Per Løfstrøm

Modelling Nitrogen Deposition on a Local Scale—A Review of the Current State of the Art

Abstract. Local ammonia emissions from agricultural activities are often associated with high nitrogen deposition in the close vicinity of the sources. High nitrogen (N) inputs may significantly affect the local ecosystems. Over a longer term, high loads may change the composition of the ecosystems, leading to a general decrease in local biodiversity. In Europe there is currently a significant focus on the impact of atmospheric N load on local ecosystems among environmental managers and policy makers. Model tools designed for application in N deposition assessment and aimed for use in the regulation of anthropogenic nitrogen emissions are, therefore, under development in many European countries. The aim of this paper is to present a review of the current understanding and modelling parameterizations of atmospheric N deposition. A special focus is on the development of operational tools for use in environmental assessment and regulation related to agricultural ammonia emissions. For the often large number of environmental impact assessments needed to be carried out by local environmental managers there is, furthermore, a need for simple and fast model systems. These systems must capture the most important aspects of dispersion and deposition of N in the nearby environment of farms with animal production. The paper includes a discussion on the demands on the models applied in environmental assessment and regulation and how these demands are fulfilled in current state-of-the-art models.

Residential exposure to outdoor air pollution from livestock operations and perceived annoyance among citizens

Epidemiological studies have shown that residential exposure to livestock odors can affect the health and wellbeing of rural citizens. However, exposure-response models for this relationship have not been developed. One of the main challenges is to identify a compound that can be used as proxy for livestock odor exposure. In this paper we developed models that describe the relationship between long-term averaged outdoor residential ammonia (NH(3)) exposures and livestock odor annoyance experienced by rural residents, and investigated person-related variables associated with annoyance responses. We used emission-based atmospheric dispersion modeling data to estimate household-specific outdoor concentrations and survey data to characterize the study subjects. Binomial and multinomial logistic regressions were used for model development. Residential NH(3) exposure was positively associated with moderate, high and extreme odor annoyance (adjusted odds ratio=10.59; 95% confidence interval: 1.35-83.13, for each unit increase in Log(e)NH(3) exposure). Specific characteristics of the exposed subjects (i.e., age, time per week spent at home, presence of children at home and job) act as co-determinants of odor annoyance responses. Predictive models showed classification accuracies of 67-72%. The results suggest that NH(3) exposure in the residential outdoor environment can be used as a predictor of livestock odor annoyance in population studies.

Integrated air-quality monitoring - combined use of measurements and models in monitoring programmes

Environmental context. Optimisation of allocated resources, improved quality, and better understanding of processes – these are the main advantages of applying integrated monitoring (IM). The paper describes IM as a combination of air pollution measuring and modelling, and describes how it is implemented in air-quality management in Denmark. However, the IM concept may also be applied to follow air-quality levels in other countries that currently do not have a corresponding system. It may also be applied to the environmental monitoring of other compartments. Abstract. Integrated air-quality monitoring (IM) is here defined as monitoring based on the combination of results of atmospheric measurements from usually fixed site stations, and results obtained from calculations with air-quality models. This paper outlines experience from the use of IM at the National Environmental Research Institute (NERI) within the two nationwide air-quality monitoring programmes for the Danish urban and rural environments, respectively. The measurements in these Danish monitoring programmes are used to determine actual levels and trends in pollutant concentrations and depositions of pollutants. The measurements are further used for process understanding, and for the development and validation of air-quality models. The results from the air-quality models are used in the interpretation of measurements, but they are also used to provide information about, for example, source apportionment. The model calculations are used to extend the geographical coverage of the monitoring, and to provide information about pollution loads at locations or regions that are not well covered by the limited number of measurement stations in the monitoring programmes. Finally, the air-quality models are applied to carry out scenario studies of future pollution loads, e.g. assessment of the effects of various emission reduction strategies. NERI operates and holds the overall responsibility for the Danish air-quality monitoring programmes. These monitoring programmes are designed to fulfil the Danish obligations in relation to the EU directives on air quality, as well as the Danish obligations in relation to the reporting of data to international organisations (EMEP, HELCOM, OSPARCOM, and WHO). The obtained results from the use of IM form the basis for the national assessment of the air pollution loads in relation to protection of the aquatic and terrestrial environment; in these assessments the use of IM plays a central role.

Perceived annoyance from environmental odors and association with atmospheric ammonia levels in non-urban residential communities: a cross-sectional study

ObjectiveOdor exposure is an environmental stressor that is responsible of many citizens complains about air pollution in non-urban areas. However, information about the exposure-response relation is scarce. One of the main challenges is to identify a measurable compound that can be related with odor annoyance responses. We investigated the association between regional and temporal variation of ammonia (NH3) concentrations in five Danish non-urban regions and environmental odor annoyance as perceived by the local residents.MethodsA cross-sectional study where NH3 concentration was obtained from the national air quality monitoring program and from emission-dispersion modelling, and odor pollution perception from questionnaires. The exposure-response model was a sigmoid model. Linear regression analyses were used to estimate the model constants after equation transformations. The model was validated using leave-one-out cross validation (LOOCV) statistical method.ResultsAbout 45% of the respondents were annoyed by odor pollution at their residential areas. The perceived odor was characterized by all respondents as animal waste odor. The exposure-annoyance sigmoid model showed that the prevalence of odor annoyance was significantly associated with NH3 concentrations (measured and estimated) at the local air quality monitoring stations (p < 0.01,R2 = 0.99; and p < 0.05,R2 = 0.93; respectively). Prediction errors were below 5.1% and 20% respectively. The seasonal pattern of odor perception was associated with the seasonal variation in NH3 concentrations (p < 0.001, adjusted R2 = 0.68).ConclusionThe results suggest that atmospheric NH3 levels at local air quality stations could be used as indicators of prevalence of odor annoyance in non-urban residential communities.

Respiratory and sensory irritation symptoms among residents exposed to low-to-moderate air pollution from biodegradable wastes.

Previous studies have reported increased occurrence of respiratory and sensory irritation symptoms among residents living close to biodegradable waste sites. However, few studies have been able to quantify direct and annoyance-mediated effects based on individual-specific assessments of chemical exposures. We examined associations between residential exposures to a proxy gas (ammonia, NH3) from biodegradable wastes (mainly from farming, animal and agricultural activities) and odor annoyance and six respiratory and sensory irritation symptoms (self-reported), using adjusted logistic regression models and mediation analyses. Individual-specific NH3 exposures (n=454) in residential environments during 2005–2010 were calculated by the Danish Eulerian long-range transport model and the local-scale transport deposition model. Residential NH3 exposure was associated with increased frequency of four symptoms, including “eyes itching, dryness or irritation” and “cough” (ORadj=1.69; 95% CI: 1.09–2.61 and ORadj=1.75; 95% CI: 1.12–2.74, for each unit increase in loge(NH3 exposure)). Odor annoyance mediated the effect of exposure on cough and three sensory irritation symptoms. Mediation was either full (indirect-only effects) or partial (direct and indirect effects). This study provides support for the existence of indirect associations between residential exposures to low-to-moderate air pollution from wastes and symptoms, as well as direct dose-response associations for some of the symptoms.

Relationship Between Atmospheric Ammonia Concentration and Nitrogen Content in Terricolous Lichen (Cladonia portentosa)

From April 2006 to April 2007, the geographical and seasonal variation in nitrogen content in terricolous lichen (Cladonia portentosa) and atmospheric ammonia concentrations were measured at five heathland sites. The seasonal variation in the nitrogen content of the lichen was small, even though there was a large seasonal variation in the air concentration of ammonia. A sizable local variation in the nitrogen content of the lichen was found even at the scale of a few kilometres. The nitrogen content in the lichen showed a high correlation to the yearly mean value of the measured ammonia concentration in air at the different locations. This investigation is part of a larger attempt to incorporate effects of nitrogen in the conservation status of terrestrial habitat types.

Characterization of exposure in epidemiological studies on air pollution from biodegradable wastes: Misclassification and comparison of exposure assessment strategies

The assignment of exposure is one of the main challenges faced by environmental epidemiologists. However, misclassification of exposures has not been explored in population epidemiological studies on air pollution from biodegradable wastes. The objective of this study was to investigate the use of different approaches for assessing exposure to air pollution from biodegradable wastes by analyzing (1) the misclassification of exposure that is committed by using these surrogates, (2) the existence of differential misclassification (3) the effects that misclassification may have on health effect estimates and the interpretation of epidemiological results, and (4) the ability of the exposure measures to predict health outcomes using 10-fold cross validation. Four different exposure assessment approaches were studied: ammonia concentrations at the residence (Metric I), distance to the closest source (Metric II), number of sources within certain distances from the residence (Metric IIIa,b) and location in a specific region (Metric IV). Exposure-response models based on Metric I provided the highest predictive ability (72.3%) and goodness-of-fit, followed by IV, III and II. When compared to Metric I, Metric IV yielded the best results for exposure misclassification analysis and interpretation of health effect estimates, followed by Metric IIIb, IIIa and II. The study showed that modelled NH3 concentrations provide more accurate estimations of true exposure than distances-based surrogates, and that distance-based surrogates (especially those based on distance to the closest point source) are imprecise methods to identify exposed populations, although they may be useful for initial studies.

Residential exposure to outdoor air pollution from livestock operations and perceived annoyance among citizens.

Odor exposure is an environmental stressor that is responsible of many citizens complains about air pollution in non-urban areas. However, there is very little information about the exposure-response relationship. One of the main challenges is to identify a measurable compound that can be related with odor annoyance responses. We investigated the association between regional and temporal variations of ammonia (NH3) concentrations in five Danish non-urban regions and environmental odor annoyance as perceived by the local residents. Ammonia concentrations were obtained from the national air quality monitoring program and from emission-dispersion modelling, and odor pollution perception from questionnaires. The model was validated using leave-one-out cross validation (LOOCV) statistical method. About 45% of the respondents were annoyed by odor pollution at their residential areas. The perceived odor was characterized by all respondents as animal waste odor. The exposure-annoyance sigmoid model showed that the prevalence of odor annoyance was significantly associated with NH3 concentrations. The seasonal pattern of odor perception was associated with the seasonal variation in NH3 concentrations. The results suggest that atmospheric NH3 levels measured at local air quality stations or estimated at the residences from emission-dispersion models could be used as indicators of odor annoyance in non-urban residential communities.

Civilian exposure to munitions-specific carcinogens and resulting cancer risks for civilians on the Puerto Rican island of Vieques following military exercises from 1947 to 1998

Abstract Estimation of legacy public health risks from munitions residues near or at former military test ranges has for the past decades been a challenge to health authorities. Parts of the island of Vieques (PR) were for six decades used for military training, and these are now declared as a Superfund site. ATSDR has conducted site assessments there and found no cause for public health concerns. The reports and findings of ATSDR have since been heavily contested and disputed. This paper provides a case study on cancer risk screening of munitions-specific carcinogens for the full period of military training on Vieques. Added cancer risks and Margins of Exposure for the different carcinogens for each year were derived. We found that there is a potential for cancer risk concern related to BaP exposures. Furthermore, there were health risks from TNT exposures. The primary exposure route of these compounds was oral. The period 1992–1997 showed a significantly elevated lung and bronchus cancer incidence rate in Vieques compared to Puerto Rico mainland mainly among women <50 yr and men 50–64 yr. These correlate with high munitions exposures in the period 1977–1984.

Assessment Methods for Ammonia Hot-Spots

To date, most attention in modelling NH3 dispersion and deposition has focused on the regional and Euopean scale, and little attention has been given to dealing with NH3 in hot-spot areas. The Working Group addressed the issue of hot-spots with four main objectives: *Identify what are the main issues of hot-spots and their consequences at different scales. *Review current modelling methods for accounting for NH3 dispersion and deposition in hot-spots. *Examine the status of methods for effect assessment and air monitoring in NH3 hot-spots. *Recommend broad principles for assessment approaches in ammonia hot-spots, including spatial approaches and the interactions between transboundary ammonia emission reduction targets and other policy measures.