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1.
For the first time, continuous aerosol measurements were performed in the ?kocjan Caves, one of the most important cave systems in the world, and listed by UNESCO as a natural and cultural world heritage site since 1986. Measurements of PM10 were performed during three different periods: (1) in December 2011, the average background concentration was found to be about 4 μg m?3; (2) in June 2012, a higher concentration was measured (8 μg m?3); and (3) from 8 to 20 August 2012, the highest concentration of 15.3 μg m?3 was measured. Based on the PM10 measurement results, and as compared to similar measurements outside the cave, it can be hypothesized that the increase in the cave's aerosol concentration during the summer was connected to both the higher number of visitors and the polluted atmospheric air entering the cave upon entering of the cave system. Additional measurement of nanoparticles with scanning mobility particle sizer spectrometer (size between 14.1 and 710.5 nm) confirmed these findings; during the summer period, a severe raise in the total aerosol concentration of 30–50 times was found when groups of visitors entered the cave. Our results on nanoparticles demonstrated that we were able to detect very small changes and variations in aerosol concentration inside the cave. To our knowledge, these are the first results on nanoaerosol measurements in a cave, and we believe that such measurements may lead to the implementation of better protection of delicate cave systems.  相似文献   

2.
Aerosols from urbanized areas of the western United States and Nigeria, as well as from rural air basins with elevated vehicular traffic, contain extractable organic matter composed mainly of petroleum residues, with subordinate waxes from vascular plants and minor polynuclear aromatic hydrocarbons. Petroleum residues can be distinguished from the natural background by their unique compound distributions and molecular marker signatures. The predominant source of the atmospheric petroleum residues is from vehicular exhaust in the form of lubricants. A minor component of PAH is found in aerosols receiving an input of smoke from wood combustion. These anthropogenic constituents are a significant part of urban aerosols and their molecular signature may prove of utility as tracers for air parcels from particular geographic regions and as specific tags for vehicular (especially diesel) emissions.  相似文献   

3.
Higher plant waxes are the predominant natural components in the lipid fractions (> C15) of aerosols sampled over rural and oceanic regions. Hydrocarbon, fatty acid, ketone and fatty alcohol fractions of the lipids were characterized in terms of their contents of homologous compound series and specific biogenic molecular markers. Paniculate samples from the rural western United States have been analyzed and compared with samples from urban Los Angeles and remote areas over the Atlantic Ocean. The samples from rural sites contained predominantly vascular plant wax and lesser amounts of higher plant sterols and resin residues. Urban samples and, to varying degrees, some rural samples contained primarily higher weight residues of petroleum products. The loadings of hydrocarbons derived from higher plant waxes ranged approximately from 10 to 160 ng m−3 of air (for fatty acids, 10–100 ng m−3 and for fatty alcohols, 10–200 ng m−3). Higher molecular weight lipids (i.e. plant epicuticular wax, terpenes, etc.) from flora comprise a significant component of the organic carbon in rural aerosols. Primary biogenic residues are major components of aerosols in all areas and they are important components in the global cycling of organic carbon.  相似文献   

4.
Environmental Science and Pollution Research - The question of how Brazil, Russia, India, China, and South Africa (BRICS countries) can substantially dissipate environmental pollution (EVP) remains...  相似文献   

5.
In Burkina Faso where cooking with biomass is very common, little information exists regarding kitchen characteristics and their impact on air pollutant levels. The measurement of air pollutants such as respirable particulate matter (PM10), an important component of biomass smoke that has been linked to adverse health outcomes, can also pose challenges in terms of cost and the type of equipment needed. Carbon monoxide could potentially be a more economical and simpler measure of air pollution. The focus of this study was to first assess the association of kitchen characteristics with measured PM10 and CO levels and second, the relationship of PM10 with CO concentrations, across these different kitchen characteristics in households in Nouna, Burkina Faso. Twenty-four-hour concentrations of PM10 (area) were measured with portable monitors and CO (area and personal) estimated using color dosimeter tubes. Data on kitchen characteristics were collected through surveys. Most households used both wood and charcoal burned in three-stone and charcoal stoves. Mean outdoor kitchen PM10 levels were relatively high (774 μg/m3, 95 % CI 329–1,218 μg/m3), but lower than indoor concentrations (Satterthwaite t value, ?6.14; p?<?0.0001). In multivariable analyses, outdoor kitchens were negatively associated with PM10 (OR?=?0.06, 95 % CI 0.02–0.16, p value <0.0001) and CO (OR?=?0.03, 95 % CI 0.01–0.11, p value <0.0001) concentrations. Strong area PM10 and area CO correlations were found with indoor kitchens (Spearman’s r?=?0.82, p?<?0.0001), indoor stove use (Spearman’s r?=?0.82, p?<?0.0001), and the presence of a smoker in the household (Spearman’s r?=?0.83, p?<?0.0001). Weak correlations between area PM10 and personal CO levels were observed with three-stone (Spearman’s r?=?0.23, p?=?0.008) and improved stoves (Spearman’s r?=?0.34, p?=?0.003). This indicates that the extensive use of biomass fuels and multiple stove types for cooking still produce relatively high levels of exposure, even outdoors, suggesting that both fuel subsidies and stove improvement programs are likely necessary to address this problem. These findings also indicate that area CO color dosimeter tubes could be a useful measure of area PM10 concentrations when levels are influenced by strong emission sources or when used in indoors. The weaker correlation observed between area PM10 and personal CO levels suggests that area exposures are not as useful as proxies for personal exposures, which can vary widely from those recorded by stationary monitors.  相似文献   

6.
Air pollution is a thoroughly hybrid phenomenon. It is composed of inseparable physical, scientific, cultural, social, economic and political dimensions. It is both an object of environmental science and embedded in our everyday social and cultural worlds. Nevertheless, much air pollution scholarship focuses solely on the physical dimensions of air pollution which are expressed quantitatively and pays little or no regard to the identities, discourses, bodies and emotions which constitute and are constituted by air pollution as a physical reality. This article argues for a more reflexive and hybrid approach to air pollution research which bridges intellectually confining binaries. Drawing on the work of Bruno Latour and other actor–network theorists, it argues that if we can let go of a foundational nature, disrupt our humanism and take non-scientific knowledges seriously, we might develop a new respect for the atmospheric environment and begin the task of building a better common world.  相似文献   

7.
Interest in long time series of organic matter data has recently increased due to concerns about the effects of global climate change on aquatic ecosystems. This study presents and evaluates unique time series of chemical oxygen demand (COD) and water color from Lake Mälaren, Sweden, stretching almost seven decades (1935–2004). A negative linear trend was found in COD, but not in water color. The decrease was mainly due to installation of sewage works around 1970. Time series of COD and water color had cyclic pattern. It was strongest for COD, with 23 years periodicity. Similar periodicity observed in air temperature and precipitation in Sweden has been attributed to the North Atlantic Oscillation index and solar system orbit, suggesting that COD in Lake Mälaren is partly derived from algae. Discharge influenced water color more than COD, possibly because water color consists of colored substances brought into the lake from surrounding soils.  相似文献   

8.
PM2.5 (particulate matter with an aerodynamic diameter <2.5 μm) samples (n = 58) collected every sixth day in Xi’an, China, from 5 July 2008 to 27 June 2009 are analyzed for levoglucosan (1,6-anhydro-β-d-glucopyranose) to evaluate the impacts of biomass combustion on ambient concentrations. Twenty-four-hour levoglucosan concentrations displayed clear summer minima and winter maxima that ranged from 46 to 1889 ng m?3, with an average of 428 ± 399 ng m?3. Besides agricultural burning, biomass/biofuel combustion for household heating with straws and branches appears to be of regional importance during the heating season in northwestern China. Good correlations (0.70 < R < 0.91) were found between levoglucosan relative to water-soluble K+, Cl?, organic carbon (OC), elemental carbon (EC), and glyoxal. The highest levoglucosan/OC ratio of 2.3% was found in winter, followed by autumn (1.5%). Biomass burning contributed to 5.1–43.8% of OC (with an average of 17.6 ± 8.4%).

Implications:?PM2.5 levoglucosan concentrations and the correlation between levoglucosan relative to other compounds during four seasons in Xi’an showed that the influence of biomass burning is maximum during the residential heating season (winter), although some important influences may be detected in spring (field preparation burnings) and autumn (corn stalks and wheat straw burning, fallen dead leaves burning) at Xi’an and surrounding areas. Household heating with biomass during winter was quite widespread in Guanzhong Plain. Therefore, the control of biomass/biofuel combustion could be an effective method to reduce pollutant emission on a regional scale.  相似文献   

9.
A year-long study was conducted in Pinal County, AZ, to characterize coarse (2.5 – 10 μm aerodynamic diameter, AD) and fine (< 2.5 μm AD) particulate matter (PMc and PMf, respectively) to further understand spatial and temporal variations in ambient PM concentrations and composition in rural, arid environments. Measurements of PMc and PMf mass, ions, elements, and carbon concentrations at one-in-six day resolution were obtained at three sites within the region. Results from the summer of 2009 and specifically the local monsoon period are presented.

The summer monsoon season (July – September) and associated rain and/or high wind events, has historically had the largest number of PM10 NAAQS exceedances within a year. Rain events served to clean the atmosphere, decreasing PMc concentrations resulting in a more uniform spatial gradient among the sites. The monsoon period also is characterized by high wind events, increasing PMc mass concentrations, possibly due to increased local wind-driven soil erosion or transport. Two PM10 NAAQS exceedances at the urban monitoring site were explained by high wind events and can likely be excluded from PM10 compliance calculations as exceptional events. At the more rural Cowtown site, PM10 NAAQS exceedances were more frequent, likely due to the impact from local dust sources.

PM mass concentrations at the Cowtown site were typically higher than at the Pinal County Housing and Casa Grande sites. Crustal material was equal to 52-63% of the PMc mass concentration on average. High concentrations of phosphate and organic carbon found at the rural Cowtown were associated with local cattle feeding operations. A relatively high correlation between PMc and PMf (R2?=?0.63) indicated that the lower tail of the coarse particle fraction often impacts the fine particle fraction, increasing the PMf concentrations. Therefore, reductions in PMc sources will likely also reduce PMf concentrations, which also are near the value of the 24-hr PM2.5 NAAQS.

Implications: In the desert southwest, summer monsoons are often associated with above average PM10 (<10 μm AD) mass concentrations. Competing influences of monsoon rain and wind events showed that rain suppresses ambient concentrations while high wind increase them. In this region, the PMc fraction dominates PM10 and crustal sources contribute 52-63% to local PMc mass concentrations on average. Cattle feedlot emissions are also an important source and a unique chemical signature was identified for this source. Observations suggest monsoon wind events alone cannot explain PM10 NAAQS exceedances, thus requiring these values to remain in compliance calculations rather than being removed as exceptional wind events.  相似文献   

10.
Environmental Science and Pollution Research - This study examines the role of industrialization in the energy-growth-FDI nexus for the case of South Africa using data over the period 1970 to 2018....  相似文献   

11.
In urban area, management of stormwater leads to the accumulation of polluted sediments at the water-sediment interface of various aquatic ecosystems. In many cases, these sediments are colonised by dense populations of tubificid worms. However, the influence of tubificid worms on the fate of stormwater sediments has never been tackled. The aim of this study was to measure in sediment columns the influence of tubificid worms on sediment reworking, organic matter processing (O(2) uptake and release of NH(4)(+), NO(3)(-), PO(4)(3-), and dissolved organic carbon), release of hydrocarbons and heavy metals, and microbial characteristics. Results showed that tubificid worms increased the release of NH(4)(+), PO(4)(3-), and dissolved organic carbon by 2-, 4-, and 3-fold, respectively. O(2) uptake also increased by more than 35% due to tubificid activity. The increase in the percentages of active bacteria and hydrolytic activity in the presence of worms indicated that the higher sediment respiration was caused by the stimulation of microbial communities. A reduction of the number of sulphate-reducing bacteria in the uppermost layers of the sediment was attributed to the penetration of O(2) due to worm activity. These significant effects of tubificid worms were probably linked to the dense network of burrows, which enhanced the exchange surface between the water column and the sediment. No release of heavy metals and hydrocarbons to the water phase was detected in the sediment columns. Understanding the fate and effect of organic stormwater sediments in the natural environment requires the integration of the role of bioturbation in urban pollution studies.  相似文献   

12.
Inhalable particulate matter (PM10) concentrations were measured over 24-h intervals at six different urban sites in the city of Chillán from September 2001 to April 2003. Sampling locations were selected to represent central city, commercial, residential, and industrial portions of the city. Chemical composition of PM10 was performed to samples of 47 mm diameter Teflon membranes within the city of Chillán. The spatial and temporal variability of the chemical composition of PM10 was evaluated taking into account additional data from meteorology and further air pollutants. The majority of PM mass was comprised of carbon, nitrate, sulfate, ammonium, and crustal components but in different proportion on different days and at different sites. The chemical analyses showed that carbonaceous substances and crustal material were the most abundant component of PM10 during the winter and summer, respectively. The concentrations of PM10 were higher during the cold season than during the warm season. The PM10 concentrations were higher in the downtown area of the city of Chillán, where also the chemical composition was more variable due to urban traffic and other anthropogenic sources.  相似文献   

13.
Environmental Science and Pollution Research - The purpose of this research is to explore the connection of financial development, sustainable environmental-economic growth, and energy consumption...  相似文献   

14.
Intraguild predation interactions make fish communities prone to exhibit alternative stable states with either piscivore or prey fish dominance. In the Baltic Sea, local declines of coastal piscivores like perch (Perca fluviatilis) have been observed to coincide with high densities of sticklebacks (Gasterosteus aculeatus). Mechanisms behind this shift between piscivore and stickleback dominance were studied both experimentally and in field. Results showed that predation by sticklebacks has a strong negative effect on perch larvae survival, but this effect rapidly decreases with increasing perch size, likely due to gape limitations and digestion constraints in sticklebacks. Large spatial and temporal variations in patterns of stickleback migration into perch spawning sites were observed. Whether or not high density of sticklebacks will cause declines in coastal piscivore populations is suggested to depend on the availability of spawning sites in which sticklebacks do not migrate into or arrive late in the reproduction season of coastal piscivores.  相似文献   

15.
Water quality was measured at eight stations on the Buyuk Menderes River in Turkey (Ad?güzel dam, Yenice regülator, Sarayköy bridge, Feslek regülator, Yenipazar bridge, Ayd?n bridge, Koçarl? bridge, Söke regülator) between 2000 and 2013 in February, April, June, August, October and December. The resulting data were evaluated in terms of biochemical oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), ammoniac–nitrogen (NH3–N), nitrite–nitrogen (NO2–N), nitrate–nitrogen (NO3–N) and orthophosphate (o-PO4) aquaculture. According to the analysis, while river water pollution generally varied during each year, samples from certain measurement points demonstrated high pollution levels throughout the year. In this study, water parameters were classified according to the “Turkish water pollution control regulation.” The studied parameters are also compared with TS 266 and WHO guidelines. While levels at Sarayköy station were generally higher than other stations, values at Ad?güzel dam were the lowest, giving it the best water quality of the eight stations. The highest values on a yearly basis were obtained in 2007 due to the severe drought in the Menderes basin within which irrigation water levels fell to 4255 m3/ha. The BOD, COD levels are the lowest in 2009 and highest in 2007; the DO level is lowest in 2007 and highest in 2009; NH3–N, NO2–N, and NO3–N parameters are the lowest in 2007 and highest in 2009; and the o-PO4 are at the lowest level in 2004 and seen as the highest in 2007. Analysis of the data was performed by SPSS 21 statistics program. One direction ANOVA was applied to the data, which were also subject to Tukey multiple comparison tests. Differences between groups were evaluated at p?<?0.05. Box–plot graphs were used to demonstrate the data distribution. In the study, it was analyzed, the effect of fish species and pollution involved in the Büyük Menderes River so far on fish species.  相似文献   

16.
Fogwater and air samples were collected in Baton Rouge between November 2004–February 2005 and during February 2006 at Houston. Organic compounds present in the fog samples were detected, quantified and then grouped into different compound classes based on molecular size, solubility and polarity using gas chromatography/mass spectrometry, high performance liquid chromatography with diode array detection and ion chromatography. Organic compounds were grouped as n-alkanes, aromatics and polycyclic aromatics, carbonyls, alcohols, amides and esters. Organic compounds in fog and air samples in Houston indicated clear urban/industrial anthropogenic origin, while compounds detected in Baton Rouge fog and air samples showed a mix of both agricultural and urban/industrial anthropogenic inputs. Among the various polycyclic aromatic compounds detected, the total concentration of naphthalene and its derivatives was 2.8 μg m?3 in Houston and 0.08 μg m?3 in Baton Rouge air. Analysis of concentrations of organic compounds pre- and post- fog revealed that compounds with low vapor pressure had higher scavenging efficiency in fog sampled at the two locations. Concentrations of organic compounds in fog samples were higher than those predicted by conventional air-water Henry's law equilibrium. Observed higher concentrations in the aqueous phase were modeled accounting for surface adsorption and accumulation of gas phase species and the presence of humic-like substances in fogwater.  相似文献   

17.
Use of animal manure is a main source of veterinary pharmaceuticals (VPs) in soil and groundwater through a series of migration processes. The sorption–desorption and transport of four commonly used VPs including trimethoprim (TMP), sulfapyridine, sulfameter, and sulfadimethoxine were investigated in three soil layers taken from an agricultural field in Chongming Island China and two types of aqueous solution (0.01 M CaCl2 solution and wastewater treatment plant effluent). Results from sorption–desorption experiments showed that the sorption behavior of selected VPs conformed to the Freundlich isotherm equation. TMP exhibited higher distribution coefficients (K d?=?6.73–9.21) than other sulfonamides (K d?=?0.03–0.47), indicating a much stronger adsorption capacity of TMP. The percentage of desorption for TMP in a range of 8–12 % is not so high to be considered significant. Low pH (<pK a of tested VPs) and rich soil organic matter (e.g., 0–20 cm soil sample) had a positive impact on sorption of VPs. Slightly lower distribution coefficients were obtained for VPs in wastewater treatment plant (WWTP) effluent, which suggested that dissolved organic matter might affect their sorption behavior. Column studies indicated that the transport of VPs in the soil column was mainly influenced by sorption capacity. The weakly adsorbed sulfonamides had a high recovery rate (63.6–98.0 %) in the leachate, while the recovery rate of TMP was only 4.2–10.4 %. The sulfonamides and TMP exhibited stronger retaining capacity in 20–80 cm and 0–20 cm soil samples, respectively. The transport of VPs was slightly higher in the columns leached by WWTP effluent than by CaCl2 solution (0.01 M) due to their sorption interactions.  相似文献   

18.
The purpose of this study was to investigate ozone, variations, and its correlation with meteorological parameters at a remote location on the Mali Lo?inj Island, which has been a tourist and health resort area in the northern Adriatic. The measured data are discussed in relation to the EU guidelines (Directive 2002/3/EC; Directive 2008/50/EC). In order to characterize ambient air with respect to ozone vegetation injury and photochemical pollution, we calculated accumulated dose over a threshold of 40 parts per billion index and two photochemical pollution indicators. The influence of local meteorological parameters on the measured ozone volume fractions was also investigated. We used the multivariate technique principal component analysis to trace correlations between measured ozone concentration and meteorological parameters.  相似文献   

19.
Daily particle samples were collected in Chillán, Chile, at six urban locations from September 1, 2001, through September 30, 2003. Aerosol samples were collected using monitors equipped with a Sierra Andersen 246-b cyclone inlet on Teflon filters. Average concentrations of coarse particulate matter (PM10) for the 2001-2003 period ranged from 43.4 microg/m3 to 81.8 microg/m3 across the six sites. Annual PM10 concentration levels exceeded the European Union concentration limits. Mean PM10 levels during the cold season (April through September) were more than twice as high as those observed in the warm season (October through March). Average contributions to PM10 from organic matter, soil dust, nitrate (NO3-), elemental carbon, ammonium (NH4+), and sulfate (SO4(2-)) were 31%, 27%, 11%, 8%, 7%, and 5%, respectively. The chemical analyses indicated that carbonaceous substances were the most abundant components of PM10 in cold months, whereas crustal material was the most abundant component of PM10 during warm months. Higher concentration levels were observed in the downtown area suggesting a clear anthropogenic origin, whereas in the rural sites the source was mainly natural, such as resuspended soil dust associated with traffic on unpaved roads and agricultural activities.  相似文献   

20.
The influence of pH (6.0-9.0), natural organic matter (NOM) (0-10 mg C/L) and ionic strength (IS) (1.7-40 mM) on 14 nm CeO2 NP aggregation and ecotoxicity towards the alga Pseudokirchneriella subcapitata was assessed following a central composite design. Mean NP aggregate sizes ranged between 200 and 10000 nm. Increasing pH and IS enhanced aggregation, while increasing NOM decreased mean aggregate sizes. The 48 h-ErC20s ranged between 4.7 and 395.8 mg CeO2/L. An equation for predicting the 48 h-ErC20 (48 h-ErC20 = −1626.4 × (pH) + 109.45 × (pH)2 + 116.49 × ([NOM]) − 14.317 × (pH) × ([NOM]) + 6007.2) was developed. In a validation study with natural waters the predicted 48 h-ErC20 was a factor 1.08-2.57 lower compared to the experimental values.  相似文献   

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