Sea Aerosol Research Articles

The ocean fine spray

An important fraction of the atmospheric aerosols comes from the ocean spray originated by the bursting of surface bubbles. A theoretical framework that incorporates the latest knowledge on film and jet droplets from bubble bursting is here proposed, suggesting that the ejected droplet size in the fine and ultrafine (nanometric) spectrum constitutes the ultimate origin of primary and secondary sea aerosols through a diversity of physicochemical routes. In contrast to the latest proposals on the mechanistic origin of that droplet size range, when bubbles of about 10–100 μm burst, they produce an extreme energy focusing and the ejection of a fast liquid spout whose size reaches the free molecular regime of the air. Simulations show that this spout yields a jet of sub-micrometer and nanometric scale droplets whose number and speed can be far beyond any previous estimation, overcoming by orders of magnitude other mechanisms recently proposed. The model proposed can be ultimately reduced to a single controlling parameter to predict the global probability density function of the ocean spray. The model fits remarkably well most published experimental measurements along five orders of magnitude of spray size, from about 5 nm to about 0.5 mm. According to this proposal, the majority of ocean aerosols would have their extremely elusive birth in the collapsing uterus-like shape of small bursting bubbles on the ocean surface.

Spatio-temporal Variation of Meteorological Influence on PM2.5 and PM10 over Major Urban Cities of Bangladesh

A detrended seasonal analysis on a 6-year (2013–2018) dataset of daily Particulate Matter (PM) concentration and meteorological parameters is performed to understand the spatio-temporal variation of PM and the seasonal influence of meteorological factors on PM pollution over 6 major urban cities of Bangladesh. Cross-correlation and multiple non-linear regression (MNLR) of air quality and meteorological data were used to explore the meteorology-PM interactions and their spatio-temporal variability. Meteorological influence on PM was found to be stronger in the southern part of the country relative to the northwestern part. MNLR analysis implied that meteorological parameters could explain up to 39% of daily PM variability during high pollution days. The deposition effect of relative humidity was prominent during the premonsoon season, while rainfall impact becomes dominant in the monsoon season, specifically in the northeastern region. Wind speed was observed to have a dilatory effect on PM variation, although wind seemed to carry sea aerosol in southern regions. In addition, the northwestern wind appeared to contribute to PM rise in most urban areas by carrying PM loading. In winter, the low temperature was found to favor PM accumulation, while in monsoon, high temperature causes PM rise, possibly by assisting atmospheric secondary aerosol formation. Solar radiation positively influenced atmospheric PM formation, and the influence was stronger in the northwestern region. It is shown that meteorological parameters influence the seasonal variability of PM, but the extent of this influence varies depending on temporal and regional factors.

Aerosolized aqueous dust extracts collected near a drying lake trigger acute neutrophilic pulmonary inflammation reminiscent of microbial innate immune ligands

BackgroundA high incidence of asthma is prevalent among residents near the Salton Sea, a large inland terminal lake in southern California. This arid region has high levels of ambient particulate matter (PM); yet while high PM levels are often associated with asthma in many environments, it is possible that the rapidly retreating lake, and exposed playa or lakebed, may contribute components with a specific role in promoting asthma symptoms. ObjectivesOur hypothesis is that asthma may be higher in residents closest to the Salton Sea due to chronic exposures to playa dust. Playa emissions may be concentrating dissolved material from the lake, with microbial components capable of inducing pulmonary innate immune responses. To test this hypothesis, we used a mouse model of aerosol exposures to assess the effects of playa dust. MethodsFrom dust collected around the Salton Sea region, aqueous extracts were used to generate aerosols, which were injected into an environmental chamber for mouse exposure studies. We compared the effects of exposure to Salton Sea aerosols, as well as to known immunostimulatory reference materials. Acute 48-h and chronic 7-day exposures were compared, with lungs analyzed for inflammatory cell recruitment and gene expression. ResultsDust from sites nearest to the Salton Sea triggered lung neutrophil inflammation that was stronger at 48-h but reduced at 7-days. This acute inflammatory profile and kinetics resembled the response to innate immune ligands LTA and LPS while distinct from the classic allergic response to Alternaria. ConclusionLung inflammatory responses to Salton Sea dusts are similar to acute innate immune responses, raising the possibility that microbial components are entrained in the dust, promoting inflammation. This effect highlights the health risks at drying terminal lakes from inflammatory components in dust emissions from exposed lakebed.

Are Natural or Anthropogenic Factors Influencing Potentially Toxic Elements' Enrichment in Soils in Proglacial Zones? An Example from Kaffiøyra (Oscar II Land, Spitsbergen).

Arctic soils may hold potentially toxic elements (PTE); PTE can provide evidence of past or recent pollution. In this study, five soil profiles located on Oscar II Land (Kaffiøyra) were studied to (i) evaluate the ecological status of Kaffiøyra’s soils based on the determination of the possible accumulation of PTE using pollution indices; and (ii) determine the possible origin of PTE enrichment (local factors vs. long-range sources) depending on the distance from the sea. The soils were tested with standard soil science methods. The contamination of five soils was assessed by a wide spectrum of pollution soil indices: Enrichment Factor (EF), Geoaccumulation Index (Igeo), Potential Ecological Risk (RI), Pollution Load Index (PLI), and Probability of Toxicity (MERMQ). EF values calculated based on Cd, Cr, Cu, Pb and Zn content indicated an anthropogenic origin of the pollution. Values of Igeo showed the highest pollution with Cd, while CSI and MERMQ values indicated the highest Cd and Pb levels, but only in the soils located closest to the coast. RI values suggested that soils were under a strong or very strong potential ecological risk, whereas PLI confirmed the high probability of soil quality reduction. Enrichment with PTE has been conditioned by both local (natural) and long-distance (anthropogenic) factors. Among the local factors, parent material was highly relevant. The effect of long-distance anthropogenic factors, especially from European, large industrial centres, was manifested by the high content of PTE in soils located closest to the coastlines, delivered by a wet deposition and sea aerosols. The monitoring and assessment of arctic soil quality are useful practices for the verification of the sources of PTE pollution and the development of methods that can contribute to the protection and maintenance of these vulnerable ecosystems.

Trace and major elements in surface snow and fresh water bodies of the Marguerite Bay Islands, Antarctic Peninsula

The results of major and trace elements investigation in snow and fresh water on Dismal and Horseshoe Islands, Marguerite Bay, Antarctic Peninsula are presented. Samples of newly fallen snow, old snow, as well as water from lakes, ponds and streams were collected during the 4th Turkish Antarctic Expedition in February-early March 2020. Determination of Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Na, Mg, Mn, Mo, Ni, Pb, Sb, Se, Th, Tl, U, V and Zn content was carried out using the ICP-MS method. Totally 39 samples were analyzed.It was established that, variability and average concentrations of major and trace elements are significantly higher in newly fallen snow compared to old snow. The lowest concentrations of major and a number of trace elements (Fe, Cr, Se, Ba, As and Tl) were recorded in samples of old snow, and the highest - in water of streams. All types of samples have the highest Na concentrations, that confirms sea aerosols as the source of their input.High enrichment factors EFc (>100) for Zn, Cd, Se and Sb (especially in newly fallen snow) indicate possible anthropogenic impact connected with long-range air mass transfer.

МЕТОД ДИНАМИЧЕСКИХ ИЗМЕРЕНИЙ И ОПТИМАЛЬНОЙ ОЦЕНКИ СТЕПЕНИ ПРОНИКНОВЕНИЯ МОРСКОГО СОЛЕВОГО АЭРОЗОЛЯ В БЕРЕГОВЫЕ ПРОИЗВОДСТВЕННЫЕ ЗОНЫ

An accurate assessment of the emission of pollutants coming from the water surface is extremely relevant in studies of mass transfer between the sea and the atmosphere. The object of the study is a corrosive marine salt aerosol formed under the influence of wind, as a result of the dissipation of wave energy when hitting the shore. The subject of the study is the extent of the spread of sea salt aerosol under the influence of wind in coastal residential and industrial zones. The purpose of the study is to determine the nature of the change in wind speed over time, at which the total measuring signal at the output of the mobile meter would reach an extreme, i.e. the most reliable measurement result would be achieved. The aim of the study, when comparing the increasing and decreasing wind speeds, to determine such a dependence of wind speed on the current measurement time at which the measurement result would reach an extremum. The general task of estimating the amount of corrosive sea aerosol deposited in the coastal zone in this case is to estimate the amount of the current unsettled aerosol in the air. The proposed research method is to determine the penetration degree of sea salt aerosol into residential and industrial quarters, a dynamic measurement method is proposed, carried out using a mobile laboratory equipped with appropriate measuring equipment. The meter at point xi measures the aerosol generated by the wind at moment ti . For the optimal solution of the problem, the double averaging method is used. As a result a mobile measurement method is proposed to determine the degree of penetration of marine salt aerosol into the coastal production zone. The problem of determining the nature of the temporary change in wind speed in the coastal zone is solved with a known dependence of the amount of settled sea aerosol on the distance between the measuring point and the sea under the condition of a constant speed of movement of the mobile meter

Conservation state of two paintings in the Santa Margherita cliff cave: role of the environment and of the microbial community.

The conservation of ancient paintings sited in humid environments is an actual challenge for restorers, because it needs the knowledge of the materials the paintings are made up and of their interaction with a peculiar surrounding environment; thus, tailored procedures and strategies aimed at restoring and preserving paintings are necessary. Santa Margherita's cave in Castellammare del Golfo (Trapani, Italy) is a natural cave, containing the remains of paintings, in a poor state of conservation, belonging to an ancient church dated back to the Middle Age. The present manuscript reports the monitoring of environmental conditions (i.e., temperature and humidity) in a full year, as well as a study on the materials constituting the stone support and the paintings together with a survey of the microbial community. The findings allow us to define the causes that mainly involve the degradation of the paintings. In detail, the degradation of the east and the west walls occurred differently because of the exposure to the sea aerosol, which influenced the salt composition, also contributing to diversifying the bacterial community. Some specific actions to plan the conservation and restoration of paintings and to preserve the site are suggested.

Salton Sea aerosol exposure in mice induces a pulmonary response distinct from allergic inflammation

In communities surrounding the Salton Sea, high rates of asthma are associated with high aerosol dust levels. However, the Salton Sea itself may play an additional role in pulmonary health. Therefore, to investigate a potential role of the Salton Sea on pulmonary health, we exposed mice to aerosolized Salton Sea water for 7 days and assessed tissue responses, including cellular infiltration and gene expression changes. For reference, mice were also exposed to aerosolized fungal allergen (Alternaria sp.) and Pacific Ocean aerosols. Exposure to aerosolized Alternaria sp. induced dramatic allergic inflammation, including neutrophil and eosinophil recruitment to the bronchoalveolar lavage fluid (BALF) and lung tissue. By contrast, Salton Sea “spray” induced only B cell recruitment to the lung tissue without increased inflammatory cell numbers in BALF. However, there were consistent gene expression changes suggestive of an inflammatory response. The response to the Salton Sea spray was notably distinct from the response to Pacific Ocean water, which induced some B cell recruitment but without an inflammatory gene expression profile. Our studies suggest that soluble components in Salton Sea water promote induction of a unique inflammation-associated response, though any relationship to asthma remains to be explored.

Assessment of Sulfate Sources under Cold Conditions as a Geochemical Proxy for the Origin of Sulfates in the Circumpolar Dunes on Mars

Determining aqueous sulfate sources in terrestrial cold environments can provide an insight into the surface hydrological conditions and sulfur cycle on Mars. In this study, we analyzed sulfur and oxygen isotope compositions of secondary sulfate salts (e.g., gypsum, thenardite) in the surficial sediments and soils of the McMurdo Dry Valleys (MDV), Antarctica to determine contributions of sulfate from bedrock chemical weathering and atmospheric deposition under persistent dry polar conditions. The sulfate showed wider variation of δ34S (+15.8‰ to +32.5‰) compared to smaller ranges of δ18O (−8.9‰ to −4.1‰). In contrast, the δ34S of bedrock sulfide showed significantly lower and consistent values across the studied area (−0.6‰ to +3.3‰). Based on the δ34S trends, sulfide weathering may contribute up to 20–50% of secondary sulfate salts in the MDV. While the remaining 50–80% of sulfate inputs may originate from atmospheric deposition (e.g., sea aerosols, dimethulsulfide oxidation), the subglacial brines derived by relicts of seawater and/or lake/pond water influenced by microbial sulfate reduction could also be important sulfate endmembers particularly in the Antarctic lowland thaw zones. Additional field observations of frost, ponding water, and thin gypsum crusts on the terrestrial gypsum dunes at White Sands supports reactivity of gypsum on the surface of these dunes during cold winter conditions. Combined with our improved geochemical model of the sulfur cycle for cold Antarctic settings, we propose that transient liquid water or frost was available in near-surface environments at the time of gypsum formation in the north polar region on Mars. Ice and/or water interaction with basaltic sand of the basal unit (paleo-erg) would have enhanced leaching of sulfate from both sulfide oxidation and atmospheric deposition and resulted in formation of secondary gypsum salts.

Aerosol pattern changes over the dead sea from west to east - Using high-resolution satellite data

The area of the Dead Sea, a terminal lake on the border between Israel and Jordan, has gone through extensive environmental changes in recent decades, stemming from several processes including extreme evaporation and land degradation. Our study explored the distribution and the long-term high-resolution climatology of the Dead Sea aerosols, using satellite-retrieved Aerosol Optical Depth (AOD) measurements. We used the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm that provides AOD measurements at a 1 km resolution. MAIAC retrievals for the entire study period (2000–2016) have shown a very good agreement (r = 0.8) with the nearby AERONET station. For the first time, the AOD temporal distribution and its variability, on both Dead Sea coasts, were calculated on a monthly/seasonal basis. Three main aerosol pollution patterns (i.e. high-levels of AOD) emerged as follows: western focalized (75 and 59% of the months examined for Aqua and Terra, respectively), eastern focalized (14 and 24%), and similar levels of pollution on both coasts (11 and 17%, respectively). Using the Normalized AOD Difference (NAODD) metric, we studied how the AOD spatial patterns changed and when. Following the negative trends in most of the months, our analysis has demonstrated a shift towards unexplained increasing pollution levels over the Jordanian eastern side. For March–April, this shift had already occurred, and the potential reasons including changes in synoptic regimes are discussed. Local and global implications are of much regional interest because of the Dead Sea deterioration and the need for urgent environmental policy changes.

The Effect of Environmental Conditions on Pollution Deposition and Canopy Leaching in Two Pine Stands (West Pomerania and Świętokrzyskie Mountains, Poland)

This study analyzed the effect of atmospheric deposition on canopy leaching processes in stands predominantly composed of Scots pines. The research was conducted in two stands: the first located in the southwestern part of the Świętokrzyskie Mountains in the area known as Białe Zagłębie (Malik), and the second in the northwestern part of Poland in Western Pomerania (Czarne). The study was conducted in the hydrological years 2010–2013. The goal of the study was to assess the chemical transformation of precipitation as a result of various human activities. In Malik, the main factor that determined the physicochemical and chemical properties of throughfall was the cement/lime dust emitted by nearby industrial plants, which not only affected the quantity of deposit but also contributed to the alkalization process of throughfall. By contrast, the main source of pollution in Czarne, where local emitters are absent, was long-distance transport. We conducted a principal component analysis (PCA) in both stands that produced components representing local pollution (Malik) and long-distance transport (Czarne). For the stand in Czarne, sea aerosols were an important source of Na+ and Cl− ions in precipitation. In both stands, the highest enrichment ratio (ER) values were recorded for K+ ions. The contribution of leaching processes to the bulk deposition of K+ ions in Malik was 85.8%, whereas in Czarne, it was 73.8%. Regardless of the degree of anthropopressure, the intensity of quantitative and qualitative transformation in pine stands was comparable.

Hydrochemical composition of Holocene ice wedges near the town of Anadyr

The research is conducted on the Holocene ice wedges exposed in the outcrop of the first marine terrace near the town of Anadyr, on the east of the Chukchi Peninsula, on the coast of Onemen Bay. Polygonal Relief is clearly traced on the surface of the first sea terrace in the area of explorations, the size of the polygons is about 8x12 m. In the exposed terrace, turf with a capacity of about 1.5 m is striped, underlied with sand clay with  capacity up to 2 m; below is the horizontally-stratified and. Ice wedges are embedded the turf (head of wedges) and in the underlying clay sand. The ice of wedges is vertically stratifies, yellowish gray. Ice wedges are also striped in turf  outcrops with capacity of up to 2.5 m, embedded in form of a lens from the terrace surface. Ice from three most fully exposed ice wedges was sampled for hydrochemical analysis. A total of 20 ice samples were collected from Holocene ice wedges, as well as ice from modern ice veinlet and water from Onemen Bay. It was found that mineralization of the studied Holocene ice wedges is low, does not exceed 80 mg/L, Na+, Ca2+, and Cl- dominate. Similar values of mineralization and ionic composition were obtained for modern ice veinlet. The obtained data correspond with data on ice wedges studied in other regions of Chukotka, both continental and coastal. Mineralization of most of the previously studied ice wedges did not exceed 150 mg/L. Low values of mineralization of ice wedges near Anadyr demonstrate mainly meteoric source of water forming ice, i.e. winter precipitation, prevalence of sodium and chlorine indicates the capture of sea aerosols by precipitation or wind introduction of droplets from the water area of the Onemen Bay to the surface of the snow cover.

ГИДРОХИМИЧЕСКИЙ СОСТАВ И РЕДКОЗЕМЕЛЬНЫЕ ЭЛЕМЕНТЫ В ПОЛИГОНАЛЬНО-ЖИЛЬНЫХ ЛЬДАХ КЛЮЧЕВЫХ РАЙОНОВ КРИОЛИТОЗОНЫ КАРСКОГО РЕГИОНА

Актуальность исследования. Информация о составе, льдистости и геохимических особенностях мерзлых пород необходима при освоении нефтегазоконденсатных месторождений Ямала, Гыдана и Таймыра. Среди факторов, определяющих экологию тундровых ландшафтов криолитозоны, большое значение имеют подземные льды, в том числе полигонально-жильные, и последствия их вытаивания. Гидрохимический состав и содержание редкоземельных элементов в сингенетических жилах фиксируют информацию об источниках влаги и условиях, при которых происходило их формирование. Соотношение основных ионов и распределение редкоземельных элементов в растворе может быть использовано для оценки влияния на состав льда атмосферных осадков, морских и вулканических аэрозолей, антропогенного загрязнения. Цель: выявить источники поступления химических элементов и оценить влияние типа льдовыделения на гидрохимический состав и распределение редкоземельных элементов в различных генетических типах льда – полигонально-жильном, морском, озерном и фирновом льдах. Объекты: полигонально-жильный лед, вмещающие его отложения, сезонные льды, поверхностные воды, отобранные в экспедициях ИКЗ ТюмНЦ СО РАН в 2009–2014 гг. Методы исследования химического состава: масс-спектрометрия с индуктивно связанной плазмой, атомно-абсорбционная спектрометрия, эмиссионная фотометрия, хроматография. Результаты. Установлено, что на химический состав полигонально-жильных льдов, изученных в прибрежной зоне ключевых участков о. Белый, о. Сибирякова, Западного Ямала и Западного Таймыра, имели влияние морские и континентальные аэрозоли. Сингенетические полигонально-жильные льды, пресные и ультрапресные по минерализации, сформированы при промерзании талых вод, которые содержат сорбированные снегом морские аэрозоли – взвешенные в атмосфере твердые и жидкие частицы. Полигонально-жильные льды в удаленном от моря районе оз. Сохонто не имеют признаков морского влияния по соотношению основных ионов. Полигонально-жильные льды с минеральными включениями формировались не только за счет талых снеговых вод с аэрозолями континентального происхождения, но и за счет надмерзлотных вод. В полигонально-жильных льдах выявлено увеличение содержаний лантаноидов в водорастворимой форме по сравнению с кларковыми значениями и современными поверхностными льдами. По цериевой аномалии в большинстве изученных сингенетических ледяных жил подтверждается участие морских аэрозолей. По распределениям редкоземельных элементов выявлено характерное для полигонально-жильных льдов соотношение легких и тяжелых редкоземельных элементов равное 0,9, и соотношение лантана к остальным лантаноидам, равное 0,2. Морской лед наследует минерализацию и состав морской воды. Озерный лед различается по глубине и отражает сезонное изменение гидрохимического состава при ледоставе и повышение концентрации морских аэрозолей в снеге, перекрывающем озерный лед. Фирновый лед полярного Урала имеет очень низкую минерализацию, в нем отсутствуют примеси морского аэрозоля. В полигонально-жильных льдах голоценового и неоплейстоценового возраста реализован природный механизм накопления редкоземельных элементов в водорастворимой форме в комплексе с железом, торием и иттрием. Вытаивание ледяных жил может приводить к поступлению редкоземельных элементов в поверхностные воды.

СОДЕРЖАНИЕ РТУТИ В ЭПИФИТНЫХ ЛИШАЙНИКАХ НА ТЕРРИТОРИИ РЕСПУБЛИКИ КРЫМ

В продолжение биомониторинговых исследований ртути на территории Крымского полуострова, направленных на реализацию системного подхода к изучению ее распределения между компонентами биосферы и разработки региональных экологических нормативов этого и других металлов, проведено определение содержания ртути в эпифитных лишайниках, являющихся природными планшетами атмосферной эмиссии тяжелых металлов. Цель: определить и оценить содержание ртути в пробах эпифитных лишайников, отобранных в центральном, южном, юго-восточном и восточном регионах Крымского полуострова. Методы. Содержание ртути в лишайниках видов Xanthoria parietina, Evernia prunastri и Evernia mesomorpha определяли атомно-абсорбционным методом с использованием анализатора ртути с зеемановской коррекцией неселективного поглощения «РА-915М», пиролитической приставки «ПИРО-915+» и пакета программ RA915Р в МИНОЦ «Урановая геология» Томского политехнического университета, и методом масс-спектрометрии с индуктивно связанной плазмой в аккредитованном химико-аналитическом центре «Плазма» (г. Томск). Результаты. Содержание ртути в эпифитных лишайниках, отобранных преимущественно на заповедных территориях южного региона Крыма, а также в парковых зонах городов его центрального, юго-восточного и восточного регионов и вблизи очистных сооружений варьировало в пределах от 0,054 до 0,306 мкг/г и не отличалось от фоновых значений содержания ртути в лишайниках на других территориях Российской Федерации. В то же время наблюдалась существенная неоднородность в территориальном распределении ртути: в лишайниках парковых зон на территории городов ее содержание колебалось в пределах 0,063–0,088 мкг/г, а в горных и предгорных районах южного Крыма было выше в 2 раза. Это может быть связано с геоморфологическими и геохимическими особенностями Главной гряды (глубинные разломы ортогональной системы с ртутными рудопроявлениями и зонами геодинамической активности), а также ее барьерной функцией для воздушных масс, насыщенных морскими аэрозолями, содержащими ртуть. Помимо этого, как свидетельствуют данные моделирования экспертной группы Конвенции LRTAP, существенный вклад может вносить трансграничный перенос ртути. Вариабельность содержания ртути в лишайниках на условно фоновых территориях и интенсивное технологическое развитие Крыма диктуют необходимость дифференцированного подхода к оценке экологической ситуации в отношении этого глобального и опасного загрязнителя на различного типа территориях Крымского полуострова.

Effect of altitude and distance from the sea on fractionation processes of Persistent Organic Pollutants (POPs) associated to atmospheric aerosol from Ross Sea to Dome C, Antarctica

This paper deals with both the transport processes of several classes of organic pollutants in a large area of Victoria Land and Ross Sea (Antarctica) and the role played by marine aerosol which involves the exchange process between the sea surface and the atmosphere.The mechanisms of transfer process from the seawater to the atmosphere and aerosol of three major classes of pollutants (Polycyclic Aromatic Hydrocarbons, PAHs, Polychlorobiphenyls, PCBs, and Organochloride Pesticides, OCPs) were investigated in samples of snow and firn collected during several Italian Expeditions from 1996 to 2014 in a large area of Antarctica. The samples were gathered at different distances from the sea (Rennick Glacier and traverse GV7-Talos Dome-Dome C), at different altitudes (Mt. Melbourne) and at different depths (Evans Nevé). The strategic sampling spots allowed the study of the mechanisms involved in the transfer process that occurs from the seawater to the aerosol and the atmosphere and the consequent diffusion of these pollutants in the environment.Organic compounds linked to sea aerosol showed a fractionation depending on the altitude and on the distance from the sea in agreement with their volatility and affinity to aerosol particles. The results highlighted a decreasing trend of the concentration with the increase of the altitude.This behavior is significant for samples coming from the winter storm, when the very heavy sea produces a high quantity of marine aerosol, where the amount of PCBs, OCPs and PAHs reaches respectively a decrease of 50, 70 and 40% compared to the value found at the lowest altitude. A significant decrease of the concentration of the heavier PAHs and of DDT with the altitude was common in all the samples collected in Mount Melbourne, showing a differentiation in the transportation, and hence in the diffusion, of the analytes on the base of their molecular weight. The dependence of the pollutants on the distance from the sea showed an increase of the contaminant in proximity to the Ross Sea. The samples collected on Evans Nevé and GV7 showed a content of PAHs and DDT 1.5 and 3 times higher on superficial snow than the values found at greater depth. This seems to be connected to a significant flow increase of these pollutants in Antarctica in the last decades.

UTJECAJ ZMORCA NA ONEČIŠĆENOST ZRAKA NA SPLITSKOM PODRUČJU

U radu se istražuje utjecaj zmorca na koncentraciju NO2, SO2, PM2.5 i PM10 na
 splitskom području prema mjernim postajama Split-centar i Kaštel Sućurac. Za
 proučavanje su izdvojeni dani u kojima je obalna cirkulacija bila neporemećena.
 U izdvojenim danima polje tlaka zraka bilo je bezgradijentno. Posebno su istraženi
 čestina i brzina vjetra u takvim danima. Zmorac u Splitu ima SW smjer, a u Kaštel
 Sućurcu WSW i W. Koncentracije onečišćujućih tvari uspoređene su s brzinama
 vjetra. Najprisutnija onečišćujuća tvar je NO2. Najviše ga ima u večernjim i jutarnjim
 satima dok zmorac još nije razvio veću brzinu ili mu se brzina smanjuje
 približavanjem večernjeg zatišja. Što je brzina zmorca veća, koncentracija NO2 je
 manja. Nastupom zmorca povećava se koncentracija lebdećih čestica zbog turbulencije
 vjetra unutar grada te mogućeg donosa morskog aerosola i nusprodukata
 pomorskog prometa. NO2 dostiže veće vrijednosti u Splitu nego u Kaštel Sućurcu.
 Lebdeće čestice imaju veće koncentracije u Kaštel Sućurcu nego u Splitu. Vrijednosti
 svih onečišćujućih tvari ispod su graničnih vrijednosti za zdravlje ljudi.

Utjecaj zmorca na onečišćenost zraka na splitskom području

U radu se istražuje utjecaj zmorca na koncentraciju NO2, SO2, PM2.5 i PM10 na splitskom području prema mjernim postajama Split-centar i Kaštel Sućurac. Za proučavanje su izdvojeni dani u kojima je obalna cirkulacija bila neporemećena. U izdvojenim danima polje tlaka zraka bilo je bezgradijentno. Posebno su istraženi čestina i brzina vjetra u takvim danima. Zmorac u Splitu ima SW smjer, a u Kaštel Sućurcu WSW i W. Koncentracije onečišćujućih tvari uspoređene su s brzinama vjetra. Najprisutnija onečišćujuća tvar je NO2. Najviše ga ima u večernjim i jutarnjim satima dok zmorac još nije razvio veću brzinu ili mu se brzina smanjuje približavanjem večernjeg zatišja. Što je brzina zmorca veća, koncentracija NO2 je manja. Nastupom zmorca povećava se koncentracija lebdećih čestica zbog turbulencije vjetra unutar grada te mogućeg donosa morskog aerosola i nusprodukata pomorskog prometa. NO2 dostiže veće vrijednosti u Splitu nego u Kaštel Sućurcu. Lebdeće čestice imaju veće koncentracije u Kaštel Sućurcu nego u Splitu. Vrijednosti svih onečišćujućih tvari ispod su graničnih vrijednosti za zdravlje ljudi.

Environmental characteristics of a tundra river system in Svalbard. Part 2: Chemical stress factors

Bacterial communities in the Arctic environment are subject to multiple stress factors, including contaminants, although typically their concentrations are small. The Arctic contamination research has focused on persistent organic pollutants (POPs) because they are bioaccumulative, resistant to degradation and toxic for all organisms. Pollutants have entered the Arctic predominantly by atmospheric and oceanic long-range transport, and this was facilitated by their volatile or semi-volatile properties, while their chemical stability extended their lifetimes following emission. Chemicals present in the Arctic at detectable and quantifiable concentrations testify to their global impact. Chemical contamination may induce serious disorders in the integrity of polar ecosystems influencing the growth of bacterial communities. In this study, the abundance and the types of bacteria in the Arctic freshwater were examined and the microbial characteristics were compared to the amount of potentially harmful chemical compounds in particular elements of the Arctic catchment. The highest concentrations of all determined PAHs were observed in two samples in the vicinity of the estuary both in June and September 2016 and were 1964 ng L−1 (R12) and 3901 ng L−1 (R13) in June, and 2179 ng L−1 (R12) and 1349 ng L−1 (R13) in September. Remarkable concentrations of the sum of phenols and formaldehyde were detected also at the outflow of the Revelva river into the sea (R12) and were 0.24 mg L−1 in June and 0.35 mg L−1 in September 2016. The elevated concentrations of chemical compounds near the estuary suggest a potential impact of the water from the lower tributaries (including the glacier-fed stream measured at R13) or the sea currents and the sea aerosol as pollutant sources. The POPs' degradation at low temperature is not well understood but bacteria capable to degrading such compounds were noted in each sampling point.

Molecular composition and origin of water-soluble organic matter in marine aerosols in the Pacific off China

The atmospheric deposition of water-soluble organic carbon (WSOC) contributes to the open ocean dissolved organic carbon (DOC) reservoir similarly to riverine discharge. However, information on the sources and composition of water-soluble organic matter (WSOM) in marine aerosols remains scarce, particularly at the molecular level. By using ultra-high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), we identified approximately ten thousand molecular formulas in marine aerosols collected over the China coastal seas and the northwestern Pacific Ocean (NWPO). Even though their molecular compositions were highly variable (Bray-Curtis distance: 0.12–0.74), four distinctive origins, namely, marine biogenic sources, secondary organic aerosols (including CHO, CHON formulas derived from biogenic volatile organic compounds (VOCs) and organosulfate derived from both biogenic and anthropogenic VOCs), soil-derived organic matter (OM) and biomass and fossil fuel burning-derived polycyclic aromatics (including highly condensed organosulfur compounds) and unsaturated compounds, were discovered. Moreover, the different types of aerosols, including aerosols from the NWPO (marine-influenced), NWPO (dust) and China coastal seas, contained various proportions of organics from different sources. The NWPO (marine-influenced) aerosols were enriched with sea spray-derived OM, which was widely distributed and was likely related to marine biological activity. The NWPO (dust) aerosols exhibited a higher fraction of soil-derived OM, while the China coastal sea aerosols exhibited a much higher fraction of organosulfate than the other aerosols. Our investigation provided detailed molecular compositional and source information for marine aerosols over the northwestern Pacific Ocean, which can be utilized to understand the composition of WSOM deposited on the sea surface.

On the rubidium and lithium content and availability in the sub-arid south-eastern Mediterranean: potential health implications.

Rubidium and lithium are rather rare elements in environmental research, despite their affiliation with a group of chemically active metals and the abundance of Rb in the environment. A growing body of evidence, although controversial, has indicated that both elements possess unique essential and neurophysiological characteristics in biota and humans. Both elements may concentrate in soil and vegetation of sub-arid environments. We investigated the content and (potential) availability of Rb and Li in the soils and natural waters of Galilee, the Coastal Plain, and the northern Negev of Israel. A newly developed chromatographic technique for the separation of truly dissolved Rb and Li compounds has been applied. High concentrations of Rb, together with high values of the potentially vital Rb-to-K ratio, were found in the soils, the soil solutions, rainwater, throughfall water, and the plant litter leachates, but not in the surface and spring waters. This may indicate a sequestration of Rb in the local soils and a semi-closed Rb turnover in the soil-plant system with a major input from sea aerosols. Low Li bulk and available concentrations were determined in all the natural compartments. Possible implications of such specific environmental features on the local population health were discussed.