Immission

In Europe, various regulations and schemes for the assessment of VOCs are in use according to special conditions, e.g.  

When defining threshold limit values, it is important that prevailing conditions and methods are specified, e.g., ventilation rates, methods of sampling, determination and cal-eulation. 

Immission processes of solvents from paints and varnishes are determined by surrounding conditions e.g., parameters of the ambient air, indoor air parameters, e.g., ventilation (ventilation rates), air distribution, air movements, composition of ambient air, concentrations of air compounds, humidity, temperature, volume of the indoor air, extreme conditions (e.g., worst case). 

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F.ciuipment Heavy loads Materials I hermal conditions lAQ Heating 6c cooling Emissions Immissions... 

Outdoor environment Materials Insulation Heating 6c cooling Heating Sc cooling Air distribution Emissions Immissions l.ayoLit ... 

Immission The rate at which a receptor of pollution encounters a pollutant. 

Determination of environmental carcinogens is not an end in itself. Although often misunderstood or misinterpreted, the aim of scientific work in this area is to collect data on human exposure, to pinpoint emission and immission sources and to determine the causes of potential health risks to humans. The ultimate aim is always elimination or reduction of human exposure and thereby prevention of human cancer. In view of the slow progress in the treatment of human cancer this approach is an important strategy in the fight against this disease. 

XtraFood Xenobiotics transfer in the primary FOOD Chain model calculates transfer of contaminants in the primary food chain. This model describes the whole chain from immission of contaminants at the farm level over concentrations in food to human exposure. The model focuses on the terrestrial food chain... 

Table 8.3. Common factors of immissions of airborne particulates during the heating period (bold key elements) according to Einax and Danzer [1989]...

In the early 70 s the increase of stock caused increasing problems with odour immissions from livestock farming. For a practicable research work in this field, a portable olfactometer was required to get objective results direct from the different odour emitting sources. Since that time portable and transportable types of olfactometers have been developed. Some of our experience concerning the application of portable and transportable olfactometers is presented in this paper. 

Fig. 1. Emission-Transmission-Immission of airbom pollutants. Quelle=source, Luftbewegung=atmospheric flow, Verdunnung= dilution, Belastigung=nuisance.

As the sample time is set to 2-10 minutes by adjustment of the water flow throttle, this experimental setup delivers time mean values, as usual in immission monitoring as well as in established dispersion models. 

Observations of smoke plumes, first brief tests and some papers 15, 6/ suggest that the immission concentration is fluctuating in a wide range near the source. Human nose is more sensitive to odour concentration fluctuation than, due to adaption, to constant odour concentration. In fig. 5 it is shown qualitativly that odour perception may occur due to concentration fluctuations although the mean value is far below the odour threshold. In table 1 it is indicated that the distance between agricultural emission sources and receptor is relatively small in relationship to industrial emissions. 

However, we must keep in mind the limitations of this approach, especially the transfer of consistent sets of dispersion parameters to the propagation of air pollution in the vicinity of a source. The Gaussian plume formula should be used only for those downwind distances for which the empirical diffusion coefficients have been determined by standard diffusion experiments. Because we are interested in emissions near ground level and immissions nearby the source, we use those diffusion parameters which are based on the classification of Klug /12/ and Turner /13/. The parameters are expressible as power functions,... 

VDI2450 Blatt 1 Messen von Emission, Transmission und Immission luftverunreinigender Stoffe, Begriffe, Definitionen, Erlauterungen. Sept. 1977. 

As part of a study to test the use of population panels as a method for assessing odour annoyance in a direct way, a comparison of the odour annoyance experienced by such population panels and the odour immission concentrations expressed in odour units/m3 of air samples taken simultaneously, was made. It was found that in a city where odour annoyance occurs regularly, no relationship could be found between the amount of odour annoyance experienced and the immission concentrations. Furthermore, it was shown that the odour concentrations of pleasant smells (meadows forest) in an unpolluted area may be as high as 24 odour units. It is concluded that the amount of annoyance caused by odours can not be deduced from concentration measurements, but should be assessed in a direct way. Population panels provide a good means of obtaining such data. They are reliable and can give indications about the important sources of annoying odours in complex industrial areas. 

During some of the weeks, in Hoogvliet air samples were collected in order to make a direct comparison between immission concentration and experienced annoyance. The sampling was done by the Division for Nutrition and Food Research TNO Zeist. The samples were collected by a mobile unit of this institute during the same hour in which the panels made their measurements. Fourty teflon bags of 40 liters each were filled at three locations in such a way that all bags contained equal amounts from all three... 

In this paper, we will compare the data obtained in these immission measurements with the data on perceived annoyance in Hoogvliet. We will also show some data on immission measurements on samples taken at various places in the village of Zeist, our control location. 

Fig. 3. Comparison between Odour Annoyance Indexes and immission measurements in Hoogvliet.

As can be seen from the figure the relationship between the immission concentration (dotted line) and the odour annoyance is very poor. The correlation coefficient (r=(). 12) is statistically non-significant. 

The odour annoyance experienced fluctuates much more than the immission concentration, which seems rather stable. 

This might be due to the fact that even without any annoying substances present, the background level of odour concentration is high. Therefore, as a control, a number of immission measurements were made on samples collected at several locations in the village of Zeist. 

The main conclusion that can be drawn from this, is that odour annoyance cannot be inferred from emission or immission measurements, but should be measured directly... 

Chemical analysis of odorants in ambient air is hampered by the presence of a plethora of volatile organic compounds, which do not contribute to the odour. Nevertheless application of either powerful separation and identification techniques, such as the GC-MS combination, or specific GC-detection or absorption procedures allow qualitative and quantitative determination of odourants. Improvements are under way to achieve the sensitivity necessary for relevant immission concentrations, which go down to 0.1 ppb for some odorants. 

The actual scope and limitations of chemical analysis of odour show that all problems can be tackled as far as emission is concerned. For immission measurements some progress is necessary, but there is no essential reason why chemical analysis would be unable to attain the desired sensitivity for all types of odorants. There is no doubt that in a few years the last difficulties will be solved. In order to achieve real control of odour nuisance, automatic measurement is necessary on a long time basis. There again some technical development is to be expected. 

Totally the discussed coverings are useful possibilities to control immissions. For a lot of farms located in villages or in a short distance to residential quarters an effective covering on the liquid manure storing tanks is the only convenient possibility to get restocking permitted. 

KOWALEWSKY, H.H., SCHEV, R. VETTER, H. (1980). Measurement of odour emissions and immissions. Effluents from Livestock, Applied Science Publishers 609-626. 

When comparing the dust-borne concentrations of butyric acid and p-cresol with the odour thresholds it seems that the concentrations are too small to be relevant for an odour nuisance. However, if the dust is removed from the gas phase of the air from animal houses the odour disappears (39), (40), (14). This supports the opinion of HAMMOND et al. (40) that the odor is concentrated on the dust particles. The authors conclude from their data that the concentration of the two odorants butyric acid and p-cresol is about 4TO7 greater on an aerosol particle than it is in an equal volume of air. Thus, an aerosol particle deposited on the olfactory organ carries odour equivalent to a much greater volume of air (40). These considerations indicate that dust from animal houses should be taken into account in connection with odour emission/immission measurements not only by chemical analysis but by sensory evaluations using olfactometers without dustfilters, as well. 

Schneider, E., P. Krenmayr, and K. Varmuza, A Routine Method for the Analysis of Mononitro-PAH in Immission and Emission Samples, Monatsh. Chem, 121, 393-401 (1990). 

Eikenberg, J., Bajo, S. et al. 2002. Spezialnuklid-Analysen fuer die Beweissicherung ZWILAG 1997-2001 Final Report of the Immission Measurements PS1 Technical Report No 02-15. Paul Scherrer Institut, CH-5232 Villigen, 40 pp. 

If the dispersed medium is a solid,immissible with dispersion liquid, it is called "suspensoid and the combination a "suspension (Eg colliodal gold or ferric oxide in water), and if the dispersed medium is a liquid immissible with dispersion liquid, it is known as "emulsoid and the combination as "emulsion (Eg milk, rubber latex, etc)... 

Hainsch A (2003) Ursachenanalyse der PMIO-Immission inurbanen Gebieten am Beispiel der Stadt Berlin. Dissertation. Technische Universitat, Berlin... 

Pimpl, M. 1992. Increasing the sensitivity of 241Pu determination for emission and immission control of nuclear installations by aid liquid scintillation counting. J. Radioanal. Nucl. Chem. 161 429—435. 

Morselli L, Zappoli S, Liberti A, et al. 1989. Evaluation and comparison of organic and inorganic compounds between emission and immission samples from municipal solid waste incinerator. Chemosphere 18 2263-2273. 

Van Haut, H., Stratmann, H., Schriftenr. Landesanstalt Immissions Boden-... 

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