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1.
Lammel G Klöpffer W Semeena VS Schmidt E Leip A 《Environmental science and pollution research international》2007,14(3):153-165
Background, Aim and Scope Modelling of the fate of environmental chemicals can be done by relatively simple multi-media box models or using complex
atmospheric transport models. It was the aim of this work to compare the results obtained for both types of models using a
small set of non-ionic and non-polar or moderately polar organic chemicals, known to be distributed over long distances.
Materials and Methods Predictions of multimedia exposure models of different types, namely three multimedia mass-balance box models (MBMs), two
in the steady state and one in the non-steady state mode, and one non-steady state multicompartment chemistry-atmospheric
transport model (MCTM), are compared for the first time. The models used are SimpleBox, Chemrange, the MPI-MBM and the MPI-MCTM.
The target parameters addressed are compartmental distributions (i.e. mass fractions in the compartments), overall environmental
residence time (i.e. overall persistence and eventually including other final sinks, such as loss to the deep sea) and a measure
for the long-range transport potential. These are derived for atrazine, benz-[a]-pyrene, DDT, α and γ-hexachlorocyclohexane,
methyl parathion and various modes of substance entry into the model world.
Results and Discussion Compartmental distributions in steady state were compared. Steady state needed 2–10 years to be established in the MCTM. The
highest fraction of the substances in air is predicted by the MCTM. Accordingly, the other models predict longer substance
persistence in most cases. The results suggest that temperature affects the compartmental distribution more in the box models,
while it is only one among many climate factors acting in the transport model. The representation of final sinks in the models,
e.g. burial in the sediment, is key for model-based compartmental distribution and persistence predictions. There is a tendency
of MBMs to overestimate substance sinks in air and to underestimate atmospheric transport velocity as a consequence of the
neglection of the temporal and spatial variabilities of these parameters. Therefore, the long-range transport potential in
air derived from MCTM simulations exceeds the one from Chemrange in most cases and least for substances which undergo slow
degradation in air.
Conclusions and Perspectives MBMs should be improved such as to ascertain that the significance of the atmosphere for the multicompartmental cycling is
not systematically underestimated. Both types of models should be improved such as to cover degradation in air in the particle-bound
state and transport via ocean currents. A detailed understanding of the deviations observed in this work and elsewhere should
be gained and multimedia fate box models could then be ‘tuned in’ to match better the results of comprehensive multicompartmental
transport models.
ESS-Submission Editor: Prof. Dr. Michael Matthies (matthies@uos.de) 相似文献
2.
QSAR approach to POPs screening for atmospheric persistence 总被引:1,自引:0,他引:1
3.
Ana Cvitei Kuan Ana Krofli Irena Grgi Irena Cigleneki Sanja Frka 《Environmental science and pollution research international》2020,27(10):10249-10264
Fine particulate matter (PM2.5) concentrations at the Middle Adriatic coastal site of Croatia were affected by different air-mass inflows and/or local sources and meteorological conditions, and peaked in summer. More polluted continental air-mass inflows mostly affected the area in the winter period, while southern marine pathways had higher impact in spring and summer. Chemical characterization of the water-soluble inorganic and organic ionic constituents is discussed with respect to seasonal trends, possible sources, and air-mass inputs. The largest contributors to the PM2.5 mass were sea salts modified by the presence of secondary sulfate-rich aerosols indicated also by principal component analysis. SO42− was the prevailing anion, while the anthropogenic SO42− (anth-nssSO42−) dominantly constituted the major non-sea-salt SO42− (nssSO42−) fraction. Being influenced by the marine origin, its biogenic fraction (bio-nssSO42−) increased particularly in the spring. During the investigated period, aerosols were generally acidic. High Cl− deficit was observed at Middle Adriatic location for which the acid displacement is primarily responsible. With nssSO42− being dominant in Cl− depletion, sulfur-containing species from anthropogenic pollution emissions may have profound impact on atmospheric composition through altering chlorine chemistry in this region. However, when accounting for the neutralization of H2SO4 by NH3, the potential of HNO3 and organic acids to considerably influence Cl− depletion is shown to increase. Intensive open-fire events substantially increased the PM2.5 concentrations and changed the water-soluble ion composition and aerosol acidity in summer of 2015. To our knowledge, this work presents the first time-resolved data evaluating the seasonal composition of water-soluble ions and their possible sources in PM2.5 at the Middle Adriatic area. This study contributes towards a better understanding of atmospheric composition in the coastal Adriatic area and serves as a basis for the comparison with future studies related to the air quality at the coastal Adriatic and/or Mediterranean regions. 相似文献
4.
Observation based analysis for the determination of equilibrium time constant between ammonia, acid gases, and fine particles 总被引:2,自引:0,他引:2
《国际环境与污染杂志》2011,23(3):239-247
Experimental measurements of ammonia, acid gases, and the inorganic components of atmospheric aerosols were made at a commercial hog farm in eastern North Carolina from May 1998 to June 1999 by an annular denuder system (ADS). The ADS consisted of a cyclone separator, one diffusion denuder coated with sodium carbonate, another diffusion denuder with citric acid, and a filter pack containing Teflon and nylon filters in series. The equilibrium time constant for transfer between ammonia, acid gases, and aerosol phase of ammonium nitrate and ammonium chloride was determined based on kinetic rate constants (kN as the rate constant of ammonium nitrate aerosol: 2.04 × 10-4 m³/µmole/sec; kCl as the rate constant of ammonium chloride aerosol: 3.44 × 10-4 m³/µmole/sec) and the observed inorganic components of atmospheric aerosols. The equilibrium time constant was determined based on kinetic rate constants and the observed inorganic components of atmospheric aerosols. The equilibrium time constant has a wide range of values, with an average value of 15.26 (±10.94) minutes for ambient equilibrium time between ammonia, nitric acid gas and ammonium nitrate aerosol; and 8.22 (±6.81) minutes for ammonia, hydrochloric acid, and ammonium chloride. Significant correlations were determined between comparisons of equilibrium time constant estimates with meteorological parameters, such as ambient temperature and relative humidity. The predicted chemical compositions in the particle by EQUISOLV II Model are in good agreement with the observed chemical composition at the experimental site. 相似文献
5.
María Pilar Martín Porrero Maria Paz Gallego-Iniesta García Jose Luis Espinosa Ruiz Araceli Tapia Valle Beatriz Cabañas Galán Maria Sagrario Salgado Muñoz 《Environmental science and pollution research international》2010,17(3):539-546
Background, aim, and scope
Acrylate and methacrylate esters are α,β-unsaturated esters that contain vinyl groups directly attached to the carbonyl carbon (CH2=CHCOO– and CH2=CCH3COO–, respectively) and are widely used in the polymer plastic and resin production. Rate coefficients for Cl reactions for most of the unsaturated esters have not been previously determined, and a good understanding is needed of all the atmospheric oxidation processes of these compounds in order to determine lifetimes in the atmosphere and to evaluate the impact of these reactions on the formation of photo-oxidants and therefore on health and environment. 相似文献6.
María B. Blanco Iustinian Bejan Ian Barnes Peter Wiesen Mariano A. Teruel 《Environmental science and pollution research international》2009,16(6):641-648
Background, aim, and scope
Unsaturated esters are emitted to the atmosphere from biogenic and anthropogenic sources, including those from the polymer industry. Little information exists concerning the atmospheric degradation of unsaturated esters, which are mainly initiated by OH radicals. Limited information is available on the degradation of alkenes by Cl atoms and almost no data exists for the reactions of unsaturated esters with Cl atoms. This data is necessary to assess the impact of such reactions in maritime environments where, under circumstances, OH radical- and Cl atom-initiated oxidation of the compounds can be important. Rate coefficients for the reactions of chlorine atoms with vinyl acetate, allyl acetate, and n-butyl acrylate have been determined at 298 ± 3 K and atmospheric pressure. The kinetic data have been used in combination with that for structurally similar compounds to infer the kinetic contributions from the possible reaction channels to the overall reaction rate. 相似文献7.
Ryunosuke Kikuchi Tamara T. Gorbacheva 《Environmental science and pollution research international》2009,16(4):431-438
Background, aim, and scope The Arctic holds large stores of minerals, and extracted materials are provided to the world’s economy; in this sense, the
Arctic issue associated with mining is not local but global. In a part of the Arctic region (the Kola Peninsula, 66–70° N
and 28–41° E), metal levels are generally elevated in the lake sediment. There is a question as to what results in elevated
metal levels—a natural process (naturally abundant minerals) or an anthropogenic process (mining and metallurgy). In terms
of solving this question, Staroe lake located on the Kola Peninsula was researched as a case study.
Materials and methods The following parameters were determined in relation with Staroe lake: (1) the current quality of the lake’s water—each 1,000-ml
sample was collected at a surface point and a deep point (near the bottom layer), and the collected samples were directly
analyzed after filtration; (2) atmospheric bulk deposition—bulk deposition was collected using a set of three rainwater samplers
near the lake. In addition, bulk deposition was collected in a background site (250 km to the southwest of the smelter complex)
as a reference; and (3) sediment profile (plus principal component analysis)—lake-bottom sediment was collected by an open-gravimetric
column sampler equipped with an automatic diaphragm. After collection, the sample columns were cut at a 1-cm interval for
analysis. Eigenvalues and variances by factor were calculated from the correlation coefficients.
Results The obtained data show that (1) naturally poor elements (Cu, Ni, Si, and SO4
2−) dominantly influence the lake’s water quality; (2) they are transported from the anthropogenic sources to the study lake
through the atmospheric pathway; (3) mainly the contents of Cu, Ni, Sr, and Ca have influenced the sediment quality since
the 1950s, corresponding to the industrial movement; and (4) Cu, Ni, and Sr originate from an anthropogenic source (smelter),
and Ca originates from both natural and anthropogenic sources.
Discussion As compared with the Russian standard (San Pin 2.1.980–00), the contents of NO3
− (50.3 ± 0.1 mg l−1) and particulates (2.3 ± 0.2 mg l−1) exceeded the standard levels (0.7 mg l−1 NO3
− and 45 mg l−1 particulates); Staroe lake may be slightly contaminated. However, the contamination factor (comparison with the background
data) implies that Staroe lake is considerably contaminated. There is a strong possibility that fine overburden detritus (<0.1 mm
diameter) may be transported from an open pit to the study lake by natural forces such as wind. Although it is difficult to
suppose that one factor dominantly affects the sediment quality, it follows from a factor analysis that factors 1 and 2 account
for about 70% of the total variance: Factor 1 is the most dominant, and factor 2 is the second most dominant in the variability
of sediment quality. It is considered that Cu, Sr, and Ni in factor 1 originate from anthropogenic sources because they are
poor in sediment rocks.
Conclusions The field survey conducted in Staroe lake can give the following answers to the key objectives: (1) The present water quality
is affected by Cu, Ni, Si, and SO4
2− in light of the contamination factor, and these elements originate from anthropogenic sources (the smelter and the open pit)
and are transported to the lake through the atmospheric pathway; (2) the sediment profile and statistic analysis show that
the lake quality has been influenced by deposition of metals since the 1950s; and (3) Cu, Ni, Sr, and Ca have influenced the
sediment quality in light of the most dominant factor—Cu, Ni, and Sr originate from an anthropogenic source, whereas Ca comes
from both natural and anthropogenic sources.
Recommendations and perspectives The presented lake survey shows that the dispersion of human-related pollutants via the atmospheric pathway takes place in
the Arctic region. If the current pollution continues without countermeasures, the high-latitude environment may lose its
original characteristics; hence, this subject is important when considering how to implement a wide range of environmental
protection measures in the Arctic. 相似文献
8.
Salgado MS Gallego-Iniesta MP Martín MP Tapia A Cabañas B 《Environmental science and pollution research international》2011,18(6):940-948
Background, aim, and scope
Methacrylates are α, β-unsaturated esters that are widely used in the polymer plastics and resins production. Kinetic information of NO3 radical reactions is especially scarce and a good understanding of all the atmospheric oxidation processes of these compounds is necessary in order to determine lifetimes in the atmosphere and to evaluate the impact of these reactions on the formation of ozone and other photooxidants. 相似文献9.
Atmospheric fall-out of metals around the Murano glass-making district (Venice,Italy) 总被引:1,自引:0,他引:1
Paolo Rossini Gabriele Matteucci Stefano Guerzoni 《Environmental science and pollution research international》2010,17(1):40-48
Background, aim and scope
Murano’s glass-makers have held a monopoly on quality glass-making for centuries known all over the world. Artistic glass manufacture entails exposure to complex mixtures of pollutants, including metals. A few studies have reported high levels of trace elements in marine waters, sediments and mussels around Murano and shown that emissions from Murano glass-making workshops significantly influence air quality in the Venice area. Nevertheless, to date, there is very little information on atmospheric concentrations and virtually none on atmospheric deposition fluxes of trace elements around the island. This study presents data on the distribution of trace elements in the air and atmospheric depositions around Murano, based on a 2-year sampling period. 相似文献10.
Díaz-de-Mera Y Aranda A Bravo I Rodríguez D Rodríguez A Moreno E 《Environmental science and pollution research international》2008,15(7):584-591
Background, aim, and scope The adverse environmental impacts of chlorinated hydrocarbons on the Earth’s ozone layer have focused attention on the effort
to replace these compounds by nonchlorinated substitutes with environmental acceptability. Hydrofluoroethers (HFEs) and fluorinated
alcohols are currently being introduced in many applications for this purpose. Nevertheless, the presence of a great number
of C–F bonds drives to atmospheric long-lived compounds with infrared absorption features. Thus, it is necessary to improve
our knowledge about lifetimes and global warming potentials (GWP) for these compounds in order to get a complete evaluation
of their environmental impact. Tropospheric degradation is expected to be initiated mainly by OH reactions in the gas phase.
Nevertheless, Cl atoms reaction may also be important since rate constants are generally larger than those of OH. In the present
work, we report the results obtained in the study of the reactions of Cl radicals with HFE-7000 (CF3CF2CF2OCH3) (1) and its isomer CF3CF2CF2CH2OH (2).
Materials and methods Kinetic rate coefficients with Cl atoms have been measured using the discharge flow tube–mass spectrometric technique at 1 Torr
of total pressure. The reactions of these chlorofluorocarbons (CFCs) substitutes have been studied under pseudo-first-order
kinetic conditions in excess of the fluorinated compounds over Cl atoms. The temperature ranges were 266–333 and 298–353 K
for reactions of HFE-7000 and CF3CF2CF2CH2OH, respectively.
Results The measured room temperature rate constants were k(Cl+CF3CF2CF2OCH3) = (1.24 ± 0.28) × 10−13 cm3 molecule−1 s−1and k(Cl+CF3CF2CF2CH2OH) = (8.35 ± 1.63) × 10−13 cm3 molecule−1 s−1 (errors are 2σ + 10% to cover systematic errors). The Arrhenius expression for reaction 1 was k
1(266–333 K) = (6.1 ± 3.8) × 10−13exp[−(445 ± 186)/T] cm3 molecule−1 s−1 and k
2(298–353 K) = (1.9 ± 0.7) × 10−12exp[−(244 ± 125)/T] cm3 molecule−1 s−1 (errors are 2σ). The reactions are reported to proceed through the abstraction of an H atom to form HCl and the corresponding halo-alkyl
radical. At 298 K and 1 Torr, yields on HCl of 0.95 ± 0.38 and 0.97 ± 0.16 (errors are 2σ) were obtained for CF3CF2CF2OCH3 and CF3CF2CF2CH2OH, respectively.
Discussion The obtained kinetic rate constants are related to the previous data in the literature, showing a good agreement taking into
account the error limits. Comparing the obtained results at room temperature, k
1 and k
2, HFE-7000 is significantly less reactive than its isomer C3F7CH2OH. A similar behavior has been reported for the reactions of other fluorinated alcohols and their isomeric fluorinated ethers
with Cl atoms. Literature data, together with the results reported in this work, show that, for both fluorinated ethers and
alcohols, the kinetic rate constant may be considered as not dependent on the number of –CF2– in the perfluorinated chain. This result may be useful since it is possible to obtain the required physicochemical properties
for a given application by changing the number of –CF2– without changes in the atmospheric reactivity. Furthermore, lifetimes estimations for these CFCs substitutes are calculated
and discussed. The average estimated Cl lifetimes are 256 and 38 years for HFE-7000 and C3H7CH2OH, respectively.
Conclusions The studied CFCs’ substitutes are relatively short-lived and OH reaction constitutes their main reactive sink. The average
contribution of Cl reactions to global lifetime is about 2% in both cases. Nevertheless, under local conditions as in the
marine boundary layer, τ
Cl values as low as 2.5 and 0.4 years for HFE-7000 and C3H7CH2OH, respectively, are expected, showing that the contribution of Cl to the atmospheric degradation of these CFCs substitutes
under such conditions may constitute a relevant sink. In the case of CF3CF2CF2OCH3, significant activation energy has been measured, thus the use of kinetic rate coefficient only at room temperature would
result in underestimations of lifetimes and GWPs.
Recommendations and perspectives The results obtained in this work may be helpful within the database used in the modeling studies of coastal areas. The knowledge
of the atmospheric behavior and the structure–reactivity relationship discussed in this work may also contribute to the development
of new environmentally acceptable chemicals. New volatile materials susceptible of emission to the troposphere should be subject
to the study of their reactions with OH and Cl in the range of temperature of the troposphere. The knowledge of the temperature
dependence of the kinetic rate constants, as it is now reported for the case of reactions 1 and 2, will allow more accurate
lifetimes and related magnitudes like GWPs. Nevertheless, a better knowledge of the vertical Cl tropospheric distribution
is still required. 相似文献
11.
Hartmut Frank Harald Scholl Dirk Renschen Benoît Rether Abdelkrim Laouedj Yrjö Norokorpi 《Environmental science and pollution research international》1994,1(1):4-14
Haloacetic acids are atmospheric oxidation products of airborne C2-halocarbons which are important solvents and propellants. Levels of trichloroacetate (TCA) in conifer needles from mountain
ranges in Germany (Black Forest, Erzgebirge) and from two sites in Finland are compared; TCA is present in conifer needles
at concentrations up to 0.7 μmol/kg, MCA up to 0.2 μmol/kg. At the Finnish sites, TCA-concentrations and branch degeneration
symptoms of Scots pine are correlated. Monochloroacetate (MCA) has been determined in needle samples from Southern Germany
in concentrations exceeding its phytotoxicity threshold towards photoautotrophic organisms. Data on atmospheric chloroacetate
levels in Germany are also given; ambient air levels of chloroacetic acids range from about 2 pmol/m3 (TCA) to 390 pmol/m3 (MCA). TCA and dichloroacetic acid (DCA) arise from atmospheric oxidation of airborne C2-chlorocarbons, while the source of MCA is not yet known; several tentative pathways are suggested. 相似文献
12.
Results of research into climate and glacier dynamics in the Altai Mountains (Russia) over the period of instrumental observations
(1952–2008) are presented in this article. About 1030 glaciers with a total area of 805 km2 and volume of 42.5 km3 have been recorded in the Altai Region. The average summer air temperature in different regions of the Altai has increased
during the study period from about 0.2°C (Aktru) to 1.1°C (Akkem). The annual atmospheric precipitation rate has also increased,
by 8–10%. Since 1952, the glacier area in different regions of the Altai has decreased by 9–27%, and volume by 12–24%. By
2008, as a result of degradation, the total number of glaciers was 953 with an area of 724 km2 and volume of 38 km3. 相似文献
13.
Ozone measurements along vertical transects in the Alps 总被引:1,自引:1,他引:0
Herbert Werner Manfred Kirchner Gerhard Welzl Markus Hangartner 《Environmental science and pollution research international》1999,6(2):83-87
To investigate the vertical profiles of air pollutants in the boundary layer, aircraft and balloon-born measurements and measurements
using a cable car as an instrument platform have been performed in different parts of the Alps. This on-line monitoring of
atmospheric pollutants requires expensive and sophisticated techniques. In order to control ambient air quality in remote
regions, where no infrastructure like power supply is available, simple instruments are required. The objective of this study,
which was coordinated and evaluated by the GSF-Forschungszentrum für Umwelt und Gesundheit was first, to investigate the vertical
distribution of ozone in different parts of the Alps and secondly, in addition to continuous analyser measurements, to test
monitoring by means of two types of passive samplers. The selection of these samplers — one for one week use and another one
for two week application — was based on a passive sampler intercomparison done in a preliminary study one year earlier. 相似文献
14.
Minero C Maurino V Pelizzetti E Vione D 《Environmental science and pollution research international》2007,14(4):241-243
Based on available literature data of [NO2
−], steady-state [·OH], and ·OH generation rate upon nitrate photolysis in environmental aqueous samples under sunlight, the
steady-state [·NO2], could be calculated. Interestingly, one to two orders of magnitude more ·NO2 would be formed in photochemical processes in atmospheric water droplets compared to transfer from the gas phase. The relative
importance of nitrite oxidation compared to nitrate photolysis as an ·NO2 source would be higher in atmospheric than in surface waters. The calculated levels of ·NO2 could lead to substantial transformation of phenol into nitrophenols in both atmospheric and surface waters. 相似文献
15.
Soil and atmospheric concentrations, dry deposition and soil-air gas exchange of organochlorine pesticides (OCPs) were investigated at an industrial site in Aliaga, Izmir, Turkey. Current-use pesticides, endosulfan and chlorpyrifos, had the highest atmospheric levels in summer and winter. Summertime total (gas + particle) OCP concentrations in air were higher, probably due to increased volatilization at higher temperatures and seasonal local/regional applications of current-use pesticides. Particle deposition fluxes were generally higher in summer than in winter. Overall average dry particle deposition velocity for all the OCPs was 4.9 ± 4.1 cm s−1 (average ± SD). ΣDDXs (sum of p,p′-DDT, p,p′-DDD, and p,p′-DDE) were the most abundant OCPs in Aliaga soils (n = 48), probably due to their heavy historical use and persistence. Calculated fugacity ratios and average net gas fluxes across the soil-air interface indicated volatilization for α-CHL, γ-CHL, heptachlorepoxide, cis-nonachlor, trans-nonachlor, and p,p′-DDT in summer, and for α-CHL, γ-CHL, trans-nonachlor, endosulfan sulfate, and p,p′-DDT in winter. For the remaining OCPs, soil acted as a sink during both seasons. Comparison of the determined fluxes showed that dry particle, gas-phase, and wet deposition are significant OCP input mechanisms to the soil in the study area. 相似文献
16.
Günther Umlauf Michael McLachlan 《Environmental science and pollution research international》1994,1(4):209-222
The accumulation of atmospheric HCB, Lindane, DDT, DDE and the PCB congeners 52, 101, 138, 153 and 180 in spruce needles (Picea abies) was investigated at outdoor locations and in greenhouses supplied with ambient air. The air supply of the greenhouses was
modified to dinstinguish between gaseous and particle-associated deposition of the compounds. Accumulation of the compounds
occurred in all spruce except those grown in the greenhouse where the gaseous concentration of the compounds was reduced.
Spruce grown in the greenhouse supplied with particle-free ambient air behaved similarity to those grown outdoors. Protecting
the spruce located outdoors from rain did not affect the accumulation. The results show that under spring and summer conditions
at a typical central European rural environment dry gaseous deposition is the dominant pathway of these compounds to needles.
For Part I “Calculation of Dry and Wet Fluxes” see issue 3, pp. 146–150. 相似文献
17.
Daniel Grosjean 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1397-140
Using structure-reactivity relationships between reaction rate constants and ionlzatlon potentials for structural homologues, estimates are presented for the rate constants of the reactions of ozone, the hydroxyl radical, and the nitrate radical with forty toxic air contaminants for which no or little data are available. These rate constants are in turn used to estimate the atmospheric persistence of saturated allphatics, unsaturated allphatics, and aromatic toxic organics. The corresponding atmospheric half-lives for removal by chemical reactions range from a few hours for the most reactive toxics (chloroprene, hexachlorocyclo-pentadiene, cresols, nitrosamines, maleic anhydride) to several months for the least reactive compounds (nitrobenzene, methyl bromide, phosgene). 相似文献
18.
R. Herterich 《Umweltwissenschaften und Schadstoff-Forschung》1991,3(4):196-200
Am Beispiel des Wirkstoffes Atrazin wird die atmosph?rische Verbreitung und der atmosph?rische Eintrag von Pflanzenschutzmitteln
mit einer geringen Flüchtigkeit aufgezeigt. Immissions-Konzentrationen lagen zwischen weniger als 0.005 ng·m−3 und maximal 0.32 ng·m−3 Atrazin wird fast ausschlie?lich in der Partikelphase, offensichtlich im Ungleichgewicht mit der Gasphase, verfrachtet. Dies
verz?gert wahrscheinlich den photochemischen Abbau in der Atmosph?re. Die Konzentrationen im Flüssigwasser aufliegender Wolken
erreichten zu den Applikationsterminen nahezu 1.6 μg·1−1. Die Eintr?ge über die Atmosph?re betrugen in exponierter Lage im Fichtelgebirge mit 0.13 mg·m−2·a−1 ca. 0.4% der Aufwandmengen in 3j?hrigen Maisfruchtfolgen. Im Alpenraum wurden mit 0.012 mg·m−2·a−1 deutlich niedrigere Frachten gemessen als im Fichtelgebirge.Das Umweltrisiko durch die atmosph?rische Verbreitung und Deposition von Atrazin und anderen Pflanzenschutzmitteln mit vergleichbaren
physikalisch-chemischen Eigenschaften ist als ?u?erst gering einzustufen.
Atmospheric occurrence and deposition of atrazine are measured. During the application of atrazine, highest concentrations
reached 1.6 μg·1−1 in liquid water of lowlying clouds touching mountain tops. Atmospheric deposition, however, hardly amounts to 0.4% of the
flux on crop land by direct spraying. Airborne concentrations ranged from less than 0.005 ng·m−3 to 0.32 ng·m−3. Contrary to theoretical expectations, almost all atrazine was found in the particulate matter, indicating nonequilibrium
with the gas phase. This may inhibit a rapid photochemical decomposition. Human health concerns and environmental risks due
to the atmospheric occurrence and deposition of atrazine are judged as minor. This conclusion can be applied to many other,
physicochemically related pesticides. 相似文献
19.
20.
M. Mojašević C.S. Helling T. J. Gish M. A. Doherty 《Journal of environmental science and health. Part. B》2013,48(3):469-476
Abstract Pesticides are often applied in combination, but less‐often is soil persistence measured this way. The present field and laboratory study determined relative persistence of five herbicides and two insecticides, co‐applied, as a function of three soil water contents. Losses were modeled adequately by first‐order dissipation, with no significant improvement by using a two‐compartment model. The order of persistence in a silt loam, at 25% moisture, was carbofuran < cyanazine < metribuzin = alachlor < atrazine < ethoprop < metolachlor (t½ ranged from 7–91 days). Carbofuran degradation increased greatly from 12–25% soil moisture; atrazine was unaffected by 12–35%, whereas the remaining compounds showed limited increasing loss in wetter soil. Field‐based persistence was more variable, but generally similar to lab rankings. 相似文献