Monoterpene emissions from soil in a Sitka spruce forest

A dynamic soil enclosure was used to characterise monoterpene emissions from 3 soil depths within a Picea sitchensis (Sitka spruce) forest. In addition, a dynamic branch enclosure was used to provide comparative emissions data from foliage. In all cases, limonene and α-pinene dominated monoterpene soil emissions, whilst camphene, β-pinene and myrcene were also present in significant quantities. α-Phellandrene, 3-carene and α-terpinene were occasionally emitted in quantifiable amounts whilst cymene and cineole, although tentatively identified, were always non-quantifiable. Total daily mean monoterpene emission rates, normalised to 30°C, varied considerably between soil depths from 33.6 μg m⁻² h⁻¹ (range 28.3–38.4) for undisturbed soil, to 13.0 μg m⁻² h⁻¹ (8.97–16.4) with uppermost layer removed, to 199 μg m⁻² h⁻¹ (157–216) with partially decayed layer removed, suggesting that the surface needle litter was the most likely source of soil emissions to the atmosphere. Relative monoterpene ratios did not vary significantly between layers. Foliar monoterpenes exhibited a similar emission profile to soils with the exceptions of camphene and 3-carene whose contributions decreased and increased, respectively. Emission rates from foliage, normalised to 30°C were found to have a daily mean of 625 ng g⁻¹ dw h⁻¹ (299–1360). On a land area basis however, total soil emissions were demonstrated to be relatively insignificant to total emissions from the forest ecosystem.     

Pesticide and PCB levels in fish from Alberta (Canada)

Pesticide and PCB analyses were completed on fat and muscle samples of 750 fish collected from 11 major lakes and rivers in Alberta. Although phenoxy and organophosphate residues were always below detectable limits, traces of chlorinated pesticides and their derivatives, particularly DDE, DDD and chlordane, were detected in most fat samples. Methoxychlor was frequently found in goldeye from the North Saskatchewan River but not recorded in fish from any other lake or river. Its presence in goldeye, a highly migratory species, was probably a result of biting-fly control programs in the Saskatchewan part of the river. PCB levels exceeded 25 mg/kg in the fat of several species from the North Saskatchewan River but were generally lower in the other systems. Analysis of 160 sediment samples from the North Saskatchewan River revealed no point source of PCB contamination, with residues always <0.01 mg/kg dry weight.     

Peroxyacetylnitrate (PAN) in the atmosphere of Edmonton,Alberta, Canada

Peroxyacetyl nitrate (PAN) concentrations were measured from December 1982 to May 1984 in downtown Edmonton, Alberta, as well as upwind and downwind of the city. The highest PAN concentration recorded in Edmonton was 7.5 ppb, and the mean daily maximum was 0.6 ppb. Maximum PAN and ozone concentrations were often reached in the early afternoon but there were many exceptions, with maxima as early as 0900 MST and as late as 2000 MST. PAN often persisted throughout the night in Edmonton, whereas in Calgary it disappeared rapidly in the evening. Edmonton PAN concentrations showed seasonal variation and were limited in the wintertime by the lack of solar radiation and in the summer by the low concentration of pollutants. PAN episodes were highly correlated with the presence of anticyclonic synoptic disturbances (ridges) in the upper air flow. Surface synoptic conditions varied but weak pressure gradients were common to all episodes. Seasonal and diurnal variations of PAN are discussed in relation to observations from Calgary, Alberta; Los Angeles, CA; and other North American cities.     

A comparison of Alpine emissions to forest soil and spruce needle loads for persistent organic pollutants (POPs)

The project MONARPOP analysed the concentrations of semivolatile organic compounds (SVOCs) in two important sink compartments, needles of Norway spruce (Picea abies [L.] Karst.) and forest soil from 40 remote Alpine forest sites in Austria, Germany, Italy, Slovenia and Switzerland.In the present study the load of PCDD/F, PCB, PBDE, PAH, HCB, HCH and DDT in the Alps calculated on the basis of measured data are compared with their estimated emissions in the Alpine region. It comes out that the masses of the studied pollutants stored in the forests are higher than the corresponding emissions in the Alpine area indicating that the Alps are a sink for POPs advected from surrounding areas. It is assumed that local emissions of PCDD/F and PAH deriving from biomass burning are probably underestimated and that the pool of these pollutants in the forests represents the accumulation over some decades.     

Hydrocarbon emissions from industrial release events in the Houston-Galveston area and their impact on ozone formation

Ambient measurements have shown that ozone formation in the Houston-Galveston area of Texas is frequently much more rapid than in other urban areas. One of the contributing factors is believed to be short-term episodic or “event” emissions from industrial facilities, particularly releases that contain significant mass fractions of highly reactive volatile organic compounds (HRVOCs). In this work, time series analyses are used to compare average annual flow rates for air pollutant emissions with those released during reported emission events. The results indicate that the magnitude and frequency of HRVOC event emissions are an important element in accurately reflecting ozone precursor emission patterns in the Houston-Galveston area, particularly in Harris, Brazoria, Galveston, and Chambers counties. More than 50% of the reported episodic (event) emissions of HRVOCs are ethene and approximately a third are propene; the remainders are isomers of butene and 1,3-butadiene. Most events last less than 24 h. The mass released in an event can vary from a few hundred to more than 100,000 lb, and the dominant type of industrial source is chemical manufacturers (SIC 2869). Daily emissions from a single facility can vary from annual average emissions by multiple orders of magnitude at a frequency of several times a year. Because there are so many facilities in the Houston-Galveston area, HRVOC emission variability of this magnitude can be expected daily, at some time and some location in the Houston-Galveston area. If the emission variability occurs at times and locations where atmospheric conditions are conducive to ozone formation, both ambient data and photochemical modeling indicate that industrial emission events can lead to elevated concentrations of ozone. Specifically, peak, area-wide ozone concentration can be increased by as much as 100 ppb for large HRVOC emission events.     

中国SO_2排放对日本SO_2浓度及硫沉降的影响

利用相关文献及来自酸沉降网的中、日两国各观测站点的SO2监测资料,分析了近十年来中国SO2的污染现状、趋势及排放量对下风向日本各观测站点SO2浓度及硫沉降量的影响。结果表明,通过文献分析可知,2001—2009中国的SO2年均质量浓度分布在40~50μg/m3,总体呈下降趋势;中国部分城市的SO2年均浓度与中国SO2排放量的相关性总体高于日本各观测站点的SO2年均浓度与中国SO2排放量的相关性,中国的SO2排放对日本各观测站点的SO2年均浓度影响总体较小;情景模拟分析发现,中国SO2排放量对日本各观测站点SO2年均浓度的贡献率在7.5%~44.0%,平均贡献率为22.6%;中国SO2排放量对日本各观测站点硫沉降的贡献率在8%~41%,平均贡献率为22.1%。     

The impact trilemma of energy prices,taxation, and population on industrial and residential greenhouse gas emissions in Europe

Environmental Science and Pollution Research - As a major source of pollution and the cause of climate change, greenhouse gas emissions are attracting the attention of scholars, policymakers, and...     

Negative responses of Collembola in a forest soil (Alptal,Switzerland) under experimentally increased N deposition

The response of specific groups of organisms, like Collembola to atmospheric nitrogen (N) deposition is still scarcely known. We investigated the Collembola community in a subalpine forest (Alptal, Switzerland) as subjected for 12 years to an experimentally increased N deposition (+25 on top of ambient 12 kg N ha^?1 year^?1). In the 0–5 cm soil layer, there was a tendency of total Collembola densities to be lower in N-treated than in control plots. The density of Isotomiella minor, the most abundant species, was significantly reduced by the N addition. A tendency of lower Collembola group richness was observed in N-treated plots. The Density-Group index (d_DG) showed a significant reduction of community diversity, but the Shannon–Wiener index (H′) was not significantly affected by the N addition. The Collembola community can be considered as a bioindicator of N inputs exceeding the biological needs, namely, soil N saturation.     

Ambient isoprene and monoterpene concentrations in a Greek fir (Abies Borisii-regis) forest. Reconciliation with emissions measurements and effects on measured OH concentrations

Ambient biogenic hydrocarbons were monitored in a forested site in Northern Greece during the summer of 1997 as part of the AEROBIC campaign. Significant concentrations of isoprene were observed, consistent with enclosure measurements presented in the previous paper (Harrison et al., 2001, Atmospheric Environment 35, 4687–4698). In addition, significant concentrations of monoterpenes were observed (nighttime maximum of 2.9 ppbv for total monoterpene concentration). Isoprene and the monoterpenes exhibited pronounced, but different, diurnal cycles which are interpreted via enclosure and OH measurements. The combination of relatively high emission rates at a time when OH concentrations are significantly lower leads to peak isoprene concentrations (∼3.0 ppbv) during the late evening. The temporal behaviour of the biogenic hydrocarbons is used to interpret the radical chemistry at the site and may indicate the presence of high (∼1×10⁶ cm⁻³) nighttime concentrations of the OH radical. Biogenic hydrocarbon measurements were supported by a range of organic and inorganic measurements which are also presented in this paper.     

The effect of diesel fuel sulfur content on particulate matter emissions for a nonroad diesel generator

The effect of sulfur content on diesel particulate matter (DPM) emissions was studied using a diesel generator (Generac Model SD080, rated at 80 kW) as the emission source to simulate nonroad diesel emissions. A load simulator was used to apply loads to the generator at 0, 25, 50, and 75 kW, respectively. Three diesel fuels containing 500, 2100, and 3700 ppm sulfur by weight were selected as generator fuels. The U.S. Environmental Protection Agency sampling Method 5 "Determination of Particulate Matter Emissions from Stationary Sources" together with Method 1A "Sample and Velocity Traverses for Stationary Sources with Small Stacks or Ducts" was adopted as a reference method for measurement of the exhaust gas flow rate and DPM mass concentration. The effects of various parameters on DPM concentration have been studied, such as fuel sulfur contents, engine loads, and fuel usage rates. The increase of average DPM concentrations from 3.9 mg/Nm3 (n cubic meter) at 0 kW to 36.8 mg/Nm3 at 75 kW is strongly correlated with the increase of applied loads and sulfur content in the diesel fuel, whereas the fuel consumption rates are only a function of applied loads. An empirical correlation for estimating DPM concentration is obtained when fuel sulfur content and engine loads are known for these types of generators: Y = Zm(alphaX + beta), where Y is the DPM concentration, mg/m3, Z is the fuel sulfur content, ppm(w) (limited to 500-3700 ppm(w)), X is the applied load, kW, m is the constant, 0.407, alpha and beta are the numerical coefficients, 0.0118 +/- 0.0028 (95% confidence interval) and 0.4535 +/- 0.1288 (95% confidence interval), respectively.     

Historic emissions of fluorotrichloromethane (CFC-11) based on a market survey

Releases of CFCs occur promptly from applications such as aerosol sprays, or over a period of several years from refrigeration and air conditioning or more slowly still from use as blowing agents for closed cell plastic foams. As a consequence of the Montreal Protocol, the emissions have fallen and their pattern is continuing to change. To help quantify these changes the emissions from closed cell foam blowing have been re-examined in a comprehensive market survey, developing a lifecycle assessment for each foam type, production method and foaming agent.The original model for the time series of emissions from foam applications was shown to remain a robust representation in general terms. There is an “immediate” loss when the foam is manufactured, a slow emission from the foam itself during use and a loss on disposal of the artefact made with the foam. The original model used an initial loss rate of 10% and a subsequent loss of 4.5% yr⁻¹ over 20 yr.The new survey showed a wide range of initial and service loss rates. Immediate release ranges from 95% down to 4%; similarly, the rate of loss during service varies from 0.5% to 5% yr⁻¹ and the service lifetimes of the artefacts made with the foams varies from 12 to 50 yr. The apparent emission function, in terms of the mean value of the annual fractional release from the bank of CFC-11 residing in foams, was calculated from the survey to be 0.043±0.008 over 28 yr. There is a small and non-significant fall in this function with time; so that over the last ten years of the data record the more appropriate value is 0.0366±0.0008. However, up to the early 1990s, it is the original emission function that is consistent with the observed atmospheric concentrations. Thenceforth this function seriously overpredicts the concentrations but, if the new emissions function for foams is used from 1993 onwards in conjunction with the original emission functions for all other uses, the fit becomes better. This suggests that the emission functions for prompt and short term releases remain valid and should be coupled with the new function to calculate emissions of CFC-11 or other fluorocarbon foam blowing agents from the early 1990s onwards.     

Immunolocalization of non-extractable (bound) residues of pesticides and industrial contaminants in plants and soil.

The application of immunochemical methods for the investigation of non-extractable (bound) residues is reviewed. Non-extractable residues may be presented to antibodies as antigenic determinants, which are exposed for instance in plant tissue and humic substances. Fluorescent probes as well as enzyme markers have been applied for the detection of bound residues. The application of antibodies labeled with fluorescein isothiocyanate (FITC) and phycoerythrin revealed the presence of atrazine in cryosections of atrazine-treated corn leaves and water plants. Atrazine could be localized by antibodies coupled to fluorescent markers in soil from corn fields but not in atrazine-free soil. Quantitative results were obtained by the application of enzyme immunoassays to the investigation of triazine and 2,4,6-trinitrotoluene (TNT) residues, bound to soil humic acids. Finally, the use of antibodies with different recognition patterns provides information on the ligation of non-extractable residues to the matrix.     

The effect of variability in industrial emissions on ozone formation in Houston, Texas

Ambient observations have indicated that high concentrations of ozone observed in the Houston/Galveston area are associated with plumes of highly reactive hydrocarbons, mixed with NO_x, from industrial facilities. Ambient observations and industrial process data, such as mass flow rates for industrial flares, indicate that the VOCs associated with these industrial emissions can have significant temporal variability. To characterize the effect of this variability in emissions on ozone formation in Houston, data were collected on the temporal variability of industrial emissions or emission surrogates (e.g., mass flow rates to flares). The observed emissions variability was then used to construct regionwide emission inventories with variable industrial emissions, and the impacts of the variability on ozone formation were examined for two types of meteorological conditions, both of which lead to high ozone concentrations in Houston. The air quality simulations indicate that variability in industrial emissions has the potential to cause increases and decreases of 10–52 ppb (13–316%), or more, in ozone concentration. The largest of these differences are restricted to regions of 10–20 km², but the variability also has the potential to increase regionwide maxima in ozone concentrations by up to 12 ppb.     

Impact of free calcium oxide content of fly ash on dust and sulfur dioxide emissions in a lignite-fired power plant

Emitted pollutants from the Agios Dimitrios lignite-fired power plant in northern Greece show a very strong linear correlation with the free calcium oxide content of the lignite ash. Dust (fly ash) emissions are positively correlated to free calcium oxide content, whereas sulfur dioxide (SO2) emissions are negatively correlated. As a result, at present, the Agios Dimitrios Power Plant operates very strictly within the legislative limits on atmospheric particulate emission. In the present study, the factors to be considered in assessing the impact of lignite combustion on the environment are presented and evaluated statistically. The ash appears to have a remarkable SO2 natural dry scrubbing capability when the free calcium oxide content ranges between 4 and 7%. Precipitator operating problems attributable to high ash resistivity can be overcome by injecting sulfur trioxide to reduce the ash resistivity, with, of course, a probable increase in operating costs.     

The impact of the 2005 Gulf hurricanes on pollution emissions as inferred from Ozone Monitoring Instrument (OMI) nitrogen dioxide

The impact of Hurricanes Katrina and Rita in 2005 on pollution emissions in the Gulf of Mexico region was investigated using tropospheric column amounts of nitrogen dioxide (NO₂) from the Ozone Monitoring Instrument (OMI) on the NASA Aura satellite. Around New Orleans and coastal Mississippi, we estimate that Katrina caused a 35% reduction in NO_x emissions on average in the three weeks after landfall. Hurricane Rita caused a significant reduction (20%) in NO_x emissions associated with power generation and intensive oil refining activities near the Texas/Louisiana border. We also found a 43% decrease by these two storms over the eastern Gulf of Mexico Outer Continental Shelf mainly due to the evacuation of and damage to platforms, rigs, and ports associated with oil and natural gas production.     

An on-line analysis of reduced sulfur gases in the ambient air surrounding a large industrial complex

In this study, the concentrations of reduced sulfur compounds (RSC: H₂S, CH₃SH, DMS, and DMDS) were continuously measured from an odor monitoring station over a 4-month period (August–November 2005) using an on-line GC system. The hourly measurement data of RSC, collected along with some major aromatic VOCs (benzene, toluene, xylene, etc.), approached the sum of 1500; the mean for all hourly H₂S was computed to be 295 ppt, while those of the others were seen at 7 (DMS), 1 (CH₃SH), and 0.4 ppt (DMDS). When these RSC data were compared across two seasons and on a 24 h scale basis, the values for either the summer or nighttime periods were generally high relative to their counterparts in the fall and daytime. Analysis of these RSC data generally suggests that most RSCs occur at some ppt concentration ranges and that their values frequently fall below detection limits (DL) values (except for H₂S). If the total number of effective data sets (i.e., above DL values) are compared to each other, the results tend to differ significantly between H₂S and the others: the proportion of effective number was as high as 75% for H₂S, while the others were very low (6% of DMS and even less than that for the others). The distributions of RSC were hence clearly distinguished from those of VOCs in that the determination of the latter was scarcely limited by the instrumental detectability. According to the present study, the H₂S data exhibit strong potential as the malodor tracers, while those of the other RSCs are unlikely due to the limited detectability. The overall results of this study hence suggest that several factors which include the selection of target compounds, the location of the monitoring points, and the scale (or number) of total monitoring points should be considered simultaneously to effectively track down the odor occurrence patterns in areas near strong source processes.     

Relative effect of soil moisture on emissions and distribution of 1,3-dichloro-propene and chloropicrin in soil columns

Emissions of soil fumigants are regulated to protect air quality in California. Irrigation prior to fumigation can reduce fumigant emissions at relatively low costs; however, the optimum range of soil water content that reduces emissions without reducing efficacy is not clearly defined. The objective of this study was to determine the effects of soil water content [at 30, 45, 60, 75, 90 and 100% field capacity (FC)] on the emission and distribution of fumigants 1,3-dichloropropene (1,3-D) and chloropicrin (CP) in columns packed with a sandy loam soil. After injecting equal amounts of cis-1,3-D, trans-1,3-D, and CP, fumigant emissions and distribution in soil were monitored for 14 days. Emissions of all three compounds showed similar response to soil water content except that CP emissions were lower than both isomers of 1,3-D. The emission peak flux was highest and occurred earliest in the driest soil while it was reduced and delayed as soil water content increased. After the peak, emission flux decreased rapidly in the driest soil but more slowly in higher water content treatments. Initially, higher soil water content resulted in substantially lower cumulative emissions among the treatments, but as time progressed, the differences in cumulative emissions decreased or even disappeared. These trends were likely due to the effect of the closed-bottom short soil columns which allowed fumigants to only move upward and contribute to emission. Higher fumigant concentrations in the soil–gas phase were observed in high soil water content treatments, due to less emission loss and more fumigant retained in the soil.     

Processes affecting the movement of organochlorine pesticides (OCPs) between soil and air in an industrial site in Turkey

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.