Groundwater and Nutrient Discharge into Jiaozhou Bay,North China

The health of near shore marine ecosystems has long been a concern because of its importance to coastal areas. Jiaozhou Bay (JZB) is one such marine ecosystem experiencing rapid water quality degradation in the last several decades. From the area surrounding the bay, the nutrients discharged into the bay through surface water and groundwater has been greatly changed. The thickness of the aquifers and the permeability is relatively high, the concentrations of nutrients in the groundwater are generally high, and so the groundwater discharged into JZB is very significant. However, no attempt has ever been made to evaluate the amount of nutrients discharged into the bay area via groundwater. In this study, the cross-section method and water balance method were used to estimate the amount of groundwater and nutrients discharged into JZB via the subsurface. Groundwater was monitored and sampled at aquifers surrounding the bay area, and some previously available data was also analyzed. The results indicated that groundwater from the Baisha Aquifer east of JZB now is the major source of nutrients (nitrate, dissolved SiO₂) being discharged into the bay. The concentrations of nutrients in the groundwater have been increasing with intensive agricultural land use. However, Dagu Aquifer, the largest aquifer north of JZB, only provides limited nutrients to the bay area because of the construction of a low permeability subsurface dam. Historically, during the 1970s to the 1990s, the Baisha Aquifer experienced seawater intrusion due to excessive groundwater withdrawal. The same was true for the Dagu Aquifer from the 1980s to the 1990s. Because of this, no significant nutrients were discharged into the bay.     

Evaluation of natural attenuation at a 1,4‐dioxane‐contaminated site

1,4‐Dioxane entered the environment as a result of historic leaks and spills in the production area at an industrial facility in the southeastern coastal plain. The areal extent of the 1,4‐dioxane plume is several hundred acres and is largely contained on the site. Land use adjacent to the plant property is primarily undeveloped (wetlands or woods) or industrial, with a small area of mixed land use (commercial/residential) to the southwest and north. The surficial aquifer is a relatively simple hydrogeologic system with well‐defined boundaries and is comprised of a 50‐ to 70‐foot‐thick deposit of alluvial/fluvial sand and gravel that overlies an aquitard in excess of 100 feet thick. A groundwater flow model, developed and calibrated using field‐measured data, was used for the fate‐and‐transport modeling of 1,4‐dioxane. The flow‐and‐transport model, combined with the evaluation of other site geochemical data, was used to support the selection of monitored natural attenuation (MNA) as the proposed groundwater remedy for the site. Since the active sources of contamination have been removed and the modeling/field data demonstrated that the plume was stable and not expanding, the proposed MNA approach was accepted and approved by the regulatory agency for implementation in 2004. Subsequent accumulated data confirm that concentrations in the 1,4‐dioxane plume are declining as predicted by the fate‐and‐transport modeling. © 2008 Wiley Periodicals, Inc.     

Modelling Seasonal Dynamics from Temporal Variation in Agricultural Practices in the UK Ammonia Emission Inventory

Most ammonia (NH₃) emission inventories have been calculated on an annual basis and do not take into account the seasonal variability of emissions that occur as a consequence of climate and agricultural practices that change throughout the year. When used as input to atmospheric transport models to simulate concentration fields, these models therefore fail to capture seasonal variations in ammonia concentration and dry and wet deposition. In this study, seasonal NH₃ emissions from agriculture were modelled on a monthly basis for the year 2000, by incorporating temporal aspects of farming practice. These monthly emissions were then spatially distributed using the AENEID model (Atmospheric Emissions for National Environmental Impacts Determination). The monthly model took the temporal variation in the magnitude of the ammonia emissions, as well as the fine scale (1-km) spatial variation of those temporal changes into account to provide improved outputs at 5-km resolution. The resulting NH₃ emission maps showed a strong seasonal emission pattern, with the highest emissions during springtime (March and April) and the lowest emissions during summer (May to July). This emission pattern was mainly influenced by whether cattle were outside grazing or housed and by the application of manures and fertilizers to the land. When the modelled emissions were compared with measured NH₃ concentrations, the comparison suggested that the modelled emission trend corresponds fairly well with the seasonal trend in the measurements. The remaining discrepancies point to the need to develop functional parametrisations of the interactions with climatic seasonal variation.     

An Evaluation of Daumod Model in Estimating Urban Background Concentrations

This article presents an evaluation of the performance of the urban atmospheric dispersion model (DAUMOD) in estimating nitrogen oxides (NO_x) background concentrations in Copenhagen. Estimations of hourly average (averaged over a year), mean daily and mean monthly concentrations of NO_x are compared with observed values for two years of data. The model slightly underestimates low hourly average values and overestimates high values. The cumulative frequency distribution of mean daily concentration obtained from model estimations is in good agreement with the obtained from observed data. We performed a statistical analysis to determine the agreement between estimated and observed concentration values. The results show that 95.8% of hourly average estimations, 86.8% of mean daily and 100% of monthly average concentrations are within a factor of two of the observed values. The normalised mean square error of predictions is +0.13 for hourly average estimations, +0.22 for mean daily values and +0.02 for monthly mean concentrations. The fractional bias values are: –0.049 for hourly mean estimations, –0.047 for mean daily values and –0.053 for monthly average estimations. The values of the statistical parameters allow us to consider that though estimations are lightly larger than the observed values, the model performance is acceptable.     

The influence of atmospheric pressure on landfill methane emissions

Landfills are the largest source of anthropogenic methane (CH4) emissions to the atmosphere in the United States. However, few measurements of whole landfill CH4 emissions have been reported. Here, we present the results of a multi-season study of whole landfill CH4 emissions using atmospheric tracer methods at the Nashua, New Hampshire Municipal landfill in the northeastern United States. The measurement data include 12 individual emission tests, each test consisting of 5-8 plume measurements. Measured emissions were negatively correlated with surface atmospheric pressure and ranged from 7.3 to 26.5 m3 CH4 min(-1). A simple regression model of our results was used to calculate an annual emission rate of 8.4 x 10(6) m3 CH4 year(-1). These data, along with CH4 oxidation estimates based on emitted landfill gas isotopic characteristics and gas collection data, were used to estimate annual CH4 generation at this landfill. A reported gas collection rate of 7.1 x 10(6) m3 CH4 year(-1) and an estimated annual rate of CH4 oxidation by cover soils of 1.2 x 10(6) m3 CH4 year(-1) resulted in a calculated annual CH4 generation rate of 16.7 x 10(6) m3 CH4 year(-1). These results underscore the necessity of understanding a landfill's dynamic environment before assessing long-term emissions potential.     

Prediction of Soil and Nutrient Losses in A Highland Catchment

Highland catchments in tropical regions are frequently subjected to soil erosion and the transport of chemicals downstream. Any drastic changes in land use will increase the severity of these processes of land degradation. A simulation study using GLEAMS (Groundwater Loading Effects of Agricultural Management Systems) was conducted at a catchment presently under tea farming in Cameron Highlands, Malaysia. Soil, water and nutrient transport associated with several alternative land uses was studied. In addition, the effect of a disruptive form of land clearing on soil, water and nutrient losses was also investigated. Modelling with GLEAMS required information from field measurements and observations, laboratory analyses, guide tables, industry records, maps and reports published by soil survey and meteorological departments. The most critical step in simulating soil and water movement using GLEAMS is the identification of a representative flow sequence. In the catchment under study, the representative flow sequence was overland flow–channel 1–channel 2. Input data on soil erodibility, porosity and surface roughness were manipulated to represent various degrees and forms of disturbance to the surface soil layer. For all land uses studied, the highest soil loss was predicted for the overland flow area where slope gradient is high and the soil friable. The variations in soil loss, runoff and nutrient loss between landscape elements and between land uses were consistent with soil erosion features observed in the field. Soil and nutrient losses were substantial for crops such as cabbage that required land shaping activities and frequent ploughing of the soil. Predicted data on enrichment ratio of specific surface (ERSS) are consistent with nutrient enrichment processes in the field and could prove to be useful in studies on chemical transport in highland catchments.     

The Development of a GIS-based Inventory of Standing Waters in Great Britain together with a Risk-based Prioritisation Protocol

An inventory of standing waters (freshwater lakes and lochs) wasderived from Ordnance Survey digital map data at a scale of 1:50 000 and represents the most comprehensive survey of its kind for Great Britain. The inventory includes 43 738 water bodies in England, Scotland, Wales and the Isle of Man and contains basic physical data such as location, surface area, perimeter and altitude. Catchment areas were computed for water bodies with a surface area larger than 1 ha from a digital terrain model (DTM) using customised routines in a geographical information system (GIS). The resulting polygons were then used to derive catchment-related information from a variety of national datasets including population density, livestock density, land cover, solid and drift geology, meteorological data, freshwater sensitivity status, acid deposition and conservation status. Using data derived from the inventory a risk-based prioritisation protocol was developed to identify standing waters at risk of harm from acidification and eutrophication. This information is required by the Environment Agency, Scottish Environmental Protection Agency and the U.K. statutory conservation bodies to co-ordinate actions and monitor change under international, European and national legislation.     

Incorporation of Seasonal Nitrogen Dynamics within a Long-Term Acidification Model

This paper describes an application of the long termdynamic model, MAGIC, on a monthly timestep, enablingincorporation of the seasonal dynamics associated with abroad understanding of the ecosystem N cycle. The modelhas been applied to the Dargall Lane catchment in theGalloway region of Scotland where marked seasonal Ndynamics are apparent. Mean monthly proportions ofrainfall, runoff, deposition fluxes and net retention ofN are utilised to drive the model on a monthly timestep.Calibration of the model has successfully reproduced thepresent day observed seasonal variation in streamNO₃ and ANC. Prediction of recovery at the siteunder the second sulphur protocol indicates that,although mean annual ANC increases, mean monthly ANC doesnot rise above zero for all months of the year until2010.     

In-situ biological treatment of vinyl acetate-contaminated soil: An emergency response action

In-situ biological solid-phase (or land) treatment was cost-effectively used to remediate 1,500 cubic yards (1,100 m³) of contaminated soil within three months of field operation following spillage of an estimated 12,000 gallons (45,000 L) of vinyl acetate from a railroad tank car onto surface soil. The vinyl acetate rapidly hydrolyzed to acetate and acetaldehyde with concentrations ranging up to 22,000 and 3,000 mg/kg, respectively. Ethanol, a metabolic intermediate, was found to accumulate in soil to concentrations as high as 280 mg/kg. The estimate for excavation, transportation, and disposal of the contaminated soil as a special waste, and for backfilling of the excavated area, was $850,000. The cost for biological remediation of the contaminated soil was $400,000, which was less than half the cost of excavation. In-situ biological treatments have been used to readily remove contaminants, such as acrylonitrile, styrene, butylcellosolve, ethylacrylate, and n-butylacrylate, at other sites involving railroad incidents.     

Simulation model for gas diffusion and methane oxidation in landfill cover soils

Landfill cover soils oxidize a considerable fraction of the methane produced by landfilled waste. Despite many efforts this oxidation is still poorly quantified. In order to reduce the uncertainties associated with methane oxidation in landfill cover soils, a simulation model was developed that incorporates Stefan-Maxwell diffusion, methane oxidation, and methanotrophic growth. The growth model was calibrated to laboratory data from an earlier study. There was an excellent agreement between the model and the experimental data. Therefore, the model is highly applicable to laboratory column studies, but it has not been validated with field data. A sensitivity analysis showed that the model is most sensitive to the parameter expressing the maximum attainable methanotrophic activity of the soil. Temperature and soil moisture are predicted to be the environmental factors affecting the methane oxidizing capacity of a landfill cover soil the most. Once validated with field data, the model will enable a year-round estimate of the methane oxidizing capacity of a landfill cover soil.     

Future landfill emissions and the effect of final cover installation--a case study

Municipal solid waste (MSW) landfills are potential long-term sources of emissions. Hence, they need to be managed after closure until they do not pose a threat to humans or the environment. The case study on the Breitenau MSW landfill was performed to evaluate future emission levels for this site and to illustrate the effect of final cover installation with respect to long-term environmental risks. The methodology was based on a comprehensive assessment of the state of the landfill and included analysis of monitoring data, investigations of landfilled waste, and an evaluation of containment systems. A model to estimate future emission levels was established and site-specific predictions of leachate emissions were presented based on scenario analysis. The results are used to evaluate the future pollution potential of the landfill and to compare different aftercare concepts in view of long-term emissions. As some leachable substances became available for water flow during cover construction due to a change in the water flow pattern of the waste, a substantial increase in leachate concentrations could be observed at the site (e.g. concentrations of chloride increased from 200 to 800 mg/l and of ammonia-nitrogen from 140 to about 500 mg/l). A period of intensive flushing before the final cover installation could have reduced the amount of leachable substances within the landfill body and rapidly decreased the leachate concentrations to 11 mg Cl/l and 79 mg NH₄-N/l within 50 years. Contrarily, the minimization of water infiltration is associated with leachate concentrations in a high range for centuries (above 400 mg Cl/l and 200 mg NH₄-N/l) with low concomitant annual emission loads (below 12 kg/year of Cl or 9 kg/year of NH₄-N, respectively). However, an expected gradual decrease of barrier efficiency over time would be associated with higher emission loads of 50 kg of chloride and 30 kg of ammonia-nitrogen at the maximum, but a faster decrease of leachate concentration levels.     

Characteristics of environmental factors and their effects on CH4 and CO2 emissions from a closed landfill: An ecological case study of Shanghai

To elucidate the influence of landfill gas (LFG) emission on environmental factors, an ecological investigation that was primarily concerned with the characteristics of vegetation, cover soil, and solid waste in the landfill was carried out. Temporal and spatial variations in vegetation diversity and coverage and their effects on reducing the emission of methane in the landfill were investigated. The results showed that both vegetation coverage and diversity increased with elapsed landfill closure time. The transition trend of the vegetation species was from perennial plant (Phragmites australis) to annual plants. Perennial vegetation was the dominant type of vegetation during the early closure period, and annual vegetation coverage increased with closure time. Vegetation preferentially appeared in areas of comparatively high depth of cover soil, which was characterized by high moisture retentiveness that enabled vegetation growth. The concentrations of methane and carbon dioxide in the cover soil significantly decreased with increasing closure time. The concentrations of methane and carbon dioxide from bare cover soil were higher than those from vegetated cover soil whereas the CO₂ flux of bare cover soil was less than that of vegetated cover soil.     

Estimation of Cumulative Frequency Distribution for Carbon Monoxide Concentration from Wind-Speed Data, in Buenos Aires (Argentina)

In this article we apply and test a methodology to estimate cumulative frequency distribution for air pollutant concentration from wind-speed data. We use the inverse relationship after Simpson et al. (Atmospheric Environment, 19, 75–82, 1985) between the opposing percentile values in the statistical distributions for air pollutant concentrations and wind-speed data. This relationship is valid, irrespective of the statistical distributions of both variables, if an inverse relationship between them is also applicable. The available data are five years of 8-h average carbon monoxide concentration and 8-h mean wind-speed, observed in Buenos Aires (Argentina). The performance of the obtained empirical expressions in estimating cumulative frequency distributions for 8-h CO is statistically evaluated. The results show that it is possible to obtain an acceptable cumulative frequency distribution for 8-h CO concentration at the site if the cumulative frequency distribution for wind-speed is known. Q–Q plots show a good agreement between estimated and observed values. From our data, the mean relative error of the estimations was found to be as much as 8.0%.     

Long Term Trends in Concentration of Major Pollutants (SO<Subscript>2</Subscript>, CO,NO, NO<Subscript>2</Subscript>, O<Subscript>3</Subscript> and PM<Subscript>10</Subscript>) in Prague – Czech Republic (Analysis of Data Between 1992 and 2005)

To assess the effect of changes in traffic density and fuels used for heating at the beginning of the 1990s, 1992–2005 monthly averages of PM₁₀, SO₂, NO₂, NO, CO and O₃ from Prague, the Czech capital, were analyzed together with long term trends in emissions of major pollutants, fuel consumption and number of vehicles registered in Prague. The data from all monitoring stations were retrieved from the database of the state automated monitoring system. Correlation coefficients between ambient monthly averaged temperature and all pollutants of concern showed distinct seasonal trends. The results showed that while SO₂ and to some extent also CO concentrations dropped namely in the first half of the analyzed period (1992–1997) as a result decreased fossil fuel consumption for local heating, the behaviour of other pollutant concentrations followed a different pattern. PM₁₀ concentrations decreased during the beginning of the 1990s but showed a sign of increase after 2000. Concentrations of ozone and NO₂ did not reveal any significant change throughout the whole studied period. It can be concluded that during the studied period traditional urban sources of pollution, such as coal and oil combustion, lost their importance but were simultaneously substituted by pollutants from automotive transport (namely PM and NO₂) making the problem of air quality even worse.     

Integrated Assessment of Abatement Strategies to Improve Air Quality in Urban Environments, the USIAM Model

Planning effective strategies to combat air pollution in amajor city such as London requires integration ofinformation on atmospheric concentrations and where theyexceed prescribed air quality standards, detailed data onemissions and potential measures to reduce them includingcosts, and a good understanding of the relativecontributions of different emission sources to pollutantconcentrations plus the remaining background. The UrbanScale Integrated Assessment Model (USIAM) is designed as atool to integrate such information, and to explore andassess a variety of potential strategies for improving airquality. It is based on the same principles as theAbatement Strategies Assessment Model (ASAM) that has beenused in the UN Economic Commission for Europe. To startwith the USIAM model is being developed with respect to theparticulate PM₁₀ only, and in particular the primaryparticulate contribution. The secondary particulate istreated as part of the background superimposed on theprimary particulate concentrations; this may need to betreated more specifically at a later stage, particularlywith respect to nitrate formation over the city. The USIAMmodel therefore sets out to examine a selection of severeepisode conditions as well as long-term annual averageconcentrations, and aims to find strategies that aresuccessful in eliminating exceedance of the prescribedtarget concentrations. By ranking different options forabatement of emissions, for example in terms of cost orease of implementation, the USIAM model can also select andprioritise different potential strategies.     

Predicting biodegradable volatile solids degradation profiles in the composting process

This paper presents a new method for the prediction of the pattern of biodegradable volatile solids (BVS) degradation in the composting process. The procedure is based on a re-arrangement of the heat balance around a composting system to numerically solve for the rate of BVS carbon (BVS-C) disappearance. Input data for the model was obtained from composting experiments conducted in a laboratory-scale, constant temperature difference (CTD) reactor simulating a section of an aerated static pile, and using a simulated feedstock comprising ostrich feed, shredded paper, finished compost and woodchips. These experiments also provided validation data in the form of exit gas CO(2) carbon (CO(2)-C) profiles. The model successfully predicted the generic shape of experimental substrate degradation profiles obtained from CO(2) measurements, but under the conditions and assumptions of the experiment, the profiles were quantitatively different, giving an over-estimate of BVS-C. Both measured CO(2)-C and predicted BVS-C profiles were moderately to well fitted by a single exponential function, with replicated rate coefficient values of 0.08 and 0.09 d(-1), and 0.06 and 0.07 d(-1), respectively. In order to explore the underlying shape of the profiles, measured and predicted data at varying temperature were corrected to a constant temperature of 40 degrees C, using the temperature correction function of Rosso et al. [Rosso, L., Lobry, J.R., and Flandrois, J.P., 1993. An unexpected correlation between cardinal temperatures of microbial growth highlighted by a new model. Journal of Theoretical Biology, 162, 447-463], with cardinal temperatures of 5, 59 and 85 degrees C. Multi-phase profiles were generated for both the measured CO(2)-C and the predicted BVS-C data in this case. However, when alternative cardinal temperatures of 5, 55 and 80 degrees C, or 5, 50 and 80 degrees C, were used, the predicted profiles assumed an exponential shape, and excellent fits were obtained using a double exponential function. These findings support the argument that a substrate degradation curve generated under laboratory conditions at 40 degrees C, would, given correct cardinal temperatures, generate a correct substrate degradation profile under varying temperature conditions and that this in turn would enable an accurate and precise prediction of the temperature profile, using a heat and mass balance approach. In order to realise this prospect, it is proposed that further work to obtain experimental data under completely mixed conditions, more accurately estimate the overall heat transfer coefficient and obtain correct values for the cardinal temperatures used in the temperature correction function, is required.     

Simulating the Impact of Cover Degradation on RCRA Landfill Performance

The ability of near‐surface disposal facility cover designs to meet percolation performance criteria is influenced by degradation occurring over long periods of time. This study was conducted to determine the effect of degradation on percolation based on probabilistic distributions derived from historical climate data. Water‐balance predictions were evaluated using the HELP model, employing several variations of degradation in a traditional Resource Conservation and Recovery Act disposal facility cover design over a 100‐year simulation period. Analysis results were evaluated relative to two different selected thresholds for annual percolation (1 mm and 3 mm). Approximately 20 percent of the results did not exceed both the 1‐mm and 3‐mm thresholds, while 10 percent of the realizations exceeded the 1‐mm threshold but not the 3‐mm threshold, with remaining cases exceeding the 3‐mm threshold. These results demonstrate the importance of considering degradation in designing near‐surface disposal facilities, especially given the very long performance periods desired by different regulators. © 2013 Wiley Periodicals, Inc.     

Sustainable sanitary landfills for neglected small cities in developing countries: The semi-mechanized trench method from Villanueva,Honduras

Open dumping is the most common practice for the disposal of urban solid wastes in the least developed regions of Africa, Asia and Latin America. Sanitary landfill design and operation has traditionally focused on large cities, but cities with fewer than 50,000 in population can comprise from 6% to 45% of a given country’s total population. These thousands of small cities cannot afford to operate a sanitary landfill in the way it is proposed for large cities, where heavy equipment is used to spread and compact the waste in daily cells, and then to excavate, transport and apply daily cover, and leachate is managed with collection and treatment systems. This paper presents an alternative approach for small cities, known as the semi-mechanized trench method, which was developed in Villanueva, Honduras. In the semi-mechanized trench method a hydraulic excavator is used for 1–3 days to dig a trench that will last at least a month before it is filled with waste. Trucks can easily unload their wastes into the trench, and the wastes compact naturally due to semi-aerobic biodegradation, after which the trenches are refilled and covered. The exposed surface area is minimal since only the top surface of the wastes is exposed, the remainder being covered by the sides and bottom of the trench. The surplus material from trench excavation can be valorized for use as engineering fill onsite or off. The landfill in Villanueva has operated for 15 years, using a total land area of approximately 11 ha for a population that grew from 23,000 to 48,000, with a land requirement of 0.2 m²/person year, a cover to waste ratio of 0.2, and an estimated soil surplus of 298,000 m³ that is valorized and used onsite. The landfill has been operated solely by the municipality with an operational cost in 2010 estimated at US$4.60 per ton. A modified water balance analysis at Villanueva shows negligible leachate generation from covered trenches and 700 m³/yr (60 m³/ha yr) from the two open trenches required for daily operation. If the site were an open dump, however, leachate generation is estimated to be 3900 m³/ha yr and contaminated runoff 5000 m³/ha yr. A simple model used to estimate dilution of generated leachate based on groundwater flow data and aquifer stratigraphy suggests that the leachate will be diluted by a factor of 0.01 in the aquifer. Leachate contaminants will not accumulate because the aquifer discharges to the Ulua River 2 km south of the landfill. While not suitable for all sites, the Villanueva method nevertheless serves as an excellent example of how a small city landfill with natural compaction of waste and attenuation of leachate can be sustainably operated.     

Reporting central tendencies of chamber measured surface emission and oxidation

Methane emissions, concentrations, and oxidation were measured on eleven MSW landfills in eleven states spanning from California to Pennsylvania during the three year study. The flux measurements were performed using a static chamber technique. Initial concentration samples were collected immediately after placement of the flux chamber. Oxidation of the emitted methane was evaluated using stable isotope techniques. When reporting overall surface emissions and percent oxidation for a landfill cover, central tendencies are typically used to report “averages” of the collected data. The objective of this study was to determine the best way to determine and report central tendencies. Results showed that 89% of the data sets of collected surface flux have lognormal distributions, 83% of the surface concentration data sets are also lognormal. Sixty seven percent (67%) of the isotope measured percent oxidation data sets are normally distributed. The distribution of data for all eleven landfills provides insight of the central tendencies of emissions, concentrations, and percent oxidation. When reporting the “average” measurement for both flux and concentration data collected at the surface of a landfill, statistical analyses provided insight supporting the use of the geometric mean. But the arithmetic mean can accurately represent the percent oxidation, as measured with the stable isotope technique. We examined correlations between surface CH₄ emissions and surface air CH₄ concentrations. Correlation of the concentration and flux values using the geometric mean proved to be a good fit (R² = 0.86), indicating that surface scans are a good way of identifying locations of high emissions.     

PM10, O3, CO Concentrations and Elemental Analysis of Airborne Particles in a School Building

Measurements of indoor and outdoor PM10, as well as indoor O₃ and CO concentrations were conducted and are presented here. These measurements were carried out at an institute building, located in a suburban industrial area in Greece. Both indoor and outdoor PM10 samples were also collected and their elemental composition was identified by ED-XRF analysis. Twenty seven major, minor and trace elements were identified. The measurements took place generally in different periods of institute operation, from June 2004 to February 2005. The indoor PM10 concentrations which were measured during the normal operation period of the institute were found to be many times higher than the respective outdoor PM10 concentrations of the same periods. On the contrary, the indoor PM10 concentrations which were measured during the holiday period were found to be lower than their corresponding outdoor values. Indoor O₃ and CO concentrations were found to be in low level. Indoor PM10 concentrations were found to be in a relative good correlation with O₃ (r = 0.45) and in high correlation (r = 0.98) with CO concentrations. On average, total elements concentrations were much higher indoors relative to outdoors. Based on above findings we attempted to determine the pollution sources of the indoor environment and to investigate some parameters or chemical processes that affect indoor pollutants’ levels.