Total Atmospheric Deposition Research Articles

Litter mercury deposition in the Amazonian rainforest

The objective of this work was to assess the flux of atmospheric mercury transferred to the soil of the Amazonian rainforest by litterfall. Calculations were based on a large survey of published and unpublished data on litterfall and Hg concentrations in litterfall samples from the Amazonian region. Litterfall based on 65 sites located in the Amazon rainforest averaged 8.15 ± 2.25 Mg ha−1 y−1. Average Hg concentrations were calculated from nine datasets for fresh tree leaves and ten datasets for litter, and a median concentration of 60.5 ng Hg g−1 was considered for Hg deposition in litterfall, which averaged 49 ± 14 μg m−2 yr−1. This value was used to estimate that in the Amazonian rainforest, litterfall would be responsible for the annual removing of 268 ± 77 Mg of Hg, approximately 8% of the total atmospheric Hg deposition to land. The impact of the Amazon deforestation on the Hg biogeochemical cycle is also discussed.

An automatic collector to monitor insoluble atmospheric deposition: application for mineral dust deposition

Abstract. Deposition is one of the key terms of the mineral dust cycle. However, dust deposition remains poorly constrained in transport models simulating the atmospheric dust cycle. This is mainly due to the limited number of relevant deposition measurements. This paper aims to present an automatic collector (CARAGA), specially developed to sample the total (dry and wet) atmospheric deposition of insoluble dust in remote areas. The autonomy of the CARAGA can range from 25 days to almost 1 year depending on the programmed sampling frequency (from 1 day to 2 weeks respectively). This collector is used to sample atmospheric deposition of Saharan dust on the Frioul islands in the Gulf of Lions in the Western Mediterranean. To quantify the mineral dust mass in deposition samples, a weighing and ignition protocol is applied. Almost 2 years of continuous deposition measurements performed on a weekly sampling basis on Frioul Island are presented and discussed with air mass trajectories and satellite observations of dust. Insoluble mineral deposition measured on Frioul Island was 2.45 g m−2 for February to December 2011 and 3.16 g m−2 for January to October 2012. Nine major mineral deposition events, measured during periods with significant MODIS aerosol optical depths, were associated with air masses coming from the southern Mediterranean Basin and North Africa.

Emission of SO2 and SO42- from copper smelter and its influence on the level of total s in soil and moss in Bor and the surroundings

Bor and the surroundings (Eastern Serbia) have been known for exploitation and processing of sulphide copper ores for more than 100 years. Emissions of waste gases and particulate matter rich in heavy metals are characteristic for pyrometallurgical production of copper. Long-term measurement results (2005-2008) indicate an increased sulphur dioxide level in the urban-industrial zone of Bor since it is closest to the copper smelter which is a dominant source of air pollution in the studied area. Average annual sulphur dioxide concentrations at four measuring sites in the urban-industrial zone exceeded the maximum allowable value of 50 ?g/m3. However the maximum allowable value of the total atmospheric depositions (200 mg/m2/day on an annual basis) exceeded only at two of 15 measuring sites in the urban-industrial and rural zone. The highest annual deposition rate of sulphates from deposition was detected in the urban-industrial zone. Since the maximum permitted value for sulphates is not defined by the Serbian Regulations, the extent of the pollution cannot be discussed. Since the environment can continuously be polluted through the wet and dry deposition, biomonitoring by moss was conducted, which revealed significantly higher concentrations of total sulphur in moss in the urban-industrial zone, compared to the background zone. The obtained results confirm the reliability of moss as a bioindicator of ambient pollution. Higher total S concentration in soil samples was noted at the rural site (Ostrelj) located in the close vicinity of two tailing ponds.

Sample pretreatment to differentiate between bioconcentration and atmospheric deposition of polycyclic aromatic hydrocarbons in mosses

In this first approach a comparison using different sample pretreatment methodologies has been made to differentiate between total atmospheric deposition and bioconcentration of polycyclic aromatic hydrocarbons (PAHs) in moss samples (Brachythecium rutabulum). Samples were collected in a densely polluted urban area in Barakaldo (Biscay, Basque Country) and submitted to different cleaning procedures with the aim to remove as many deposited atmospheric particles as possible. Analysis by means of Scanning Electron Microscopy coupled to Energy Dispersive Spectroscopy (SEM–EDS) allowed to quantify the removal efficiency of each cleaning procedure and to chemically characterise particles still present in the pre-cleaned sample. Cleaning moss samples twice with deionised water in an ultrasound bath showed up as the most suitable way to remove solid particles deposited on their surface. Discerning between bioconcentration and atmospheric deposition is therefore possible after GC–MS quantitative analysis of non-washed and washed moss samples.

Air‐sea exchange of methanol and acetone during HiWinGS: Estimation of air phase, water phase gas transfer velocities

AbstractThe air‐sea fluxes of methanol and acetone were measured concurrently using a proton‐transfer‐reaction mass spectrometer (PTR‐MS) with the eddy covariance (EC) technique during the High Wind Gas Exchange Study (HiWinGS) in 2013. The seawater concentrations of these compounds were also measured twice daily with the same PTR‐MS coupled to a membrane inlet. Dissolved concentrations near the surface ranged from 7 to 28 nM for methanol and from 3 to 9 nM for acetone. Both gases were consistently transported from the atmosphere to the ocean as a result of their low sea surface saturations. The largest influxes were observed in regions of high atmospheric concentrations and strong winds (up to 25 m s−1). Comparison of the total air‐sea transfer velocity of these two gases (Ka), along with the in situ sensible heat transfer rate, allows us to constrain the individual gas transfer velocity in the air phase (ka) and water phase (kw). Among existing parameterizations, the scaling of ka from the COARE model is the most consistent with our observations. The kw we estimated is comparable to the tangential (shear driven) transfer velocity previously determined from measurements of dimethyl sulfide. Lastly, we estimate the wet deposition of methanol and acetone in our study region and evaluate the lifetimes of these compounds in the surface ocean and lower atmosphere with respect to total (dry plus wet) atmospheric deposition.

Decreased atmospheric sulfur deposition across the Southeastern U.S.: when will watersheds release stored sulfate?

Emissions of sulfur dioxide (SO2) to the atmosphere lead to atmospheric deposition of sulfate (SO4(2-)), which is the dominant strong acid anion causing acidification of surface waters and soils in the eastern United States. Since passage of the Clean Air Act and its Amendments, atmospheric deposition of SO2 in this region has declined by over 80%, but few corresponding decreases in streamwater SO4(2-) concentrations have been observed in unglaciated watersheds. We calculated SO4(2-) mass balances for 27 forested, unglaciated watersheds from Pennsylvania to Georgia, by using total atmospheric deposition (wet plus dry) as input. Many of these watersheds still retain SO4(2-), unlike their counterparts in the northeastern U.S. and southern Canada. Our analysis showed that many of these watersheds should convert from retaining to releasing SO4(2-) over the next two decades. The specific years when the watersheds crossover from retaining to releasing SO4(2-) correspond to a general geographical pattern of later net watershed release from north to south. The single most important variable that explained the crossover year was the runoff ratio, defined as the ratio of annual mean stream discharge to precipitation. Percent clay content and mean soil depth were secondary factors in predicting crossover year. The conversion of watersheds from net SO4(2-) retention to release anticipates more widespread reductions in streamwater SO4(2-) concentrations in this region.

Fractionation of trace elements in total atmospheric deposition by filtrating-bulk passive sampling

We have developed and validated a new simple and effective methodology for fractionation of soluble and insoluble forms of trace elements in total atmospheric deposition. The proposed methodology is based on the modification of a standard total deposition passive sampler by integrating a quartz fiber filter that retains the insoluble material, allowing the soluble fraction to pass through and flow to a receiving bottle. The quartz filter containing the insoluble fraction and the liquid containing the soluble fraction are then separately assayed by standardized ICP–MS protocols. The proposed atmospheric elemental fractionation sampler (AEFS) was validated by analyzing a Coal Fly Ash reference material with proper recoveries, and tested for field fractionation of a set of 10 key trace elements in total atmospheric deposition at the industrial area of Puchuncaví–Ventanas, Chile. The AEFS was proven useful for pollution assessment and also to identify variability of the soluble and insoluble fractions of the selected elements within the study area, improving the analytical information attainable by standard passive samplers for total deposition without the need of using sophisticated and high cost wet-only/dry only collectors.

Wet and dry atmospheric depositions of inorganic nitrogen during plant growing season in the coastal zone of Yellow River Delta.

The ecological problems caused by dry and wet deposition of atmospheric nitrogen have been widespread concern in the world. In this study, wet and dry atmospheric depositions were monitored in plant growing season in the coastal zone of the Yellow River Delta (YRD) using automatic sampling equipment. The results showed that SO4 2− and Na+ were the predominant anion and cation, respectively, in both wet and dry atmospheric depositions. The total atmospheric nitrogen deposition was ~2264.24 mg m−2, in which dry atmospheric nitrogen deposition was about 32.02%. The highest values of dry and wet atmospheric nitrogen deposition appeared in May and August, respectively. In the studied area, NO3 −–N was the main nitrogen form in dry deposition, while the predominant nitrogen in wet atmospheric deposition was NH4 +–N with ~56.51% of total wet atmospheric nitrogen deposition. The average monthly attribution rate of atmospheric deposition of NO3 −–N and NH4 +–N was ~31.38% and ~20.50% for the contents of NO3 −–N and NH4 +–N in 0–10 cm soil layer, respectively, suggested that the atmospheric nitrogen was one of main sources for soil nitrogen in coastal zone of the YRD.

Heavy metal deposition fluxes affecting an Atlantic coastal area in the southwest of Spain

The present study seeks to estimate the impact of industrial emissions and harbour activities on total atmospheric deposition in an Atlantic coastal area in the southwest of the Iberian Peninsula. Three large industrial estates and a busy harbour have a notable influence on air quality in the city of Huelva and the surrounding area. The study is based on a geochemical characterization of trace elements deposited (soluble and insoluble fractions) in samples collected at a rate of 15 days/sample from June 2008 to May 2011 in three sampling sites, one in the principal industrial belt, another in the city of Huelva, and the last, 56 km outside Huelva city in an area of high ecological interest.The industrial emissions emitted by the Huelva industrial belt exert a notable influence on atmospheric deposition. Major deposition fluxes were registered for Fe, Cu, V, Ni, P, Pb, As, Sn, Sb, Se and Bi, principally in the insoluble fraction, derived from industrial funnel emissions and from harbour activities. Metals such as Mn, Ni, Cu and Zn, and elements such as P also have a significant presence in the soluble fraction converting them into potentially bio-available nutrients for the living organism in the ocean.A principal component analysis certifies three common emissions sources in the area: 1) a mineral factor composed mainly of elements derived from silicate minerals mixed with certain anthropogenic species (Mg, K, Sr, Na, Al, Ba, LREE, Li, Mn, HREE, Ti, Fe, Se, V, SO42−-, Ni, Ca and P); 2) an industrial factor composed of the same trace elements in the three areas (Sb, Mo, Bi, As, Pb, Sn and Cd) thus confirming the impact of the emissions from the Huelva industrial belt on remote areas; and 3) a marine factor composed of Na, Cl, Mg and SO42−.

Atmospheric deposition fluxes of 26 elements over the Southern Indian Ocean: Time series on Kerguelen and Crozet Islands

Atmospheric deposition of dust is suspected to have a significant impact on biogeochemical processes in high‐nutrient‐low‐chlorophyll waters of the open ocean. In this study, we report time series of atmospheric deposition samples collected over two years at three different sites on Kerguelen and Crozet Islands in the Southern Indian Ocean. Total atmospheric deposition fluxes were measured for a large suite of elements (Al, As, Ba, Ca, Ce, Co, Cr, Cu, Fe, K, La, Li, Mg, Mn, Na, Nd, Ni, Pb, Rb, S, Si, Sr, Ti, U, V, and Zn). Most of them are identified as coming from sea‐salt or crustal sources, but enrichment factor variabilities of Pb, As, Cr, Cu, and V highlight an anthropogenic contribution during the austral winter for these five elements. For Al, Fe, Mn, and Si, deposition fluxes are similar for both Kerguelen and Crozet Islands. Fluxes for the other non‐sea‐salt elements exhibit differences below a factor of five with a decreasing gradient from Crozet to Kerguelen.

Modeling and mapping of atmospheric mercury deposition in adirondack park, new york.

The Adirondacks of New York State, USA is a region that is sensitive to atmospheric mercury (Hg) deposition. In this study, we estimated atmospheric Hg deposition to the Adirondacks using a new scheme that combined numerical modeling and limited experimental data. The majority of the land cover in the Adirondacks is forested with 47% of the total area deciduous, 20% coniferous and 10% mixed. We used litterfall plus throughfall deposition as the total atmospheric Hg deposition to coniferous and deciduous forests during the leaf-on period, and wet Hg deposition plus modeled atmospheric dry Hg deposition as the total Hg deposition to the deciduous forest during the leaf-off period and for the non-forested areas year-around. To estimate atmospheric dry Hg deposition we used the Big Leaf model. The average atmospheric Hg deposition to the Adirondacks was estimated as 17.4 g m yr with a range of −3.7–46.0 g m yr. Atmospheric Hg dry deposition (370 kg yr) was found to be more important than wet deposition (210 kg yr) to the entire Adirondacks (2.4 million ha). The spatial pattern showed a large variation in atmospheric Hg deposition with scattered areas in the eastern Adirondacks having total Hg deposition greater than 30 μg m−2 yr−1, while the southwestern and the northern areas received Hg deposition ranging from 25–30 μg m−2 yr−1.

Contribution of mine wastes to atmospheric metal deposition in the surrounding area of an abandoned heavily polluted mining district (Rio Tinto mines, Spain)

The present study seeks to estimate the impact of abandoned mine wastes on the levels and chemical profile of total atmospheric deposition in one of the oldest and largest mining districts in Europe (Rio Tinto mines, Iberian Pyrite Belt), on the basis of a complete geochemical characterization of particulate matter samples periodically collected in five sampling stations located around the mining district between March 2009 and February 2011.The annual levels of total bulk deposition (soluble and insoluble fractions) registered in the Rio Tinto Mining District ranged between 18 and 43g/m2 depending on the distance from the sampling station with regard to the mine waste deposits. As a general pattern in the area, high mass levels of Zn and Cu were deposited in a range of 9–62mg/m2 not only in the insoluble but also in the soluble fraction. Other potentially toxic trace elements such as As, Sb, Ba, Pb, Sn and Bi showed greater deposition fluxes in the locations closest to the mine waste deposits.A principal component analysis with a Multilinear Regression Analysis certifies the presence of two common sources in the mining area: 1) a mineral factor composed mainly of elements derived from silicate minerals (Al, Ca, Sr, Ti, Li, Mg, Mn, K, Na and Fe), mixed with other anthropogenic species (NH4+, SO42−, NO3−) within the village closest to the mine; and 2) a marine factor composed of Na, Cl, Mg, SO42− and Sr. In addition, a mine waste factor made up of toxic elements (Cu, Zn, Ga, As, Sb, Ba, Pb, Sn, Cd and Bi) has been recognized in the sampling sites exposed to dust-bearing winds downwind of the mining area, suggesting that mine wastes are a relevant source of heavy-mineral particles with potentially adverse environmental effects to surrounding soils, plants and humans.

Wet precipitation chemistry at a high-altitude site (3,326 m a.s.l.) in the southeastern Tibetan Plateau

This paper presents the results of wet precipitation chemistry from September 2009 to August 2010 at a high-altitude forest site in the southeastern Tibetan Plateau (TP). The alkaline wet precipitation, with pH ranging from 6.25 to 9.27, was attributed to the neutralization of dust in the atmosphere. Wet deposition levels of major ions and trace elements were generally comparable with other alpine and remote sites around the world. However, the apparently greater contents/fluxes of trace elements (V, Co, Ni, Cu, Zn, and Cd), compared to those in central and southern TP and pristine sites of the world, reflected potential anthropogenic disturbances. The almost equal mole concentrations and perfect linear relationships of Na(+) and Cl(-) suggested significant sea-salts sources, and was confirmed by calculating diverse sources. Crust mineral dust was responsible for a minor fraction of the chemical components (less than 15%) except Al and Fe, while most species (without Na(+), Cl(-), Mg(2+), Al, and Fe) arose mainly from anthropogenic activities. High values of as-K(+) (anthropogenic sources potassium), as-SO4(2-), and as-NO3(-) observed in winter and spring demonstrated the great effects of biomass burning and fossil fuel combustion in these seasons, which coincided with haze layer outburst in South Asia. Atmospheric circulation exerted significant influences on the chemical components in wet deposition. Marine air masses mainly originating from the Bay of Bengal provided a large number of sea salts to the chemical composition, while trace elements during summer monsoon seasons were greatly affected by industrial emissions from South Asia. The flux of wet deposition was 1.12 kg N ha(-1) year(-1) for NH4(+)-N and 0.29 kg N ha(-1) year(-1) for NO3(-)-N. The total atmospheric deposition of N was estimated to be 6.41 kg N ha(-1) year(-1), implying potential impacts on the alpine ecosystem in this region.

Bulk Atmospheric Mercury Fluxes for the Northern Great Plains, USA

Total atmospheric bulk mercury (Hg) concentration and deposition were measured from August 2008 to November 2010 at nine locations in the Northern Great Plains, USA using passive bulk mercury samplers. Monthly mercury concentrations ranged from 1.3 to 51.0 ng L−1 with an overall volume weighted mean of 12.9 ng L−1. Normalized daily Hg fluxes ranged from 0.43 to 110 ng m−2 day−1 with higher rates occurring during high precipitation months as rainfall during spring and summer. Annual deposition rates ranged from 5.82 to 9.21 μg m−2 year−1 and were comparable to studies performed at similar latitudes and to estimates from the Mercury Deposition Network (MDN). There was no significant difference (p > 0.05) between measured atmospheric mercury for one colocated bulk Hg sampler and an existing MDN wet-only sampler at Eagle Butte, South Dakota, demonstrating measurement unity between the two sampling techniques in this geographic area.

Critical issues for critical loads

In the United States and most other countries, primary air quality standards are designed to protect human health and are based on concentrations of pollutants in the air. However, from the perspective of ecosystem health, a more appropriate metric for the impacts of nitrogen (N) and sulfur (S) pollutants is the total atmospheric deposition (or “load,” in kg⋅ha−1⋅y−1) of N and S, because ecosystem effects are more strongly determined by cumulative annual loading than by short-term atmospheric concentrations. The European Commission has adopted the concept of a “critical load,” defined as the load of a pollutant “below which significant harmful effects on specified sensitive elements of the environment do not occur according to present knowledge” (1). In PNAS, Payne et al. (2) provide new information on the impact of N deposition on European grassland ecosystems and illustrate some of the important complexities involved in quantifying and implementing critical loads.

Direct measurements of atmospheric iron, cobalt, and aluminum‐derived dust deposition at Kerguelen Islands

Atmospheric deposition is one of the major sources of nutrients bringing trace metals to remote marine biota. In this study, total atmospheric deposition and crustal aerosol concentrations were monitored at Kerguelen Islands (49°18′S; 70°07′E) in the Southern Ocean during a short campaign in early 2005 and then continuously for about 2 years (2009–2010). Results show very low levels of atmospheric dust and trace metals concentrations but higher deposition fluxes than expected. The averaged total dust deposition flux as derived from Al deposition measurements is 659 μg m−2 d−1. Simultaneously measured Fe and Co deposition fluxes are respectively 29 μg m−2 d−1 (520 nmol m−2 d−1) and 0.014 μg m−2 d−1 (0.24 nmol m−2 d−1), giving typically crustal elemental ratios to Al of 0.54 and 2.6 10−4. Measured dust deposition is in relatively good agreement with those simulated by current atmospheric models, but suggest that previous indirect calculations from field experiments are too low by a factor of 20. Observations and model results show that dust is transported above the marine atmospheric boundary layer to Kerguelen Islands, and thus that surface concentrations are not representative of the total dust column. Indeed, using surface concentrations leads to very large computed wet scavenging ratios, and to the conclusion that it is not appropriate to derive deposition fluxes from surface concentrations at remote ocean sites.

Comparison of collection methods to determine atmospheric deposition in a rural Mediterranean site (NE Spain)

Wet-only, dry-only, bulk deposition and deposition of sedimentary particles and gases deposited after the last rain (DAR) were collected weekly at La Castanya station in the Montseny mountains (NE Spain, 41°46′N, 2°21′E) from February 2009 to July 2010. These samples were analysed for pH, alkalinity, and the concentrations of major ions (Cl−, NO3 −, SO4 2−, Na+, K+, Ca2+, Mg2+, NH4 +). Significant differences were observed between bulk and wet-only precipitation, with an enrichment of ions associated to coarse particles in bulk deposition. The comparison between wet and dry fluxes revealed that the removal of compounds at Montseny occurred mainly by wet deposition, which accounted for 74 % of total deposition. The dry flux was characterised by the predominance of K+, Ca2+ and Mg2+, which are related to coarse particles. Bulk collection methods at Montseny were considered representative of total atmospheric deposition, since bulk deposition plus DAR accounted for 97 % of total deposition measured with wet and dry-only collection devices. Thus, bulk deposition collectors can be recommended for deposition networks at remote sites (lacking electricity connection) in environments, where coarse particles are a predominant fraction of the aerosol mass.

Miniaturized voltammetric stripping on screen printed gold electrodes for field determination of copper in atmospheric deposition

The applicability of commercial screen-printed gold electrodes (SPGEs) connected to a portable potentiostat and a laptop has been explored to optimize a new square wave anodic stripping voltammetric method for on-site determination of soluble Cu(II) in atmospheric deposition samples taken around an industrial complex. Electrode conditioning procedures, chemical and instrumental variables have been optimized to develop a reliable method capable of measuring dissolved copper with a detection limit of 3.7ngmL−1, useful for pollution monitoring or screening purposes. The proposed method was tested with the SLRS-5 River Water for Trace Metals (recoveries 109.9–113.1%) and the SPS-SW2 Batch 121 Elements in Surface Waters (recoveries 93.2–97.6%). The method was applied to soluble Cu(II) measurement in liquid samples taken by a total atmospheric deposition collector modified with a quartz filter for soluble and insoluble elemental speciation. The voltammetric measurements on field samples were tested in the lab by a reference ICP-MS method, with good agreement. The proposed method proved capability for field operation during a two weeks monitoring campaign.

Spatial distribution of mercury deposition fluxes in Wanshan Hg mining area, Guizhou province, China

Abstract. The legacy of long-term mining activities in Wanshan mercury (Hg) mining area (WMMA), Guizhou, China including a series of environmental issues related to Hg pollution. The spatial distribution of gaseous elemental mercury (Hg0) concentrations in ambient air were monitored using a mobile RA-915+ Zeeman Mercury Analyzer during daytime and night time in May 2010. The data imply that calcines and mine wastes piles located at Dashuixi and on-going artisanal Hg mining activities at Supeng were major sources of atmospheric mercury in WMMA. For a full year (May 2010 to May 2011), sampling of precipitation and throughfall were conducted on a weekly basis at three sites (Shenchong, Dashuixi, and Supeng) within WMMA. Hg in deposition was characterized by analysis of total Hg (THg) and dissolved Hg (DHg) concentrations. The corresponding data exhibit a high degree of variability, both temporarily and spatially. The volume-weighted mean THg concentrations in precipitation and throughfall samples were 502.6 ng l−1 and 977.8 ng l−1 at Shenchong, 814.1 ng l−1and 3392.1 ng l−1 at Dashuixi, 7490.1 ng l−1and 9641.5 ng l−1 at Supeng, respectively. THg was enhanced in throughfall compared to wet deposition samples by up to a factor of 7. The annual wet Hg deposition fluxes were 29.1, 68.8 and 593.1 μg m−2 yr−1 at Shenchong, Dashuixi and Supeng, respectively, while the annual dry Hg deposition fluxes were estimated to be 378.9, 2613.6 and 6178 μg m−2 yr−1 at these sites, respectively. Dry deposition played a dominant role in total atmospheric Hg deposition in WMMA since the dry deposition fluxes were 10.4–37.9 times higher than the wet deposition fluxes during the whole sample period. Our data showed that air deposition was still an important pathway of Hg contamination to the local environment in WMMA.

Radioactivity from Fukushima nuclear accident detected in Lisbon, Portugal

The radioactivity released from the Fukushima Dai-ichi nuclear accident was transported around the globe by atmospheric processes. Several artificial radionuclides were detected and measured in aerosols and atmospheric surface depositions in the Lisbon area during late March and early April 2011. The highest concentrations measured in aerosols were those of particulate 131I, 1.39 ± 0.08 mBq m−3. Cesium-134, 137Cs and 132Te were also determined but at lower concentrations. The total atmospheric depositions on the ground were higher on the first week of April with values for 131I, 134Cs, and 137Cs of 0.92 ± 0.11, 0.59 ± 0.06, and 0.62 ± 0.12 Bq m−2, respectively. The four artificial radionuclides measurable, 131I, 132Te 134Cs, and 137Cs, caused little radiation exposure to the members of the public, that was five orders of magnitude lower than the ionizing radiation effective dose limits for members of the public for one year (1 mSv y−1).