Multi-element composition of soil, mosses and mushrooms and assessment of natural and artificial radioactivity of a pristine temperate rainforest system (Slavonia, Croatia)

Composition, environmental implication and source identification of elements in soil and moss from a pristine spruce forest ecosystem, Northwest China

The environmental quality of remote alpine ecosystem has been drawn increasing attention owing to the increasingly severe atmospheric pollution. This study investigated the composition and sources of elements in the soil and moss collected from a pristine spruce forest in the Qilian Mountains, Northwest China. The order of mean concentrations of elements investigated in soil was Fe > K > Na > Mg > Ca > Mn > Cr > Zn > Pb > Ni > Cu > As > Cd > Hg, and that of moss was Ca > Fe > Mg > K > Na > Mn > Cr > Zn > Pb > Ni > Cu > As > Cd > Hg. The concentrations of trace metals (except for As) in soil were greater than the soil background values, with Pb contamination more serious than the other elements. The Nemerow integrated pollution index (NIPI) values indicated that the soils were heavily polluted by Pb, Cd and Ni. The potential ecological risk index (PERI) suggested that the soils were at moderate risk. In particular, Hg and Cd were the most critically potential factors for ecological risk. According to the bioaccumulation factors (BAF), the accumulated concentrations of Ca, Hg, Cd, Pb, Ni, Mg, Cr and Zn in moss were higher than those in soil. By performing the multivariate analyses, natural sources (airborne soil particles) were identified to be the major contributors for all elements, whereas anthropogenic sources also contributed to the accumulations of Pb and Cd in the soil and moss in this region.

Physiochemical responses of earthworms (Eisenia fetida) under exposure to lanthanum and cerium alone or in combination in artificial and contaminated soils

Rare earth elements inevitably release into the soil due to their widespread application. However, it is unclear how they affect the soil animals. The study surveyed the growth and physiological responses of earthworm (Eisenia fetida) exposed into artificial soils spiked with La, Ce, and their mixture, and actual mine soil collected from an abandoned La-Ce mining area (Mianning, Sichuan). The results showed that the 1000-1200 mg/kg combined exposure in two soils induced significant histopathological and phenotypic changes of earthworms. Concentration significantly affected the superoxide dismutase (SOD), peroxidase (POD), malondialdehyde (MDA), and protein of E. fetida and the effects differentiated with the prolonging duration. These indicators were negatively affected under the La stress ≥800 mg/kg (SOD, POD, and protein), the 1200 mg/kg (SOD), Ce stress ≥1000 mg/kg (protein), and the combination ≥800 mg/kg (SOD, POD) and ≥1000 mg/kg (protein). Artificial combination had -15.04% (SOD), 8.87% (POD), 5.64% (MDA), and -8.34% (protein) difference compared with the contamination soil, respectively. Overall, E. fetida respond sensitively under the La and Ce stress, the antioxidant defense system and the lipid peroxidation were stimulated, and the artificial soil might overestimate eco-toxicological effect.

Distribution and Origin of Major, Trace and Rare Earth Elements in Wild Edible Mushrooms: Urban vs. Forest Areas

This paper investigates the composition of major, trace, and rare earth elements in 15 different species of wild edible mushrooms and the possible effect of urban pollution on elemental uptake. The collected mushrooms include different species from the green areas of the city, exposed to urban pollution, and from the forests, with limited anthropogenic influence. Through a comprehensive approach that included the analysis of 46 elements, an attempt was made to expand knowledge about element uptake by mushroom fruiting bodies. The results showed a wide variability in the composition of mushrooms, suggesting a number of factors influencing their element uptake capacity. The data obtained do not indicate significant exposure to anthropogenic influences, regardless of sampling location. While major elements’ levels appear to be influenced more by species-specific affinities, this is not true for trace elements, whose levels presumably reflect the geochemical characteristics of the sampling site. However, the risk assessment showed that consumption of excessive amounts of the mushrooms studied, both from urban areas and from forests, may have adverse health effects.

Radiocaesium Contamination of Mushrooms at High- and Low-Level Chernobyl Exposure Sites and Its Consequences for Public Health

We compare the specific activities of 137Cs and 40K in stipes and caps of three different common mushroom species (Xerocomus badius, Russula ochroleuca and Armillariella mellea) measured at the Czech Chernobyl hot spot in the Opava area (Silesia) and at a low-exposed site at the Beskydy mountains in 2011. The highest values of 137Cs were found in caps of Xerocomus badius and Russula ochroleuca in the Opava area (11.8 and 8.77 kBq/kg, respectively). The source of 137Cs was verified by the measurement of the 134Cs/137Cs ratio. Based on our results, we estimate an effective dose per year due to radiocaesium intake in the two investigated areas for Xerocomus badius, one of the most popular edible mushrooms in the Czech Republic. In 2011, the effective dose reached the maximum value of 0.102 mSv in the Opava area and 0.004 mSv at the low-exposed site at the Beskydy mountains. Therefore, it does not represent a significant risk for public health.

Natural radioactivity and total K content in wild-growing or cultivated edible mushrooms and soils from Galicia (NW, Spain)

The radioactive isotope, ⁴⁰K, of naturally occurring potassium (0.012%) is present in the Earth's crust in a low percentage of all potassium, leading to its presence in almost all foodstuffs. The impact of ⁴⁰K activity concentrations was assessed in wild and cultivated edible mushrooms and in growing substrates. Samples were analysed by gamma spectroscopy. In the wild mushroom species, the average activity concentration of ⁴⁰K was 1291 Bq kg^-1 dry weight (dw), approximately 140 Bq kg^-1 fresh weight (fw), with a range of average values per species from 748 in Lactarius deliciosus to 1848 Bq kg^-1 dw in Tricholoma portentosum. The cultivated species presented an average value of 1086 Bq kg^-1 dw; and the soils, compost of cultivation and wood of substrate are 876, 510 and 59.4 Bq kg^-1 dw, respectively. The total K content reached a maximum of 59,935 mg kg^-1 dw in T. portentosum. The transfer factors (TF > 1) suggested that mushrooms preferentially bioconcentrated ⁴⁰K. Cantharellus cibarius, Craterellus tubaeformis, Hydnum repandum and T. portentosum by most TF could be considered as bioindicators of ⁴⁰K. Taking into account that the annual radiation dose of ⁴⁰K due to the average consumption of mushrooms analysed (0.15 μSv/year) is very low, it can be concluded that the consumption of these mushrooms does not represent a toxicological risk for human health. Finally, according to the total K content, from the nutritional point of view, these mushrooms could be considered as a potential source of potassium for the human diet.

Strontium accumulation by the terrestrial and aquatic plants affected by mining and municipal wastewaters (Elazig, Turkey)

The mining and municipal wastewaters in the study area are located around Elazig, Turkey. This study investigated the translocation and accumulation of Sr into 9 terrestrial-aquatic plants from the Elazig municipal wastewater, Keban Pb-Zn and Maden Cu wastewaters. Plants and their soil samples were collected from the stream/rivers on the municipal and mining areas, and Sr values in both plant parts and their soils were analyzed by ICP-MS. The mean Sr concentrations in the soil, root and shoot of the terrestrial-aquatic plants were 101, 48.2 and 80.5 ppm, respectively (on the dried weight basis). The enrichment coefficients of root (ECR) and shoots (ECS) and translocation factors of studied plants were calculated and, then, divided into several groups as a candidate, bioaccumulator and hyperaccumulator plants according to their ECR and ECSs. These groups indicated the candidate plants: Salix sp. and Tamarix tetrandra; bioaccumulator plants: Pragmites sp. and Xanthium, and hyperaccumulator plants: Typha latifolia, Bolboscholnus ascbersus and Lythnium salicaria for Sr. These results showed that both bioaccumulator and hyperaccumulator plant groups had very high ability to accumulate strontium to plant parts from their soil. Therefore, these studied plants may be helpful/useful for the rehabilitation studies of municipal and mining soils contaminated by Sr.

Identification of radionuclides' altitudinal distribution In soil and mosses In highlands of Armenia

The present study was conducted in mountain regions of Armenia with the aim to assess the activity concentrations of natural K-40 and artificial Cs-137 in soil and mosses and reveal the distribution similarities and differences. Most widespread moss species and surface soils were sampled concurrently from eight mountain ridges and massifs by different altitudinal belts. Statistical analysis revealed significant differences and opposite characteristics for K-40 and Cs-137. In case of K-40 the activity concentrations decreased in mosses by altitude but with no significant correlation. The mean activity concentrations of K-40 in the soils of different altitudinal belts are close, nevertheless, the higher activity concentrations are common for soils derived from ingenious rocks. For Cs-137 in mosses, the correlation with altitude is statistically insignificant, but the altitudinal dependence is noticeable within separate ridges and massifs. A significant correlation was identified between Cs-137 in soil, altitude and precipitation rate. Studying natural K-40 and artificial Cs-137 radionuclides together yielded interesting contrasting results confirming the dissimilar behaviour of radionuclides with different origins in the environment.

Occurrence, behavior, and human exposure and health risks of potentially toxic elements in edible mushrooms with focus on Africa

Understanding the occurrence, behavior, and fate of potentially toxic elements (PTEs) in the substrate-mushroom-human nexus is critical for assessing and mitigating their human health risks. In this review, we (1) summarized the nature, sources, and biogeochemical behavior of PTEs in the substrate-mushroom systems; (2) discussed the occurrence, exposure, and human health risks of PTEs in mushrooms with emphasis on African geological hotspots such as metalliferous and highly mineralized substrates; (3) developed a 10-step conceptual framework for identifying, assessing, and mitigating the human health risks of PTEs in mushrooms, and highlight future directions. High human exposure risks potentially exist in Africa due to the following: (1) widespread consumption of mushrooms from various metalliferrous and highly mineralized substrates such as serpentines and mine waste dumps, (2) inadequate and poorly enforced environmental health and food safety regulations and policies, (3) limited environmental and human health monitoring data, and (4) potential synergistic interactions among PTEs in mushrooms and human health stressors such as a high burden of human diseases and infections. Although the human health effects of individual PTEs are well known, scientific evidence linking human health risk to PTEs in mushrooms remains weak. A framework for risk assessment and mitigation, and future research directions are recommended.

Assessment of potential human health risk of trace element in wild edible mushroom species collected from Yunnan Province, China

Wild edible mushrooms are rich in nutritions and popular among people, but wild edible mushrooms easily accumulate potentially harmful trace elements, and excessive intake will harm health. The aim of this study was to investigate the potential health hazards of long-term intake of wild edible mushrooms in Yunnan Province, China. The concentrations of trace element (As, Cd, Cr, Cu, Hg, Pb, Ni, and Zn) in 19 species of wild edible mushrooms in Yunnan Province were determined by inductively coupled plasma mass spectrometry (ICP-MS). Further processing of the data, the potential health risk assessments of consumers were evaluated by the target hazard quotient (THQ), hazard index (HI), and incremental lifetime cancer risk (ILCR), respectively. Results showed that concentrations of trace element in wild edible mushrooms decreased in the order of Zn > Cu > As > Ni > Cr > Cd > Pb > Hg. Compared with the maximum standard by the WHO/China, the averages of As, Cd, Cr, Hg, and Zn were significantly greater than the standard. Among the tested wild edible mushrooms, HI values of Leccinum crocipodium, Thelephora ganbajun, Lactarius luteolus, Tricholoma matsutake, and Polyporus ellisii were more than 1. Thus, Leccinum crocipodium, Thelephora ganbajun, Lactarius luteolus, Tricholoma matsutake, and Polyporus ellisii are the main sources of risk. The value of THQ in ascending order was as follows: Pb (0.11) < Cd (0.75) < As (4.27) < Hg (6.87). Thus, Hg are the primary sources of health risk in the wild edible mushrooms in Yunnan Province. ILCR_(As) values of Thelephora ganbajun, Tricholoma matsutake, Laccaria amethystea, and Polyporus ellisii were more than 10^-4, these four samples are the primary sources of health risk. The mean values of ILCR for As in wild mushroom were 1.01 × 10^-4. The results suggest that there was potential health risk to the consumer associated with the long-term consumption of wild edible mushrooms collected from Yunnan Province. We propose that the concentrations of trace element should be periodically monitored in wild edible mushrooms.

Elemental composition of Russula cyanoxantha along an urbanization gradient in Cluj-Napoca (Romania)

How far-reaching is the influence of the urban area over the mineral composition of the Russula cyanoxantha mushroom? We studied the metal uptake behavior of this fungus relying on the soil properties. We sampled mushroom and soil from six forests according to an urbanization gradient, and two city parks in Cluj-Napoca (Romania). The elements were quantified using inductively coupled plasma - optical emission spectroscopy (ICP-OES). The concentrations of some elements differed significantly (p < 0.05) in the samples from the city (0.39 ± 0.35 mg kg^-1 for cadmium (Cd), 0.40 ± 0.19 mg kg^-1 for chromium (Cr), 69.1 ± 29.9 mg kg^-1 for iron (Fe), 10.9 ± 1.3 mg kg^-1 for manganese (Mn), 0.76 ± 0.45 mg kg^-1 for titanium (Ti) compared with the samples from the forests (3.15-14.1 mg kg^-1 Cd, < 0.18 mg kg^-1 for Cr, 22.6-34.5 mg kg^-1 for Fe, 15.9-19.1 mg kg^-1 for Mn, 0.19-0.36 mg kg^-1 for Ti). We observed a definite negative trend in the mineral accumulation potential of this fungus along the urbanization gradient. The fungus turned from a cadmium-accumulator to a cadmium-excluder. This highlights a positive environmental influence of the urbanization over the toxic metal uptake of R. cyanoxantha. The hypothesis, that the urban soil pollution would increase the metal content of the mushroom was disproved. The possible explanation might be the elevated carbonate content of the urban soil, which is known to immobilize the metals in the soil.