- Roskilde, Denmark
... (Agriculture) as one sector; minor emissions in other SN AP sectors Simple schematic daily and seasonal v ariations D AMOS/ DEHM NERI (Christensen 1997; Frohn 2001, 2002, 2004) Nested grid 3-D Euler ian 20 v ertical layers with... more
... (Agriculture) as one sector; minor emissions in other SN AP sectors Simple schematic daily and seasonal v ariations D AMOS/ DEHM NERI (Christensen 1997; Frohn 2001, 2002, 2004) Nested grid 3-D Euler ian 20 v ertical layers with highest resolution in the PBL. ...
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• A range of chemical transport models are used across the Convention to model the emission, transport and deposition of atmospheric ammonia at the national and regional scale. These models have been developed from a range of historical... more
• A range of chemical transport models are used across the Convention to model the emission, transport and deposition of atmospheric ammonia at the national and regional scale. These models have been developed from a range of historical backgrounds and with different purposes in mind. • Six models ranging from describing the national scale up to the full European scale
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Abstract Methods, parameterisations and models have been developed, which give insight in processes that are important for deposition of nitrogen compounds to the sea. This knowledge has been applied to the Kattegat Strait for which a... more
Abstract Methods, parameterisations and models have been developed, which give insight in processes that are important for deposition of nitrogen compounds to the sea. This knowledge has been applied to the Kattegat Strait for which a nitrogen deposition of 960 kg N km-2 yr-1 was calculated with an atmospheric transport model.
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... Berge, Haldis; Bleeker, Albert; Cuvelier, Kees; Dentener, Frank; Dore, Tony; Erisman, Jan Willem; Fagerli, Hilde; Flechard, Chris; Hertel, Ole ... Howard, Clare M.; Erisman, Jan Willem; Billen, Gilles; Bleeker, Albert; Grennfelt,... more
... Berge, Haldis; Bleeker, Albert; Cuvelier, Kees; Dentener, Frank; Dore, Tony; Erisman, Jan Willem; Fagerli, Hilde; Flechard, Chris; Hertel, Ole ... Howard, Clare M.; Erisman, Jan Willem; Billen, Gilles; Bleeker, Albert; Grennfelt, Peringe; van Grinsven, Hans; Grizzetti, Bruna, (eds.) The ...
Very few studies on human exposure to allergenic pollen have been conducted using direct methods, with background concentrations measured at city center monitoring stations typically taken as a proxy for exposure despite the inhomogeneous... more
Very few studies on human exposure to allergenic pollen have been conducted using direct methods, with background concentrations measured at city center monitoring stations typically taken as a proxy for exposure despite the inhomogeneous nature of atmospheric pollen concentrations. A 2003 World Health Organization report highlighted the need for an improved understanding of the relation between monitoring station data and actual exposure. To investigate the relation between grass pollen dose and background concentrations measured at a monitoring station, to assess the fidelity of monitoring station data as a qualitative proxy for dose, and to evaluate the ratio of dose rate to background concentration. Grass pollen dose data were collected in Aarhus, Denmark, in an area where grass pollen sources were prevalent, using Nasal Air Samplers. Sample collection lasted for approximately 25 to 30 minutes and was performed at 2-hour intervals from noon to midevening under moderate exercise by 2 individuals. A median ratio of dose rate to background concentration of 0.018 was recorded, with higher ratio values frequently occurring at 12 to 2 PM, the time of day when grass species likely to be present in the area are expected to flower. From 4 to 8 PM, dose rate and background concentration data were found to be strongly and significantly correlated (rs = 0.81). Averaged dose rate and background concentration data showed opposing temporal trends. Where local emissions are not a factor, background concentration data constitute a good quantitative proxy for inhaled dose. The present ratio of dose rate to background concentration may aid the study of dose-response relations.
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The frequently observed eutrophication problems in Danish marine waters are associated with high nutrient loads. This paper outlines how the atmospheric part of the load is determined within the framework of the Danish Background... more
The frequently observed eutrophication problems in Danish marine waters are associated with high nutrient loads. This paper outlines how the atmospheric part of the load is determined within the framework of the Danish Background Monitoring Programme. The analyses within the programme are carried out by use of both measurements and model calculations, where the modelling part receives the main focus
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This exposure study addresses the validity of the exposure assessment method of an epidemiological study of traffic-related air pollution and childhood cancer. In particular, this paper concerns the question of whether the concentration... more
This exposure study addresses the validity of the exposure assessment method of an epidemiological study of traffic-related air pollution and childhood cancer. In particular, this paper concerns the question of whether the concentration of nitrogen dioxide (NO2) outside the front door is a valid marker of the exposure of the child living at the address. The study includes 100 children living on streets with dense traffic in central parts of Copenhagen and 100 children living in rural areas. Preliminary results, based on 25% of the study subjects, suggest that both the outdoor NO2-concentration and the exposure of the children are two to three times higher in Copenhagen than in the rural districts. Moreover, the results suggest that the NO2-concentration outside the front door is a poor marker of the exposure of the children in Copenhagen, but a marker of some relevance for the exposure of the children in rural districts. The preliminary results must be treated with caution, as among other things, the analysis did not consider seasonal changes and indoor NO2-sources such as passive smoking, candles, and gas appliances.
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Page 1. CSIRO PUBLISHING Review www.publish.csiro.au/journals/env O. Hertel et al., Environ. Chem. 2006, 3, 317337. doi:10.1071/EN06038 Modelling Nitrogen Deposition on a Local ScaleA Review of the Current State of the Art ...
Research Interests: Earth Sciences, Computational Chemistry, Ethics, Climate Change, Forensic Science, and 43 moreAtmospheric Chemistry, Green Chemistry, Speciation, Membranes, Electrochemistry, Catalysis, Kinetics, Photochemistry, Biotechnology, Astrochemistry, Biogeochemical cycles, Soil Chemistry, Capillary electrophoresis, Environmental Chemistry, Risk assessment, Chemical Oceanography, Instrumentation, Quality Control, Ab initio calculations, DNA, Sensors, Environmental Sciences, Photocatalysis, Micelles, HPLC, Scientific, Educational, Biomagnification, Ecosystems, Nitrogen deposition, Sediments, Microbial Degradation, Pollutants, Social Issues, CHEMICAL SCIENCES, Hazard Assessment, Greenhouse gases, Ozone, Xenobiotics, Contaminants, Risk Assessment, Radicals, and Environmental
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Research Interests: Environmental Monitoring, England, Aerosols, Denmark, Pollen, and 6 moreWind, Poaceae, Urticaceae, Humidity, Seasons, and Air Pollutants
Benzene has been implicated as an environmental risk factor in leukaemia and other haematological diseases. Relationships between urban benzene exposure, oxidative DNA damage and polymorphisms in metabolism enzymes were examined in 40... more
Benzene has been implicated as an environmental risk factor in leukaemia and other haematological diseases. Relationships between urban benzene exposure, oxidative DNA damage and polymorphisms in metabolism enzymes were examined in 40 volunteers living and working in Copenhagen. Personal exposures to benzene, toluene and methyl tert-butyl ether (MTBE) were monitored during a 5-day period. DNA damage was measured by 7-hydro-8-oxo-2′-deoxyguanosine (8-oxodG) in lymphocyte DNA and urine and by comet assay with use of fapyguanine glycosylase (FPG) and endonuclease III (ENDO). Excretion of the benzene metabolites trans,trans-muconic acid (ttMA) and S-phenylmercapturic acid (S-PMA) were measured in urine. Polymorphisms in glutathione-S-transferases T1 (GSTT1), M1 (GSTM1) and P1 (GSTP1) and NAD(P)H:quinone oxidoreductase (NQO) were determined. Median exposures to benzene, toluene and MTBE were 2.5, 18.7 and 0.86 μg/m3. No significant correlations between external benzene exposure and any of the biomarkers were found. However, a significant correlation between S-PMA excretion and 8-oxodG in lymphocytes was found (Rs=0.39). Men were found to excrete significantly more ttMA than the women did and ttMA excretion in men was found to be significantly associated with external benzene exposure (R=0.53, P=0.025). In addition, ttMA and S-PMA excretion was significantly higher in subjects with the NQO+/−genotype compared with subjects with the wild type (P=0.004 and P=0.011, respectively). Even though there are some limitations in this study due to the low range of benzene exposure and biomarker concentrations as well as a small number of subjects, these results could suggest that even at ambient concentrations exposure to benzene could have genotoxic effects in susceptible individuals.
Research Interests: Polymorphism, Oxidative Stress, DNA damage, Multidisciplinary, Humans, and 15 moreFemale, Male, Glutathione, Enzyme, Comet Assay, Urinalysis, Middle Aged, Adult, Genetic Polymorphism, Biological markers, Benzene, Glutathione Transferase, Environmental Pollutants, Lymphocytes, and Oxidative Dna Damage
In most cities the traffic is the prime source of air pollution. The wind flow determines the levels of air pollution in urban areas. For ground level sources, like traffic, the highest concentrations occur at low wind speed conditions.... more
In most cities the traffic is the prime source of air pollution. The wind flow determines the levels of air pollution in urban areas. For ground level sources, like traffic, the highest concentrations occur at low wind speed conditions. The frequency of low wind speed conditions is considerably higher in Milan than in Copenhagen. As a result of that, the pollution levels in Milan are much higher than in Copenhagen. An additional factor is that the contribution of domestic heating to NOx concentration in Milan is substantial especially in winter months. In the case of higher wind speeds, pollution levels in Milan and Copenhagen are comparable. The atmospheric stability is less important for dispersion of pollutants from vehicle exhaust gases within the street. Urban background concentrations exhibit strong dependence on wind speed too. The highest levels occur during conditions with a strong ground level inversion, conditions which are also characterized by low wind speed.
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The aim of the study was to evaluate the predictions derived from the Danish Operational Street Pollution Model (OSPM) when the input data are obtained by simple methods that could be used in large-scale epidemiological studies. The model... more
The aim of the study was to evaluate the predictions derived from the Danish Operational Street Pollution Model (OSPM) when the input data are obtained by simple methods that could be used in large-scale epidemiological studies. The model calculations were thus compared with passive sampler measurements of nitrogen dioxide and benzene at 103 street locations in Copenhagen, Denmark, and at 101 locations in rural areas. Data on traffic and street configuration were collected by means of a simple registration scheme in which forms were filled out by local municipal authorities. Meteorological data were derived from routine measurements at Copenhagen airport, and data on background air pollution were based on a simple empirical model. Differences in air pollution levels between rural areas and Copenhagen and differences in nitrogen dioxide concentrations at various locations in Copenhagen were well reproduced by the OSPM. The correlation coefficients (r) between the measured and the predicted half-year average concentrations of nitrogen dioxide in Copenhagen were between 0.75 and 0.80 for various degrees of precision of the input data for the model. The results indicate that the OSPM used with the presented methods for generation of input data might be useful in assessing long-term exposure to air pollutants in epidemiological studies.
Research Interests: Research Design, Air pollution, Environmental Pollution, Denmark, Environmental Sciences, and 14 moreHumans, Vehicle Emissions, CHEMICAL SCIENCES, Shell Half-Life, Theoretical Models, Benzene, Correlation coefficient, Rural Area, Passive sampler, Large Scale, Nitrogen Dioxide, Epidemiologic Studies, Empirical Model, and Air Pollutants
Research Interests: Environmental Health, Environmental Monitoring, Oxidative Stress, DNA damage, Environmental Sciences, and 16 moreHumans, Bicycling, Carbon Monoxide, Cooking, Vehicle Emissions, Female, Male, Exercise, Indoor air pollution, Adult, Particle Size, Dust, Nitrogen Oxides, Oxidative Dna Damage, Cross-Over Studies, and Air Pollutants
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A new prototype model system named AirGIS has been developed to support local authorities in air quality management for big Danish cities. The system is based on the Danish operational street pollution model (OSPM), technical and... more
A new prototype model system named AirGIS has been developed to support local authorities in air quality management for big Danish cities. The system is based on the Danish operational street pollution model (OSPM), technical and cadastral digital maps and Danish national administrative databases on buildings, cadastres and populations. It applies a geographic information system (GIS). AirGIS estimates ambient air pollution levels at high temporal and spatial resolutions. The model system enables mapping of traffic emissions, air quality levels and human exposures at residence addresses, at workplace addresses and in streets. Mapping and scenario results can be compared with air quality limits. Impact assessment of traffic air pollution abatement measures can also be carried out.
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Measurements of urban air pollution are usually confined to a few locations within a city area. Monitoring stations are often situated in streets with significant traffic levels or in places where severe pollution problems are expected.... more
Measurements of urban air pollution are usually confined to a few locations within a city area. Monitoring stations are often situated in streets with significant traffic levels or in places where severe pollution problems are expected. Such measurements are naturally influenced by very local conditions and care must be taken in interpreting the results. This is especially important when the measurements are used for estimating urban air pollution levels or comparing air quality in different cities. Another frequent application of street measurements is for public information or warning the population of elevated pollution levels. Estimating the dangers of long-term exposure to air pollution means careful consideration must be given to how representative these measurements actually are. In this paper the influence of local conditions on air pollution concentrations is discussed, regarding especially the dependency of pollution levels on street configuration and meteorolgical parameters. The examples used are based on measurements from locations in Copenhagen and on model calculations using the Danish Operational Street Pollution Model (OSPM). It is shown that large concentration gradients can occur in street canyons with leeward concentrations far higher than windward concentrations. Thus, street measurements are site-dependent and not representative for urban areas. Model calculations with OSPM agree well with measurements.
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ABSTRACT Ammonia emissions are mainly related to agricultural activities, and depositions related to these emissions constitute a treat to local ecosystems but possibly also to human health through the contribution for formation of... more
ABSTRACT Ammonia emissions are mainly related to agricultural activities, and depositions related to these emissions constitute a treat to local ecosystems but possibly also to human health through the contribution for formation of secondary fine fraction particles in ambient air. European ammonia emissions are highly heterogeneously distributed, and the temporal variations in these emissions follow very different pattern as a result of differences in climate but also as a results of significant differences in agricultural practice over Europe. A minor fraction of ammonia emission is related to nonagricultural sources, especially traffic. These sources are mainly found in areas with intense traffic and the use of catalyst converters. Simple and comprehensive models for the spatial and temporal variation in ammonia emissions have been shown useful in modelling of atmospheric nitrogen input to sensitive ecosystems for assessments of critical loads. For the spatial distribution various emission inventories are available at different resolutions. These inventories are derived using different approaches, and as a result they can differ up to a factor of two for certain areas. The overall European ammonia emissions are decreasing as a result of regulation related to the National Emission Ceiling Directive (NEC) and the Integrated Pollution Prevention and Control (IPPC) directive, regulation that has been implemented in national legislation in the single European countries. Some countries have adopted screening methods to be used by local authorities when assessing impact on local ecosystems in relation to applications from farmers to obtain permissions to increase agricultural production. In general Northern European countries have more strict regulation of ammonia emissions compared with Central and Southern European countries.
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Low DNA-repair capacity has been associated with increased risk of several types of cancer. mRNA levels of the nucleotide excision repair genes ERCC1 and XPD have been shown to correlate with the DNA-repair capacity. Likewise, mRNA levels... more
Low DNA-repair capacity has been associated with increased risk of several types of cancer. mRNA levels of the nucleotide excision repair genes ERCC1 and XPD have been shown to correlate with the DNA-repair capacity. Likewise, mRNA levels of several DNA-repair genes including ERCC1 have been shown to be lower in lymphocytes from patients with lung cancer and head and neck cancer compared with healthy persons. In these studies, the low DNA-repair gene expression levels could be either a risk factor for disease or a consequence of the same. In this nested case-cohort study, which to our knowledge, is the first prospective study of DNA-repair gene mRNA levels as predictors of lung cancer, we have investigated the occurrence of lung cancer in relation to the mRNA level of the two DNA-repair genes ERCC1 and XPD and the NF kappaB inhibitor RAI in blood samples prior to disease. Among 54,220 members of a Danish prospective cohort study, 265 lung cancer cases were identified and a sub-cohort comprising 272 individuals was used for comparison. The expression levels of the three adjacent genes were found to be highly inter-correlated, to be higher in women compared to men and to be lower in older individuals. The incidence rate ratios for lung cancer in association with one log-unit increase (natural logarithm) in mRNA levels were 1.12 (CI=0.89-1.41) for ERCC1, 1.00 (CI=0.83-1.21) for XPD and 1.25 (0.89-1.74) for RAI. In conclusion, this study indicated no association between mRNA expression of the DNA-repair genes ERCC1 and XPD and risk of subsequent development of lung cancer.
Research Interests: DNA repair, Apoptosis, Gene expression, Lung Cancer, Denmark, and 15 moreProspective studies, Humans, Mutation, Head and Neck Cancer, Blood sampling, Cohort Study, Nucleotide Excision Repair, Risk factors, Middle Aged, mRna expression levels, mRNA, Risk Factors, Lymphocytes, DNA binding proteins, and Prospective Study
The atmospheric chemistry and deposition model has been applied for calculation of nitrogen and sulphur depositions to the entire North Sea area for the year 1999. The total atmospheric nitrogen and sulphur depositions to the North Sea... more
The atmospheric chemistry and deposition model has been applied for calculation of nitrogen and sulphur depositions to the entire North Sea area for the year 1999. The total atmospheric nitrogen and sulphur depositions to the North Sea area were determined to 709 kton (kt) N and 551 kt S, respectively. Since the North Sea area was calculated to be 747,988 km2, this is equivalent to an average deposition of 0.9 ton N km−2 and 0.7 ton S km−2, respectively. The depositions decrease strongly from the south end (about 2–3 kt N km−2) to the north end (about 0.2 kt N km−2) of the North Sea, due to increasing distance to the large source areas in the northern part of the European continent. The territorial waters of Belgium, the Netherlands and Germany receive about 50% higher deposition densities than the average value for the entire North Sea area. For the remaining territorial waters of the North Sea the depositions follow more or less the fraction of the area. The results furthermore show that about 60% of the total nitrogen deposition is related to emissions from combustion sources (nitrogen oxides) and about 40% from emissions related to agricultural activities (ammonia).
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... effect of pollution exposure, for example, in terms of oxidative damage of DNA determined in ... Theretention time is relatively short (few minutes) and only very fast reactions take place ... traffic categories, ie high NOx emitters... more
... effect of pollution exposure, for example, in terms of oxidative damage of DNA determined in ... Theretention time is relatively short (few minutes) and only very fast reactions take place ... traffic categories, ie high NOx emitters (diesel vehicles especially heavy-duty vehicles) are also ...
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A method to determine emissions from the actual car fleet under realistic driving conditions has been developed. The method is based on air quality measurements, traffic counts and inverse application of street air quality models. Many... more
A method to determine emissions from the actual car fleet under realistic driving conditions has been developed. The method is based on air quality measurements, traffic counts and inverse application of street air quality models. Many pollutants are of importance for assessing the adverse impact of the air pollution, e.g. NO2, CO, lead, VOCs and particulate matter. Aromatic VOCs are of special great concern due to their adverse health effects. Measurements of benzene, toluene and xylenes were carried out in central Copenhagen since 1994. Significant correlation was observed between VOCs and CO concentrations, indicating that the petrol engine vehicles are the major sources of VOC air pollution in central Copenhagen. Hourly mean concentrations of benzene were observed to reach values of up to 20 ppb, what is critically high according to the WHOs recommendations. Based on inverse model calculation of dispersion of pollutants in street canyons, an average emission factor of benzene for the fleet of petrol fuelled vehicles was estimated to be 0.38 g/km in 1994 and 0.11 in 1997. This decrease was caused by the reduction of benzene content in Danish petrol since summer 1995 and increasing percentage of cars equipped with three-way catalysts. The emission factors for benzene for diesel-fuelled vehicles were low.
Research Interests: Air Quality, Modeling, Air pollution, Urban Health, Multidisciplinary, and 17 moreDenmark, Humans, Vehicle Emissions, Lead, Trend Analysis, Inverse Problem, Air Pollution Modelling, Inverse Modeling, Atmospheric Dispersion, Theoretical Models, Urban Air Quality, Time Factors, Street Canyon, Particulate Matter, Benzene, Health Effect, and Air Pollutants
We investigated whether there is an interaction between distance from residence at birth to nearest power line and domestic radon and traffic-related air pollution, respectively, in relation to childhood leukemia risk. Further, we... more
We investigated whether there is an interaction between distance from residence at birth to nearest power line and domestic radon and traffic-related air pollution, respectively, in relation to childhood leukemia risk. Further, we investigated whether adjusting for potential confounders alters the association between distance to nearest power line and childhood leukemia. We included 1024 cases aged <15, diagnosed with leukemia during 1968-1991, from the Danish Cancer Registry and 2048 controls randomly selected from the Danish childhood population and individually matched by gender and year of birth. We used geographical information systems to determine the distance between residence at birth and the nearest 132-400 kV overhead power line. Concentrations of domestic radon and traffic-related air pollution (NOx at the front door) were estimated using validated models. We found a statistically significant interaction between distance to nearest power line and domestic radon regarding risk of childhood leukemia (p = 0.01) when using the median radon level as cut-off point but not when using the 75th percentile (p = 0.90). We found no evidence of an interaction between distance to nearest power line and traffic-related air pollution (p = 0.73). We found almost no change in the estimated association between distance to power line and risk of childhood leukemia when adjusting for socioeconomic status of the municipality, urbanization, maternal age, birth order, domestic radon and traffic-related air pollution. The statistically significant interaction between distance to nearest power line and domestic radon was based on few exposed cases and controls and sensitive to the choice of exposure categorization and might, therefore, be due to chance.
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Exposure to ambient air pollution has been associated with cancer. Ambient air contains a complex mixture of toxics, including particulate matter (PM) and benzene. Carcinogenic effects of PM may relate both to the content of PAH and to... more
Exposure to ambient air pollution has been associated with cancer. Ambient air contains a complex mixture of toxics, including particulate matter (PM) and benzene. Carcinogenic effects of PM may relate both to the content of PAH and to oxidative DNA damage generated by transition metals, benzene, metabolism and inflammation.By means of personal monitoring and biomarkers of internal dose, biologically effective dose and susceptibility, it should be possible to characterize individual exposure and identify air pollution sources with relevant biological effects. In a series of studies, individual exposure to PM2.5, nitrogen dioxide (NO2) and benzene has been measured in groups of 40–50 subjects. Measured biomarkers included 1-hydroxypyrene, benzene metabolites (phenylmercapturic acid (PMA) and trans-trans-muconic acid (ttMA)), 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) in urine, DNA strand breaks, base oxidation, 8-oxodG and PAH bulky adducts in lymphocytes, markers of oxidative stress in plasma and genotypes of glutathione transferases (GSTs) and NADPH:quinone reductase (NQO1).With respect to benzene, the main result indicates that DNA base oxidation is correlated with PMA excretion. With respect to exposure to PM, biomarkers of oxidative damage showed significant positive association with the individual exposure. Thus, 8-oxodG in lymphocyte DNA and markers of oxidative damage to lipids and protein in plasma associated with PM2.5 exposure. Several types of DNA damage showed seasonal variation. PAH adduct levels, DNA strand breaks and 8-oxodG in lymphocytes increased significantly in the summer period, requiring control of confounders. Similar seasonal effects on strand breaks and expression of the relevant DNA repair genes ERCC1 and OGG1 have been reported.In the present setting, biological effects of air pollutants appear mainly related to oxidative stress via personal exposure and not to urban background levels. Future developments include personal time-resolved monitors for exposure to ultrafine PM and PM2.5, use of GPS, as well as genomics and proteomics based biomarkers.
Research Interests: Genetics, Air pollution, DNA damage, DNA repair, Transition-Metal Oxides, and 18 moreHumans, Mutation, Ambient Air Pollution, Glutathione, Time Resolved, Carcinogens, Seasonal variation, Reviews, Oxidative Damage, Neoplasms, Particulate Matter, Quinone Reductase, Environmental Pollutants, Oxidative Dna Damage, Nitrogen Dioxide, Environmental Exposure, Air Pollutants, and Transition metal oxides
... than 250,000 inhabitants and areas that otherwise justify assessment. Urban airquality management has to encompass monitoring, assessment (eg, by modelling), and information to the public (European Commission, 1996). ...