Aerial Pollutants Research Articles

The preferences of laying hens for different concentrations of atmospheric ammonia

Ammonia gas is one of the most abundant aerial pollutants of modern poultry buildings. The current chronic exposure limit for ammonia of 25 ppm is set for human safety rather than animal welfare. This study assessed the behavioural preferences of laying hens ( Gallus gallus domesticus) for different concentrations of ammonia found in commercial poultry houses. Six groups, each of six laying hens, were given the choice of three concentrations of ammonia (≈0, 25 and 45 ppm) in a preference chamber over a period of 6 days and their location and behaviour recorded every 15 min. Hens foraged ( p=0.018), preened ( p=0.009) and rested ( p=0.029) significantly more in fresh air than in the ammonia-polluted environments. There was a significant difference between the responses in 0 and 25 ppm ( p<0.05) but not between 25 and 45 ppm ( p>0.05). This suggests that ammonia may be aversive to hens with a threshold for this aversion between 0 and 25 ppm. Future studies should explore graded concentrations of ammonia between 0 and 25 ppm in order to suggest a new chronic exposure limit on the basis of animal welfare.

Assessment of Techniques for Measuring the Ventilation Rate, using an Experimental Building Section

A full-scale, laboratory building section at Silsoe Research Institute was adapted to simulate cross-ventilating airflow patterns representative of those that develop in naturally ventilated, intensive livestock buildings. In the fully controlled, steady-state environment of the building section, the distribution of aerial pollutants and/or tracers was shown to depend on source location and ventilation rate. No single location within the building showed a consistently representative concentration of tracer that would be suitable for calculating ventilation rate by the constant release tracer method. Estimates of ventilation rate using the constant release tracer method, based on the average concentration of groups of six sampling locations within the building section, ranged from 93 to 119% of the ventilation rate measured using calibrated fan-wheel anemometers placed in the ventilation ducts. The best estimates of ventilation rate were obtained when the tracer concentration was measured at the perimeter (in the outlets and inlets) of the building section—these ranged from 99 to 109% of the ventilation rate measured using the fan-wheel anemometers.Airflow and pollutant distribution in the building section were predicted using computational fluid dynamics (CFD). However, these predictions were of limited help as a tool to select sampling locations within the building section, because the use of CFD requires the selection of parameters which entails verification of predictions against experimental data. Visualization of the airflow by smoke was simpler and more suitable for the present purpose.

DAILY VARIATIONS IN ODOR AND GAS EMISSIONS FROM ANIMAL FACILITIES

Seven different animal facilities were studied to determine daily variations in emissions of odor, ammonia, and hydrogen sulfide. Air samples were collected every two hours over a 12-hour period during the day for odor and gas measurements from these facilities. A nursery building had the highest emission rates for odor and hydrogen sulfide (max: 50 OU · m 3 /s/m 2 and 140 µg/s/m 2 , respectively). The naturally ventilated swine finishing building had the highest ammonia emission rate (max: 170 µg/s/m 2 ). The data also showed that there was no significant difference in average ammonia and hydrogen sulfide concentrations over the 12-h sampling period for all the animal facilities. Ventilation rates play a key role in determining the emission rates of aerial pollutants from animal buildings. However, when comparing the overall odor and gas emissions among animal buildings with different sizes, it is necessary to consider building sizes in addition to ventilation rates.

Contributory and exacerbating roles of gaseous ammonia and organic dust in the etiology of atrophic rhinitis.

Pigs reared commercially indoors are exposed to air heavily contaminated with particulate and gaseous pollutants. Epidemiological surveys have shown an association between the levels of these pollutants and the severity of lesions associated with the upper respiratory tract disease of swine atrophic rhinitis. This study investigated the role of aerial pollutants in the etiology of atrophic rhinitis induced by Pasteurella multocida. Forty, 1-week-old Large White piglets were weaned and divided into eight groups designated A to H. The groups were housed in Rochester exposure chambers and continuously exposed to the following pollutants: ovalbumin (groups A and B), ammonia (groups C and D), ovalbumin plus ammonia (groups E and F), and unpolluted air (groups G and H). The concentrations of pollutants used were 20 mg m-3 total mass and 5 mg m-3 respirable mass for ovalbumin dust and 50 ppm for ammonia. One week after exposure commenced, the pigs in groups A, C, E, and G were infected with P. multocida type D by intranasal inoculation. After 4 weeks of exposure to pollutants, the pigs were killed and the extent of turbinate atrophy was assessed with a morphometric index (MI). Control pigs kept in clean air and not inoculated with P. multocida (group H) had normal turbinate morphology with a mean MI of 41.12% (standard deviation [SD], +/- 1. 59%). In contrast, exposure to pollutants in the absence of P. multocida (groups B, D, and F) induced mild turbinate atrophy with mean MIs of 49.65% (SD, +/-1.96%), 51.04% (SD, +/-2.06%), and 49.88% (SD, +/-3.51%), respectively. A similar level of atrophy was also evoked by inoculation with P. multocida in the absence of pollutants (group G), giving a mean MI of 50.77% (SD, +/-2.07%). However, when P. multocida inoculation was combined with pollutant exposure (groups A, C, and E) moderate to severe turbinate atrophy occurred with mean MIs of 64.93% (SD, +/-4.64%), 59.18% (SD, +/-2.79%), and 73.30% (SD, +/-3.19%), respectively. The severity of atrophy was greatest in pigs exposed simultaneously to dust and ammonia. At the end of the exposure period, higher numbers of P. multocida bacteria were isolated from the tonsils than from the nasal membrane, per gram of tissue. The severity of turbinate atrophy in inoculated pigs was proportional to the number of P. multocida bacteria isolated from tonsils (r2 = 0.909, P < 0.05) and nasal membrane (r2 = 0.628, P < 0.05). These findings indicate that aerial pollutants contribute to the severity of lesions associated with atrophic rhinitis by facilitating colonization of the pig's upper respiratory tract by P. multocida and also by directly evoking mild atrophy.

The Development of Robust Methods for Measuring Concentrations and Emission Rates of Gaseous and Particulate Air Pollutants in Livestock Buildings

Abstract Air pollutants in livestock buildings may represent a risk to the health of both the housed livestock and of the stockmen. Moreover, when these air pollutants leave a building in its ventilation air, they may also represent a risk of pollution to the wider environment. A set of versatile and robust methods for quantifying pollutant emissions was therefore developed for common use during an extensive field survey of livestock buildings (329 sets of measurements) across four Northern European countries. Measurements were made, at seven different positions in each livestock building, of air temperature and relative humidity, and of the concentrations of carbon dioxide, ammonia, airborne dust (both inhalable and respirable), microorganisms and endotoxins. Concentrations of carbon dioxide were continuously measured by an infra-red analyzer while concentrations of ammonia were continuously measured by a chemiluminescence NO x analyzer preceded by a thermal converter. Mass concentrations of inhalable and respirable dust were measured by total filters and cyclone samplers, respectively, and the exposed filters were also assayed for endotoxins. Concentrations of airborne total bacteria, Gram-negative bacteria and total fungi were measured in some of the buildings using a novel automated slit sampler. The ventilation rate of each building was estimated by a balance method from the information on both its internal and external carbon dioxide concentrations, and hence the emission rates of the different aerial pollutants from each building were estimated. The results of applying the methods are reported and discussed in detail in later papers in the series, but as an example of the results obtained, a slurry-based sow unit, monitored over 24 h in wintertime, gave internal carbon dioxide and ammonia concentrations in the ranges 1180–3765 and 5·3–17·4 p.p.m., respectively, along with internal temperatures and relative humidities in the ranges 15·7–20·4°C and 34–69% respectively. Examples of the estimated emission rates from the sow unit, averaged over the 24 h period and corrected for background, were: ammonia 0·86 g NH 3 /h (hpu) (hpu=heat production unit), inhalable dust 0·19 g/h (hpu), respirable dust 0·02 g/h (hpu), and total bacteria 2·3 M(cfu)/(hpu) where cfu is colony-forming units.

Emissions of Aerial Pollutants in Livestock Buildings in Northern Europe: Overview of a Multinational Project

Abstract The principal object of this project was to undertake a large survey of the emissions of aerial pollutants within and from livestock buildings in Northern Europe. Measurements of aerial pollutants were made using common methods which were developed in the first year of the project. This allowed reliable comparisons to be made between results from different countries, species and types of building. The survey covered pigs, cattle and poultry and the major housing types. A total of 329 livestock buildings were surveyed. All the results are described in the accompanying papers in this issue. High concentrations of ammonia, airborne dust, endotoxin and microorganisms were measured in poultry and some pig houses: air quality was acceptable in cattle houses in terms of animal health. These burdens of aerial pollutants cause some concern because of their potentially harmful effects on human and animal health. Atmospheric ammonia is an important pollutant of the atmosphere and its rates of emission per animal housed were highest from cattle buildings. Measures based on husbandry and engineering techniques should be taken to reduce these emissions.

A Comprehensive Experimental Study of Aerial Pollutants in and Emissions from Livestock Buildings. Part 2: Results

A Comprehensive Experimental Study of Aerial Pollutants in and Emissions from Livestock Buildings. Part 2: Results

A Comprehensive Experimental Study of Aerial Pollutants in and Emissions from Livestock Buildings. Part 1: Methods

Comprehensive measurements of aerial pollutants were carried out in a mechanically-ventilated fattening piggery and in a naturally-ventilated (Louisiana-type) broiler house. In the piggery, ventilation rate was directly measured using fan-wheel anemometers and indirectly estimated by a CO2balance method. Over 24 h, the indirect CO2method underestimated the direct method by ≈6·5%. Concentrations of inhalable dust and of the gases NH3and CO2were monitored quasi-continuously in both buildings. In the piggery gravimetric and wet chemical measurements were used to investigate the spatial variation of dust and ammonia concentration, respectively; only towards the walls were significant variations found. Seasonal influences were detected for inhalable dust concentration in the broiler house and for ammonia concentration in the piggery. Altogether, the comprehensive study showed that the results of a related field survey, which used an array of measuring positions in the central cross-sectional plane of each livestock building, were comparable and sufficiently representative.

A delayed aversion to atmospheric ammonia in Pigs

Intensively housed pigs are continuously exposed to aerial pollutants, such as ammonia gas (e.g. Robertson 1994). The objective of this study was to determine if exposure to ammonia, for an extended period, was aversive to a pig. The three chronic choice test experiments catalogued the behavioural responses of Duroc x Landrace pigs to concentrations of ammonia recorded frequently in commercial piggeries. The first experiment established if ammonia was aversive. The remaining experiments indirectly and directly traded off the strength of any aversion against thermal comfort. In the second experiment thermal comfort could be obtained either in the absence or presence of ammonia; in the third experiment thermal comfort could only be gained in the presence of ammonia.

John Rishbeth, 10 July 1918 - 1 June 1991

Plant pathology is about diseases of plants caused by infectious agents such as viroids, mycoplasmas, viruses, bacteria and fungi and, to a far less extent, by non-infectious agents such as aerial pollutants. Almost always, the diseases studied have been and are of economically important higher plants, and in contrast to medical and veterinary pathology, plant pathology covers all aspects of disease including control. Its scope, therefore, is unusually large, even for a biological discipline, ranging from the molecular, biochemical and physiological analyses of interactions between plants and the disease-causing agents, at sub-cellular and cellular levels through intermediate stages to the study of interactions at whole organism levels in populations of crop or wild plants. These latter were John Rishbeth's main interests whereas mine were at the other end of the scale. However, I did have an interest, albeit secondary, in biological control of plant diseases, a field in which John became an international authority. So I followed closely his work on biological control of soil-borne pathogens and also his studies of the biology and ecology of these pathogens upon which his methods of control were so firmly based. Thus I accepted with great pleasure the invitation to write about John Rishbeth despite the fact that I am far removed from forest pathology and thus, perhaps, less well placed than others to pay full tribute to his outstanding research in this field.

Aerial pollutants and the health of poultry farmers

Aerial pollutants and the health of poultry farmers

Trace metal contents ofTaraxacum officinale (dandelion) as a convenient environmental indicator

Some vascular plants are known to concentrate trace metals and are regarded to be suitable indicators of atmospheric metal deposition. Among plant species used for biogeochemical studies dandelion (Taraxacum officinale.) is convenient for monitoring air/soil pollution. The plant commonly occurs in different ecosystems with relatively parallel stages of ontogenesis over a broad area of geographical regions. Its leaves and roots are easily accessible for sampling. Leaf to root ratios of metal concentrations in dandelion may indicate the source of metals during the growing season. Trace metals in leaves and roots of dandelion from 132 sites in Poland showed higher concentrations in the plants from the SW region compared to those from the NE region of the country. However, the differences were only statistically significant (α = 0.05) for Cd, Ni, and Pb. Geometric means of metal concentrations (mg kg(-1), air dried weight) in dandelion leaves of the SW and NE regions were: Cd 0.85, 0.52; Cr 0.99, 0.81; Cu 11.2, 11.1; Fe 184.4, 100.0; Mn 59.7, 51.4; Ni 2.1, 1.5; Pb 4.4, 3.0; and Zn 49.6, 41.3, respectively. Markedly higher concentrations of Cd, Pb, and Zn were found in the leaves of the dandelion over roots in the SW region. These metals are the most serious aerial pollutants in that part of the country.

Air hygiene in a pullet house: Effects of air filtration on aerial pollutants measured in vivo and in vitro

1. The natural history of air hygiene in a pullet house was assessed at three-weekly intervals using a combination of in vitro and in vivo assays. The performance of an internal air filter was also examined as an experimental technique for providing clean air. 2. Overall, air hygiene was poor by comparison with occupational standards for human health. The mass concentrations of respirable and inspirable dust were 1.4 and 11.3 mg/m3 compared to human exposure limits of 5 and 10 mg/m3 respectively. The concentration of ammonia was typically about 20 ppm. 3. The majority (greater than 99%) of airborne particles were non-viable. Commensal bacteria from the skin were the most numerous airborne bacteria. Scopulariopsis and Aspergillus spp. were the most prevalent fungi recovered from the air and bird's lungs respectively. The concentrations of airborne and lung fungi were positively correlated with ammonia concentrations. 4. The differences between in vivo and in vitro assays of airborne microorganisms suggest that an aerosol sampler should be devised which better mimics the physical and biochemical environment of the respiratory tract.

A Survey of the concentration of ammonia recorded in pig housing in England

In animal housing ammonia is an aerial pollutant resulting from the microbial conversion of nitrogenous materials excreted in faeces and urine. Ammonia is an irritant to cells lining the respiratory tract and an increased incidence of pneumonia in pigs and humans and atrophic rhinitis in pigs have been correlated with elevated ammonia levels. In a survey of 12 farms and 49 pig buildings concentration of ammonia was identified specifically as a causative agent in the aetiology of atrophic rhinitis (Robertson, Wilson and Smith 1990). Furthermore, high levels of ammonia can delay the onset of puberty in gilts perhaps as a result of the masking of boar odour (Malayer, Brandt, Green, Kelly, Sutton and Diekman 1988).Regulations have been introduced (Control of Substances Hazardous to Health (COSHH)) limiting the exposure of humans to atmospheric ammonia to a mean level of 25 ppm over an 8h work shift and 35 ppm for 10 minute exposure. As part of a study on the effectiveness of a feed additive formulated to control atmospheric ammonia, levels of ammonia in pig housing were monitored.

Air hygiene in a pullet house: Spatial homogeneity of aerial pollutants

1. The spatial distribution of aerial pollutants was measured in a large deep-litter pullet house, initially holding 10,000 birds, at 12 sites within the birds' breathing zone: on 6 occasions when the birds were between 8 and 27 d of age and on two occasions when the birds were 29 and 34 d of age and the flock size was halved. 2. The distribution of most pollutants appeared uniform, implying that all sites could be considered representative of the overall concentration of pollutant. 3. The concentration of ammonia differed between sites, probably because of local variations in the rate of release from the litter. The number concentration of non-respirable particles (greater than 5 microns in diameter) became heterogeneous when the flock size was halved. 4. The operation of two punka fans had no effect on the spatial distribution of aerial pollutants, but increased the maximum air speed from 0.08 to 0.16 m/s. 5. Recommendations are given for the minimum number of sampling sites necessary for a predetermined level of statistical accuracy. Eight sites at least are recommended for most aerial pollutants, though more are needed for the concentration of gaseous ammonia.

Binational emissions trading in an international air shed: The case of El Paso, Texas and Ciudad Juárez

The quantitative analysis of transfrontier pollution (TFP) relative to aerial pollutants along the United States-Mexico border has been addressed in a series of publications (Applegate and Bath 1974 and 1978; Applegate 1979a, 1979b, 1981a and 1981b; Bath 1983). After defining the problem, a second series of publications were devoted to policy analysis (Applegate 1982a and 1982b; Bath 1981; Applegate and Bath 1983, 1984, 1985 and 1986). This article, based on data and policy analysis given in the earlier publications, will explore bilateral emissions trading within an international air shed. We will propose specific approaches to solve aerial TFP within the air shed covering El Paso and Cd. Juarez (EPJAZ). The approaches we suggest, modified to meet the unique requirements of other border sheds, could be used along the entire border with Mexico and possibly elsewhere in the Americas.

The scope of Quaternary paleolimnology

I describe Quaternary paleolimnology on the basis of a review of abstracts published for meetings of: (1) American Society of Limnology and Oceanography (ASLO), 10 meetings since 1980; (2) International Association of Theoretical and Applied Limnology (SIL), 4 since 1977, (3) International Symposia on Paleolimnology (ISP), 4 since 1967, and (4) International Union for Quaternary Research (INQUA), 5 since 1969. A total of 9538 abstracts were scanned to find 678 with paleolimnological content. A data base constructed from the 678 contains frequencies of coverage of techniques, variables, themes, interpretive aspects, and character and geography of study sites. These data indicate that Quaternary paleolimnology has been a diverse science dealing with many of the same aspects of lakes as neolimnology but with a longer time perspective. Most frequently studied paleolimnological characteristics were trophic state, water chemistry (particularly salinity, pH, alkalinity (ANC), micronutrients and oxygen), water levels, lake morphology, and mixis and other hydrology. Lake biological variables that received greatest attention were diatoms, pigments, Cladocera, Mallomonadaceae, non-siliceous algae, Ostracoda, and Mollusca. Most often considered to influence these characteristics and variables were climate; catchment vegetation, soil, geology, land use and erosion; water chemistry; aerial and non aerial pollutants; sedimentation; and tectonism. Most frequent chronologic sequences were (1) late-glacial to present, and (2) modern (ca. 0.3 ka to present). Lakes in moist temperate and boreal regions were most heavily studied.

Effects of aerial pollutants on the growth and yield of spring barley

SUMMARYOpen‐topped chambers were used to determine the effect of field concentrations of aerial pollutants on the growth and yield of spring barley. Experiments were conducted in the Marston Valley, Bedfordshire, where sulphur dioxide and fluoride are the major pollutants. The charcoal filtered chambers enabled pollutant concentrations to be reduced by 60–70%. Cleaning the air increased straw and grain yields. The filtration was non‐selective and did not identify the injurious agent. The chambers were found to accelerate the crop's development by 7–8 days and reduce yield by suppressing tillering.