, but only 50% in the Norwegian soil. The mixture of PAHs implied that fractionation occurred during long-range atmospheric transport and deposition. The lighter PAHs with lower K(ow) values more readily reached the most remote sites. The heavier PAHs with higher K(ow) values remained in closer proximity to sources.

Temporal trends (1990-2000) in the concentration of cadmium, lead and mercury in mosses across Europe

The European heavy metals in mosses survey provides data on the concentration of 10 heavy metals in naturally growing mosses. The survey has been repeated at five-yearly intervals and in this paper we report on the temporal trends in the concentration of cadmium, lead and mercury between 1990 and 2000. Metal- and country-specific temporal trends were observed. In general, the concentration of lead and cadmium in mosses decreased between 1990 and 2000; the decline was higher for lead than cadmium. For mercury not enough data were available to establish temporal trends between 1990 and 1995, but between 1995 and 2000 the mercury concentration in mosses did not change across Europe. The observed temporal trends for the concentrations in mosses were similar to the trends reported for the modelled total deposition of cadmium, lead and mercury in Europe.

First report of phytochelatins in a mushroom: induction of phytochelatins by metal exposure in Boletus edulis

Some species of macromycetes (mushrooms) consistently are found to contain high concentrations of toxic metals such as cadmium (Cd) and mercury (Hg), and consumption of wild-growing mushrooms is acknowledged as a significant source for Cd and Hg in humans. Yet little is known about the speciation of Cd and Hg in mushroom tissues. Here we present the first evidence of peptides of the phytochelatin family being responsible for binding a large fraction of Cd in caps of the macromycete Boletus edulis exposed to excess metals. Concentrations of Cd, Zn, Cu and Hg, as well as cytosolic Cd-binding capacity (CCBC), glutathione (GSH) and free proline (Pro) were quantified in fruiting bodies of B. edulis differentially exposed to a wide range of metals. Metal distribution among cytosolic compounds were investigated by size exclusion chromatography (SEC), followed by metal determinations with atomic absorption chromatography (AAS) and HR-ICP-MS. Cd-binding compounds in SEC elutates were investigated further by high performance liquid chromatography-mass spectrometry (HPLC-MS). CCBC was >90 times higher in the exposed group relative to the reference group (Mann-Whitney's P < 0.001), whereas concentrations of free Pro were almost identical for the two groups. For the whole study selection, CCBC correlated positively with metal exposure (Spearman's P < 0.001 for all four metals), suggesting dose-dependent induction of Cd-binding compounds by exposure to these metals, possibly as a defense mechanism. The presence of phytochelatins (PCs), a family of cystein-rich oligopeptides, was confirmed in Cd-containing SEC fractions by HPLC-MS. The appearance of more complex PCs was coupled to declining concentrations of GSH. To our knowledge this is the first report demonstrating the presence of PCs in a macromycete.

Estimation of diffusive boundary layer thickness in studies involving diffusive gradients in thin films (DGT)

Recent laboratory experiments and field investigations involving diffusive gradients in thin films (DGT) have shown that the thickness (delta) of the diffusive boundary layer (DBL), which can affect the accuracy of the technique, is generally not negligible. Accordingly, the determination of delta has become a matter of considerable practical importance. Though the problem has been addressed in the recent literature, there is room for some improvement. An expression for estimation of delta is presented here, and a practical procedure for determining delta and the concentration of DGT-labile species from sparse experimental data is proposed and illustrated by analyzing data from four experiments with DGT samplers of different diffusive gel thicknesses.

Atmospheric mercury in Norway: contributions from different sources

The environmental loadings of national Norwegian mercury emissions compared to the loadings of atmospheric long range transported mercury have been estimated using national emission data and EMEP model data. The results indicate that atmospheric long-range transport to Norway is somewhat larger than the national Norwegian emissions of mercury. Atmospheric deposition of mercury has been studied using data from Norwegian monitoring programs on mercury in precipitation, mosses, natural surface soils, and lake sediments. Precipitation data show no significant time trend during 1990-2002, whereas moss samples show similar concentrations from 1985 to 1995, but a 30% decrease from 1995 to 2000. Concentrations of mercury in peat cores and reference sediments indicate that the current mercury levels measured in surface sediments, surface soils and mosses at background sites in Norway are substantially affected by long-range atmospheric transport.

Heavy metal pollution of surface soil in the Thrace region, Turkey

Samples of surface soil were collected at 73 sites in the Thrace region, northwest part of Turkey. Two complementary analytical techniques, epithermal neutron activation analysis (ENAA) and atomic absorption spectrometry (AAS) with flame and graphite furnace atomization were used to determine 35 elements in the soil samples. Concentrations of As, Cd, Co, Cu, Mn, Ni, Pb and Zn were determined using AAS and GF AAS, and ENAA was used for the remaining 27 elements. Results for As, Ba, Br, Ca, Cd, Ce, Co, Cr, Cs, Cu Eu, Fe, Hf, I, In, K, La, Mn, Mo, Na, Nd, Ni, Pb, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Th, Ti, U, V and Zn are reported for the first time for soils from this region. The results show that concentrations of most elements were little affected by the industrial and other anthropogenic activities performed in region. Except for distinctly higher levels of Pb, Cu, Cd and Zn in Istanbul district than the median values for the Thrace region, the observed distributions seem to be mainly associated with lithogenic variations. Spatial distributions of As, Cd, Cr, Cu, Ni, Pb and Zn were plotted in relation to the concentration values in soil using Geographic Information System (GIS) technology.

Dynamic aspects of DGT as demonstrated by experiments with lanthanide complexes of a multidentate ligand

Sampling of metals with the technique of diffusive gradients in thin-films (DGT) depends on the rates of diffusion and on the kinetics of interconversion of the species present. In this study the discrimination between metal complexes with different dissociation kinetics is investigated. Samplers with differentthicknesses of diffusive and resin gels were deployed in solutions containing 10 microg/L of each metal in the lanthanide (Ln) series (except Pm) and 2.0 x 10(-6) M of the ligand quin2 at an ionic strength of 0.1 M (KNO3) and pH 7.0. Diffusion coefficients of Ln3+ ions and Ln-quin2 complexes were determined in a diffusion cell experiment. The equilibrium speciation of the metals was calculated from available stability constants. The sampling rate (mass/time) was highly dependent on the dissociation-rate constant of the complexes. For complexes with dissociation kinetics that appreciably limited the uptake, the sampling rate decreased significantly with increasing deployment times (12, 24, and 76 h) and was virtually independent of the thickness of the diffusive gel. Placing a layer of diffusive gel behind the resin did not influence the accumulation of Lns in the resin gel, but doubling the thickness of the layer containing resin increased the uptake, and more so for the Lns forming less labile complexes. The Lns forming more labile complexes were enriched in the outer layer of the resin, and there was a trend toward even distribution between the outer and deeper parts of the resin layer for the Lns forming less labile complexes. The measured DGT sampling rates (mass/ time) were reasonably well predicted by a dynamic model that used independently determined kinetic constants. This new knowledge of how metal complexes behave in the sampling process paves the way for using DGT to obtain in situ kinetic information in natural waters.

Persistent organic pollutants in European background air: derivation of temporal and latitudinal trends

Data are presented for polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyls ethers (PBDEs) and selected organochlorine compounds (OCs) in passive air samplers (PAS) along a rural/remote latitudinal transect from southern UK to northern Norway during 2002-2004. This study is part of an ongoing campaign, using semi-permeable membrane devices (SPMDs) as PAS over two year intervals since 1994. Data for PCBs, selected OCs and PBDEs are compared with that from previous campaigns. Absolute sequestered amounts of selected PCB congeners have decreased in a first order fashion between 1994-2004, with an average atmospheric clearance rate of 4.1 +/- 0.6 years and continue to fractionate with latitude. HCB has also declined between 1998-2004, with a clearance rate of 6 +/- 2.4 years. Data on DDT and its breakdown products indicate little fresh release in Europe. Comparison of PBDEs in 2000-02 and 2002-04 indicates site differences, generally with increases at UK sites and decreases in Norway. BDE-28, 47 and 49 decreased with increasing latitude (p < 0.04), while the other congeners did not show any significant latitudinal dependence. Transect data are presented for PAHs the first time. Three- and 4-ringed compounds dominated the mixture present in the SPMD. The PAH composition of the SPMDs at site 3 was compared to the average composition taken by active sampling at the same site. SPMD performance for sampling PAHs leaves many uncertainties, but they can be successfully used to semiquantitatively detect PAHs in the atmosphere. Fluorene and phenanthrene increased with latitude (p > 0.05), while 1-methylphenanthere, fluoranthene, benzo[b]fluoranthene and indeno[123-cd]pyrene decreased. Results are discussed in terms of sources, long-range atmospheric transport, global fractionation and clearance processes.

Damage to DNA and lipids in Boletus edulis exposed to heavy metals

This study investigates the potential of emissions from a zinc smelter to induce oxidative damage to DNA and lipids in Boletus edulis, the king bolete. Concentrations of cadmium, zinc, copper, and mercury were determined in 16 fruit bodies collected near the smelter (exposed group), as well as in 15 reference samples. Frequency of apurinic/apyrimidinic (AP) sites in DNA (a pre-mutagenic DNA base modification) and concentration of lipid hydroperoxides were chosen as damage parameters. Concentrations of the four metals, as well as oxidative damage to DNA and lipids were significantly elevated in the exposed group (Mann-Whitney, P<0.001). Both damage parameters correlated positively with concentrations of cadmium, zinc or copper in fruiting bodies (Spearman's P<0.01). Frequency of AP sites correlated significantly with mercury in the fruit bodies (P<0.05), whereas the association between lipid hydroperoxides and mercury was insignificant. Frequency of AP sites correlated positively with concentration of lipid hydroperoxides (P<0.001). Negative trends for the associations between concentrations of metals and AP sites or lipid hydroperoxides in the reference group (significant only for mercury and lipid hydroperoxides; P<0.05) suggest that in B. edulis low concentrations of mercury, possibly also of other of the metals determined in the present study, may induce dose-response relationships of a hormetic ('J-shaped') nature.

Transfer of (85)Sr and (134)Cs from diet to reindeer foetuses and milk

Sr-85 and (134)Cs in aqueous solution of the chlorides were administered daily to four pregnant reindeer during the last part of gestation. Radionuclide concentrations were determined in calves sacrificed at birth, and secretion of the nuclides was measured in milk. Although the gastrointestinal absorption of (85)Sr was low, an apparently higher transfer of the absorbed fraction of (85)Sr than (134)Cs from the mother to the foetus led to similar accumulation of (85)Sr and (134)Cs in foetuses. At birth 1.4-1.6 and 1.5-2.5% of the total administered activities of (85)Sr and (134)Cs, respectively, were present in the calves' bodies. Transfer coefficients (F (m)) for (85)Sr and (134)Cs from feed to milk were estimated at 0.0218+/-0.0026 and 0.185+/-0.025 day kg(-1), respectively, and the observed ratio (OR(milk-diet)) for (85)Sr was 0.124+/-0.037. Transfer of radiostrontium to reindeer milk was in agreement with previously reported relationships between Ca intake and radiostrontium transfer in ruminants. These relationships suggest that the transfer of radiostrontium to foetuses and milk of free-ranging reindeer can be 3-4 times higher than observed in this experiment (due to lower Ca intake with natural forage), but the transfer to milk will not be as high as that of ionic (134)Cs. The concentrations of (85)Sr in milk suggested that the does mobilized skeletal stores of Ca and (85)Sr for milk production, although the diet appeared to satisfy the Ca requirements. In reindeer with radiostrontium intake during the whole year, radiostrontium concentrations in milk will therefore be higher than indicated by the F (m) value observed in our study. No differences in half-times for (85)Sr and (134)Cs secretion in milk were detected. Both nuclides were secreted with short- and long-term half-times of 1-2 and 12-19 days, respectively. For (85)Sr, 80-90% of the activity was excreted with the short half-time, whereas the corresponding value for (134)Cs was 30-50%.

Molecular defense systems are expressed in the king bolete (Boletus edulis) growing near metal smelters

The induction of defense systems against metal exposure was investigated in 48 wild-growing fruiting bodies of the king bolete (Boletus edulis) from two areas polluted with several transition metals from smelters, as well as five reference areas. To determine the degree of metal exposure, cadmium (Cd), zinc (Zn), and copper (Cu) were determined in caps of fruiting bodies by atomic absorption spectrophotometry (AAS), whereas mercury (Hg) was determined by cold vapor atomic fluorescence spectrometry (CVAFS). Caps were analyzed further with respect to relative activities of the antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), as well as concentrations of total glutathione (GSHTOT = GSH + GSSG) and relative concentrations of heat shock protein 70 kDa (HSP70). The results showed that concentrations of the four metals, as well as SOD, CAT and HSP70, were significantly elevated in the exposed group (Mann-Whitney, P < or = 0.001). In contrast, GSHTOT was significantly lowered in the exposed group (P < or = 0.05). Significant positive correlations were established between concentrations of Cd, Zn, Hg, or Cu and activities of SOD (Spearman's P < or = 0.01 for the association between SOD and Cd, P < or = 0.001 for all other metal exposure parameters), CAT (P < or = 0.001 for all exposure parameters), or expression of HSP70 (P < or = 0.001 for all exposure parameters). Significant negative correlations were found between total GSH and Cd (P < or = 0.001), Zn (P < or = 0.001), or Hg (P < or = 0.05). We conclude that antioxidant enzymes are induced in wild-growing B. edulis exposed to environmentally relevant concentrations of potentially toxic transition metals; whereas the net consumption of GSH that occurs with increasing metal exposure may reflect GSH consumption by mechanisms of metal detoxification. Finally, the induction of HSP70 suggests that the antioxidant response and the mechanisms in which GSH is consumed are insufficient for protection against the harmful effects of severe metal stress.