Distribution of airborne heavy metals as measured in the lichens Ramalina stenospora and Parmotrema praesorediosum in Baton Rouge,Louisiana

The lichens Ramalina stenospora and Parmotrema praesorediosum were collected from 30 stations in the greater metropolitan area of Baton Rouge, Louisiana and analyzed for Al, Cu, Fe, Zn, and Pb content. A univariate analysis of the data showed a significant difference between metal concentrations and sampling stations. When the stations were separated into two groups representing those in the industrial and urban zones, a discriminant analysis was over 90% successful in correctly assigning stations based solely on metal concentrations. No significant differences in metal concentration with species could be observed. Average metal concentrations for the two lichen species were used to construct contours and three-dimensional plots of metal distribution across the study area which clearly demonstrate the effects of the industrial zone on airborne metal levels.     

Distribution of Al,V, and Mn in lichens across Calcasieu Parish,Louisiana

The lichen Ramalina stenospora was collected from 16 location in Calcasieu Parish and from 2 locations in Cameron Parish in Southwestern Louisiana. The metals V, Mn, and Al were measured in lichen specimens collected during three seasons — fall 1983, winter and spring 1984. The metals were determined using thermal neutron activation analysis. Vanadium was found to range in concentration from 2.1 to 10 mg kg^?1; and Al from 900 to 4500 mg kg^?1. Metal concentration was found to decrease exponentially with distance outward from the industrial corridor. The major industries included were an Al plant, two refineries and five chemical plants mostly related to plastics production.     

Temporal changes in metal levels of the lichens Parmotrema praesorediosum and Ramalina stenospora,Southwest Louisiana

Two species of lichen native to southwest Lousiana, Parmotrema praesorediosum (Nyl.) Hale and Ramalina stenospora, Mull. Arg. have been investigated as air pollution monitors. Over the period 1983–88 samples were collected at 18 stations in the Lake Charles/Westlake/Sulphur area. The samples were analyzed for A1, Fe, Cu, Pb, Cd, Hg, Cr, and Zn. When metal concentrations in lichens were plotted vs year for certain representative stations, a dramatic reduction in the concentrations of certain metals was seen after 1983. When the most recent data are compared with those previously obtained, the effects of the industrial zone, which was previously demonstrated, have now all but disappeared.     

Accumulation of mercury and other metals by the lichen,Parmelia sulcata,at an italian minesite and a volcanic area

Young thallus tissue of the epiphytic lichen, Parmelia sulcata, and surface soil associated with its host trees were collected on Mt. Amiata for analysis of metal content including Al, Fe, Mn, Cu, Zn and Hg. The purpose of this study was to achieve a better understanding of plant-soil Hg relationships by comparisons of the Mt. Amiata minesite with the summit of an active volcano — Mt. Etna — and thereby to gain more insight into metal source and eco-physiology as factors in plant-Hg distribution. Although an Hg source-plant distance relationship clearly exists on Mt. Amiata, its precise nature is still in doubt, as it was impossible to distinguish statistically at p<0.01 among linear, log-linear, exponential, and third order polynomial regressions, even with N=47. Nevertheless, the distance-from-source relationship for Hg was clearly unique. No significant pattern could be assigned to the other metals studied, nor was there evidence of a regular relationship between soil content and plant content except in the case of Hg. Parmelia from Mt. Amiata accumulates Hg from soil degassing which was not at all the case for its mercury source on Mt. Etna. The data also suggests that high Zn values in the lichen of Mt. Amiata may be based on long range atmospheric transport. The Zn content of Parmelia was not analyzed on Mt. Etna. Element atomic ratios, Fe/Al for example, provide good evidence for accumulation of surface soil particulates, other than cinnabar by the thallus. Finally, we conclude that widely separated populations of the same species can display biogeochemical differences that are best explained on an eco-physiological basis.     

Historical trends of airborne trace metals in Detroit from 1971 to 1992

Ambient concentrations of particulate Fe, Zn, Ph, Ni, Cr, Cd and Hg were measured at nine sites located in the metropolitan area of Detroit from 1971 to 1992. The ambient concentrations of all the trace metals were found to be generally higher at industrial and commercial sites. The concentrations show significant variations between residential and commercial areas and between residential and industrial areas; however, no significant variation was found between the industrial and commercial settings. The spatial variation of trace metal levels within the urban area was influenced by the frequency distribution of the wind direction as well as type and location of emission sources. The ambient concentrations of the trace metals during the decade of 1971–1981 declined by 37–88%. In the 1980s many of the trace metals reversed this trend with the exception of Fe and Pb which continued to decline at annual rates of 2% and 9.8%, respectively. The sharp decrease in Pb concentrations during the 1980s, reflected the significant reduction of Pb content in gasoline from 0.28 g/liter in the 1982 to 0.026 g/liter in the 1989. The ambient concentrations of Zn, Ni, Cr, Cd and Hg showed an upward trend during the 1980s with an annual rate in the range of 0.6% to 10.6%. The long-term trends of selected U.S. market parameters, analyzed as potential long-term indicators of emission sources activityies, were consistent with the changes of ambient concentrations, the correlation coefficient being in the range of 0.58 to 0.84 for most of the trace metals.     

Heavy metals in the lichen Ramalina duriaei transplanted at biomonitoring stations in the region of a coal-fired power plant in Israel after 3 years of operation

A survey of the heavy metal content in a transplanted lichen Ramalina duriaei (De Not.) Bagl. was carried out in the region of an Israeli coal-fired power plant. Nickel, Cr, Cu, and Zn were analyzed in the lichen exposed to environmental influences for a period of 1 yr. The concentrations of metals were compared with the concentrations of the same metals measured in R. duriaei transplanted to the study area prior to the operation of the power plant. The results show that after the 1983–1984 period, the regional concentrations of Cr in the transplanted lichen thalli were found to be higher than in the lichen thalli transplanted to the same sites during the period February 1979-March 1980, prior to the operation of the coal-fired power plant. A regional decrease in Zn concentration in the lichen exposed during the latter period is probably linked to the decrease in the use of this metal as a constituent of foliar nutrients in agriculture. The regional increase of Cr in the 1983–1984 lichen material is probably connected with the operation of the Maor David coal-fired power plant located at Sharonim. A local increase in the Ni and Cr concentrations was found in the lichen transplanted to a nature reserve located north of the power station.     

Comparison of biological collectors of airborne heavy metals near ferrochrome and steel works

The value of several biological monitors of the distribution of airborne Cr and Ni dust was studied in the vicinity of ferrochrome and stainless steel works. The following indigenous biomonitors were compared: the forest mosses Pleurozium schreberi and Hylocomium splendens, the epiphytic lichen Hypogymnia physodes, bark of Scots pine (Pinus silvestris), needle litter, earthworms (Dendrobaena octaedra) and moths (mainly Xylena vetusta). Results were compared and related to the heavy metal deposition estimated by the vertical snow sampling method. The representative sampling size at different pollution levels was investigated. In Cr it varied from 1 to 300 mg m^?2 a^?1. Of the biomonitors studied, the mosses showed most effective accumulation of heavy metals, their results having a clear relationship to the deposition and good replicability. The lichen gave almost as good results as the mosses. Both mosses and lichens collected heavy metals more effectively at low to moderate pollution loads than near the pollution source. The accumulation of heavy metals in bark was lower than in the mosses or lichen. The heavy metal content of earthworms indicated the degree of pollution well, but the replicability of the method was poor. The accumulation of heavy metals in moths was low.     

Immobilization of heavy metals in soils using inorganic amendments in a greenhouse study

The effect of red mud (10 g kg^–1), a by‐product of the alumina industry, zeolite (20 g kg^–1), a naturally‐occurring hydrous aluminosilicate, and lime (3 g kg^–1) on metal lability in soil and uptake by fescue (Festuca rubra L.) (FEST) and amaranthus (Amaranthus hybridus L.) (AMA) was investigated in four different soils from Austria. The soil collection locations were Untertiefenbach (UNT), Weyersdorf (WEY), Reisenberg (REI), and Arnoldstein (ARN). The latter was collected in the vicinity of a former Pb‐Zn smelter and was highly polluted with Pb (12300 mg kg^–1), Zn (2713 mg kg^–1), and Cd (19.7 mg kg^–1) by long‐term deposition. The other soils were spiked with Zn (700 mg kg^–1), Cu (250 mg kg^–1), Ni (100 mg kg^–1), V (100 mg kg^–1), and Cd (7 mg kg^–1) salts in 1987. The two plant species were cultivated for 15 months. Ammonium nitrate (1 M) extraction was used in a soil : solution ratio of 1:2.5 to assess the influence of the amendments on the labile metal pools. The reduction of metal extractability due to red mud was 70 % (Cd), 89 % (Zn), and 74 % (Ni) in the sandy soil (WEY). Plant uptake in this treatment was reduced by 38 to 87 % (Cd), 50 to 81 % (Zn), and 66 to 87 % (Ni) when compared to the control. Sequential extraction revealed relative enrichments of Fe‐oxide‐associated metal fractions at the expense of exchangeable metal fractions. Red mud was the only amendment that decreased lability in soil and plant uptake of Zn, Cd, and Ni consistently. Possible drawbacks of red mud application (e.g., As and Cr concentration) remain to be evaluated.     

Isolation, characterization and antifungal activity of major constituents of the Himalayan lichen Parmelia reticulata Tayl

Antifungal activity of hexane, ethyl acetate and methanol extracts of Parmelia reticulata was evaluated against soilborne pathogenic fungi, namely, Sclerotium rolfsii, Rhizoctonia solani, R. bataticola, Fusarium udum, Pythium aphanidermatum and P. debaryanum by poisoned food technique. Maximum antifungal activity was exhibited by hexane and ethyl acetate extracts against most of the test pathogens. Secondary metabolites, namely, (±)-isousnic acid, (±)-protolichesterinic acid, atranorin, evernyl, ethyl hematommate, ethyl orsellinate, methyl hematommate (3-formyl-2,4-dihydroxy-6-methylbenzoic acid methyl ester), 2-hydroxy-4-methoxy-3,6-dimethylbenzoic acid, 1-hydroxy-3,6-dimethoxy-8-methyl-xanthen-9-one, baeomycesic acid and salazinic acid, were isolated from the above extracts and identified by 1H NMR, 13C NMR and mass spectroscopic methods. When these metabolites were tested for antifungal activity against test pathogens, maximum antifungal activity was exhibited by (±)-protolichesterinic acid against R. solani (ED50=23.09 μg mL(-1)) and P. debaryanum (ED50=16.07 μg mL(-1)) and by atranorin against S. rolfsii (ED50=39.70 μg mL(-1)). The antifungal activity of protolichesterinic acid was found to be comparable to that of hexaconazole, a commercial fungicide.     

Chemical environment of coastal marshes and swamps, Louisiana

Water, sediment and interstitial water in nearshore marshes and swamps along a proposed oil pipeline route in the Louisiana coastal zone were analyzed. The primary objectives were to understand the chemical mechanisms involved and to depict the levels of chemical components in natural environments and in environments altered by man's activities. The brackish and fresh marshes showed the highest organic deposition due to low tidal flushing and runoff rate. High nutrient levels were found in waters of these environments due in part to release from the nutrientladen interstitial water which maintained a dynamic equilibrium with biological activities and organic matter in sediments. Sulfides, expressed as ratio of FeS to organic content was much higher in the saline environment than in the low saline system. Low activities of sulfate reducing microorganisms, limited sulfate and organic-S concentrations in the freshwater environment accounted for the low sulfide level. Impairment of water circulation in the salt marsh resulted in drastic fluctuation in dissolved oxygen and concurrent but inverse changes in sulfide level in sediments and in interstitial NH⁺₄ and PO⁻³₄ in spite of relatively low sediment organic matter. Drainage of fertilizer from agricultural fields and to stagnation in freshwater swamps resulted in persistently lowest dissolved oxygen in swamp water without raising the sulfide level to a great extent in sediment. Detailed discussion on the interrelationships among various factors is presented.     

南极Fildes半岛地衣在风化和成土过程中的作用

Lichens play an unparalleledly vital role in weathering and soil-forming processes in Antarctic region,In this study some related chemical components and micromorphological analyses have been carried out on the samples of the weathered rocks and the lichens grown on them from Files Peninsula,Antarctic,The results indicatied that the major chemical components in the bioweathering surface layer of the sampled rocks have been obviously altered and the weathering potential in this layer has greatly decreased by and average range around 4.66 percent in 4 samples,In the weathering surface layer ferruginiztion of some minerals in varying degress was seen by means of microscopic examination through the thin section of the weathered rocks,and its products proved to be dominated by hematitie,limonite,goethite and free iron oxides Meanwhile,the study suggested that the dissolution and absorption of lichens by their secretion accelerated the process of calcitization of minerals in the bio-weathering suface layer,Eventually,the results also show that different species of lichens play different roles in weathering and soil-forming proesses.     

Temperature effects on bioremediation of PAHs and PCP contaminated south Louisiana soils: A laboratory mesocosm study

Goal, Scope and Background  Temperature and soil moisture content are important environmental variables in bioremediation technologies. Optimizing these variables in-situ would enhance and maintain remediation of hazardous wastes during cold winter seasons or in cold regions and may lead to reduced maintenance and/or cost. The effect of elevated temperature and soil moisture on bioremediation efficiency was investigated using a laboratory mesocosm approach. Selected polycyclic aromatic hydrocarbons (PAHs) and phenols degradation in contaminated flooded soils, commonly found in Superfund sites situated in coastal plains sediments/soils, were evaluated in the mesocosms. Material and Methods  Four laboratory mesocosm treatments in triplicate simulating in-situ bioremediation of contaminated site soils using an immobilized microbe bioreactor system, i.e., bioplug, were established to evaluate temperature effects. Elevated temperature treatments of site soils with and without contaminant-specific microorganisms were established at a temperature of 42±2°C. Similarly, treatment of site soils with and without contaminant-specific microorganisms were established at an ambient temperature of 21±1°C. Composite samples were analyzed for selected PAHs and chlorinated phenols to determine rates of mineralization and overall remediation efficiency for different temperature regimes. Results  Mesocosm studies indicated that the high temperature inoculated treatment demonstrated a significant reduction in mean total PAHs and total phenols with a kinetic rate (KR) of 76±13 ng g⁻¹ d⁻¹ in 49 days (approximately 84% reduction; p<0.01) The KR for low temperature inoculated treatment was 54±1 ng g⁻¹ d⁻¹ in 49 days (approximately 66% reduction; p<0.01). High temperature non-inoculated mesocosms exhibited significant mineralization of all constituents with KR of 15±6 ng g⁻¹ d⁻¹ (approximately 65% reduction; p<0.01) in 49d compared to 54% reduction for low temperature non-inoculated treatment with KR of 12±3 ng g⁻¹ d⁻¹ (p=0.1794). Phenol compounds in inoculated treatments were also significantly reduced (65%, p<0.01) at elevated temperatures compared to ambient (52%, p<0.01). Discussion  Increased bioavailability and desorption were noted for elevated temperature and moisture in the soil laboratory mesocosms simulating a field in situ remediation protocol. This protocol employing the application of immobilized microflora indicated that in situ systems provide an economical advantage if optimal elevated temperature and moisture are controlled properly. Results also suggested that temperature and moisture optimization needs to be combined with efficient nutrients delivery systems for impacted soils/sediments. Conclusions  The study demonstrated that temperature and soil moisture contents are important factors in the success of in-situ bioremediation techniques at hazardous waste sites situated in a coastal zone. Kinetic rates were significantly enhanced to remediate known recalcitrant compounds (PAHs and phenols) in aged soil. Recommendations and Perspectives  The placement of a preferred microbial consortia such as an immobilized microbial population in an entrained bioreactor, i.e., bioplug, can significantly reduce constituents of concern in a timely manner for contaminated soils/sediments. However, frequent monitoring of the soil temperature, moisture content, nutrient level, and dissolved oxygen is necessary to achieve predictable kinetic rates of mineralization. ESS-Submission Editor: Dr. Teresa Cutright (tcutright@uakron.edu)     

美国路易斯安那州铁矿石土壤薄层磐层的表征特性

Placic horizons, defined as thin, wavy, hardened layers of iron and organic matter, are rare within the United States, occurring only in Washington, Alaska, and Hawaii. While ironstone is common in many soils of the southeastern United States, it is not known to contain appreciable organic matter. As a pilot study evaluating the justification for a larger study on ironstone in Louisiana, a 40 m lateral exposure with suspected placic horizons was evaluated in Vernon Parish, Louisiana. Results of laboratory analysis show elevated levels of iron and organic matter in the suspect horizons that meet the criteria of placic horizons as defined by the Soil Survey Staff. Based on the results of this study, additional evaluation of multiple pedons with similar features is warranted. Should additional pedons demonstrate similar properties, a new great group of ‘Petrudepts’ would be needed to describe both the placic horizons in the pedon and the udic moisture regime in which they occur.     

土壤中重金属的生物有效性研究进展

综述了年十年来国内及国际上研究土壤中重金属的生物有效性的态势，尤其是影响土壤中重金属生物有效性的诸多因素，以期进一步推动国内的土壤中重金属生物有效的研究工作和重金属污染土壤的生物治理工作。     

Potential for Enhancement of Biodegradation of Crude Oil in Louisiana Salt Marshes using Nutrient Amendments

Salt marsh ecosystems in Louisiana are at high risk of an oil contamination event while remediation of these systems is mainly limited to intrinsic bioremediation due to the physical sensitivity of salt marshes. This study investigated both the intrinsic and nutrient enhanced rates of crude oil degradation both in microcosm and core studies. In addition, limiting elements, loading rates and optimum nitrogen forms (NH ₄ ⁺ or NO ₃ ^- ) were determined. Salt marshes have relatively low intrinsic degradation rates (0–3.9% day^-1) of the alkane component (C11-C44) but high rates (8–16% day^-1) of degradation of the polycyclic aromatic hydrocarbon (PAH) fraction (naphthalene, C1, and C2-Naphthalene and Phenanthrene, C1, and C2-Phenanthrene). Additions of nitrogen statistically enhanced degradation of many alkanes and total PAHs while naturally present phosphorous was found to be sufficient. Nitrogen was found to be most effective if applied as NH ₄ ⁺ in the range of 100-500-N mg kg^-1 of soil producing a pore water range of 100-670-N mg L^-1. Core studies indicate that similar trends are observed when applying fertilizers to intact portions of salt marsh.     

Comparison of extractants for available sludge-borne metals: A residual study

To study the availability of sludge-borne Zn, Cu, Cd, Ni and Pb over time, a field study was conducted. Anaerobically digested sewage sludge (dried on sandbeds) from Huntsville and Chicago were applied to a Decatur silty clay loam soil (clayey, kaolinitic, thermic, Rhodic Paleudult), pH 6.2, for 5 consecutive yr. The sludges were applied at rates of 0, 20 (annual application for 5 yr) and 100 mt ha^?1 (single application). Corn (Zea mays L.) and sudangrass (Sorghum sudanenses) were grown on the sludge-treated plots as test crops in 1987. Plant tissue samples were collected at different growth stages. Soil samples collected from the sludge-treated plots were extracted for Zn, Cu, Cd, Ni and Pb by 0.1 M HCI, DTPA, Mehlich 1 and Mehlich 3 extractants. Statistically, Mehlich 1, Mehlich 3, DTPA and 0.1M HCI extractants all gave highly significant correlations with the plant accumulation of Zn, Cu, Ni and Cd, with DTPA giving the highest at any growth stage for both corn and sudangrass, but they gave poor correlations for Pb. Zinc removed by four extractants was more highly correlated with Zn accumulation by corn (r=0.72^** to 0.93^** p=0.01) and sudangrass (r=0.50^** to 0.96^**, p=0.01) than other metals. Based on higher significant linear correlation coefficients (r), DTPA would be the extractant of choice for both crops; however the advantage to using the Mehlich 3 extractant is that, with a shorter shaking time of 5 min (compared to 2 hr for DTPA), it may be better suited for routine analysis of large numbers of soil samples.

     

Investigation of lichens using molecular techniques and associated mineral accumulations on a basaltic flow in a Mediterranean environment

The role of lichens in the breakdown of rocks in various environments is well documented. We investigated the formation of secondary minerals under 13 different fungal species growing on a basaltic flow in Sanliurfa (Turkey) to understand the influence of lichen species on the transformation of minerals in a Mediterranean environment. We used molecular technique (rDNA sequence) to identify 13 different species of lichens (7 crustose, 5 foliose and 1 pathogenic). X-ray diffraction and scanning electron microscopy were used to determine the composition of mineral accumulations. The formation of quartz and 2:1 phyllosilicates in various layers (top, brown and white) of the weathered basaltic flows under all the lichen colonies may be the result of precipitated silica alone (quartz) or in combination with aluminum (2:1 clays) released as a by-product during the breakdown/weathering of primary silicate minerals present in the basalt. However, aeolian deposition may also be a possible source of these mineral species. Whewellite, a calcium oxalate mineral, accumulates in the weathered basalt underneath all the species of lichens. We believe that the formation of whewellite was due to organic acids excreted by fungal hyphae to dissolve primary minerals (e.g., olivine and feldspars); this lichen-mediated process released enough calcium and generated oxalate necessary for the formation of whewellite.     

Accumulation of fluoride by lichens in the vicinity of Etna volcano

Volcanoes are known to discharge gaseous fluorides to the atmosphere, but measurement of these is difficult, and the dispersion characteristics have not previously been studied in detail. Samples of lichens were collected from the slopes of Etna Volcano in 1985 and 1987, in order to monitor these gases. Subsequent analysis for fluoride showed levels ranging from 2 to 141 μg g^?1, compared with control values of < 2 μg g^?1 The fluoride accumulation patterns clearly show that there is a major input from the volcano's plume, with the highest levels on the downwind side; these are attributed to the prevailing winds and to the local topographic influences. The fluoride levels in the lichens are compared with those resulting from industrial pollution.     

Adsorption and desorption of arsenate in Louisiana rice soils

Adsorption and desorption of arsenic (As) in the soil are dominant parameters that affect the mobility and bioavailability of arsenic. Batch arsenate adsorption and desorption experiments were conducted using soils collected from three Louisiana, USA, aquaculture ponds representing different crayfish farming and rice cultural practices. Arsenate adsorption behavior in the soils was investigated using Freundlich and Langmuir sorption equations. Results demonstrated that the Langmuir isotherm model was the best fit based on statistical correlation with soil properties governing adsorption, for the entire range of arsenate concentrations for all soils. Adsorption of As(V) was governed by soil physicochemical properties especially Fe and Al oxides, clay and organic matter. Desorption of As(V) was initially fast, but with increasing incubation times desorption occurred progressively slower. Chemical fractionation of arsenic in the soils showed that the most mobile fraction represented 4.74–5.18% of the total arsenic. A part of this mobile fraction could potentially be taken up by rice and enter the food chain, but would require additional research to quantify.     

基于多元统计学和地统计学的土壤重金属源解析

The main objectives of this study were to introduce an integrated method for effectively identifying soil heavy metal pollution sources and apportioning their contributions, and apply it to a case study. The method combines the principal component analysis/absolute principal component scores (PCA/APCS) receptor model and geostatistics. The case study was conducted in an area of 31 km² in the urban-rural transition zone of Wuhan, a metropolis of central China. 124 topsoil samples were collected for measuring the concentrations of eight heavy metal elements (Mn, Cu, Zn, Pb, Cd, Cr, Ni and Co). PCA results revealed that three major factors were responsible for soil heavy metal pollution, which were initially identified as “steel production”, “agronomic input” and “coal consumption”. The APCS technique, combined with multiple linear regression analysis, was then applied for source apportionment. Steel production appeared to be the main source for Ni, Co, Cd, Zn and Mn, agronomic input for Cu, and coal consumption for Pb and Cr. Geostatistical interpolation using ordinary kriging was finally used to map the spatial distributions of the contributions of pollution sources and further confirm the result interpretations. The introduced method appears to be an effective tool in soil pollution source apportionment and identification, and might provide valuable reference information for pollution control and environmental management.