Emissions In Air Research Articles

Environmental Impact Monitoring of a Minero-chemical Complex in Catalão Urban Area of Pts, Pm10 and Pm2.5 by Edx Characterization

Depending on its nature, particulate matter has very different size, composition and morphology. By the combination of these criteria it is possible to distinguish the emitting sources (primary or secondary). The shape and the dimension of the particles have also a direct interaction with the risk assessment for human health. The minero-chemical complex consists of phosphate fertilizer manufacturing, rock phosphate and niobium mining open pits and it is located northeast of the urban area of the city. Environmental issues associated with it include the following: fugitive emissions which are primarily associated with operational leaks from tubing, valves, connections, flanges, packings, open ended lines, floating roof storage tank and pump seals, gas conveyance systems, compressor seals, pressure relief valves, tanks or open its/containments, and loading and unloading operations of products. Furthermore the area of study is characterized by a predominantly northeast winds direction. The monitoring was performed weekly particulates samples were collected in two seasonal episodes at one representative places in the urban area of Catalao (a Brazilian city located in Goias state) in the period from August to November of 2014. Suspended particles were sampled on pure fiberglass filters by using a High Volume air sampler and were analyzed via an energy dispersive X-ray microanalysis system (EDX). The airborne particulate matter was characterized from a physico-chemical point of view to supply information on the particle composition and the compounds carried on their surfaces. The microanalysis enables identification of several groups of particles such as: soot, Si-rich, metal-rich and biological particules. These results may help in controlling and preventing fugitive emissions in atmospheric air.

Using metal ratios to detect emissions from municipal waste incinerators in ambient air pollution data

This study aimed to fingerprint emissions from six municipal waste incinerators (MWIs) and then test if these fingerprint ratios could be found in ambient air samples. Stack emissions tests from MWIs comprised As, Cd, Cr, Cu, Pb, Mn, Ni, V and Hg. Those pairs of metals showing good correlation (R > 0.75) were taken as tracers of MWI emissions and ratios calculated: Cu/Pb; Cd/Pb; Cd/Cu and Cr/Pb. Emissions ratios from MWIs differed significantly from those in ambient rural locations and those close to traffic. In order to identify MWI emissions in ambient air two analysis tests were carried out. The first, aimed to explore if MWI emissions dominate the ambient concentrations. The mean ambient ratio of each of the four metal ratios were calculated for six ambient sampling sites within 10 km from a MWI under stable meteorological conditions when the wind blew from the direction of the incinerator. Under these meteorological conditions ambient Cd/Pb was within the range of MWI emissions at one location, two monitoring sites measured mean Cr/Pb ratios representative of the MWI emissions and the four sites measured values of Cu/Pb within the range of MWI emissions. No ambient measurements had mean Cd/Cu ratios within the MWI values. Even though MWI was not the main source determining the ambient metal ratios, possible occasional plume grounding might have occurred. The second test then examined possible plume grounding by identifying the periods when all metal ratios differed from rural and traffic values at the same time and were consistent with MWI emissions. Metal ratios consistent with MWI emissions were found in ambient air within 10 km of one MWI for about 0.2% of study period. Emissions consistent with a second MWI were similarly detected at two ambient measurement sites about 0.1% and 0.02% of the time. Where plume grounding was detected, the maximum annual mean particulate matter (PM) from the MWI was estimated to be 0.03 μg m−3 to 0.12 μg m−3; 2–3 orders of magnitude smaller than background ambient PM10 concentrations. Ambient concentrations of Cr increased by 1.6–3.0 times when MWI emissions were detected. From our analysis we found no evidence of incinerator emissions in ambient metal concentrations around four UK MWIs. The six UK MWIs studied contributed little to ambient PM10 concentrations.

Sustainability of reinforced concrete frame structures – a case study

Traditionally, the engineering education is aiming to establish quantifiable, measurable units, and after that comparing those to utilise the unit considered more suitable. When thinking about sustainability of structures, traditional mentality has to be set aside, as comparing different structural systems is becoming a complex task. Choosing different materials for the same reinforced concrete structure has immediate comparable impact on the environment. Reinforced concrete structures are using excessively the limited limestone and other resources and, in the same time, a large quantity of energy for producing the rebar, the clinker and the structural concrete, having negative impact on the environment. Even if reinforced concrete structures are not generally known as the most sustainable solutions for several structural queries, reinforced concrete structural solutions are preferred for most of the situations due to the other advantages presented by these structures. Hence, considering that specific building indispensable for the society, the aim of obtaining sustainable buildings becomes equiva lent to decrease their negative impact on the environment while still taking full advantage of their strength. This target can be achieved by judicious choose of the built-in materials. For a given multistorey reinforced concrete frame building, the scope is to establish the concrete and the reinforcing steel classes in such a way that the impact of these materials on the environment to be kept at the lowest possible level. This paper presents a study on an ordinary reinforced concrete frame structure designed using two different concrete classes (C16/20 and C30/37) and two different reinforcing bar classes (PC52 and S500), obtaining four different possibilities for the same solution. Different combinations of built-in materials are resulting different economic and environmental impacts. The environmental impact for the whole life cycle of the studied solutions, using different material qualities, is estimated using Athena Impact Estimator for Buildings, taking into consideration weighted life-cycle analysis indicators (total energy used, the quantity of solid emissions in air and water, the required natural resources consumed – especially the non-renewable ones – the impact owed to the depletion of the natural resources, human health and the impact on the ecosystems). Besides the environmental impact estimation, realisation cost is also evaluated for each structural solution, obtaining a relationship between the cost (as the major decision influencer) and the sustainability of the studied solutions.

The development of GADD45α luciferase reporter assays in human cells for assessing the genotoxicity of environmental pollutants

Objectives: In order to assess the potential carcinogenic and genotoxic responses induced by environmental pollutants, genotoxicity test systems based on a GADD45α promoter-driven luciferase reporter in human A549 and HepG2 cells were established.Materials and methods: Four different types of environmental toxicants including DNA alkylating agents, precarcinogenic agents, DNA cross-linking agents and non-carcinogenic agents, and three environmental samples collected from a coke oven plant were used to evaluate the test systems. After treated with the tested agents and environmental samples for 12 h, the cell viabilities and luciferase activities of the luciferase reporter cells were determined, respectively.Results: Methyl methanesulfonate, benzo[a]pyrene, formaldehyde and the extractable organic matter (EOM) from coke oven emissions in ambient air generally produced significant induction of relative luciferase activity in a similar dose-dependent manner in A549- and HepG2-luciferase cells. No significant increases in relative luciferase activity were observed in pyrene-treated A549- or HepG2-luciferase cells. Significant increase in relative luciferase activity was already evident after 2.5 µM benzo[a]pyrene, 5 µM formaldehyde, 0.006 µg/L bottom-EOM, 0.10 µg/L side-EOM or 0.06 µg/L top-EOM, where no cytotoxic damage was observed. Compared with the A549-luciferase cells, the tested pollutants produced higher induction of relative luciferase activity in HepG2-luciferase cells.Discussion and conclusion: Therefore, the new genotoxicity test systems can detect different types of genotoxic agents and low concentrations of environmental samples. The luciferase reporter cells, especially the HepG2-luciferase cells, could provide a valuable tool for rapid screening of the genotoxic damage of environmental pollutants and their complex mixtures.

Numerical simulation on pulverized coal combustion and NOx emissions in high temperature air from circulating fluidized bed

High temperature air combustion is a prospecting technology in energy saving and pollutants reduction. Numerical simulation on pulverized coal combustion and NOx emissions in high temperature air from circulating fluidized bed was presented. The down-fired combustor, taken as the calculation domain, has the diameter of 220 mm and the height of 3000 mm. 2 cases with air staging combustion are simulated. Compared the simulation results with experimental data, there is a good agreement. It is found that the combustion model and NOx formation model are applicable to simulate the pulverized coal combustion and NOx emissions in high temperature air from circulating fluidized bed. The results show that there is a uniform temperature profile along the axis of the down-fired combustor. The NOx emissions are lower than those of ordinary pulverized coal combustion, and the NOx emissions are 390 mg/m3 and 352 mg/m3 in Case 1 and Case 2, respectively. At the range of 300–600 mm below the nozzle, the NO concentration decreases, mainly resulting from some homogeneous reactions and heterogeneous reaction. NO concentration has a little increase at the position of 800 mm below the nozzle as the tertiary air supplied to the combustor at the position of 600 mm below the nozzle.

Identification of the physical mechanism of generation of coherent N_2 ^+ emissions in air by femtosecond laser excitation

Recently, amplification of harmonic-seeded radiation generated through femtosecond laser filamentation in air has been observed, giving rise to coherent emissions at wavelengths corresponding to transitions between different vibrational levels of the electronic B(2)Σ(u)(+) and X(2)Σ(g)(+) states of molecular nitrogen ions [Phys. Rev. A. 84, 051802(R) (2011)]. Here, we carry out systematic investigations on its physical mechanism. Our experimental results do not support the speculation that such excellent coherent emissions could originate from nonlinear optical processes such as four-wave mixing or stimulated Raman scattering, leaving stimulated amplification of harmonic seed due to the population inversion generated in molecular nitrogen ions the most likely mechanism.

Remote creation of coherent emissions in air with two-color ultrafast laser pulses

We experimentally demonstrate the generation of narrow-bandwidth emissions with excellent coherent properties at ∼391 and ∼428 nm from N2+ (B2Σu+ (v′ = 0) → X2Σg+ (v = 0, 1)) inside a femtosecond filament in air by an orthogonally polarized two-color driver field (i.e. 800 nm laser pulse and its second harmonic). The durations of the coherent emissions at 391 and 428 nm are measured to be ∼2.4 and ∼7.8 ps, respectively, both of which are much longer than the duration of the pump and its second harmonic pulses. Furthermore, the measured temporal decay characteristics of the excited molecular systems suggest an ‘instantaneous’ population inversion mechanism that may be achieved in molecular nitrogen ions at an ultrafast time scale comparable to the 800 nm pump pulse.

Large Industrial Point Sources in Italy: a focus on mercury concentrations resulting from three seasonal ship-borne measurements

In Italy there are 25 Large Industrial Point Sources whose mercury emissions in air exceed the established threshold of 10 kg year -1 . Many of these mercury point sources, mostly distributed along the Italian coastal area, are located at sites qualified as National Interest Rehabilitation Sites because of documented contamination in qualitative and/or quantitative terms and of potential health impact. Atmospheric mercury emissions related to Italian Large Industrial Point Sources, with a value of 1.04 Mg·yr -1 for 2007, have a not negligible contribution, accounting, on their own, for more than 10% of the total mercury emissions resulting from all activity sectors at a national level. Among others, thermal power stations, pig iron and steel as well as basic inorganic chemical production, result to be the main contributing industrial activities. In order to assess how mercury species concentrations and distribution in the Marine Boundary Layer (MBL) change with vicinity to large industrial sites, measurements of atmospheric mercury were performed during three oceanographic campaigns aboard the Research Vessel (R.V.) Urania of the Italian CNR. Collection of GEM, GOM and PBM was conducted across the Adriatic sea, during autumn 2004 (27 th of October to 12 th of November) and summer 2005 (17 th to 29 th of June), and across the Tyrrhenian sea during autumn 2007 (12 th of September to 1 st October). Analysis were carried out with reference to the period in which the R.V. Urania has stopped close to the main Italian industrial contaminated sites. Explorative statistical parameters of atmospheric mercury species were computed over each single stop-period and then compared with the overall cruise campaign measurements. Results are herein presented and discussed.

Fugitive greenhouse gas emissions in ventilation air from Australian underground coal mines

Seam gas released during coal mining is a substantial source of fugitive greenhouse gas emissions worldwide. Most of these emissions originate from underground mining; however, lack of robust global data means that the scale of emissions remains uncertain. Some coal-producing countries are attempting to improve the quality of emission estimates by using ventilation data to calculate emissions from individual mines. Legislation recently introduced in Australia now requires coal mine operators to estimate and report annual fugitive emissions. This article examines the methodology currently used at most Australian mines to meet these requirements. To assess the performance of this methodology, we compared the results of routine measurements of ventilation air flow rate and gas composition to those made with reference methods. The primary sources of uncertainty in the techniques are identified and their contributions to the uncertainty of the reported fugitive emission fluxes are estimated.

The effect of dust emissions from open storage piles to particle ambient concentration and human exposure

The current study focus on the determination of dust emissions from piles in open storage yards of a municipal solid waste (MSW) composting site and the subsequent atmospheric dust dispersion. The ISC3-ST (Industrial Source Complex Version 3 – Short Term) model was used for the evaluation of the PM10 ambient concentrations associated with the dispersion of MSW compost dust emissions in air. Dust emission rates were calculated using the United States Environmental Protection Agency proposed dust resuspension formulation from open storage piles using local meteorological data. The dispersion modelling results on the spatial distribution of PM10 source depletion showed that the maximum concentrations were observed at a distance 25–75m downwind of the piles in the prevailing wind direction. Sensitivity calculations were performed also to reveal the effect of the compost pile height, the friction velocity and the receptor height on the ambient PM10 concentration. It was observed that PM10 concentrations (downwind in the prevailing wind direction) increased with increasing the friction velocity, increasing the pile height (for distances greater than 125m from the source) and decreasing the receptor height (for distances greater than 125m from the source). Furthermore, the results of ISC3-ST were analysed with the ExDoM (Exposure Dose Model) human exposure model. The ExDoM is a model for calculating the human exposure and the deposition dose, clearance, and finally retention of aerosol particles in the human respiratory tract (RT). PM10 concentration at the composting site was calculated as the sum of the concentration from compost pile dust resuspension and the background concentration. It was found that the exposure to PM10 and deposited lung dose for an adult Caucasian male who is not working at the composting site is less by 20–74% and 29–84%, respectively, compared to those for a worker exposed to PM concentrations at the composting site.

Development of stable HSPA1A promoter-driven luciferase reporter HepG2 cells for assessing the toxicity of organic pollutants present in air

HSPA1A (HSP70-1) is a highly inducible heat shock gene up-regulated in response to environmental stresses and pollutants. The aim of our study was to evaluate the sensitivity of the stable metabolically competent HepG2 cells containing a human HSPA1A promoter-driven luciferase reporter (HepG2-luciferase cells) for assessing the toxicity of organic pollutants present in air. The HepG2-luciferase cells were validated by heat shock treatment and testing three organic compounds (pyrene, benzo[a]pyrene, and formaldehyde) that are ubiquitous in the air. The maximal level of HSPA1A (HSP70-1) and relative luciferase activity induced by heat shock were over three and nine times the control level, respectively. Pyrene, benzo[a]pyrene, and formaldehyde all induced significantly elevated levels of relative luciferase activity in a dose-dependent manner. Extractable organic matter (EOM) from urban traffic and coke oven emissions in ambient air were tested on the HepG2-luciferase cells. The traffic EOM induced significant increase in relative luciferase activity at concentrations of picogram per liter. The coke oven EOM produced a strong dose-dependent induction of relative luciferase activity up to six times the control value. Significant increases in relative luciferase activity were observed at concentrations that were as low, or lower than the concentrations that the tested organic pollutants decreased cell viability, and increased malondialdehyde concentration, Olive tail moment, and micronuclei frequency. Therefore, we conclude that the HepG2-luciferase cells are a valuable tool for rapid screening of the overall toxicity of organic pollutants present in air.

On-board measurements of emissions from diesel trucks in five cities in China

Abstract This paper, which focuses on diesel trucks, is the third in a series of three papers published in Atmospheric Environment to understand vehicle emissions in China by conducting on-board emission measurements. Diesel trucks are a significant source of emissions in ambient air, especially for NOx. Recently, China announces an aggressive target to reduce national NOx emissions by 10% from 2010 to 2015 in the “Twelfth Five-Year Plan (2011–2015)” and diesel vehicles are identified as a key target for NOx control. However, the understanding of the real-world emissions of diesel trucks is limited. In this study, we measured HC, CO, NOx, and PM 2.5 emissions from 175 diesel trucks of different sizes and technologies in five Chinese cities during 2007 and 2011, and generated emission factors on the basis of the measurements. The results show that the HC, CO, and PM 2.5 emission factors have been reduced significantly as the emission standards become more stringent from Euro 0 to Euro IV, but the NOx emission factors change differently. Euro II trucks have 3–6% higher NOx emission levels than Euro I technologies and Euro III trucks fail to show a reduction as regulated by the standards. More stringent NOx requirements (e.g. Euro IV) for diesel vehicles need to be enforced. The comparison with the emission factors used in recent emission inventory studies shows that these inventories may have overestimated or underestimated diesel emissions for the years after 2006. This study emphasizes the importance of conducting local measurement research to improve the accuracy of the estimates of mobile emissions in China.

Life cycle inventory processes of the ArcelorMittal Poland (AMP) S.A. in Kraków, Poland—basic oxygen furnace steel production

The goal of this paper is to describe the life cycle inventory (LCI) approach to steel produced by ArcelorMittal’s Basic Oxygen Furnace (AMBOF) in Krakow, Poland. The present LCI is representative for the reference year 2005 by application of PN-EN ISO 14040:2009 (PN-EN ISO 2009). The system boundaries were labeled as gate-to-gate (covering a full chain process of steel production). The background input and output data from the basic oxygen furnace (BOF) steelmaking process has been inventoried as follows: pig iron, scrap, slag forming materials (CaO), ferroalloys, Al, carbon and graphite carburizer (material for carburization of steel), isolating powder, consumption of energy and fuels including natural gas, blast furnace gas and coke oven gas, electric energy, steam, air, oxygen, industrial water and heat, emission of air pollutants, waste, internal transport and land use. LCI steelmaking process was developed mainly on the basis of the following sources: site-specific measured or calculated data, study carried out by the AGH University of Science and Technology in Krakow, AMP Environmental Impact Report, study carried out by the Faculty of Mining Surveying and Environmental Engineering of the AGH University of Science and Technology in Krakow, literature information and expert consultations. The functional unit (FU) is represented by 1,677,987 Mg of steel, produced by BOF steelmaking process. Time coverage is 2005. Operating parameters as well as air emissions associated with the BOF steelmaking process were presented. The production data (steel) was given. The emissions of SO2, NO2, CO, CH4, CO2, dust, heavy metals (Cr, Cd, Cu, Pb, Ni and Mn) and waste (slag and gas cleaning sludge) are the most important outcomes of the steel process. With regard to 1,677,987 Mg of steel produced by AMBOF, the consumption of natural gas, blast furnace gas and coke oven gas amounted to 10,671,997, 755,094 and 13,222,537.6 m3/year, respectively. Electric energy, steam, air, oxygen and heat input amounts were in the order of 45,003,611.3 kWh, 21,646.03 Mg, 107,592,526 m3, 90,611,298 m3 and 16,779.87 GJ, respectively. Direct emissions in air of SO2, NO2, dust, Cr, Cd, Cu, Pb, Ni, Mn, CO and CH4 from three converters (Nos. 1–3) were on the order of 28.966, 71.331, 752.05, 0.025, 0.024, 0.0216, 0.0156, 0.0163, 1.5694, 540.449 and 0.364 Mg, respectively. Total CO2 emission was 138,374 Mg. The amounts of slag and gas cleaning sludge were 276,709.64 and 16,749 Mg, respectively. The LCI study resulted in the development of a database with a vast inventory of data regarding steelmaking process in AMBOF referring to the year 2005. The output of the AMBOF LCI study is a set of gate-to-gate LCI data for steel production in BOF technology. This is the first tentative study to express steel production in Poland in terms of LCA/LCI in the steelmaking industry. The FU chosen for the present study is 1,677,987 Mg of steel produced in a classical BOF. The quality of data input in this LCI study is very good. The rules were used in accordance with ISO Standard for LCA. The methodological approach and boundaries that were made are transparent and fully documented. The purpose of this study is to help AMP authorities solve environmental and technical aspects as well as to train steel industry people in the field of life cycle assessment. In addition, this study can be extended to other processes involved in steelmaking route (via sintering plant/hot rolling plant). Moreover, these results move the LCI study on the steelmaking process one step forward. The LCI offers environmental information consisting of the list of environmental loads. The impact assessment phase aims to present more understandable results from the inventory analysis, and life cycle impact assessment (LCIA) will be the direction for future research. Another issue to discuss is the integration of LCA with risk assessment for industrial processes.

Study of Mass Oxygen Transfer in a Biotrickling Filter for Air Pollution Control

Abstract Biotrickling filtration is a potential and cost effective alternative for the treatment of volatile organic compound (VOC) emissions in air, so it is necessary to deepen into the key aspects of design and operation for the optimization of this technology. One of these factors is the oxygen mass transfer of the process. This study would facilitate the selection of the packing material and the mathematical modelling and simulation of bioreactors. Four plastic packing materials with a different specific surface area have been evaluated in terms of oxygen mass transfer. For the tested range of superficial liquid velocities, data show a relationship between the kLa and the superficial liquid velocity in all packing materials used, except for the biggest plastic rings. No significant differences in mass transfer coefficients at low liquid velocities were observed, however dependency between oxygen transfer and specific surface area increased considerably for high liquid velocities. No significant influences of the superficial air velocity were observed.

The impact of plug-in vehicles on greenhouse gas and criteria pollutants emissions in an urban air shed using a spatially and temporally resolved dispatch model

With the introduction of plug-in vehicles (PEVs) into the light-duty vehicle fleet, the tail-pipe emissions of GHGs and criteria pollutants will be partly transferred to electricity generating units. To study the impact of PEVs on well-to-wheels emissions, the U.S. Western electrical grid serving the South Coast Air Basin (SoCAB) of California is modeled with both spatial and temporal resolution at the level of individual power plants. Electricity load is calculated and projected for future years, and the temporal electricity generation of each power plant within the SoCAB is modeled based on historical data and knowledge of electricity generation and dispatch. Due to the efficiency and pollutant controls governing the performance of the Western grid, the deployment of PEVs results in a daily reduction of greenhouse gases (GHGs) and tail-pipe emissions, especially in the critical morning and afternoon commute hours. The extent of improvement depends on charging scenarios, future grid mix, and the number and type of plug-in vehicles. In addition, charging PEVs using wind energy that would otherwise be curtailed can result in a substantial emissions reduction. Smart control will be required to manage PEV charging in order to mitigate renewable intermittencies and decrease emissions associated with peaking power production.

Determining the atmospheric sedimentation coefficient for emissions of ash taking its dispersion composition into account

Results from work on experimentally determining the dispersion composition of fly ash from Irkutskenergo TETs-9 cogeneration station, a procedure for correcting the coefficient for sedimentation of ash emissions in the atmosphere, and use of the obtained results in calculations on determining the dispersion of ash emissions in the atmospheric air are presented.

Effects of Riyadh cement industry pollutions on some physiological and morphological factors of Datura innoxia Mill. plant

Cement factory emissions into air cause serious air pollution and affect the plant and animal life in the environment. Herein, we report the effects of cement industry emissions (O 3, SO 2 and NO 2) in air, as pollutants, at Riyadh City on Datura innoxia Mill. plant. Morphological characters including plant height, leaves area and number, fresh and dry weight of shoot and root systems of D. innoxia showed a significant reduction from their normal control plants as a response to exposure to pollutant emissions. Chlorophyll and carotenoid contents recorded reductions in values compared to control plant, and the lowest values of chlorophyll A, B, total chlorophyll, carotenoids and total pigments were 0.431, 0.169, 0.60, 0.343 and 0.943 mg/g respectively at a distance of 1–5 m from the cement factory in fruiting stage. These changes in values may be attributed to a probable deceleration of the biosynthetic process rather than degradation of pigments. Further D. innoxia showed a significant ( P < 0.01) reduction in non-reducing and total sugars, protein and total lipid contents compared with the control plant. The root system recorded the lowest values of reducing sugars (0.350 mg/g f. wt.), non-reducing sugars (0.116 mg/g f. wt.), total sugars (0.466 mg/g f. wt.), protein content (0.931 mg/g f. wt.) and total lipids content (0.669 mg/g f. wt.) in fruiting stage at a distance of 1–5 m from the cement factory. The peroxidase activity of shoot and root systems of the studied plant was also significantly higher than those of control plant. Thus a highest value of (29.616 units/g f. wt.) peroxidase activity was recorded in vegetative stage of shoot system at a distance 1–5 m from the cement factory. Results of the study indicated that cement industry emission strongly influence the physiology and morphology of date palm D. innoxia which contribute date fruits, a staple food in the Arab world.

North American isoprene influence on intercontinental ozone pollution

Abstract. Changing land-use and climate may alter emissions of biogenic isoprene, a key ozone (O3) precursor. Isoprene is also a precursor to peroxy acetyl nitrate (PAN) and thus affects partitioning among oxidized nitrogen (NOy) species, shifting the balance towards PAN, which more efficiently contributes to long-range transport relative to nitric acid (HNO3) which rapidly deposits. With a suite of sensitivity simulations in the MOZART-2 global tropospheric chemistry model, we gauge the relative importance of the intercontinental influence of a 20% increase in North American (NA) isoprene and a 20% decrease in NA anthropogenic emissions (nitrogen oxides (NOx), non-methane volatile organic compounds (NMVOC) and NOx + NMVOC + carbon monoxide + aerosols). The surface O3 response to NA isoprene emissions (ΔO3_ISOP) in surface air over NA is about one third of the response to all NA anthropogenic emissions (ΔO3_ANTH; although with different signs). Over intercontinental distances, ΔO3_ISOP is relatively larger; in summer and fall, ΔO3_ISOP in surface air over Europe and North Africa (EU region) is more than half of ΔO3_ANTH. Future increases in NA isoprene emissions could thus offset decreases in EU surface O3 resulting from controls on NA anthropogenic emissions. Over the EU region, ΔPAN_ISOP at 700 hPa is roughly the same magnitude as ΔPAN_ANTH (oppositely signed). Outside of the continental source region, the percentage changes in PAN are at least twice as large as for surface O3, implying that long-term PAN measurements at high altitude sites may help to detect O3 precursor emission changes. We find that neither the baseline level of isoprene emissions nor the fate of isoprene nitrates contributes to the large diversity in model estimates of the anthropogenic emission influence on intercontinental surface O3 or oxidized nitrogen deposition reported in the recent TF HTAP multi-model studies (TFHTAP, 2007).

Chemosensory irritations and pulmonary effects of acute exposure to emissions from oriented strand board

Due to the reduction of air change rates in low-energy houses, the contribution to indoor air quality of volatile organic compounds (VOCs) emitting from oriented strand boards (OSB) has become increasingly important. The aim of this study was to evaluate sensory irritations, pulmonary effects and odor annoyance of emissions from OSB in healthy human volunteers compared to clean air. Twenty-four healthy non-smokers were exposed to clean air and OSB emissions for 2 h under controlled conditions in a 48 m(3) test chamber at three different time points: to fresh OSB panels and to the same panels after open storage for 2 and 8 weeks. Chemosensory irritation, exhaled nitric oxide (NO) concentration, eye blink frequency, lung function and subjective perception of irritation of eyes, nose and throat were examined before, during and after exposure. Additionally, olfactory perception was investigated. Total VOC exposure concentrations reached 8.9 ± 0.8 mg/m(3) for the fresh OSB panels. Emissions consisted predominantly of α-pinene, Δ(3)-carene and hexanal. Two-hour exposure to high VOC concentrations revealed no irritating or pulmonary effects. All the subjective ratings of discomfort were at a low level and the medians did not exceed the expression 'hardly at all.' Only the ratings for smell of emissions increased significantly during exposure in comparison to clean air. In conclusion, exposure of healthy volunteers to OSB emissions did not elicit sensory irritations or pulmonary effects up to a VOC concentration of about 9 mg/m(3). Sensory intensity of OSB emissions in the chamber air was rated as 'neutral to pleasant.'

A Study of Sources of Airborne Pollutants and Poor Hygiene in Schools

Poor indoor air quality is a large problem in Swedish schools, since the health of occupants may be affected. Resources are consumed without identification of utility indicators and there is risk of problems, even after remedial measures have been taken. This can mean both unnecessary suffering for many people and considerable resources being wasted. The building itself is often in focus and other building-related problems may be neglected. The hypothesis of the present work is that other factors than the building itself have decisive influence on indoor air quality. An assessment of these nonbuilding-related reasons for bad indoor air quality has been made in the present study using particle measurements. Results show that it is possible to decrease emissions in indoor air by over 90% through identifying and eliminating activity-related sources of airborne contaminants.