Airborne reduced nitrogen: ammonia emissions from agriculture and other sources

Polyester conversion by homogeneous catalysis for separating and recycling ammonia from biogas

Biogas is being promoted as a renewable and clean energy source. However, NH3 is a precursor of NOx and PM2.5 within the biogas, threatening ecological and human health. Therein, recycling waste NH3 from the biogas as a raw material of nitrogen fertilizer was tested by optimizing polyester as a sorbent material. After homogeneous catalysis, the converted polyester significantly increased the NH3 adsorption sites within polyester nanopores; correspondingly, the NH3 adsorption capacity increased from 0.56 mg·g-1 to 84.07 mg·g-1. Based on the structural characterization of polyesters, functional groups analysis before and after adsorption, and kinetic analysis during adsorption, chemical adsorption was identified as the dominant mechanism for NH3 adsorption. Moreover, selective adsorption and the regeneration experiments to optimize polyester indicated that NH3 could be efficiently separated from biogas with good regeneration performance. The results demonstrate the efficacy of recycling waste polyester and NH3 from the biogas.

Insights into national distribution of NH3 concentrations in Republic of Korea: findings from passive sampler observations and implications for sources and management

Gas-phase NH3 is one of the significant contributors to secondary aerosol formation in the atmosphere, and it is a crucial consideration in any strategy aiming to reduce PM2.5 emissions. This study aimed to investigate the spatial distributions of NH3 in verity source areas in Republic of Korea using passive samplers. NH3 concentrations were observed at 45 locations over a period of approximately 35 weeks, from June 2022 to February 2023. As a result, NH3 concentration was found to be more affected by local sources rather than long-distance influx from outside. The average concentration of NH3 observed in 7 source areas excluding the background area was all less than 20.91 ppb, except for livestock sources. These results suggest that atmospheric NH3 concentrations are significantly influenced from livestock sources. In addition, in major cities, the need for NH3 management was confirmed to be more focused on emissions from automobiles and industrial complexes than emissions from livestock and farmland. Moreover, even for the same source, NH3 concentrations varied depending on the type of livestock species, breeding methods and scale, products produced, crops cultivated, and vehicle traffic volume. These findings indicate the importance of considering factors such as breeding methods and manure treatment practices in emission factors, and it is expected that the results can be used as basic data for NH3 emission estimation and management.

Environmental impact and optimization suggestions of pig manure and wastewater treatment systems from a life cycle perspective

With the rapid development of the pig farming industry in China, a large amount of pig manure is inevitably generated. The management and utilization of pig manure in a sustainable approach require a systematic analysis of the environmental impacts generated from the existing pig manure treatment and disposal routes. In this study, three typical pig manure treatment and disposal routes: pig manure solid-liquid separation, i) wastewater biological treatment, direct land application of manure/sludge; ii) black-film anaerobic digestion of wastewater, mono-composting of manure/sludge and land use; iii) wastewater biological treatment, co-composting of manure/sludge and land use, were comparatively assessed in terms of their environmental impacts using the life cycle assessment. The results show that the added chemicals in wastewater treatment and the consumed electricity in composting the manure/sludge are the two main contributors to all environmental impacts. Thus, using green chemicals, controlling the dosage of added chemicals accurately, and selecting composting types with low energy consumption will significantly reduce the environmental burden of pig manure treatment and disposal routes. For the global warming potential of the evaluated three pig manure treatment and disposal routes, direct emissions of greenhouse gases during the composting process contribute the most, accounting for 77 %, 95 %, and 79 %, respectively. Furthermore, the struvite recovery with anaerobic digestion from pig manure will bring excellent environmental benefits, which will markedly offset the toxicity impacts and carbon emissions derived from pig manure treatment and disposal process. Overall, this work quantitatively evaluates the potential environmental impacts of the existing pig manure treatment and disposal routes, providing insights on optimization for future technical improvement and development.

Abundance and variation of gaseous NH3 in relation with inorganic fertilizers and soil moisture during Kharif and Rabi season

In an agricultural country like India, inorganic fertilizers are the major contributors of atmospheric NH₃ in rural areas affecting soil, vegetation and water bodies. In this study, day-night and seasonal variation of ammonia emissions were measured from July 2017 to June 2018 during Kharif and Rabi crop seasons at a rural agricultural site in Jhajjar district of Haryana. Also, NH₃ emission inventory is prepared for the amount of fertilizers applied during its basal and top dressing. NH₃ concentrations were noticed significantly lower after basal dressing of DAP fertilizers as compared to the concentrations after top dressing of urea. NH₃ concentration in air increased with decrease in water saturation of the soil. NH₃ emission was recorded as 1.4 to 45.2, 63.1 to 190.9, and 98.9 to 187.5 μg m^-3 during sowing, fertilizer addition, and grain filling stages, respectively, in Kharif season. Apart from these crop stages, NH₃ was measured as 56.8 to 249.5 μg m^-3 during crop residue burning period. On the other hand, NH₃ emissions ranged from 22.9 to 68.4, 59.4 to 104.71, 26.3 to 56.0, 48.2 to 147.2, and 21.5 to 80.4 μg m^-3 during sowing, crown root initiation (CRI), panicle initiation, grain filling, and maturity crop, respectively, in Rabi season. The average NH₃ concentrations during Kharif season (125.3 μg m^-3) were significantly greater than the concentrations during Rabi season (51.8 μg m^-3). However, a reduction in the NH₃ values was observed in the period between Kharif and Rabi seasons, which could be attributed to the wet deposition during monsoon and gas to particle conversion due to less temperature conditions during the periods.

Ammonia emissions from agriculture and their contribution to fine particulate matter: A review of implications for human health

Atmospheric ammonia (NH₃) released from agriculture is contributing significantly to acidification and atmospheric NH₃ may have on human health is much less readily available. The potential direct impact of NH₃ on the health of the general public is under-represented in scientific literature, though there have been several studies which indicate that NH₃ has a direct effect on the respiratory health of those who handle livestock. These health impacts can include a reduced lung function, irritation to the throat and eyes, and increased coughing and phlegm expulsion. More recent studies have indicated that agricultural NH₃ may directly influence the early on-set of asthma in young children. In addition to the potential direct impact of ammonia, it is also a substantial contributor to the fine particulate matter (PM_2.5) fraction (namely the US and Europe); where it accounts for the formation of 30% and 50% of all PM_2.5 respectively. PM_2.5 has the ability to penetrate deep into the lungs and cause long term illnesses such as Chronic Obstructive Pulmonary Disease (COPD) and lung cancer. Hence, PM_2.5 causes economic losses which equate to billions of dollars (US) to the global economy annually. Both premature deaths associated with the health impacts from PM_2.5 and economic losses could be mitigated with a reduction in NH₃ emissions resulting from agriculture. As agriculture contributes to more than 81% of all global NH₃ emissions, it is imperative that food production does not come at a cost to the world's ability to breathe; where reductions in NH₃ emissions can be easier to achieve than other associated pollutants.

Assessment of Indoor Air Quality for Group-Housed Macaques (Macaca spp.)

Indoor Air Quality (IAQ) is strongly associated with animal health and wellbeing. To identify possible problems of the indoor environment of macaques (Macaca spp.), we assessed the IAQ. The temperature (°C), relative humidity (%) and concentrations of inhalable dust (mg/m3), endotoxins (EU/m3), ammonia (ppm) and fungal aerosols were measured at stationary fixed locations in indoor enclosures of group-housed rhesus (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis). In addition, the personal exposure of caretakers to inhalable dust and endotoxins was measured and evaluated. Furthermore, the air circulation was assessed with non-toxic smoke, and the number of times the macaques sneezed was recorded. The indoor temperature and relative humidity for both species were within comfortable ranges. The geometric mean (GM) ammonia, dust and endotoxin concentrations were 1.84 and 0.58 ppm, 0.07 and 0.07 mg/m3, and 24.8 and 6.44 EU/m3 in the rhesus and cynomolgus macaque units, respectively. The GM dust concentrations were significantly higher during the daytime than during the nighttime. Airborne fungi ranged between 425 and 1877 CFU/m3. Personal measurements on the caretakers showed GM dust and endotoxin concentrations of 4.2 mg/m3 and 439.0 EU/m3, respectively. The number of sneezes and the IAQ parameters were not correlated. The smoke test revealed a suboptimal air flow pattern. Although the dust, endotoxins and ammonia were revealed to be within accepted human threshold limit values (TLV), caretakers were exposed to dust and endotoxin levels exceeding existing occupational reference values.

Current status of global warming potential reduction by cleaner composting

The global living standards are currently undergoing a stage of growth; however, such improvement also brings some challenges. Global warming is the greatest threat to all living things and attracts more and more attention on a global scale due to the rapid development of economy. Carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are the common components of greenhouse gases, which contribute to the global warming. Mitigation technologies for these gas emissions are urgently needed in every industry for the aim of cleaner production. Traditional agriculture also contributes significantly to enhance the greenhouse gases emission. Composting is a novel and economic greenhouse gases mitigation strategy compared to other technologies in terms of the organic waste disposal. Some of the European countries showed an increase of more than 50% in the composting rate. The microbial respiration, nitrification and denitrification processes, and the generation of anaerobic condition makes the emission of greenhouse gases inevitable during composting. However, although there have been a lot of papers that focused on the reduction of greenhouse gases emission in composting, none of these has summarized the methods of reducing the emission of greenhouse gases during the composting. This review discusses the benefit of composting in greenhouse gases mitigation in the organic waste management and the current methods to improve mitigation efficiency during cleaner composting. Key physical, chemical, and biological parameters related to greenhouse gases mitigation strategies were precisely studied to give a deep understanding about the emission of greenhouse gases during cleaner composting. Furthermore, the mechanism of greenhouse gases emission mitigation strategies for cleaner composting based on various external measures would be helpful for the exploration of novel and effective mitigation strategies.

Immunosuppression, oxidative stress, and apoptosis in pig kidney caused by ammonia: Application of transcriptome analysis in risk assessment of ammonia exposure

Ammonia (NH₃) is a recognized environmental contaminant around the world and has adverse effects on animal and human health. However, the mechanism of the renal toxicity of NH₃ is not well understood. Pigs are considered an ideal model for biomedical and toxicological research because of the similarity to humans in physiological and biochemical basis. Therefore, in this study, twelve pigs were selected as research objects and randomly divided into two groups, namely the control group and the NH₃ group. The formal experiment lasted 30 days. The effects of excessive NH₃ inhalation on the kidney of fattening pig were evaluated by chemical analysis, ELISA, transcriptome analysis and real-time quantitative PCR (qRT-PCR) from the renal antioxidant level, renal function, blood ammonia content and gene level. Our results showed that excessive NH₃ exposure could cause an increase in blood NH₃ content, a reduction in renal GSH-Px, SOD and GSH, as well as an increase in MDA levels and an increase in serum creatinine, urea and uric acid levels. In addition, transcriptome analysis showed that NH₃ exposure caused changes in 335 differentially expressed genes (DEGs) (including 126 up-regulated DEGs and 109 down-regulated DEGs). Some highly expressed DEGs were enriched into GO terms associated with immune function, oxidative stress, and apoptosis and were verified by qRT-PCR. The qRT-PCR results were comsistent with the transcriptome results. Our results indicated that NH₃ exposure could cause changes in renal transcriptional profiles and kidney function, and induce kidney damage in the fattening pigs through oxidative stress, immune dysfunction and apoptosis. Our present study provides novel insights into the immunotoxicity mechanism of NH₃ on kidney.

Evolution of secondary inorganic aerosols amidst improving PM2.5 air quality in the North China plain

The Clean Air Action implemented by the Chinese government in 2013 has greatly improved air quality in the North China Plain (NCP). In this work, we report changes in the chemical components of atmospheric fine particulate matter (PM_2.5) at four NCP sampling sites from 2012/2013 to 2017 to investigate the impacts and drivers of the Clean Air Action on aerosol chemistry, especially for secondary inorganic aerosols (SIA). During the observation period, the concentrations of PM_2.5 and its chemical components (especially SIA, organic carbon (OC), and elemental carbon (EC)) and the frequency of polluted days (daily PM_2.5 concentration ≥ 75 μg m^-3) in the NCP, declined significantly at all four sites. Asynchronized reduction in SIA components (large decreases in SO₄^2- with stable or even increased NO₃^- and NH₄⁺) was observed in urban Beijing, revealing a shift of the primary form of SIA, which suggested the fractions of NO₃^- increased more rapidly than SO₄^2- during PM_2.5 pollution episodes, especially in 2016 and 2017. In addition, unexpected increases in the sulfur oxidation ratio (SOR) and the nitrogen oxidation ratio (NOR) were observed among sites and across years in the substantially decreased PM_2.5 levels. They were largely determined by secondary aerosol precursors (i.e. decreased SO₂ and NO₂), photochemical oxidants (e.g. increased O₃), temperature, and relative humidity via gas-phase and heterogeneous reactions. Our results not only highlight the effectiveness of the Action Plan for improving air quality in the NCP, but also suggest an increasing importance of SIA in determining PM_2.5 concentration and composition.

Characterising and communicating the potential hazard posed by potentially toxic elements in indoor dusts from schools across Lagos, Nigeria

Ambient and indoor air pollution results in an estimated 7 million premature deaths globally each year, representing a major contemporary public health challenge, but one poorly quantified from a toxicological and source perspective. Indoor exposure represents possibly the greatest potential overall exposure, yet our indoor environments are still poorly understood, modelled and characterized. In rapidly growing cities, such as Lagos, Nigeria, environmental monitoring can play an important role in establishing baseline data, monitoring urban pollution trends and in environmental education. Classroom dust samples were collected from 40 locations from across the twenty local government areas (LGAs) of Lagos, in June 2019. The aim of the study was to assess the potential hazard posed by PTE in indoor dusts and to develop a suitable risk communication strategy to inform and educate the public, promoting environmental health literacy. Concentrations of total PTE in indoor dusts were assessed using Energy Dispersive X-Ray Fluorescence (ED-XRF) spectrometry. Oral bioaccessibility determinations using the unified BARGE method, and analysis by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) were also performed on the dust samples to determine the fraction available for absorption in the gastrointestinal tract. Results showed that the indoor dust samples were largely uncontaminated, with only few exceptions (2 samples). Enrichment factor pollution trend for the total PTE concentrations was in the order of Pb > Zn > U > Cr > Cu > Ba > Mn > V > As > Cd > Ni > Al. Source apportionment studies using factor analysis suggests concentrations of Al, As, Fe, Mn, Ni, and U may be influenced largely by lithogenic factors, while Cd, Cu and Pb originated principally from anthropogenic sources. Chromium, V and Zn appear to originate from mixed sources of both lithogenic and anthropogenic origin. Our oral bioaccessibility determinations indicate that the assumption of 100% bioavailability based on pseudototal or total concentrations would overestimate the hazard potential of PTE in these indoor dusts. Zinc was the most bioaccessible PTE (mean of 88%), with Mn (57%), Pb (48%), Ba (48%), Al (41%), As (37%), Cu (36%), Ni (28%), Cr (10%) and Fe (7%) the least bioaccessible. Human health risk assessment, for both children and adults using the bioaccessible fraction, showed values to be within acceptable risk levels.

Ammonia volatilization modeling optimization for rice watersheds under climatic differences

The ammonia (NH₃) volatilization mechanism is complicated with pronounced watershed differences of climate conditions, soil properties, and tillage practices. The watershed NH₃ emission dynamics model was developed with the combination of field measurements, Soil Water Assessment Tool and NH₃ volatilization algorithms. The temporal NH₃ emissions patterns and the watershed NH₃ volatilization dynamics were simulated with the improved NH₃ volatilization modeling. Five monitoring sites and three case watersheds across China were selected to highlight the impacts of climatic conditions and validated the modeling. The average NH₃ emissions of the three watersheds ranged from 14.94 to 120.33 kg N ha^-1, which were mainly positively correlated with temperatures (r = 0.56, p < 0.01) and negatively correlated with soil organic carbon content (r = -0.33, p < 0.01). Analysis of similarities indicated that significant differences existed between the watersheds in terms of NH₃ volatilization (R_ANOSIM = 0.758 and 0.834, p < 0.01). These analysis imply that environmental variabilities were more important than N input amounts.

Describing the trend of ammonia, particulate matter and nitrogen oxides: The role of livestock activities in northern Italy during Covid-19 quarantine

Nitrogen oxides (NOx), sulphur oxides (SOx) and ammonia (NH3) are among the main contributors to the formation of secondary particulate matter (PM2.5), which represent a severe risk to human health. Even if important improvements have been achieved worldwide, traffic, industrial activities, and the energy sector are mostly responsible for NOx and SOx release; instead, the agricultural sector is mainly responsible for NH3 emissions. Due to the emergency of coronavirus disease, in Italy schools and universities have been locked down from late February 2020, followed in March by almost all production and industrial activities as well as road transport, except for the agricultural ones. This study aims to analyze NH3, PM2.5 and NOx emissions in principal livestock provinces in the Lombardy region (Brescia, Cremona, Lodi, and Mantua) to evaluate if and how air emissions have changed during this quarantine period respect to 2016-2019. For each province, meteorological and air quality data were collected from the database of the Regional Agency for the Protection of the Environment, considering both data stations located in the city and the countryside. In the 2020 selected period, PM2.5 reduction was higher compared to the previous years, especially in February and March. Respect to February, PM2.5 released in March in the city stations reduced by 19%-32% in 2016-2019 and by 21%-41% in 2020. Similarly, NOx data of 2020 were lower than in the 2016-2019 period (reduction in March respect to February of 22-42% for 2016-2019 and of 43-62% for 2020); in particular, this can be observed in city stations, because of the current reduction in anthropogenic emissions related to traffic and industrial activities. A different trend with no reductions was observed for NH3 emissions, as agricultural activities have not stopped during the lockdown. Air quality is affected by many variables, for which making conclusions requires a holistic perspective. Therefore, all sectors must play a role to contribute to the reduction of harmful pollutants.

Bacillus subtilis biofertilizer mitigating agricultural ammonia emission and shifting soil nitrogen cycling microbiomes

Excessive ammonia (NH₃) emitted from nitrogen fertilizer application in farmland have caused serious disturbance to global environment, including reduction of visibility, formation of regional haze, and increase of nitrogen deposition. Application of biofertilizer has been considered as an effective approach for soil improvement and agriculture sustainability. In this study, a field experiment was conducted to evaluate the potential of B. subtilis biofertilizer on mitigating NH₃ volatilization and to investigate the underlying mechanisms. Compared with organic fertilizer, the incorporation of B. subtilis biofertilizer reduced NH₃ volatilization by up to 44%. Moreover, the application of B. subtilis biofertilizer reduced the abundance of ureC gene, and increased the abundance of functional genes (bacterial amoA and comammox amoA) and ammonia-oxidizing bacteria (AOB). This indicated that the conversion of fertilizer nitrogen to NH₄⁺-N was decreased and the nitrification process was increased. In brief, the application of B. subtilis biofertilizer reduced the "source" and increased the "sink" of NH₄⁺-N, thus reducing the retention of NH₄⁺-N in alkaline soil, and mitigating NH₃ volatilization. These results indicated that B. subtilis biofertilizer is an effective control strategy for agricultural NH₃ emission, maintaining high crop yield and mitigating environmental disturbance.

Variability of Ammonia and Methane Emissions from Animal Feeding Operations in Northeastern Colorado

Concentrated animal feeding operations (CAFOs) are major emitters of both ammonia (NH₃) and methane (CH₄). However, current emission inventories have limited temporal resolution and use data derived from a small subset of farms. To this end, we deployed three mobile laboratories during the DISCOVER-AQ campaign in summer 2014 with a focus on northeastern Colorado. Observations of NH₃ and CH₄ plumes downwind of 43 CAFOs were used to investigate the diurnal and site-to-site variability of emissions with an inverse area source plume modeling approach. Ammonia emissions scaled to all permitted animals in Weld, Morgan, and Larimer counties were estimated at 1.9 Gg month^-1, 50% greater than the U.S. NEI 2014 and 360% greater than EDGAR for the month of August. Methane emissions were likewise estimated at 10.6 Gg month^-1, consistent with the U.S. GHGI but 99% greater than EDGAR. Significant differences between individual CAFOs with repeat observations were also observed for both CH₄ and NH₃ emissions. The large subfarm, site-to-site, and diurnal variabilities observed show the importance of measurements taken across these scales in order to derive representative emission factors.

Environmental contaminant ammonia triggers epithelial-to-mesenchymal transition-mediated jejunal fibrosis with the disassembly of epithelial cell-cell contacts in chicken

Ammonia (NH₃) is an environmental contaminant that is causing increasing problems with human and animal health due to the development of poultry industry. There are limited studies on the effect of NH₃ inhalation toxicity on the intestinal tract of animals, and underlying molecular mechanisms remain unclear. In the present study, we established a chicken model of NH₃ aspiration-induced injury for 42 days and observed histopathological changes of the jejunum. Tandem mass tag-based quantitative proteomic analysis was applied to investigate changes in the protein profile in the jejunum tissue of chickens that were exposed to NH₃. Overall, 48 significantly differentially expressed proteins (DEPs) were identified. GO and KEGG analyses revealed that most DEPs were closely related to epithelial-to-mesenchymal transition (EMT), cell-cell junctions, and fibrosis-related factors. Regarding fibrosis, type I collagen and fibronectin were significantly increased. With respect to EMT, epithelial marker proteins (such as E-cadherin and keratin) were repressed, while mesenchymal marker proteins (such as vimentin) were activated. Loss of epithelial cell-cell junctions (such as tight junctions, adherens junctions and desmosomes) were observed. Additionally, overexpression of transforming growth factor-beta (TGF-β) may play a key role in the EMT process and fibrosis. Taken together, these findings suggested that NH₃ triggered the EMT and disassembly of epithelial cell-cell contacts, resulting in jejunal fibrosis that was mediated by TGF-β in chickens. The results of our study will contribute to provide a technical reference regarding the research methods of intestinal toxicity of NH₃ and have largely regulatory implications for ecological risk assessment of human health.

Ammonia Volatilization Reduced by Combined Application of Biogas Slurry and Chemical Fertilizer in Maize–Wheat Rotation System in North China Plain

Digestate and biogas slurry (BS) are the byproduct of biogas engineering that could be used for elevating plant growth. However, the consequent emissions of ammonia from BS are considered a severe threat to the atmosphere. Herein, we conducted two consecutive field experiments with wheat–maize rotations to find out the optimum ratio of BS to combine with chemical fertilizer (CF) to reduce ammonia volatilization (AV) while keeping the stable crop yield. In maize season, 226.5 kg N/ha of CF was applied. In wheat season, 226.5 kg N/ha was applied at different ratios (100%, 80%, and 50%) between BS and CF. Our results found that the maximum yield of 6250 kg/ha was produced by CF, and this yield could be obtained through a combined application of 38% BS mixed with CF. Highest AV produced of 16.08 kg/ha by CF. BS treatments significantly reduced the emission from 18% to 32% in comparison to CF. The combined application of BS-CF produced the highest yield due to essential nutrients coming from both BS-CF. Subsequently, it reduced the AV depending on fertilizer type and fertilizer rate. An optimal ratio of 38% BS was recommended to produce the highest yield and lowest ammonia emissions. The application of BS together with different ratios of CF could be an alternative agricultural strategy to obtain desired crop yield and reduce AV in North China Plain (NCP).

Inhibition of urease activity by different compounds provides insight into the modulation and association of bacterial nickel import and ureolysis

The nickel-dependent urease enzyme is responsible for the hydrolysis of urea to ammonia and carbon dioxide. A number of bacteria produce urease (ureolytic bacteria) and are associated with various infectious diseases and ammonia emissions from agriculture. We report the first comprehensive comparison of the inhibition of urease activity by compounds analysed under the same conditions. Thus, 71 commercially available compounds were screened for their anti-ureolytic properties against both the ureolytic bacterium Klebsiella pneumoniae and purified jack bean urease. Of the tested compounds, 30 showed more than 25% inhibition of the ureolytic activity of Klebsiella pneumoniae or jack bean urease, and among these, carbon disulfide, N-phenylmaleimide, diethylenetriaminepentaacetic acid, sodium pyrrolidinedithiocarbamate, 1,2,4-butanetricarboxylic acid, tannic acid, and gallic acid have not previously been reported to possess anti-ureolytic properties. The diverse effects of metal ion chelators on ureolysis were investigated using a cellular nickel uptake assay. Ethylenediaminetetraacetic acid (EDTA) and dimethylglyoxime (DMG) clearly reduced the nickel import and ureolytic activity of cells, oxalic acid stimulated nickel import but reduced the ureolytic activity of cells, 1,2,4-butanetricarboxylic acid strongly stimulated nickel import and slightly increased the ureolytic activity of cells, while L-cysteine had no effect on nickel import but efficiently reduced the ureolytic activity of cells.

Assessment of Reducing Pollutant Emissions in Selected Heating and Ventilation Systems in Single-Family Houses

The article presents the results of a study aiming to select the optimal source of heat for a newly designed single-family home. Commercial software was used to compare heating and ventilation systems involving a bituminous coal boiler, a condensing gas boiler, a biomass boiler, a heat pump with water and glycol as heat transfer media. The effectiveness of natural ventilation, mechanical ventilation with a ground-coupled heat exchanger, and solar heater panels for water heating were evaluated. The analysis was based on the annual demand for useful energy, final energy, and non-renewable primary energy in view of the pollution output of the evaluated heating systems. The analysis revealed that the heat pump with water and glycol was the optimal solution. However, the performance of the heat pump in real-life conditions was below its maximum theoretical efficiency. The biomass boiler contributed to the highest reduction in pollutant emissions (according to Intergovernmental Panel on Climate Change Change guidelines, carbon dioxide emissions have zero value), but it was characterized by the highest demand for final energy. Mechanical ventilation with heat recovery was required in all analyzed systems to achieve optimal results. The introduction of mechanical ventilation decreased the demand for final energy by 10% to around 40% relative to the corresponding heating systems with natural ventilation.

Rapid naked-eye colorimetric detection of gaseous alkaline analytes using rhodamine B hydrazone-coated silica strips

Development of rhodamine B hydrazone-coated silica strips for rapid detection of alkaline vapors by the naked-eye or using a smartphone camera.

Enhancing Potential of Trimethylamine Oxide on Atmospheric Particle Formation

The role of an oxidation product of trimethylamine, trimethylamine oxide, in atmospheric particle formation is studied using quantum chemical methods and cluster formation simulations. Molecular-level cluster formation mechanisms are resolved, and theoretical results on particle formation are confirmed with mass spectrometer measurements. Trimethylamine oxide is capable of forming only one hydrogen bond with sulfuric acid, but unlike amines, trimethylamine oxide can form stable clusters via ion–dipole interactions. That is because of its zwitterionic structure, which causes a high dipole moment. Cluster growth occurs close to the acid:base ratio of 1:1, which is the same as for other monoprotic bases. Enhancement potential of trimethylamine oxide in particle formation is much higher than that of dimethylamine, but lower compared to guanidine. Therefore, at relatively low concentrations and high temperatures, guanidine and trimethylamine oxide may dominate particle formation events over amines.

Evaluation of Sustainable Development Management in EU Countries

The term sustainable development is used in many areas and spheres of life and is becoming a modern phenomenon determining the direction of progress of every society. Sustainable development implies continuous economic development with respect to environmental principles and focuses on overcoming conflicts between economy and ecology. The aim of this paper is to evaluate sustainable development management in EU countries through selected indicators characterizing sustainable development and its core dimensions. We present the results of an evaluation of the sustainable development of EU countries using cluster analysis. Countries that are similar in terms of sustainability are identified by cluster analysis. Four clusters were separated, the affiliation of each country to a particular cluster was determined, and the characteristics of each cluster were defined. The goal of sustainability management is to create an adequate approach to development of the economic and environmental performance, and therefore achieve sustainability. The achievements of most developed countries should be an incentive for those that are at a lower level of development. In addition, this research provides insight into some specific goals of sustainable development where some countries are lagging behind. This could be the basis for directing efforts in specific areas of sustainable development to improve their own position in such an important global issue.

Reducing Wet Ammonium Deposition in Rocky Mountain National Park: the Development and Evaluation of A Pilot Early Warning System for Agricultural Operations in Eastern Colorado

Agricultural emissions are the primary source of ammonia (NH₃) deposition in Rocky Mountain National Park (RMNP), a Class I area, that is granted special air quality protections under the Clean Air Act. Between 2014 and 2016, the pilot phase of the Colorado agricultural nitrogen early warning system (CANEWS) was developed for agricultural producers to voluntarily and temporarily minimize emissions of NH₃ during periods of upslope winds. The CANEWS was created using trajectory analyses driven by outputs from an ensemble of numerical weather forecasts together with the climatological expertize of human forecasters. Here, we discuss the methods for the CANEWS and offer preliminary analyses of 33 months of the CANEWS based on atmospheric deposition data from two sites in RMNP as well as responses from agricultural producers after warnings were issued. Results showed that the CANEWS accurately predicted 6 of 9 high N deposition weeks at a lower-elevation observation site, but only 4 of 11 high N deposition weeks at a higher-elevation site. Sixty agricultural producers from 39 of Colorado's agricultural operations volunteered for the CANEWS, and a two-way line of communication between agricultural producers and scientists was formed. For each warning issued, an average of 23 producers responded to a postwarning survey. Over 75% of responding CANEWS participants altered their practices after an alert. While the current effort was insufficient to reduce atmospheric deposition, we were encouraged by the collaborative spirit between agricultural, scientific, and resource management communities. Solving a broad and complex social-ecological problem requires both a technological approach, such as the CANEWS, and collaboration and trust from all participants, including agricultural producers, land managers, university researchers, and environmental agencies.

Modeling ammonia volatilization following the application of synthetic fertilizers to cultivated uplands with calcareous soils using an improved DNDC biogeochemistry model

Simulation of ammonia (NH₃) volatilization by process-oriented biogeochemical models, such as the widely used DeNitrification DeComposition (DNDC), is an imperative need to identify the best management strategies that can improve nitrogen use efficiency in crop production while alleviating environmental pollution. However, scarce validation has been impeding the applicability of the DNDC for this purpose. Using the micrometeorological or wind tunnel-based observations of NH₃ volatilization in 44 cases with at seven nationwide field sites in China, which were cultivated with summer maize and winter wheat in calcareous soils and applied with synthetic fertilizers, the DNDC was tested, modified, and evaluated in this study. The following major modifications were made in the model source codes. Primarily, pedo-transfer functions were introduced into the model to provide three soil hydraulic parameters that are required to simulate soil moisture. Then, the temperature effect on ammonium bicarbonate decomposition, which was originally missing, was parameterized. Finally, the effect of soil texture on ammonia volatilization from the liquid phase was re-parameterized while an adaption factor was set. Seven typical cases were involved in the model modifications and the other 37 independent cases were used for the modified model evaluation. Compared to the original model, the modified DNDC performed better. For instance, it showed a higher index of agreement of 0.77 versus 0.38, a higher modeling efficiency (Nash-Sutcliffe index) of 0.19 versus -0.52, and a greater determination coefficient (R²) of 0.35 (p < 0.001) versus no available value (i.e., R² ≤ 0) in the zero-intercept linear regression of the observed cumulative NH₃ volatilizations during individual measurement periods against the simulations. Future studies are needed to further improve the modified DNDC so as to better simulate the effects of rainfall/irrigation and deep placement of fertilizers on NH₃ volatilization from calcareous soils cultivated with upland crops.

Modeling ammonia volatilization following urea application to winter cereal fields in the United Kingdom by a revised biogeochemical model

Urea accounts for over half of the global ammonia volatilization from synthetic nitrogen fertilization. Process-oriented models, such as the widely applied DeNitrification DeComposition 9.5 version (DNDC95), are expected to predict ammonia volatilization from agricultural urea applications under various conditions. However, compared to the wind-tunnel ammonia observations of a nationwide, seven-site/ten-case network in the United Kingdom, the DNDC95 greatly underestimated the ammonia volatilization from winter cereal fields applied with urea at a constant dose. The model was revised in this study mainly through (i) newly parameterizing the effects of clay fraction, plant standings and canopy wetting on ammonia release from the soil solution, and (ii) re-calibrating the parameters of the urea hydrolysis function and the original parameterizations of wind, soil temperature and moisture effects on ammonia volatilization using the observations in one case of the network. Next, the performances of the revised model (DNDC95_NH₃) in simulating grain yield, full crop nitrogen uptake, cumulative ammonia volatilization (CAV) and daily ammonia fluxes were evaluated using the observations of these variables in the other nine network cases. The DNDC95_NH₃ performed considerably better than the DNDC95. Particularly, the slopes of the zero-intercept regression for the observations versus simulations decreased from 1.97 to 0.86 and 1.65 to 0.75 for the CAV and daily ammonia fluxes, respectively. In addition, the number of the cases with significant discrepancies between simulated and observed CAV was reduced from six of the nine network cases to only two. The simulations by the revised model for these two cases showed a significant underestimation and an extremely large overestimation, respectively. However, reasons especially for the significant overestimation still remain unclear. Future studies still need to diagnose and solve the other existing problems so as to further improve the model's performance.

Analysis of the diversity in emissions of selected gaseous and particulate pollutants in the European Union countries

The article presents the analysis results of the grouping of the European Union countries with regard to emission levels of gaseous pollutants (NH3, NMVOCs, SO_x, NO_x) and particulate air pollutants (PM10 and PM2.5) which are one of the most dangerous type of pollution for human health. Their long-lasting effects on the human body may negatively affect health and life expectancy. The analysis was based on the taxonomic method of grouping data using the K-means method which is a non-hierarchical method. The analysis used the data published by Eurostat. Organizing countries into categories of emissions of gaseous and dust pollutants to the atmosphere was conducted for four cases: the total level of emission, the level of emissions related to the GDP, the area, and per capita. The Euclidean distance was a measure of the distance between Member States. The obtained results indicate that, depending on the adopted criterion, there is a significant change in the composition of individual clusters. This confirms the assumptions of the Authors who claimed that in order to develop a more comprehensive analysis and assessment of the state of atmospheric pollution in EU countries it is necessary to include additional criteria, other than only the total emission of a given pollution. The objective of the research was to indicate that the analysis of emissions of selected type of pollution, and at the same time most threatening to human health, does not fully reflect the actual state of the problem when presented only in terms of the emitted amount. It is therefore appropriate for EU institutions to take more account of the differences between the individual countries in terms of the criteria presented in the paper, during the decision-making process concerning the sustainable development policy in the field of environmental protection.

Molecular Characterization of Cloud Water Samples Collected at the Puy de Dôme (France) by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Cloud droplets contain dynamic and complex pools of highly heterogeneous organic matter, resulting from the dissolution of both water-soluble organic carbon in atmospheric aerosol particles and gas-phase soluble species, and are constantly impacted by chemical, photochemical, and biological transformations. Cloud samples from two summer events, characterized by different air masses and physicochemical properties, were collected at the Puy de Dôme station in France, concentrated on a strata-X solid-phase extraction cartridge and directly infused using electrospray ionization in the negative mode coupled with ultrahigh-resolution mass spectrometry. A significantly higher number (n = 5258) of monoisotopic molecular formulas, assigned to CHO, CHNO, CHSO, and CHNSO, were identified in the cloud sample whose air mass had passed over the highly urbanized Paris region (J1) compared to the cloud sample whose air mass had passed over remote areas (n = 2896; J2). Van Krevelen diagrams revealed that lignins/CRAM-like, aliphatics/proteins-like, and lipids-like compounds were the most abundant classes in both samples. Comparison of our results with previously published data sets on atmospheric aqueous media indicated that the average O/C ratios reported in this work (0.37) are similar to those reported for fog water and for biogenic aerosols but are lower than the values measured for aerosols sampled in the atmosphere and for aerosols produced artificially in environmental chambers.

Nitrogen concentration in moss compared with N load in precipitation and with total N deposition in Switzerland

Intensification of farming and an increase in motorised traffic have led to elevated nitrogen (N) emissions and thus to eutrophication of the environment, which threatens the nutrient balance in ecosystems. Earlier studies have demonstrated the suitability of mosses as biomonitors for measuring N deposition by comparing the N concentration in moss with that in precipitation. In our study however, we extended the comparison to the dry deposition of gases (nitrogen dioxide, nitric acid, ammonia) and aerosols (nitrate, ammonium), which, together with the N in precipitation, represent the main contributions to total N deposition. The aim of including several N compounds was to see whether the correlation with the N concentration in moss could be improved. We determined total N input from the atmosphere to the ecosystem at 24 sites in Switzerland and compared this value to the N concentration in two moss species collected <1000 m from these sites. Including the gases and aerosols improved the correlation between the N concentration in moss and N deposition. Ammonia was found to be the most important of the additionally included compounds at these sites. Especially at sites with a relatively high ammonia concentration in the air, the inclusion of ammonia improved the correlation of the comparison. We also demonstrate that the particular moss species tested had no influence on the correlation between N in moss and total N deposition. Our data supports the suitability of mosses as biomonitors for estimating N input into ecosystems.

Guanidine: A Highly Efficient Stabilizer in Atmospheric New-Particle Formation

The role of a strong organobase, guanidine, in sulfuric acid-driven new-particle formation is studied using state-of-the-art quantum chemical methods and molecular cluster formation simulations. Cluster formation mechanisms at the molecular level are resolved, and theoretical results on cluster stability are confirmed with mass spectrometer measurements. New-particle formation from guanidine and sulfuric acid molecules occurs without thermodynamic barriers under studied conditions, and clusters are growing close to a 1:1 composition of acid and base. Evaporation rates of the most stable clusters are extremely low, which can be explained by the proton transfers and symmetrical cluster structures. We compare the ability of guanidine and dimethylamine to enhance sulfuric acid-driven particle formation and show that more than 2000-fold concentration of dimethylamine is needed to yield as efficient particle formation as in the case of guanidine. At similar conditions, guanidine yields 8 orders of magnitude higher particle formation rates compared to dimethylamine. Highly basic compounds such as guanidine may explain experimentally observed particle formation events at low precursor vapor concentrations, whereas less basic and more abundant bases such as ammonia and amines are likely to explain measurements at high concentrations.

An environmental friendly animal waste disposal process with ammonia recovery and energy production: Experimental study and economic analysis

Animal manure waste is considered as an environmental challenge especially in farming areas mainly because of gaseous emission and water pollution. Among all the pollutants emitted from manure waste, ammonia is of greatest concern as it could contribute to formation of aerosols in the air and could hardly be controlled by traditional disposal methods like landfill or composting. On the other hand, manure waste is also a renewable source for energy production. In this work, an environmental friendly animal waste disposal process with combined ammonia recovery and energy production was proposed and investigated both experimentally and economically. Lab-scale feasibility study results showed that 70% of ammonia in the manure waste could be converted to struvite as fertilizer, while solid manure waste was successfully gasified in a 10kW downdraft fixed-bed gasifier producing syngas with the higher heating value of 4.9MJ/(Nm³). Based on experimental results, economic study for the system was carried out using a cost-benefit analysis to investigate the financial feasibility based on a Singapore case study. In addition, for comparison, schemes of gasification without ammonia removal and incineration were also studied for manure waste disposal. The results showed that the proposed gasification-based manure waste treatment process integrated with ammonia recovery was most financially viable.

Land altitude, slope, and coverage as risk factors for Porcine Reproductive and Respiratory Syndrome (PRRS) outbreaks in the United States

Porcine reproductive and respiratory syndrome (PRRS) is, arguably, the most impactful disease on the North American swine industry. The Swine Health Monitoring Project (SHMP) is a national volunteer initiative aimed at monitoring incidence and, ultimately, supporting swine disease control, including PRRS. Data collected through the SHMP currently represents approximately 42% of the sow population of the United States. The objective of the study here was to investigate the association between geographical factors (including land elevation, and land coverage) and PRRS incidence as recorded in the SHMP. Weekly PRRS status data from sites participating in the SHMP from 2009 to 2016 (n = 706) was assessed. Number of PRRS outbreaks, years of participation in the SHMP, and site location were collected from the SHMP database. Environmental features hypothesized to influence PRRS risk included land coverage (cultivated areas, shrubs and trees), land altitude (in meters above sea level) and land slope (in degrees compared to surrounding areas). Other risk factors considered included region, production system to which the site belonged, herd size, and swine density in the area in which the site was located. Land-related variables and pig density were captured in raster format from a number of sources and extracted to points (farm locations). A mixed-effects Poisson regression model was built; and dependence among sites that belonged to a given production system was accounted for using a random effect at the system level. The annual mean and median number of outbreaks per farm was 1.38 (SD: 1.6), and 1 (IQR: 2.0), respectively. The maximum annual number of outbreaks per farm was 9, and approximately 40% of the farms did not report any outbreak. Results from the final multivariable model suggested that increments of swine density and herd size increased the risk for PRRS outbreaks (P < 0.01). Even though altitude (meters above sea level) was not significant in the final model, farms located in terrains with a slope of 9% or higher had lower rates of PRRS outbreaks compared to farms located in terrains with slopes lower than 2% (P < 0.01). Finally, being located in an area of shrubs/ herbaceous cover and trees lowered the incidence rate of PRRS outbreaks compared to being located in cultivated/ managed areas (P < 0.05). In conclusion, highly inclined terrains were associated with fewer PRRS outbreaks in US sow farms, as was the presence of shrubs and trees when compared to cultivated/ managed areas. Influence of terrain characteristics on spread of airborne diseases, such as PRRS, may help to predicting disease risk, and effective planning of measures intended to mitigate and prevent risk of infection.

Evaluation of the use of moss transplants (Pseudoscleropodium purum) for biomonitoring different forms of air pollutant nitrogen compounds

We investigated whether three different types of moss transplants (devitalized moss bags with and without cover and auto-irrigated moss transplants) are suitable for use as biomonitors of the deposition of oxidised and/or reduced forms of N. For this purpose, we determined whether the concentration of atmospheric NO2 was related to the % N, δ(15)N and the activity of the enzyme biomarkers phosphomonoesterase (PME) and nitrate reductase (NR) in the tissues of moss transplants. We exposed the transplants in 5 different environments of Galicia (NW Spain) and Cataluña (NE Spain): industrial environments, urban and periurban environments, the surroundings of a cattle farm and in a monitoring site included in the sampling network of the European Monitoring Programme. The results showed that the moss in the auto-irrigated transplants was able of incorporating the N in its tissues because it was metabolically active, whereas in devitalized moss bags transplants, moss simply intercepts physically the N compounds that reached it in particulate or gaseous form. In addition, this devitalization could limit the capacity of moss to capture gaseous compounds (i.e. reduced N) and to reduce the oxidised compounds that reach the specimens. These findings indicate that devitalized moss transplants cannot be used to monitor either oxidised or reduced N compounds, whereas transplants of metabolically active moss can be used for this purpose. Finally, the NR and PME biomarkers should be used with caution because of the high variability in their activities and the limits of quantification should be evaluated in each case.

Acidification with sulfur of the separated solid fraction of raw and co-digested pig slurry: effect on greenhouse gas and ammonia emissions during storage

A study was performed to assess: (1) the feasibility to acidify the separated solid fraction of raw and co-digested pig slurry by using a powdery sulfur-based product; and (2) the effect of this acidification method on greenhouse gases and ammonia emissions during manure storage. Samples of raw and co-digested pig slurry were collected at two commercial farms and mechanically separated by a laboratory-scale screw press device. The sulfur powder (80% concentration) was added to the obtained separated solid fractions at three application rates: 0.5%, 1% and 2% (w/w). Carbon dioxide, methane, nitrous oxide and ammonia emissions were afterwards measured during storage of the acidified samples and compared with those measured from untreated samples (Control). Gaseous emissions were determined with dynamic chamber method by Infrared Photoacoustic Detection. Gaseous losses were monitored along 30 and 60 days of storage time for raw solid fraction and digested solid fraction, respectively. The addition of the tested sulfur powder to solid fractions showed to be a reliable and effective method to acidify raw and co-digested solid fractions. Results showed a significant reduction of both greenhouse gases and ammonia emission regardless of the separated solid fraction type. The highest sulfur application rate (2% w/w) led to a reduction of up to 78% of greenhouse gas emission and 65% of ammonia losses from raw separated solid fraction when compared with the Control. Similar results were achieved from the co-digested solid fraction, with emission reduction of up to 67% for ammonia and 61% for greenhouse gas.

Synergistic inflammatory effect of PM10 with mycotoxin deoxynivalenol on human lung epithelial cells

The presence of deoxynivalenol (DON), a mycotoxin produced by Fusarium species, has been reported worldwide in food and feedstuffs. Even though oral intake is the main route of exposure, DON inhalation is also of concern in workers and exposed population. Particulate matter (PM) is one of the most important causes of air quality detriment and it induces several adverse health effects. Therefore it is of primary importance to understand possible combined effects of DON and PM. The alveolar type II, A549, and the bronchial epithelial, BEAS-2B, cell lines were exposed for 24 h to different concentrations of DON (10-1000 ng/ml), PM10 (5 μg/cm(2), sampled in summer or winter season), and a combination of these pollutants. Cell death, interleukins release and cell cycle alteration were analysed; protein array technique was also applied to evaluate proteins activation related to MAP-kinases cascade. Our results demonstrate that low doses of PM and DON used alone have scarce toxic effects, while induce cytotoxicity and inflammation when used in combination. This observation outlines the importance of investigation on the combined effects of air pollutants for their possible outcomes on human health.

Acidification of animal slurry--a review

Ammonia emissions are a major problem associated with animal slurry management, and solutions to overcome this problem are required worldwide by farmers and stakeholders. An obvious way to minimize ammonia emissions from slurry is to decrease slurry pH by addition of acids or other substances. This solution has been used commonly since 2010 in countries such as Denmark, and its efficiency with regard to the minimization of NH3 emissions has been documented in many studies. Nevertheless, the impact of such treatment on other gaseous emissions during storage is not clear, since the studies performed so far have provided different scenarios. Similarly, the impact of the soil application of acidified slurry on plant production and diffuse pollution has been considered in several studies. Also, the impact of acidification upon combination with other slurry treatment technologies (e.g. mechanical separation, anaerobic digestion …) is important to consider. Here, a compilation and critical review of all these studies has been performed in order to fully understand the global impact of slurry acidification and assess the applicability of this treatment for slurry management.

A statistical comparison of active and passive ammonia measurements collected at Clean Air Status and Trends Network (CASTNET) sites

Atmospheric concentrations of ammonia (NH3) are not well characterized in the United States due to the sparse number of monitors, the relatively short lifetime of NH3 in the atmosphere, and the difficulty in measuring non-point source emissions such as fertilized agricultural land. In this study, we compare measured weekly concentrations of NH3 collected by two denuder systems with a bi-weekly passive NH3 sampler used by the National Atmospheric Deposition Program's (NADP) Ammonia Monitoring Network (AMoN). The purpose of the study was to verify the passive samplers used by AMoN and characterize any uncertainties introduced when using a bi-weekly versus weekly sampling time period. The study was conducted for 1 year at five remote Clean Air Status and Trends Network (CASTNET) sites. Measured ambient NH3 concentrations ranged from 0.03 μg NH3 m(-3) to 4.64 μg NH3 m(-3) in upstate New York and northwest Texas, respectively, while dry deposition estimates ranged from 0.003 kg N ha(-1) wk(-1) to 0.47 kg N ha(-1) wk(-1). Results showed that the bi-weekly passive samplers performed well compared to annular denuder systems (ADS) deployed at each of the five CASTNET sites, while the MetOne Super SASS Mini-Parallel Plate Denuder System (MPPD) was biased low when compared to the ADS. The mean relative percent difference (MRPD) between the ADS and MPPD and the ADS and AMoN sampler was -38% and -9%, respectively. Precision of the ADS and MPPD was 5% and 13%, respectively, while the precision of the passive samplers was 5%. The results of this study demonstrate that the NH3 concentrations measured by AMoN are comparable to the ADS and may be used to supplement the high-time resolution measurements to gain information on spatial gradients of NH3, long-term trends and seasonal variations in NH3 concentrations.

Chronic ammonia exposure does not influence hepatic gene expression in growing pigs

Housed pigs are often exposed to elevated concentrations of atmospheric ammonia. This aerial pollutant is widely considered to be an environmental stressor that also predisposes to reduced growth rates and poor health, although evidence to support this view is limited. Hepatic gene expression is very responsive to stress and metabolic effects. Two batches of growing pigs were therefore exposed to a nominal concentration of atmospheric ammonia of either 5 ppm (low) or 20 ppm (high) from 4 weeks of age for 15 weeks. Growth rates were monitored. Samples of liver were taken after slaughter (at ∼19 weeks of age). Samples from the second batch were analysed for global gene expression using 23 K Affymetrix GeneChip porcine genome arrays. Samples from both batches were subsequently tested for five candidate genes using quantitative real-time PCR (qPCR). The array analysis failed to detect any significant changes in hepatic gene expression following chronic exposure to atmospheric ammonia. Animals clustered into two main groups but this was not related to the experimental treatment. There was also no difference in growth rates between groups. The qPCR analyses validated the array results by showing similar fold changes in gene expression to the arrays. They revealed a significant batch effect in expression of lipin 1 (LPIN1), Chemokine (C-X-C motif) ligand 14 (CXCL14), serine dehydratase (SDS) and hepcidin antimicrobial peptide (HAMP). Only CXCL14, a chemotactic cytokine for monocytes, was significantly down-regulated in response to ammonia. As chronic exposure to atmospheric ammonia did not have a clear influence on hepatic gene expression, this finding implies that 20 ppm of atmospheric ammonia did not pose a significant material risk to the health or metabolism of housed pigs.

Aerosol and precipitation chemistry in the southwestern United States: spatiotemporal trends and interrelationships

This study characterizes the spatial and temporal patterns of aerosol and precipitation composition at six sites across the United States Southwest between 1995 and 2010. Precipitation accumulation occurs mostly during the wintertime (December-February) and during the monsoon season (July-September). Rain and snow pH levels are usually between 5-6, with crustal-derived species playing a major role in acid neutralization. These species (Ca²⁺, Mg²⁺, K⁺, Na⁺) exhibit their highest concentrations between March and June in both PM_2.5 and precipitation due mostly to dust. Crustal-derived species concentrations in precipitation exhibit positive relationships with [Formula: see text], [Formula: see text], and Cl^-, suggesting that acidic gases likely react with and partition to either crustal particles or hydrometeors enriched with crustal constituents. Concentrations of particulate [Formula: see text] show a statistically significant correlation with rain [Formula: see text] unlike snow [Formula: see text], which may be related to some combination of the vertical distribution of [Formula: see text] (and precursors) and the varying degree to which [Formula: see text]-enriched particles act as cloud condensation nuclei versus ice nuclei in the region. The coarse : fine aerosol mass ratio was correlated with crustal species concentrations in snow unlike rain, suggestive of a preferential role of coarse particles (mainly dust) as ice nuclei in the region. Precipitation [Formula: see text] : [Formula: see text] ratios exhibit the following features with potential explanations discussed: (i) they are higher in precipitation as compared to PM_2.5; (ii) they exhibit the opposite annual cycle compared to particulate [Formula: see text] : [Formula: see text] ratios; and (iii) they are higher in snow relative to rain during the wintertime. Long-term trend analysis for the monsoon season shows that the [Formula: see text] : [Formula: see text] ratio in rain increased at the majority of sites due mostly to air pollution regulations of [Formula: see text] precursors.

Estimating the volatilization of ammonia from synthetic nitrogenous fertilizers used in China

Although it has long been recognized that significant amounts of nitrogen, typically in the form of ammonia (NH(3)) applied as fertilizer, are lost to the atmosphere, accurate estimates are lacking for many locations. In this study, a detailed, bottom-up method for estimating NH(3) emissions from synthetic fertilizers in China was used. The total amount emitted in 2005 in China was estimated to be 3.55 Tg NH(3)-N, with an uncertainty of ± 50%. This estimate was considerably lower than previously published values. Emissions from urea and ammonium bicarbonate accounted for 64.3% and 26.5%, respectively, of the 2005 total. The NH(3) emission inventory incorporated 2448 county-level data points, categorized on a monthly basis, and was developed with more accurate activity levels and emission factors than had been used in previous assessments. There was considerable variability in the emissions within a province. The NH(3) emissions generally peaked in the spring and summer, accounting for 30.1% and 48.8%, respectively, of total emissions in 2005. The peaks correlated with crop planting and fertilization schedules. The NH(3) regional distribution pattern showed strong correspondence with planting techniques and local arable land areas. The regions with the highest atmospheric losses are located in eastern China, especially the North China Plain and the Taihu region.

Dry deposition velocity of atmospheric nitrogen in a typical red soil agro-ecosystem in Southeastern China

Atmospheric dry deposition is an important nitrogen (N) input to farmland ecosystems. The main nitrogen compounds in the atmosphere include gaseous N (NH3, NO2, HNO3) and aerosol N (NH4+/NO3-). With the knowledge of increasing agricultural effects by dry deposition of nitrogen, researchers have paid great attention to this topic. Based on the big-leaf resistance dry deposition model, dry N deposition velocities (Vd) in a typical red soil agro-ecosystem, Yingtan, Jiangxi, Southeastern China, were estimated with the data from an Auto-Meteorological Experiment Station during 2004-2007. The results show that hourly deposition velocities (Vdh) were in the range of 0.17-0.34, 0.05-0.24, 0.57-1.27, and 0.05-0.41 cm/s for NH3, NO2, HNO3, and aerosol N, respectively, and the Vdh were much higher in daytime than in nighttime and had a peak value around noon. Monthly dry deposition velocities (Vdm) were in the range of 0.14-0.36, 0.06-0.18, and 0.07-0.25 cm/s for NH3, NO2, and aerosol N, respectively. Their minimum values appeared from June to August, while their maximum values occurred from February to March each year. The maximum value for HNO3 deposition velocities appeared in July each year, and Vdm(HNO3) ranged from 0.58 to 1.31 cm/s during the 4 years. As for seasonal deposition velocities (Vds), Vds(NH3), Vds(NO2), and Vds(aerosol N) in winter or spring were significantly higher than those in summer or autumn, while Vds(HNO3) in summer were higher than that in winter. In addition, there is no significant difference among all the annual means for deposition velocities (Vda). The average values for NH3, NO2, HNO3, and aerosol N deposition velocities in the 4 years were 0.26, 0.12, 0.81, and 0.16 cm/s, respectively. The model is convenient and feasible to estimate dry deposition velocity of atmospheric nitrogen in the typical red soil agro-ecosystem.

A comparative assessment of four methods for estimating ammonia emissions at microclimatic locations in a dairy building

Ammonia emissions were estimated at five microclimatic locations in a free stall dairy building using four different methods. Measurements were performed simultaneously with the different methods to enable comparison. In the first method, the rate of ammonia emission from manure was theoretically modeled utilizing Fick's law and boundary layer theory. In the second method, recirculation flux-chamber technique was used to model ammonia emission from manure. In the third and fourth methods, respectively, carbon dioxide and methane balances were employed to calculate ammonia emission. The mean ammonia emissions measured from the five locations using the different methods ranged from 0.10 to 0.15 g m(-2) h(-1). The percentage of variation of ammonia emission from the different location ranged between 8 and 52% for the different methods. Recorded ammonia emission rates in the dairy building were from 0.04 to 0.25 g m(-2) h(-1). The percentage of variation in ammonia, carbon dioxide, methane, and manure properties in the building was 50%. Two-way statistical analysis of variance showed that there were no significant differences (p > 0.63) between the four different methods or between the measurements obtained at the five locations (p > 0.90).

Airborne Fungi in Dwellings for Dairy Cows and Laying Hens

The air of animal dwellings can contain great amounts of bioaerosol composed of dust, bacteria, fungi, and endotoxins. The composition may depend on animal species, building construction, animal accommodation, and microclimate parameters, to name just a few factors. Pathogens contained may be a serious threat to animal and human health.

The aim of our study was to analyse the fungi aerosol content in a stable housing dairy cows and in a coop for laying hens over the three autumn months of 2007. The air was sampled on Petri dishes with Sabouraud glucose agar. After laboratory treatment, we identified the most common fungi. Their count in the stable ranged from 3.98×103 CFU m-3 to 5.11×104 CFU m-3 and in the coop from 6.89 ×104 CFU m-3 to 1.13×105 CFU m-3. The difference between the two animal dwellings was statistically different at the level of p<0.05. In both dwellings, the most common were the fungi Aspergillus sp., Penicillium sp., and yeasts, followed by Cladosporium sp., Fusarium sp., Mucor sp., Scopulariopsis sp., Alternaria sp., and Rhizopus sp.

Our results are entirely in line with values reported in literature and are at the lower end of the range. They call for further investigation that would eventually lead to setting air quality standards for animal dwellings and to developing reliable monitoring systems in order to ensure safe food and safe environment.

Livestock waste treatment systems for environmental quality, food safety, and sustainability

The intensification of livestock operations has benefited production efficiency but has introduced major environmental issues, becoming a concern in both developed and developing countries. The aim of this paper is primarily to address the impact of the livestock sector on environmental pollution (ammonia, greenhouse gases and pathogens), evaluate the related health risks and, subsequently, assess the potential role of waste treatment systems in attenuating these environmental and health issues. This paper is a collection of data pertaining to world trends in livestock production, since the mid 1990s and intensive livestock farming practices along with their impact on: water pollution by nitrates and through eutrophication; air pollution, particularly ammonia and greenhouse gases emissions, and soil pollution because of nutrient accumulation. Finally, this paper examines some of the benefits of treating livestock manures, issues related to the adoption of treatment systems by livestock operations and current as well as past technological developments.

Season and bedding impacts on ammonia emissions from tie-stall dairy barns

Federal and state regulations are being promulgated under the Clean Air Act to reduce hazardous air emissions from livestock operations. Few data are available on emissions from livestock facilities in the USA and the management practices that may minimize emissions. The objective of this study was to measure seasonal and bedding impacts on ammonia emissions from tie-stall dairy barns located in central Wisconsin. Four chambers each housed four Holstein dairy heifers (approximately 17 mo of age; body weights, 427-522 kg) for three 28-d trial periods corresponding to winter, summer, and fall. A 4x4 Latin Square statistical design was used to evaluate four bedding types (manure solids, chopped newspaper, pine shavings, and chopped wheat straw) in each chamber for a 4-d ammonia monitoring period. Average ammonia-N emissions (g heifer(-1) d(-1)) during summer (20.4) and fall (21.0) were similar and twice the emissions recorded during winter (10.1). Ammonia-N emissions accounted for approximately 4 to 7% of consumed feed N, 4 to 10% of excreted N, and 9 to 20% of manure ammonical N. Cooler nighttime temperatures did not result in lower ammonia emissions than daytime temperatures. Ammonia emissions (g heifer(-1) d(-1)) from chambers that contained manure solids (20.0), newspaper (18.9), and straw (18.9) were similar and significantly greater than emissions using pine shavings (15.2). Chamber N balances, or percent difference between the inputs feed N and bedding N, and the outputs manure N, body weight N, and ammonia N were 105, 90, and 89% for the winter, summer, and fall trials, respectively. Relatively high chamber N balances and favorable comparisons of study data with published values of ammonia emissions, feed N intake, and manure N excretion provided confidence in the accuracy of the study results.

Air emission inventories in North America: a critical assessment

Although emission inventories are the foundation of air quality management and have supported substantial improvements in North American air quality, they have a number of shortcomings that can potentially lead to ineffective air quality management strategies. Major reductions in the largest emissions sources have made accurate inventories of previously minor sources much more important to the understanding and improvement of local air quality. Changes in manufacturing processes, industry types, vehicle technologies, and metropolitan infrastructure are occurring at an increasingly rapid pace, emphasizing the importance of inventories that reflect current conditions. New technologies for measuring source emissions and ambient pollutant concentrations, both at the point of emissions and from remote platforms, are providing novel approaches to collecting data for inventory developers. Advances in information technologies are allowing data to be shared more quickly, more easily, and processed and compared in novel ways that can speed the development of emission inventories. Approaches to improving quantitative measures of inventory uncertainty allow air quality management decisions to take into account the uncertainties associated with emissions estimates, providing more accurate projections of how well alternative strategies may work. This paper discusses applications of these technologies and techniques to improve the accuracy, timeliness, and completeness of emission inventories across North America and outlines a series of eight recommendations aimed at inventory developers and air quality management decision-makers to improve emission inventories and enable them to support effective air quality management decisions for the foreseeable future.