Bags with oven-dried moss for the active monitoring of airborne trace elements in urban areas

To define a harmonized methodology for the use of moss and lichen bags as active monitoring devices of airborne trace elements in urban areas, we evaluated the element accumulation in bags exposed in Naples in different spring weather conditions for 6- and 12-weeks. Three different pre-exposure treatments were applied to moss and lichen materials: water-washing, acid-washing and oven-drying. During the different exposure periods in the Naples urban environment the moss accumulated always higher amounts of elements (except Hg) than lichens and the element accumulation increased during wetter weather and higher PM₁₀ conditions. The oven pre-treatment did not substantially modify the morphology and element composition of moss and the exposure in bags of this material for 6-weeks was sufficient to detect the pattern of airborne trace elements.     

Comparison of the heavy metal bioaccumulation capacity of an epiphytic moss and an epiphytic lichen

This study compared the heavy metal bioaccumulation capacity in the epiphytic moss Scorpiurum circinatum and the epiphytic lichen Pseudevernia furfuracea, exposed in bags for 3 months in the urban area of Acerra (S Italy). The content of Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Ti, V, and Zn was measured by ICP-MS. The results showed that both species accumulated all the heavy metals assayed. The moss had the highest bioaccumulation capacity for all metals and showed a more constant and linear accumulation trend than the lichen. Intra-tissue heavy metal bioaccumulation was assessed by X-ray microanalysis applied to ESEM operated in high and low vacuum and ESEM modes.     

Active moss biomonitoring of trace elements with Sphagnum girgensohnii moss bags in relation to atmospheric bulk deposition in Belgrade, Serbia

Active biomonitoring with wet and dry moss bags was used to examine trace element atmospheric deposition in the urban area of Belgrade. The element accumulation capability of Sphagnum girgensohnii Russow was tested in relation to atmospheric bulk deposition. Moss bags were mounted for five 3-month periods (July 2005-October 2006) at three representative urban sites. For the same period monthly bulk atmospheric deposition samples were collected. The concentrations of Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, and Pb were determined by instrumental neutron activation analyses and atomic absorption spectrometry. Significant accumulation of most elements occurred in the exposed moss bags compared with the initial moss content. High correlations between the elements in moss and bulk deposits were found for V, Cu, As, and Ni. The enrichment factors of the elements for both types of monitor followed the same pattern at the corresponding sites.     

Accumulation of trace elements in the peripheral and central parts of two species of epiphytic lichens transplanted to a polluted site in Portugal

This paper compares the dynamics, i.e. the rates of change in element concentrations of young and older lichen thallus parts, of one foliose and one fruticose lichen, during a transplant experiment to a polluted site. Both lichen parts respond to environmental changes. Here, differential accumulation suggests that differential constitution leads to differential uptake and release, and/or the overall behaviour is partly due to internal translocation and regulation mechanisms within the whole lichen. For thallus parts, internal translocation should be taken into account as one more factor affecting lichen “memory length”. Young parts of the thallus presented higher rates of change, but different lichen parts accumulate different elements to different extents. Therefore tissue selection in monitoring may depend on the element of interest, and cannot be made into a generalized approach in survey set-ups: the choice depends on the element.     

Geographic distribution of selected elements in the livers of polar bears from Greenland, Canada and the United States

To assess geographic distributions of elements in the Arctic we compared essential and non-essential elements in the livers of polar bears (Ursus maritimus) collected from five regions within Canada in 2002, in Alaska between 1994 and 1999 and from the northwest and east coasts of Greenland between 1988 and 2000. As, Hg, Pb and Se varied with age, and Co and Zn with gender, which limited spatial comparisons across all populations to Cd, which was highest in Greenland bears. Collectively, geographic relationships appeared similar to past studies with little change in concentration over time in Canada and Greenland for most elements; Hg and Se were higher in some Canadian populations in 2002 as compared to 1982 and 1984. Concentrations of most elements in the polar bears did not exceed toxicity thresholds, although Cd and Hg exceeded levels correlated with the formation of hepatic lesions in laboratory animals.     

Inhibition kinetics of certain enzymes in the nervous tissue of vector snail Lymnaea acuminata by active molluscicidal components of Sapindus mukorossi and Terminalia chebula

Effect of active molluscicidal components of Sapindus mukorossi and Terminalia chebula on the acetylcholinesterase (AChE), acid and alkaline phosphatase (ACP/ALP) activity in the nervous tissue of freshwater snail Lymnaea acuminata were studied. In vivo and in vitro exposure of saponin (active component of S. mukorossi pericarp) and tannic acid (active component of T. chebula) significantly inhibited the AChE, ACP and ALP activity in the nervous tissue of L. acuminata. The inhibition kinetics of these enzymes indicate that saponin and tannic acid caused competitive and competitive-non-competitive inhibition of AChE, respectively. Saponin also caused competitive and competitive-non-competitive inhibition of ACP and ALP, respectively, whereas tannic acid caused competitive-non-competitive inhibition of ACP and ALP. Thus the inhibition of AChE, ACP and ALP by saponin and tannic acid in the nervous tissue of L. acuminata may be the cause of molluscicidal activity of S. mukorossi and T. chebula.     

Early changes in the fatty acid composition of photosynthetic membrane lipids from Populus nigra grown on a metallurgical landfill

We compared the fatty acid composition of leaves taken from poplars on a metal-contaminated landfill, and on the uncontaminated roadside bordering this site. For the first time, it is shown that the percentage of linolenic acid, which is mainly associated with thylakoid lipids, was significantly lower in tree species within the landfill than within the control area. A correlation study was carried out to investigate relationships between the C18:3/(C18:0 + C18:1 + C18:2) fatty acid ratios and the metal contents in soils and leaves. Lead and chromium leaf contents were significantly negatively correlated to this fatty acid ratio. The impact of each of these metals remains difficult to evaluate, but chromium in leaf likely plays a major role in toxicity. In addition, the decrease in the C18:3/(C18:0 + C18:1 + C18:2) fatty acid ratio occurred at low leaf metal content, and therefore it is shown that this ratio can be used as an early indicator of the effect of metals.     

Mutagenic and recombinagenic activity of airborne particulates, PM10 and TSP, organic extracts in the Drosophila wing-spot test

The genotoxicity associated with air pollution in the city of Canoas, Rio Grande do Sul (Brazil), was assessed in November (spring) and January (summer). We applied the somatic mutation and recombination test (SMART) in Drosophila melanogaster in its standard version with normal bioactivation (ST) and in its variant with increased cytochrome P450-dependent biotransformation capacity (HB). The data indicated the genotoxicity of TSP and PM10 collected in November, in both ST and HB crosses. The genotoxic activity of the PM10 material in the spring sample was exclusively associated with the induction of mitotic recombination, whereas the TSP genetic toxicity was due to both recombinational as well as point and/or chromosomal mutation events. Considering PM10 collected in January, a positive response--100% (17.10 m3/ml) concentration--was observed in the HB cross, which was not detected in the ST cross.     

Development of enzyme-linked immunosorbent assay (ELISA) for glutathione S-transferase (GST-S) protein in the intertidal copepod Tigriopus japonicus and its application for environmental monitoring

To utilize the GST-S protein as a useful biomarker for environmental contamination, we developed a polyclonal antibody-based enzyme-linked immunosorbent assay (ELISA) in the intertidal copepod Tigriopus japonicus. Two polyclonal antibodies, TJ-GST-S1 and TJ-GST-S2, were raised against two TJ-GST-S synthetic peptides. Also a recombinant TJ-GST-S protein was purified as a standard for ELISA development. Each polyclonal antibody was tested by Western blot analysis and indirect ELISA. Of two polyclonal antibodies, TJ-GST-S2 ELISA was further employed due to its wide range of detection and the limit of specificity compared to those of TJ-GST-S1 ELISA system. After exposure to 4 metals (Ag, As, Cd, and Cu) to T. japonicus, the amount of TJ-GST-S protein was significantly elevated in a concentration-dependent manner. Also, TJ-GST-S protein was upregulated at relative high concentrations of B[α]P, PCB, and TBT. In this paper, we suggest that T. japonicas ELISA for TJ-GST-S2 is useful as a potential indicator system for marine contaminants.     

Histopathological and biochemical alternations of the heart induced by acute cadmium exposure in the freshwater crab Sinopotamon yangtsekiense

Cadmium (Cd) is a highly toxic element in water. Its toxicity has been attributed to oxidative stress mediated by free radicals. Here we investigated the effects of Cd on the histopathology, antioxidant enzymes and lipid peroxidation of crustacean heart. The freshwater crabs Sinopotamon yangtsekiense were exposed to different concentrations of Cd for 1, 3, 5 and 7 d. After exposure, histological abnormalities were discovered, including myocardial edema, vacuolar and vitreous degeneration, and infiltration of inflammatory cells. Additionally, alterations in nuclei, mitochondria, rough endoplasmic reticulum as well as myofibrils were observed. Meanwhile, superoxide dismutase (SOD) activity was significantly increased after Cd exposure. Catalase (CAT) activity was only increased in the group exposed to 14.50 mg L⁻¹ Cd on day 5 and decreased with increasing Cd concentration and exposure time. Glutathione peroxidase (GPx) activity was increased in groups treated with 29.00, 58.00 and 116.00 mg L⁻¹ on days 1 and 3, and decreased thereafter. Besides, malondialdehyde (MDA) levels were significantly increased after 3 d of Cd exposure at all the indicated concentrations. These results showed that acute Cd exposure led to harmful effects on the histology of crab heart, which are most likely linked to Cd-induced oxidative stress.     

Historical alteration in the nitrogen concentration and N natural abundance of mosses in Germany: Indication for regionally varying changes in atmospheric nitrogen deposition within the last 140 years

Historical alterations of nitrogen deposition in the western part of Germany were investigated by comparing nitrogen concentrations and ¹⁵N natural abundance of historical and recent samples of the two pleurocarpous mosses Pleurozium schreberi and Scleropodium purum. Pooling of the data revealed only slight tissue N increases over the past 140 years which were significant nevertheless. At closer examination on the single site level historical increases of N concentrations were found particularly for some sites in regions where agricultural activities were considerably intensified during the second half of the 20th century. The comparison of δ¹⁵N values showed a strong depletion of ¹⁵N natural abundance in areas currently heavily influenced by livestock management. This indicates an increased impact of NH_y compounds. However, the almost unchanged δ¹⁵N values in some low mountain range areas with only moderate intensification of agriculture point to a more or less constant ratio of NH_y/NO_x input over time. Significant correlations of both tissue N concentrations and ¹⁵N natural abundance between the two species justify the assumption that they use the same nitrogen source, probably atmospheric deposition.     

Calibration of the Chemcatcher passive sampler for monitoring selected polar and semi-polar pesticides in surface water

Passive sampling is a powerful method for continuous pollution monitoring, but calibration experiments are still needed to generate sampling rates in order to estimate water concentrations for polar compounds. We calibrated the Chemcatcher device with an uncovered SDB-XC Empore disk as receiving phase for 12 polar and semi-polar pesticides in aquatic environments in flow-through tank experiments at two water flow velocities (0.135 m/s and 0.4 m/s). In the 14-day period of exposure the uptake of test substances in the sampler remained linear, and all derived sampling rates R(s) were in the range of 0.1 to 0.5 L/day. By additionally monitoring the release of two preloaded polar pesticides from the SDB-XC disks over time, very high variation in release kinetics was found, which calls into question the applicability of performance reference compounds. Our study expands the applicability of the Chemcatcher for monitoring trace concentrations of pesticides with frequent occurrence in water.     

Analysis of a Farquhar-von Caemmerer-Berry leaf-level photosynthetic rate model for Populus tremuloides in the context of modeling and measurement limitations

The balance of mechanistic detail with mathematical simplicity contributes to the broad use of the Farquhar, von Caemmerer and Berry (FvCB) photosynthetic rate model. Here the FvCB model was coupled with a stomatal conductance model to form an [A,g_s] model, and parameterized for mature Populus tremuloides leaves under varying CO₂ and temperature levels. Data were selected to be within typical forest light, CO₂ and temperature ranges, reducing artifacts associated with data collected at extreme values. The error between model-predicted photosynthetic rate (A) and A data was measured in three ways and found to be up to three times greater for each of two independent data sets than for a base-line evaluation using parameterization data. The evaluation methods used here apply to comparisons of model validation results among data sets varying in number and distribution of data, as well as to performance comparisons of [A,g_s] models differing in internal-process components.     

Flow cytometric measurement of the clearance rate in the blue mussel Mytilus edulis and the development of a new individual exposure system for aquatic immunotoxicological studies

Animals in poor health condition are not relevant biological models. The current study focused on the use of the clearance rate of Mytilus edulis to assess the gross physiological condition of individuals maintained in stressful experimental conditions. This approach was developed in a new, highly controlled experimental exposure device designed to investigate individual responses in aquatic ecotoxicological studies. Both clearance rate values and immune parameters analysis indicated that the health condition of mussels kept in 50ml tubes for 24h or 48h was not altered compared to controls, while most parameters were depressed after 72h. Moreover, this study confirms the relevance of flow cytometric for the measurement of clearance rate compared to techniques utilizing microscopy. Current results prompted us to perform further 24h chemical exposure using this "in tubo" device.     

Validation and use of in vivo solid phase micro-extraction (SPME) for the detection of emerging contaminants in fish

A variety of emerging chemicals of concern are released continuously to surface water through the municipal wastewater effluent discharges. The ability to rapidly determine bioaccumulation of these contaminants in exposed fish without sacrificing the animal (i.e. in vivo) would be of significant advantage to facilitate research, assessment and monitoring of their risk to the environment. In this study, an in vivo solid phase micro-extraction (SPME) approach was developed and applied to the measurement of a variety of emerging contaminants (carbamazepine, naproxen, diclofenac, gemfibrozil, bisphenol A, fluoxetine, ibuprofen and atrazine) in fish. Our results indicated in vivo SPME was a potential alternative extraction technique for quantitative determination of contaminants in lab exposures and as well after exposure to two municipal wastewater effluents (MWWE), with a major advantage over conventional techniques due to its ability to non-lethally sample tissues of living organisms.