Literatura científica selecionada sobre o tema "Moss-bag"

To assess the validity of the moss bag monitoring technique in the radioactivity control of ground level urban air, a study on radionuclide contents in moss was performed in the city of Belgrade, Serbia. From May 2006 to May 2007, moss (Sphagnum girgensohni, Dubna, Russia) was exposed to the aero pollution in a location in the central area of the city. The activity of 40K, 210Pb, and 137Cs was measured on an HPGe detector (Canberra, relative efficiency 23%) by standard gamma spectrometry. The activities 245 ? 25 Bq/kg for 40K, 315 ? 34 Bq/kg for 210Pb, and 28 ? 4 Bq/kg for 137Cs are in the range of values reported for the region; the differences are due to the moss species, local climate and measuring technique. Taking into consideration the time of the exposure and appropriate calibration procedure, moss bag biomonitoring could be used as a complementary method for determination of radionuclides in urban air.

Moss Barbula vinealis and Rhodobryum roseum used as biomonitor of metal precipitation at Nainital during 2004 - 2005 to examine deposition of Zn, Cu, Cd, Pb at Nainital area, around point sources in all the four directions. Moss bags were transplanted at 8 sites for fixed exposure time in sampling seasons (summer, monsoon and winter) and were harvested periodically after 4 months of exposure. An increase in amount of metals in 2004 - 2005 reflects an increase in metals in air. High metallic load was observed in locations in proximity of higher traffic density. From the result, it is concluded that local sources in Nainital, especially due to enhanced tourism during summer, contributes to elevated metal deposition in comparison to winter and monsoon season. Active monitoring by 4 months of exposure of mosses gives reliable results on metal contamination. Study also aim at assessing the suitability of both mosses as a biomonitor for metal deposition. Study confirms that in Nainital, where due to higher vehicular traffic, wear and tear of vehicular parts and beside it increasing tourist activity, high level of Zn, Pb was measured in moss transplant bags.Bioaccumulation ability in these two mosses was evaluated statistically using Dunkun's Multiple Range Test and was presented on contour maps obtained from SURFER program.

Introduction: In Vietnam, the government has invested in monitoring stations in a few big cities like Hanoi and Ho Chi Minh City, which have transportation centers and industrial zones, to assess and predict levels of air pollution. However, the main disadvantage of installing monitoring stations is the cost of investment for operations, maintenance, and equipment. It is also time-consuming to collect and analyze the results. Therefore, it is generally not suitable for the country as a whole. Methods: Using mosses to monitor air quality brings qualitative and quantitative data with simple, environmentally-friendly economic methods. Mosses have particular biological characteristics that make them very suitable adsorbents for a wide variety of chemical elements. When used as transplants like moss bags, allow them to monitor a highly dense sampling network of any site easily. Mosses are bioindicators, plants with artificial roots. Results: In this study, moss bag and native moss were the two methods used to evaluate the accumulation of trace elements in air through Barbula Indica. Observations showed that both methods could detect the same elements: Al, Si, P, S, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Rb, Y, Sb, Ba, Pb, and U. However, the accumulation of the elements in native moss is higher than in moss bag. The main reason is that the absorption efficiency of native moss in air-deposited elements is higher than in moss bags. Conclusion: Moss bags have been used most extensively and successfully in urban areas, where vegetation samples are either unobtainable or are poorly located to the source. These areas can lack moss, or the native moss simply does not grow during the dry season.

Moscow is a large metropolis in which the air is affected by the constant effects of chemicals produced by industrial facilities, vehicles, residential heating and other human activities on a daily basis. The protected and park areas on the territory of Moscow have an important recreational role, therefore, air quality control in these territories should be carried out first. Active moss biomonitoring has been used as an alternative method to conventional atmospheric monitoring for more than 40 years. This type of biomonitoring is successfully applied all over the world: in China, Serbia, Moldova, Azerbaijan, Italy, Romania, etc. In this study, active moss biomonitoring was used for the first time on the territory of the Tsaritsyno Museum-Reserve to assess the air pollution. The moss species Sphagnum girgensohnii was chosen for the experiment. Neutron activation analysis was used to determine the concentrations of the elements: Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, Se, As, Br, Rb, Mo, Sr , Sb, Ba, Cs, La, Sm, Tb, Ce, Hf, Ta, W, Th, and U. The concentrations of Pb, Cu, and Cd were determined by atomic absorption spectrometry.

For the first time, transplants with moss-bags and mussels together were applied to study the water quality in standing water bodies. The tested species: Fontinalis antipyretica Hedw. and Sinanodonta woodiana (Lea, 1834) were collected from unpolluted sites and analyzed to obtain background levels. Then, the moss and mussels were left in cages for a period of 30 days in three reservoirs where both are not present naturally. Two of the reservoirs suffer from old industrial contamination and one is affected by untreated wastes. Twenty-four compounds were studied, among them trace elements Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Zn and organic priority substances: six polybrominated diphenyl ethers (PBDEs) congeners and short-chain chlorinated paraffins (SCCPs). The trace element accumulation was significant after the exposition period in all studied stations. PBDEs and SCCPs were also accumulated up to two times more in the moss tissues. PBDEs in the mussels exceeded the environmental quality standard (EQS). The applied combined transplants, and especially the moss-bags, revealed severe contamination with heavy metals not detected by the water samples. The moss and the mussel followed a different model of trace element and PBDEs accumulation. The SCCPs levels were alarmingly high in all plant samples. The study confirmed PBDEs and SCCPs as bioaccumulative compounds and suggested that an EQS for SCCPs in biota needs to be established.

Three moss (Pleurosium spp., Polytrichum spp., Rhytidiadelphus spp.) and two lichen taxa (Hypogymnia physodes L., Pseudevernia furfuracea L.), were exposed for four weeks in six petrol stations, two consecutive years (2015–2016), in urban area of the Prešov city (Slovakia), to assess accumulation of selected airborne elements Cd, Co, Cu, Fe, Hg, Mn, Ni, Pb and Zn. Significantly highest (P < 0.01) ability to accumulate Zn, Ni, Co and Fe was found in Pleurosium spp.; Pseudevernia furfuracea was determined the best accumulator of Hg, whereas Rhytidiadelphus spp. was found as the least suitable for this purpose. No significant differences in heavy metal accumulation between moss and lichen taxonomic group were found. Samples of conifer (used as a moss/lichen bag holder) showed significantly lower content of heavy metals compared to mosses and lichens. Major content of heavy metals trapped in the air around petrol stations, did not originate from the petrol combustion, but predominantly from the car body, which is mechanically disrupted during fuelling.

Moss-bags were applied to study the effect of contamination in three standing water bodies in Bulgaria (Kardzhali, Studen Kladenets and Zhrebchevo Reservoirs), the first two with old industrial contamination and the last polluted with short-chain chlorinated paraffins (SCCPs). Fontinalis antipyretica Hedw. collected from background (unpolluted) site was placed in cages for a period of 30 days. The present study examined whether inorganic and organic pollution detected with moss-bags resulted in corresponding differences in molecular, chemical and micromorphological markers. Suppressed large subunit of ribulose-1,5-bisphosphate carboxylase (rbcL) expression was assessed in moss-bags from two of the reservoirs, contaminated with heavy metals. There was a decrease of the total phenolic content (TPC) in the moss-bags, which provides a basis for further studies of the chemical content of aquatic mosses. Fontinalis antipyretica also showed a response through leaf micromorphological characteristics. In the all three reservoirs, an increase of the twig leaf cell number was recorded (p ≤ 0.01 for Kardzhali and p ≤ 0.001 for Studen Kladenets and Zhrebchevo reservoirs), as well as of the stem leaf cell number in Zhrebchevo Reservoir (p ≤ 0.001). On the contrary, the width of the cells decreased in the studied anthropogenically impacted reservoirs. All three studied groups of biomarkers (molecular, chemical and micromorphological) appeared to be sensitive to freshwater pollution. The results achieved indicated that rbcL gene expression, TPC, cell number and size are promising biomonitoring tools.

The use of biological indicators of environmental quality is an alternative method of monitoring ecosystem pollution. Various groups of contaminants, including organic ones, can be measured in environmental samples. Polycyclic aromatic hydrocarbons (PAHs) have not yet been determined by the moss bag technique. This technique uses several moss species simultaneously in urban areas to select the best biomonitoring of these compounds, which are dangerous to humans and the environment. In this research, a gas chromatography coupled with mass spectrometry was used for the determination of selected PAHs in three species of mosses: Pleurozium schreberi, Sphagnum fallax and Dicranum polysetum (active biomonitoring) and for comparison using an air filter reference method for atmospheric aerosol monitoring. The chlorophyll fluorescence of photosystem II (PSII) was also measured to assess changes in moss viability during the study. As a result of the study, the selective accumulation of selected PAHs by mosses was found, with Pleurozium schreberi being the best bioindicator—9 out of 13 PAHs compounds were determined in this species. The photosynthetic yield of photosystem (II) decreased by 81% during the exposure time. The relationship between PAHs concentrations in mosses and the total suspended particles (TSP) on the filter indicated the possibility of using this bioindicator to trace PAHs in urban areas and to apply the moss bag technique as a method supporting classical instrumental air monitoring.

The monitoring of the air quality by mosses provides qualitative and quantitative data using economic, easy-to-manage and eco-friendly methods. Due to peculiar morphological and physiological characteristics, mosses are very suitable adsorbents for a wide variety of pollutants (i.e. metals and metalloids, PAHs, radionuclides) and, when used as transplants in nylon bags, they allow an easy monitoring potentially of any site, with a highly dense sampling network. Nevertheless, the moss-bag technique, although widely applied, is still not based on standardized protocols. It follows that the data collected from biomonitoring surveys are not comparable, thus relegating the active biomonitoring exclusively to academic field or to scientific purposes. Moreover, there are not enough studies comparing bioaccumulation data with those obtained by estimation models or traditional monitoring approaches, neither it is clear how the moss-bag technique can discriminate pollution inputs on a very small scale and within areas relatively close to each other or characterized by different land uses. Another important issue is that the mosses employed as biomonitors are naturally grown species. The collection in nature implies an intrinsic variability of mosses in terms of elemental and chemical composition and, as a consequence, it poses a high degree of uncertainty in the interpretation of the results. Moreover, an uncontrolled harvesting of mosses could lead to a severe environmental impact. In this context, aims of this Doctoral Thesis are: 1) to test the variables affecting the exposure protocol in the view of a standard moss-bag method for the biomonitoring of air pollution; 2) to integrate biomonitoring results with emission data provided by inventories for the evaluation of the atmospheric pollution; 3) to characterize a novel moss biomaterial for biomonitoring purposes. For the standardization assay, more than one thousand moss bags were exposed contemporary in three European territories (Austria, Italy, Spain) belonging to three different climatic areas (Mediterranean, continental and oceanic). For each area, four distinct scenarios (background, urban, agricultural, industrial) were selected for the exposure, on the basis of their level and type of contamination. The moss included in bags was the Pseudoscleropodium purum (Hedw.) M. Fleisch, collected in a pristine area of the Galicia (NE Spain). Shoot apical parts were selected, EDTA-washed and finally devitalized by oven drying at 100 °C. For the first time, all the variables affecting the air pollutant uptake by moss exposed in bags were considered: 1) the moss bags characteristics (round, spherical and flat shapes; nylon net mesh size of 1, 2 and 4 mm; moss amount and moss weight/bag surface area ratio of 15, 30, 45 mg cm-2); 2) the exposure criteria (exposure time of 3, 6, 12 weeks; exposure heights of 4, 7, 10 m above ground); 3) the climatic conditions of the exposure area. The concentrations of metals and metalloids were determined by ICP mass spectrometry and the results were evaluated comparing pre- and post-exposure moss samples. Results showed that the amount of moss included in bags was the most important factor affecting the pollutant accumulation by mosses: the more the moss density inside bags increases, the less metal uptake occurs. The other variables (climate, bag size and shape, exposure time and height) had low or no influence at all. As consequence of the obtained results, the project Mossclone proposed the use of a standard moss bag, spherical-shaped, with a mesh size of 2 mm and filled with a moss amount less than 15 mg per cm2 of bag surface area. In addition, it was suggested to expose the moss-bags for not less than six weeks (to increase the detectability of metal concentrations in moss) and, for practical reasons, at 4 m above the ground. The proposed standardized protocol for moss-bag exposure was then tested in a biomonitoring campaign carried out in the framework of the LIFE-Ecoremed project, in order to assess the air quality of five municipalities belonging to the Italian RIPS “Litorale Domizio-Agro Aversano” (Campania Region, south Italy). In each municipality, two scenarios (urban and agricultural) and two sub-scenarios (a street side and a corresponding green area) were selected, in order to evaluate the anthropogenic pollution, with a particular attention to the vehicular traffic impact on the surrounding areas. The concentrations of twenty PAHs and of thirty-nine elements including rare earths were determined by ICP mass spectrometry in pre- and post-exposure samples of Hypnum cupressiforme Hedw. moss, treated and exposed following the standardized method. After exposure, the concentration of most of the elements and PAHs (in particular the 4- and 5-ringed PAHs) was significantly increased in moss material. The pollutants had a similar spatial distribution pattern over the entire study area, with road traffic and agricultural practices as the major diffuse pollution sources. Hypnum cupressiforme moss bags was able to detect airborne element and PAH inputs and to discriminate different pollution levels in a landscape characterized by a jeopardized structure in which agricultural and urban/residential sites are strictly mixed together. The data obtained in the Italian biomonitoring campaign were combined with those provided by emission inventories, which are a collection of estimations, recorded with spatial disaggregation, on the type, amount and emission sources of pollutants. As a result, it was observed that both approaches (biomonitoring and emission inventory) indicated the same most polluted municipality and a similar spatial pattern, in particular for lead. This suggests that the joint use of emission inventory and moss accumulation could be a valuable resource to reveal contaminants better than the use of a single approach, allowing a more deep investigation on the pollutant emission sources, especially for those contaminants not routinely monitored. To overcome the limits of the use of native mosses, the last part of the PhD thesis is focused on the characterization of a new moss biomaterial, provided by the cloning inside bioreactors. The cloned moss specie in question is the Sphagnum palustre L., whose elemental composition (pre- and post- treatments with EDTA and by devitalization) and molecular profile were given, in comparison with the conspecific field moss, in order to outline a defined fingerprint of the new biomaterial. The morphological and physico-chemical properties of the moss adsorbing surfaces were also examined by electron microscopy, in vitro experiments on metal adsorption and by the chemical analysis of the surface exchange sites. A field exposure test with moss-bags was performed, comparing the clone and the naturally grown P. purum. The clones exhibited a much lower metal concentration (from 10 to 100 times) in their tissues than the native samples, thus making the former better indicators of low metal loading. New DNA markers, also useful for systematic analyses of the Sphagnum genus, were provided in order to characterize and label the clone. The S. palustre clone exhibited acid base properties similar to those of naturally grown Sphagnum samples and showed a significantly higher metal uptake performance. Therefore, the use of this biomaterial, with very homogenous morphological and chemical characteristics and a remarkable metal uptake capability, is strongly recommended in the view of a rigorously standardized moss-bag protocol for the active monitoring of persistent atmospheric pollutants.