Health risk from heavy metals via consumption of food crops in the vicinity of Dabaoshan mine, South China

Heavy metal contamination of soils resulting from mining and smelting is causing major concern due to the potential risk involved. This study was designed to investigate the heavy metal (Cu, Zn, Pb and Cd) concentrations in soils and food crops and estimate the potential health risks of metals to humans via consumption of polluted food crops grown at four villages around the Dabaoshan mine, South China. The heavy metal concentrations in paddy and garden soils exceeded the maximum allowable concentrations for Chinese agricultural soil. The paddy soil at Fandong village was heavily contaminated with Cu (703 mg kg^− 1), Zn (1100 mg kg^− 1), Pb (386 mg kg^− 1) and Cd (5.5 mg kg^− 1). Rice tended to accumulated higher Cd and Pb concentration in grain parts. The concentrations of Cd, Pb and Zn in vegetables exceeded the maximum permissible concentration in China. Taro grown at the four sampled villages accumulated high concentrations of Zn, Pb and Cd. Bio-accumulation factors for heavy metals in different vegetables showed a trend in the order: Cd > Zn > Cu > Pb. Bio-accumulation factors of heavy metals were significantly higher for leafy than for non-leafy vegetable. The target hazard quotient (THQ) of rice at four sites varied from 0.66-0.89 for Cu, 0.48-0.60 for Zn, 1.43-1.99 for Pb, and 2.61-6.25 for Cd. Estimated daily intake (EDI) and THQs for Cd and Pb of rice and vegetables exceeded the FAO/WHO permissible limit. Heavy metal contamination of food crops grown around the mine posed a great health risk to the local population through consumption of rice and vegetables.     

Daily intake of manganese by local population around Kylleng Pyndengsohiong Mawthabah (Domiasiat), Meghalaya in India

Present work is carried out adjacent to world's highest rainfall area Kylleng Pyndengsohiong (KP) Mawthabah (Domiasiat), Meghalaya in India to establish the baseline value of manganese intake through dietary route by the local tribe population in view of proposed uranium mining. The locally available food items collected from villages surrounding the proposed uranium mining site at KP Mawthabah (Domiasiat) were analysed using Energy Dispersive X-Ray Fluorescence (EDXRF) Technique. The manganese concentration in different food categories varies from 2.76-12.50 mg kg^− 1 in cereals, 1.8-4.20 mg kg^− 1 in leafy vegetables, 0.30-13.50 mg kg^− 1 in non leafy vegetables, 0.50-15.30 mg kg^− 1 in roots and tubers, 0.70-1.50 mg kg^− 1 in fruits and 0.12-0.96 mg kg^− 1 in flesh food. The mean dietary intake of Mn was found to be 3.83 ± 0.25 mg d^− 1 compared to Recommended Dietary Allowances (RDAs) of 2-5 mg d^− 1. The daily intake of Manganese by the local tribe population is comparable with the value (3.7 mg d^− 1) recommended by International Commission on Radiological Protection (ICRP) for reference man and lower than the intake value observed for Indian and other Asian population.     

Mercury contamination in the vicinity of a chlor-alkali plant and potential risks to local population

A mercury-cell chlor-alkali plant operated in Estarreja (North-western Portugal) for 50 years causing widespread environmental contamination. Although production by this process ceased in 2002, mercury contamination from the plant remains significant. The main objective of this study was to investigate mercury impact on the nearby environment and potential risks to local population. To assess the level of contamination soil samples were collected from agricultural fields in the vicinity of the plant, extending the study by taking samples of the predominant vegetation suitable for animal and human consumption, water samples, and fish species from a nearby coastal lagoon, to gain a preliminary insight into the potential for contamination of the terrestrial and aquatic food web. To determine population exposure to mercury, hair samples were collected from local residents. Total mercury concentration in the 0-15 cm layer of soil was found to be highly variable, ranging between 0.010 and 91 mg kg^− 1, although mercury contamination of soils was found to be restricted to a confined area. Lolium perenne roots contained between 0.0070 and 2.0 mg kg^− 1, and there is evidence that root systems uptake mercury from the soil. Levels of mercury in the aerial parts of plants ranged between 0.018 and 0.98 mg kg^− 1. It appears that plants with higher mercury concentration in soils and roots also display higher mercury concentration in leaves.Total mercury concentration in water samples ranged between 12 and 846 ng L^− 1, all samples presenting concentrations below the maximum level allowable for drinking water defined in the Portuguese law (1.0 μg L^− 1).Mercury levels in fish samples were below the maximum limit defined in the Portuguese law (0.5 mg kg^− 1), ranging from 0.0040 to 0.24 mg kg^− 1. Vegetables collected presented maximum mercury concentration of 0.17 mg kg^− 1. In general, food is not contaminated and should not be responsible for major human exposure to the metal.Mercury determined in human hair samples (0.090-4.2 mg kg^− 1; mean 1.5 mg kg^− 1) can be considered within normal limits, according to WHO guidelines suggesting that it is not affecting the local population. Despite being subject to decades of mercury emissions, nowadays this pollutant is only found in limited small areas and must not constitute a risk for human health, should these areas be restricted and monitored.Considering the present data, it appears that the population from Estarreja is currently not being affected by mercury levels that still remain in the environment.     

Influence of soil properties on trace element availability and plant accumulation in a Mediterranean salt marsh polluted by mining wastes: implications for phytomanagement

The aims of this study were to determine the factors which control metal and As phytoavailability in the different microenvironments (Sand Dunes, Salt Flat, Dry River and Shrubs) present at a Mediterranean salt marsh polluted by mining wastes. We performed a field study following a plot sampling survey. The analyses of soil parameters (pH, electrical conductivity (EC), organic carbon contents, etc.), total metal and As concentrations and their phytoavailability assessed with EDTA were related to each microenvironment and the corresponding plant species uptake. The averages of pH and EC were slightly alkaline (pH ≈ 7.5) and saline (≈ 2.2 to 17.1 dS m⁻¹) respectively. The soil samples from the Salt Flat subzone showed the highest metal concentrations (e.g. 51 mg kg⁻¹ Cd, 11,600 mg kg⁻¹ Pb) while for As, the highest concentrations occurred in the Dry River (380 mg kg⁻¹ As). The total metal and EDTA-extractable concentrations occurred as it follows: Salt Flat > Dry River > Degraded Dunes > Shrubs. In relation to plant metal and As accumulation, the highest root concentrations were obtained in the species from the Salt Flat subzone: ~ 17 mg kg⁻¹ As, ~ 620 mg kg⁻¹ Pb, for both, Juncus maritimus and Arthrocnemum macrostachyum. However the highest metal and As shoot concentrations occurred in species from the Sand Dunes: ~ 23 mg kg⁻¹ As ~ 270 mg kg⁻¹ Pb for Dittrichia viscosa; ~ 23 mg kg⁻¹ As, ~ 390 mg kg⁻¹ Zn for Crucianella maritima. The occurrence of edaphic gradients including salinity and texture determined the vegetation distribution. However, it cannot be concluded that there was a disturbance due to metal(loid)s soil concentrations in terms of vegetation composition except in the Degraded Dunes and Dry River. The higher EDTA-extractable concentrations were coincidental with the most saline soils but this did not result in higher metal(loid)s plant accumulation.     

A lead isotopic study of the human bioaccessibility of lead in urban soils from Glasgow, Scotland

The human bioaccessibility of lead (Pb) in Pb-contaminated soils from the Glasgow area was determined by the Unified Bioaccessibility Research Group of Europe (BARGE) Method (UBM), an in vitro physiologically based extraction scheme that mimics the chemical environment of the human gastrointestinal system and contains both stomach and intestine compartments. For 27 soils ranging in total Pb concentration from 126 to 2160 mg kg^− 1 (median 539 mg kg^− 1), bioaccessibility as determined by the ‘stomach’ simulation (pH ~ 1.5) was 46-1580 mg kg^− 1, equivalent to 23-77% (mean 52%) of soil total Pb concentration. The corresponding bioaccessibility data for the ‘stomach + intestine’ simulation (pH ~ 6.3) were 6-623 mg kg^− 1 and 2-42% (mean 22%) of soil Pb concentration. The soil ²⁰⁶Pb/²⁰⁷Pb ratios ranged from 1.057 to 1.175. Three-isotope plots of ²⁰⁸Pb/²⁰⁶Pb against ²⁰⁶Pb/²⁰⁷Pb demonstrated that ²⁰⁶Pb/²⁰⁷Pb ratios were intermediate between values for source end-member extremes of imported Australian Pb ore (1.04) - used in the manufacture of alkyl Pb compounds (1.06-1.10) formerly added to petrol - and indigenous Pb ores/coal (1.17-1.19). The ²⁰⁶Pb/²⁰⁷Pb ratios of the UBM ‘stomach’ extracts were similar (< 0.01 difference) to those of the soil for 26 of the 27 samples (r = 0.993, p < 0.001) and lower in 24 of them. A slight preference for lower ²⁰⁶Pb/²⁰⁷Pb ratio was discernible in the UBM. However, the source of Pb appeared to be less important in determining the extent of UBM-bioaccessible Pb than the overall soil total Pb concentration and the soil phases with which the Pb was associated. The significant phases identified in a subset of samples were carbonates, manganese oxides, iron-aluminium oxyhydroxides and clays.     

Historical accumulation rates of mercury in four Scottish ombrotrophic peat bogs over the past 2000 years

The historical accumulation rates of mercury resulting from atmospheric deposition to four Scottish ombrotrophic peat bogs, Turclossie Moss (northeast Scotland), Flanders Moss (west-central), Red Moss of Balerno (east-central) and Carsegowan Moss (southwest), were determined via analysis of ²¹⁰Pb- and ¹⁴C-dated cores up to 2000 years old. Average pre-industrial rates of mercury accumulation of 4.5 and 3.7 μg m^− 2 y^− 1 were obtained for Flanders Moss (A.D. 1-1800) and Red Moss of Balerno (A.D. 800-1800), respectively. Thereafter, mercury accumulation rates increased to typical maximum values of 51, 61, 77 and 85 μg m^− 2 y^− 1, recorded at different times possibly reflecting local/regional influences during the first 70 years of the 20th century, at the four sites (TM, FM, RM, CM), before declining to a mean value of 27 ± 15 μg m^− 2 y^− 1 during the late 1990s/early 2000s. Comparison of such trends for mercury with those for lead and arsenic in the cores and also with direct data for the declining UK emissions of these three elements since 1970 suggested that a substantial proportion of the mercury deposited at these sites over the past few decades originated from outwith the UK, with contributions to wet and dry deposition arising from long-range transport of mercury released by sources such as combustion of coal. Confidence in the chronological reliability of these core-derived trends in absolute and relative accumulation of mercury, at least since the 19th century, was provided by the excellent agreement between the corresponding detailed and characteristic temporal trends in the ²⁰⁶Pb/²⁰⁷Pb isotopic ratio of lead in the ²¹⁰Pb-dated Turclossie Moss core and those in archival Scottish Sphagnum moss samples of known date of collection. The possibility of some longer-term loss of volatile mercury released from diagenetically altered older peat cannot, however, be excluded by the findings of this study.     

Retrospective determination of 137Cs specific activity distribution in spruce bark and bark aggregated transfer factor in forests on the scale of the Czech Republic ten years after the Chernobyl accident

The ¹³⁷Cs specific activities (mean 32 Bq kg⁻¹) were determined in spruce bark samples that had been collected at 192 sampling plots throughout the Czech Republic in 1995, and were related to the sampling year. The ¹³⁷Cs specific activities in spruce bark correlated significantly with the ¹³⁷Cs depositions in areas affected by different precipitation sums operating at the time of the Chernobyl fallout in 1986. The ratio of the ¹³⁷Cs specific activities in bark and of the ¹³⁷Cs deposition levels yielded bark aggregated transfer factor T_ag about 10.5 × 10⁻³ m⁻² kg⁻¹. Taking into account the residual specific activities of ¹³⁷Cs in bark 20 Bq kg⁻¹ and the available pre-Chernobyl data on the ¹³⁷Cs deposition loads on the soil surface in the Czech Republic, the real aggregated transfer factor after and before the Chernobyl fallout proved to be T*_ag = 3.3 × 10⁻³ m⁻² kg⁻¹ and T**_ag = 4.0 × 10⁻³ m⁻² kg⁻¹, respectively. The aggregated transfer factors T*_ag for ¹³⁷Cs and spruce bark did not differ significantly in areas unequally affected by the ¹³⁷Cs fallout in the Czech Republic in 1986, and the figures for these aggregated transfer factors were very similar to the mean bark T_ag values published from the extensively affected areas near Chernobyl. The magnitude of the ¹³⁷Cs aggregated transfer factors for spruce bark for the pre-Chernobyl and post-Chernobyl period in the Czech Republic was also very similar. The variability in spruce bark acidity caused by the operation of local anthropogenic air pollution sources did not significantly influence the accumulation and retention of ¹³⁷Cs in spruce bark. Increasing elevation of the bark sampling plots had a significant effect on raising the remaining ¹³⁷Cs specific activities in bark in areas affected by precipitation at the time when the plumes crossed, because the sums of this precipitation increased with elevation (covariable).     

Characterization of polychlorinated dibenzo-p-dioxin/dibenzofuran emissions from joss paper burned in a furnace with air pollution control devices

Burning joss paper, a common practice in temples in some Asian countries, can release toxic pollutants. This study investigated polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) emissions and profiles from burning joss paper in a temple furnace connected to two wet scrubbers. The mean total PCDD/F content and corresponding toxic equivalent quantity (TEQ) in joss paper were 193 ng kg^− 1 and 0.645 ng I-TEQ kg^− 1, respectively, whereas those in bottom ash from burned joss paper were 18.5 ng kg^− 1 and 1.92 ng I-TEQ kg^− 1, respectively. The wet scrubbers decreased individual PCDD/F emissions by 26.7-71.0% and those of total PCDD/Fs and I-TEQ by 47.2% and 66.0%, respectively. The total PCDD/F TEQ emission factors before and after the wet scrubbers were 8.14 and 3.42 µg I-TEQ ton-feedstock^− 1, respectively. The estimated total PCDD/F and corresponding TEQ emissions were 5.29 g year^− 1 and 0.462 g I-TEQ year^− 1, respectively, in Taiwan. Burning joss paper in temple furnaces is a significant source of PCDD/F emissions.     

Environmental impact of mining activities in the Lousal area (Portugal): chemical and diatom characterization of metal-contaminated stream sediments and surface water of Corona stream

Lousal mine is a typical “abandoned mine” with all sorts of problems as consequence of the cessation of the mining activity and lack of infrastructure maintenance. The mine is closed at present, but the heavy metal enriched tailings remain at the surface in oxidizing conditions. Surface water and stream sediments revealed much higher concentrations than the local geochemical background values, which the “Contaminated Sediment Standing Team” classifies as very toxic. High concentrations of Cu, Pb, Zn, As, Cd and Hg occurred within the stream sediments downstream of the tailings sites (up to: 817 mg kg⁻¹ As, 6.7 mg kg⁻¹ Cd, 1568 mg kg⁻¹ Cu, 1059 mg kg⁻¹ Pb, 82.4 mg kg⁻¹ Sb, 4373 mg kg⁻¹ Zn). The AMD waters showed values of pH ranging from 1.9 to 2.9 and concentrations of 9249 to 20,700 mg L⁻¹ SO₄⁻², 959 to 4830 mg L⁻¹ Fe and 136 to 624 mg L⁻¹ Al. Meanwhile, the acid effluents and mixed stream waters also carried high contents of SO₄^2−, Fe, Al, Cu, Pb, Zn, Cd, and As, generally exceeding the Fresh Water Aquatic Life Acute Criteria. Negative impacts in the diatom communities growing at different sites along a strong metal pollution gradient were shown through Canonical Correspondence Analysis: in the sites influenced by Acid Mine Drainage (AMD), the dominant taxon was Achnanthidium minutissimum. However, Pinnularia acoricola was the dominant species when the environmental conditions were extremely adverse: very low pH and high metal concentrations (sites 2 and 3). Teratological forms of Achnanthidium minutissimum (Kützing) Czarnecki, Brachysira vitrea (Grunow) Ross in Hartley, Fragilaria rumpens (Kützing) G. W. F. Carlson and Nitzschia hantzschiana Rabenhorst were found. A morphometric study of B. vitrea showed that a decrease in size was evident at the most contaminated sites. These results are evidence of metal and acidic pollution.     

Multiple site study of recent atmospheric metal (Pb, Zn and Cu) deposition in the NW Iberian Peninsula using peat cores

In order to estimate atmospheric metal deposition in Southern Europe since the beginning of the Industrial Period (~ 1850 AD), concentration profiles of Pb, Zn and Cu were determined in four ²¹⁰Pb-dated peat cores from ombrotrophic bogs in Serra do Xistral (Galicia, NW Iberian Peninsula). Maximum metal concentrations varied by a factor of 1.8 for Pb and Zn (70 to 128 μg g⁻¹ and 128 to 231 μg g⁻¹, respectively) and 3.5 for Cu (11 to 37 μg g⁻¹). The cumulative metal inventories of each core varied by a factor of 3 for all analysed metals (132 to 329 μg cm⁻² for Pb, 198 to 625 μg cm⁻² for Zn and 22 to 69 μg cm⁻² for Cu), suggesting differences in net accumulation rates among peatlands. Although results suggest that mean deposition rates vary within the studied area, the enhanced ²¹⁰Pb accumulation and the interpretation of the inventory ratios (²¹⁰Pb/Pb, Zn/Pb and Cu/Pb) in two bogs indicated that either a record perturbation or post-depositional redistribution effects must be considered. After correction, Pb, Zn and Cu profiles showed increasing concentrations and atmospheric fluxes since the mid-XX^th century to maximum values in the second half of the XX^th century. For Pb, maximum fluxes were observed in 1955-1962 and ranged from 16 to 22 mg m⁻² yr⁻¹ (mean of 18 ± 1 mg m⁻² yr⁻¹), two orders of magnitude higher than in the pre-industrial period. Peaks in Pb fluxes in Serra do Xistral before the period of maximum consumption of leaded petrol in Europe (1970s-1980s) suggest the dominance of local pollutant sources in the area (i.e. coal mining and burning). More recent peaks were observed for Zn and Cu, with fluxes ranging from 32 to 52 mg m⁻² yr⁻¹ in 1989-1996, and from 4 to 9 mg m⁻² yr⁻¹ in 1994-2001, respectively. Our results underline the importance of multi-core studies to assess both the integrity and reliability of peat records, and the degree of homogeneity in bog accumulation. We show the usefulness of using the excess ²¹⁰Pb inventory to distinguish between differential metal deposition, accumulation or anomalous peat records.     

Trace metal concentrations in the North-western Mediterranean atmospheric aerosol between 1986 and 2008: Seasonal patterns and decadal trends

Climatic and anthropogenic changes are able to engender modifications in the aerosol composition at different geographical and temporal scales. The present study addresses this question for the trace metal concentrations (TM = Al, Fe, Mn, Co, Ni, Cu, Pb, Cd and Zn) of aerosol from the North-western Mediterranean coast of France (Cap Ferrat, nearby Nice) between 1986 and 2008. From seasonal variations (2006-08) and decadal trends (1986-2008) of TM concentrations, three groups of elements can be distinguished. They consist of different aerosol sources: crustal-derived elements (Al, Fe, Mn and Co), trace metals of anthropogenic origin (Pb, Cd and Zn) and a third, intermediate, group of trace metals that presented both anthropogenic and natural/crustal influences (Ni and Cu). Reproducible seasonal patterns were observed for crustal and intermediate elements with highest concentrations between May and November, while anthropogenic trace metals did not show a pronounced seasonal cycle. Nevertheless, highest concentrations of anthropogenic trace metals occurred mostly in autumn/winter. Aerosol concentrations of anthropogenic TMs decreased remarkably over the last two decades, while crustal trace metals did not show any evolution. Nickel and copper aerosol concentrations remained constant, as well. Lead concentrations decreased from 1986 (29.34 ng m^− 3) to 2008 (3.33 ng m^− 3), overall by 90%. Cadmium and zinc aerosol concentrations decreased by 66 and 54%, respectively, between 1998 and 2006-08, from 0.27 to 0.09 ng m^− 3 and from 23.9 to 10.9 ng m^− 3, respectively. These findings demonstrate the response of the atmospheric environment to the implementation of antipollution policies. Possible changes of trace metal emissions sources and local influences are discussed.     

Lead isotopes reveal different sources of lead in balsamic and other vinegars

Fifty-eight brands of balsamic vinegars were analyzed for lead concentrations and isotopic compositions (²⁰⁴Pb, ²⁰⁶Pb, ²⁰⁷Pb, and ²⁰⁸Pb) to test the findings of a previous study indicating relatively high levels of lead contamination in some of those vinegars — more than two thirds (70%) of them exceeded California's State Maximum Level (34 μg/L) based on consumption rates ≥ 0.5 μg Pb per day. The Lead isotopic fingerprints of all those vinegars with high lead concentrations were then found to be primarily anthropogenic. This isotopic analysis unquestionably reveals multiple contamination sources including atmospheric pollutant Pb and an unidentified contamination source, likely occurring after grape harvest. Organically grown grape vinegars display the same Pb content and isotopic signatures as other vinegars. This implies that pesticides might not be a significant source of pollutant Pb in vinegars. A significant post-harvest contamination would be inherited from chemicals added during production and/or material used during transport, processing or storage of these vinegars. This is consistent with the highest Pb levels being found in aged vinegars (112 ± 112 μg/L) in contrast to other vinegars (41.6 ± 28.9 μg/L) suggesting contamination during storage. It is, therefore, projected that lead levels in most vinegars, especially aged balsamic and wine vinegars, will decrease with improvements in their manufacture and storage processes consequential to recent concerns of elevated levels of lead in some vinegars.     

The origin of lead in the organic horizon of tundra soils: atmospheric deposition, plant translocation from the mineral soil or soil mineral mixing?

Knowledge of the anthropogenic contribution to lead (Pb) concentrations in surface soils in high latitude ecosystems is central to our understanding of the extent of atmospheric Pb contamination. In this study, we reconstructed fallout of Pb at a remote sub-arctic region by using two ombrotrophic peat cores and assessed the extent to which this airborne Pb is able to explain the isotopic composition (²⁰⁶Pb/²⁰⁷Pb ratio) in the O-horizon of tundra soils. In the peat cores, long-range atmospheric fallout appeared to be the main source of Pb as indicated by temporal trends that followed the known European pollution history, i.e. accelerated fallout at the onset of industrialization and peak fallout around the 1960s-70s. The Pb isotopic composition of the O-horizon of podzolic tundra soil (²⁰⁶Pb/²⁰⁷Pb = 1.170 ± 0.002; mean ± SD) overlapped with that of the peat (²⁰⁶Pb/²⁰⁷Pb = 1.16 ± 0.01) representing a proxy for atmospheric aerosols, but was clearly different from that of the parent soil material (²⁰⁶Pb/²⁰⁷Pb = 1.22-1.30). This finding indicated that long-range fallout of atmospheric Pb is the main driver of Pb accumulation in podzolic tundra soil. In O-horizons of tundra soil weakly affected by cryoturbation (cryosols) however, the input of Pb from the underlying mineral soil increased as indicated by ²⁰⁶Pb/²⁰⁷Pb ratios of up to 1.20, a value closer to that of local soil minerals. Nevertheless, atmospheric Pb appeared to be the dominant source in this soil compartment. We conclude that Pb concentrations in the O-horizon of studied tundra soils - despite being much lower than in boreal soils and representative for one of the least exposed sites to atmospheric Pb contaminants in Europe - are mainly controlled by atmospheric inputs from distant anthropogenic sources.     

Significance and interspecific variability of accumulated trace metal concentrations in Antarctic benthic polychaetes

Trace metals were analysed in polychaetes collected on Polarstern cruise ANT XXI/2 (2003/04) to the Weddell Sea. Pb concentrations were largely less than 1.3 mg kg⁻¹ DW in all samples analysed. Statistical results indicate that the accumulated Cd, Cu and Zn concentrations are related to the feeding guild to which the animals are belonging. Relatively low Cd and Cu concentrations are found in macrophagous carnivores and relatively high concentrations in microphagous detritus feeders. The relationship between Zn concentrations and the feeding guilds of polychaetes is reverse. Cd concentrations range from (median values and interquantile ranges in brackets) 2.6 (1.5-3.2) mg kg⁻¹ DW in the carnivorous Trypanosyllis gigantea to 133 (37-176) mg kg⁻¹ in the microphagous detritus feeder Lanicides bilobata; Cu concentrations from 16 (11-19) mg kg⁻¹ in the carnivorous Antarctinoe spicoides to 40 (23-68) mg kg⁻¹ in the microphagous detritus feeder Phyllocomus crocea and Zn from 89 (69-97) mg kg⁻¹ in the microphagous detritus feeder Isocirrus yungi to 396 (372-404) mg kg⁻¹ in the carnivorous Aglaophamus trissophyllus. Ni is ranging from 3.7 (1.8-6.0) mg kg⁻¹ in Polyeunoa laevis to 34 (20-41) mg kg⁻¹ in A. spicoides, but no significant differences are obvious regarding the feeding guilds. Since information on metals in Antarctic polychaetes is almost completely lacking, our results suggest further studies to clarify the role of feeding in the bioaccumulation of metals in this ecologically important taxonomic group.     

Responses of streams in central Appalachian Mountain region to reduced acidic deposition—Comparisons with other regions in North America and Europe

Data from 5 wet deposition stations and 21 streams during 1980-2006 were analyzed to investigate chemical responses of streams to reduced acidic deposition in the central Appalachian Mountain region of West Virginia, USA. Wet deposition of acidic anions (i.e., sulfate, nitrate, and chloride) and hydrogen ions decreased significantly during the studied time period. Stream sulfate showed a delayed response to the reduced acidic deposition, and showed a decrease in the 2000s (− 5.54 µeq L^− 1 yr^− 1) and the whole period (− 0.49 µeq L^− 1 yr^− 1). No significant trend of stream nitrate + nitrite and chloride was observed. Stream alkalinity increased in the 1990s (+ 23.33 µeq L^− 1 yr^− 1) and the whole period (+ 7.26 µeq L^− 1 yr^− 1). Stream hydrogen ions decreased in the 1990s (− 0.002 µeq L^− 1 yr^− 1), 2000s (− 0.001 µeq L^− 1 yr^− 1), and the whole period (− 0.001 µeq L^− 1 yr^− 1). Compared with most acidic streams and lakes in the United States and Europe, a lower decreasing rate of hydrogen ions and higher increasing rate of alkalinity were observed in the alkaline West Virginian streams in the 1990s. However, due to their initial negative or zero alkalinity values, those acidic streams showed a higher percent increase in alkalinity than that in the alkaline West Virginian streams (from 800 µeq L^− 1 yr^− 1 to 1200 µeq L^− 1 yr^− 1). Total aluminum in the West Virginian streams decreased in the 1990s (− 0.67 µmol L^− 1 yr^− 1) and the whole period (− 0.22 µmol L^− 1 yr^− 1). The current study advanced our understanding of streams' responses to the reduced acidic deposition in the Mid-Appalachians since the passage of the 1970 and 1990 Amendments to the United States Clean Air Act (US CAAA).     

Distribution of Pb and Po concentrations in wild berries and mushrooms in boreal forest ecosystems

The activity concentrations and distribution of ²¹⁰Pb and ²¹⁰Po in wild berries and edible mushrooms were investigated in Finnish forests. The main study areas were located in Scots pine (Pinus sylvestris L.) forests in southern and northern Finland. The activity concentrations of ²¹⁰Pb and ²¹⁰Po in blueberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea L.) samples decreased in the order: stems > leaves > berries (i.e. fruits). The activity ratios of ²¹⁰Po/²¹⁰Pb in the wild berry samples were mainly higher than one, indicating elevated activity concentrations of polonium in the samples. In mushrooms the activity concentrations of ²¹⁰Pb and especially ²¹⁰Po were higher than in fruits of the wild berries. The highest activity concentration of ²¹⁰Pb was detected in Cortinarius armillatus L. (16.2 Bq kg^− 1 d.w.) and the lowest in Leccinum vulpinum L. (1.38 Bq kg^− 1 d.w.). The ²¹⁰Po activity concentrations of the whole fruiting bodies ranged from 7.14 Bq kg^− 1 d.w. (Russula paludosa L.) to 1174 Bq kg^− 1 d.w. (L. vulpinum L.). In general, the highest activity concentrations of ²¹⁰Po were recorded in boletes. The caps of mushrooms of the Boletaceae family showed higher activity concentrations of ²¹⁰Po compared to the stipes. In most of the mushrooms analyzed, the activity concentrations of ²¹⁰Po were higher than those of ²¹⁰Pb. ²¹⁰Po and ²¹⁰Pb dominate the radiation doses received via ingestion of wild berries and mushrooms in northern Finland, while in southern Finland the ingested dose is dominated by ¹³⁷Cs from the Chernobyl fallout.     

Sediment mercury dynamics and historical trends of mercury deposition in the St. Lawrence River area of concern near Cornwall, Ontario, Canada

The St. Lawrence River near Cornwall, Ontario was designated an Area of Concern by the International Joint Commission in 1985. Sediments from this area have historically been contaminated with mercury (Hg), and although concentrations have decreased since the 1970s, they still remain high. Nine sediment cores were collected from three sites within the Area of Concern in 2004/05 to determine the variability in historical profiles of Hg deposition to the river. Sediment and pore water phases were analyzed for total mercury (THg) and methyl mercury (MeHg) and cores were analyzed for ²¹⁰Pb to determine chronologies of sedimentation at these sites. Mercury diffusion rates in pore waters within the sediment column were determined to be very low (between 0 and 2.15 ng cm^− 2 year^− 1, n = 3) compared to the recent Hg sedimentation rates at these sites (183 ± 30 ng cm^− 2 year^− 1 SE, n = 9) determined by multiplying surface Hg concentrations with ²¹⁰Pb-derived sedimentation rates. These results indicate that Hg profiles in these cores accurately depict historical releases of Hg to the river bed. The influence of federal regulations in the early 1970s to restrict Hg emissions to the river was apparent in these dated sediment cores, as were the closures of several local industries in the mid 1990s. Mercury accumulation rates prior to 1970 were 60 times higher than those occurring after 1995. Methyl mercury showed surface enrichment in most of these sediment cores providing evidence that mercury methylation occurred most rapidly near the sediment surface.     

Characterisation of atmospheric deposition as a source of contaminants in urban rainwater tanks

To characterise atmospheric input of chemical contaminants to urban rainwater tanks, bulk deposition (wet + dry deposition) was collected at sixteen sites in Brisbane, Queensland, Australia on a monthly basis during April 2007-March 2008 (N = 175). Water from rainwater tanks (22 sites, 26 tanks) was also sampled concurrently. The deposition/tank water was analysed for metals, soluble anions and selected samples were additionally analysed for PAHs, pesticides, phenols, organic & inorganic carbon. Flux (mg/m²/d) of total solids mass was found to correlate with average daily rainfall (R² = 0.49) indicating the dominance of the wet deposition contribution to total solids mass. On average 97% of the total mass of analysed components was accounted for by Cl⁻ (25.0%), Na (22.6%), organic carbon (20.5%), NO₃⁻ (10.5%), SO₄²⁻ (9.8%), inorganic carbon (5.7%), PO₄³⁻ (1.6%) and NO₂⁻ (1.5%). For other minor elements the average flux from highest to lowest was in the order of Fe > Al > Zn > Mn > Sr > Pb > Ba > Cu > Se. There was a significant effect of location on flux of K, Sb, Sn, Li, Mn, Fe, Cu, Zn, Ba, Pb and SO₄²⁻ but not other metals or anions. Overall the water quality resulting from the deposition (wet + dry) was good but 10.3%, 1.7% and 17.7% of samples had concentrations of Pb, Cd and Fe respectively greater than the Australian Drinking Water Guidelines (ADWG). This generally occurred in the drier months. In comparison 14.2% and 6.1% of tank samples had total Pb and Zn concentrations exceeding the guidelines. The cumulative mean concentration of lead in deposition was on average only 1/4 of that in tank water over the year at a site with high concentrations of Pb in tank water. This is an indication that deposition from the atmosphere is not the major contributor to high lead concentrations in urban rainwater tanks in a city with reasonable air quality, though it is still a significant portion.     

Characteritization of, and health risks from, polychlorinated dibenzo-p-dioxins/dibenzofurans from incense burned in a temple

Polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) may cause adverse health effects. However, PCDD/F emissions from burning incense in temples have rarely been addressed. This study investigates PCDD/F emissions from burning incense in a temple. The mean total PCDD/F concentrations were 72.4-82.2 pg Nm^− 3 at two indoor sites; their corresponding mean total PCDD/Fs I-TEQ concentrations (0.24-0.27 pg I-TEQ Nm^− 3) were ~ 11 times that at a background location. In air samples collected from burning incense, OCDFs accounted for approximately 90% of total PCDD/Fs at the two indoor sites and an outdoor site near the temple, while the major PCDD/Fs in incense ash were PCDDs. The total PCDD/F content and toxic equivalent value of incense ash were 617 pg g^− 1 and 1.55 pg I-TEQ g^− 1, respectively. At the three sites inside/outside the temple, the air and ash samples contained the same four primary PCDD/Fs-OCDD, 1,2,3,4,6,7,8-HpCDD, OCDF and 1,2,3,4,6,7,8-HpCDF. The Cl⁻ emission factor, which is related to the PCDD/F formation, from burning incense was 0.454 mg g^− 1. The resultant lifetime average daily dose and cancer risk for temple workers were 0.00964 pg I-TEQ day^− 1 kg^− 1 and 9.64 × 10^− 6, respectively, approximately 2 times that for residents near the temple (0.00489 pg I-TEQ day^− 1 kg^− 1 and 4.89 × 10^− 6, respectively). We suggest that the chlorine content in incense must be regulated, and the high risk of PCDD/F exposure from burning incense for temple workers and visitors should be of concern.     

Distribution of (210)Pb and (210)Po in boreal forest soil

Vertical distribution and activity contents of ²¹⁰Pb and ²¹⁰Po were investigated in forest soils of Scots pine-dominated (Pinus sylvestris L.) stands from seven different locations in Finland. The mean total inventory in the soil profile, up to 20 cm, of ²¹⁰Pb was 4.0 kBq m^− 2 (range 3.1-5.0 kBq m^− 2) and ²¹⁰Po 5.5 kBq m^− 2 (range 4.0-7.4 kBq m^− 2), the organic soil layer containing 45% of the total inventory of both nuclides. In both the organic and the mineral layers the ²¹⁰Po/²¹⁰Pb ratio was close to unity indicating a radioactive equilibrium between them. In the litter layer there was, however, a clear excess of ²¹⁰Po suggesting that polonium is recycled via root uptake from the root zone to the ground surface. The activity concentration (Bq kg^− 1) of ²¹⁰Pb clearly correlated with organic matter and the Fe, Al and Mn concentrations in soil indicating that radioactive lead is associated both with humic substances and the oxides of iron, aluminium and manganese. Radioactive lead was also seen to follow the behavior of stable lead. No systematic correlation between polonium and soil properties was seen.