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Door interne filtratie van stallucht wordt het stofgehalte in de lucht met 45 verminderd. Deze methode om het stofgehalte van de lucht te verlagen is echter duur

Het beluchten van mest draagt in de pluimveehouderij bij aan de reductie van de ammoniakemissie. Dit blijkt onder andere uit het aantal systemen met een Groen Label waarbij deze techniek wordt toegepast. Ook het beluchten van strooisel geeft een reductie van de ammoniakemissie. Een negatief effect hierbij is echter dat de arbeidsomstandigheden verslechteren door een circa vijf keer hogere stofconcentratie.

De nieuwe EU-richtlijn voor het houden van leghennen stelt strooisel in verrijkte kooien op termijn verplicht. Hoewel er voldoende technieken zijn om dit te kunnen realiseren, blijkt de keuze van de juiste technieken en materialen van groot belang. Indit artikel de laatste stand van zaken.

Het schone-neuzenventilatiesysteem is een goedkope manier om het stofgehalte in de stallucht en de concentraties van andere schadelijke componenten te verlagen.

Biologische varkenshouders werken vaak langdurig in de stal vanwege de grote zorg voor de dieren. Daarnaast is strooisel een vereiste in de biologische varkenshouderij. Dit leidt ertoe dat biologische varkenshouders aan hoge stofconcentraties worden blootgesteld. Wageningen UR Livestock Research onderzocht samen met biologische varkenshouders hoe hoog de stofbelasting is en hoe zij zich tegen het stof kunnen beschermen

Filtreren geeft een sterke verlaging van het stofgehalte, wassen geeft maar een beperkte verlaging en stofzuigen heeft vrijwel geen effect op het stofgehalte. Stofverlaging is vooral in het belang van de gezondheid van de varkenshouder, want varkens bleken niet beter te groeien in een stal met wat minder stof.

Objectives: Workers in many industries are exposed to endotoxins, which may cause adverse health effects. In exposure assessment, information about exposure variability is essential. However, variability in exposure has rarely been investigated for biological agents and more specifically for endotoxin. Therefore, variance components and determinants of exposure were studied in a large database with >2000 endotoxin measurements. Methods: Data from 10 individual studies were combined to create a database with 2010 personal inhalable dust and endotoxin measurements, of which 1650 were repeated measurements. Exposure groups were defined based on job codes. Between- and within-worker variance components were estimated for different grouping strategies, and determinants of exposure were studied using mixed effects models. Results: Inhalable dust and endotoxin exposure levels are summarized for 46 industries and 4 broadly defined sectors. The between-worker variability exceeded the within-worker variability overall and within sectors and subsectors, and variance components were larger for endotoxin than for dust. Between-worker variability also exceeded within-worker variability in nearly half of the exposure groups based upon industries or job code within industries for endotoxin exposure and in 10% of the groups for dust exposure. Among other things, dustiness of the process, contact with animals, bulk production, presence of plant material or a cyclic process appeared as determinants of exposure, which largely explained the between-worker variability. Conclusions: Exposure groups were much less homogeneous for endotoxin exposure than for dust exposure. This is distinctly different than for chemical exposure. Large variability in measured exposure levels is inherent to endotoxin exposure, which is caused in part by determinants that influence growth of microorganisms. These findings have major consequences for the design of future occupational intervention and epidemiological studies. The measurement effort needs to be greater than exposure assessment for chemical agents which demonstrate lower exposure variability, especially when evaluating endotoxin exposure for compliance testing. The established determinants of exposure give direction for potential exposure control, although more information about determinants of day-to-day variability in exposure is still needed to be able to effectively control endotoxin exposure. © The Author 2008. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

This brochure describes the underlying principles that form a basis for better-informed choices with regards to the management of trees and shrubs in cities and the design of functional planting schemes.

Objectives: To effectively decrease occupational exposure to flour dust and related allergens, detailed information on exposure determinants and effectiveness of control measures is essential. In this paper, we use personal real-time exposure measurements to get more insight into the relationship between specific work characteristics, including the use of control measures, and (peak) exposure to flour dust. The study has three objectives: (i) identify tasks and activities related to peak exposure, (ii) identify control measures and other important exposure determinants and (iii) assess the potential impact of these control measures on the (peak) exposure to flour dust. Methods: A data set containing 82 real-time exposure measurements in combination with information from detailed observations was used to study the association between peak exposures and different tasks, activities and other determinants such as control measures. Descriptive statistics of peak exposure on job level were generated as well as information on contribution of task-specific peak exposures to time-weighted average (TWA) exposure levels. Finally, we evaluated the efficacy of a variety of control measures on task exposure by comparing exposure levels of groups of workers with and without controls. Results: In workers included in this study, >75% of TWA exposure is directly associated with peak exposures during a limited set of well-defined tasks/activities. The impact of a single task on population TWA exposure is generally limited (

This brochure describes the underlying principles that form a basis for better-informed choices with regards to the management of trees and shrubs in cities and the design of functional planting schemes. Mogelijkheden ter bestrijding van fijnstof

Various meteorological conditions, especially the presence of a very low and strong temperature inversion and the absence of wind, caused a sharp increase of atmospheric pollutants during the festivities at the turn of the year 1992. Especially the concentrations of fine particles were extremely high. The monitoring network for fine particles was implemented during the years 1992 and 1993, therefore no reliable estimate was available of concentrations at the turn of other years under normal meteorological conditions. The meteorological conditions at the turn of the year 1993 were normal. Concentrations of fine particles (PM10) over the first hour of the new year were, averaged over urban monitoring sites, about 500 mug/m3. The concentrations of SO2, CO and NO were higher than expected. Measurements were available on the change of the concentrations within the first hour of 1994, concentrations were highest during the first half hour. The composition of the fine particles was in agreement with measurements of the previous year.

This report presents tabulated National Air Quality Monitoring Network results for the city and street stations in all regions in the Netherlands for the calendar year 1994, summer 1994, winter 1993-1994 and 1 April 1993 - 31 March 1994 (tropical year: EC reference period). The components monitored were: fine dust (PM10), CO, Ox (=NO2+O3), O3, NO2, NO, NOx (=NO2+NO), black smoke (= suspended matter measured by the black-smoke method) and SO2. The fine dust (PM10) measurements were corrected for a systematic underestimation caused by the sampler. In a check made at all stations in the network for exceedance of Dutch limit values in 1994, exceedances for black smoke, PM10 and O3 were observed. The limit values for SO2, NO2 and CO were not exceeded.

Op basis van een aantal rekenregels, die voor het merendeel zijn afgeleid van gegeneraliseerde meetresultaten, is een verdeling van PM10 over vijf categorien nl: PM10, PM2.5, PM0.1, secundair aerosol en koolstofhoudend aerosol berekend voor de buitenlucht in een vijftal regio's in Nederland waarbij ook onderscheid gemaakt is in de bijdrage van Nederlandse en buitenlandse bronnen. Op basis van deze analyse is een verdeling van bijdrage van Nederlandse versus buitenlandse bronnen van 40% resp. 60% afgeleid. Deze berekende bijdrage van Nederlandse bronnen is groter dan vroeger was aangenomen en wordt voornamelijk veroorzaakt doordat een groter aandeel van de grovere fractie in de PM10 samenstelling is verondersteld. De concentratiegradienten van PM10 in Nederland zijn gering. Het beeld van een homogene 'deken' van PM10 concentraties moet echter onder invloed van bovenstaande resultaten worden bijgesteld tot dat van een 'lappendeken'. Concentratieverschillen in Nederland zijn beperkt door de grote dichtheid van verschillende bronnen maar de samenstelling van het PM10 aerosol kan in verschillende gebieden in Nederland wel uiteenlopen. Doordat die verschillende bronnen hun eigen emissiekarakteristiek hebben kunnen zij lokaal de concentratie en samenstelling van PM10 toch behoorlijk beinvloeden. De berekende concentraties in het beeld van de 'lappendeken' komen goed overeen met de PM10 concentraties zoals gemeten in het Landelijk Meetnet Luchtkwaliteit die in een range van 35-45 mug/m3 liggen.

The main conclusion of this report, is that the ambient levels of particulate matter in the Netherlands may lead to serious health effects in the population. This summary contains a double message. Based on epidemiological research, replicated in number of countries, it is estimated that ambient PM10 is associated with a number of thousands of cases of acute mortality, and with serious health effects in a few tens of thousands of people per year in the Netherlands. However, our current knowledge fails in completely explaining the observed associations. The sole fact, that at the ambient levels of PM10 such associations with mortality are consistenly found, is remarkable. The question remains, whether these associations are caused by PM10, or by another factor highly correlated with PM10. At the request of the Ministry of the Environment the national institute of public health and environmental protection (RIVM) has performed a quantitative risk assessment of the health effects of population exposure to PM10. PM is an acronym of particulate matter, and PM10 indicates particles with an aerodynamic diametre smaller than 10 micrometres (10 mum). These particles can enter the airways and are classified as inhalable. Their health effects have been estimated by combining the 1993 daily averages of PM10, as measured by the Dutch monitoring network with the concentration response relationships reported in open literature, including Dutch studies.

An overview and evaluation is given of important environmental data of fine dust (PM10) in the Netherlands, such as emissions, possibilities for emission abatement, air quality, exposure, toxicology and epidemiology. These data can be used to define environmental policy to prevent negative effects from exposure to fine dust.

This report presents a halfway score of the research project "Winter smog and Traffic", one of the themes of the research programme "Air Pollution and Health". A state of the art is presented of the health effects associated with exposure to winter smog and of the toxicological effects caused by the inhalation of particles. A summary of the assessment of air quality and the results of epidemiological research is presented. Some policy questions are answered as far as possible at this stage of the project. Finally, an outline of a plan of activities is presented which is based on the policy needs and the most serious gaps in knowledge.

An overview and evaluation is given of important environmental data of fine dust (PM10) in the Netherlands, such as emissions, possibilities for emission abatement, air quality, exposure, toxicology and epidemiology. These data can be used to define environmental policy to prevent negative effects from exposure to fine dust.

The main conclusion of this report, is that the ambient levels of particulate matter in the Netherlands may lead to serious health effects in the population. This summary contains a double message. Based on epidemiological research, replicated in number of countries, it is estimated that ambient PM10 is associated with a number of thousands of cases of acute mortality, and with serious health effects in a few tens of thousands of people per year in the Netherlands. However, our current knowledge fails in completely explaining the observed associations. The sole fact, that at the ambient levels of PM10 such associations with mortality are consistenly found, is remarkable. The question remains, whether these associations are caused by PM10, or by another factor highly correlated with PM10. At the request of the Ministry of the Environment the national institute of public health and environmental protection (RIVM) has performed a quantitative risk assessment of the health effects of population exposure to PM10. PM is an acronym of particulate matter, and PM10 indicates particles with an aerodynamic diametre smaller than 10 micrometres (10 mum). These particles can enter the airways and are classified as inhalable. Their health effects have been estimated by combining the 1993 daily averages of PM10, as measured by the Dutch monitoring network with the concentration response relationships reported in open literature, including Dutch studies.

This report presents tabulated National Air Quality Monitoring Network results for the city and street stations in all regions in the Netherlands for the calendar year 1994, summer 1994, winter 1993-1994 and 1 April 1993 - 31 March 1994 (tropical year: EC reference period). The components monitored were: fine dust (PM10), CO, Ox (=NO2+O3), O3, NO2, NO, NOx (=NO2+NO), black smoke (= suspended matter measured by the black-smoke method) and SO2. The fine dust (PM10) measurements were corrected for a systematic underestimation caused by the sampler. In a check made at all stations in the network for exceedance of Dutch limit values in 1994, exceedances for black smoke, PM10 and O3 were observed. The limit values for SO2, NO2 and CO were not exceeded.

A sharp increase of atmospheric pollutants was observed during the festivities at the turn of the year 1992. Concentrations of fine particles (PM10) over the first day of the new year were more than 200 mug/m3. During the first hour of 1993, concentrations of 1,000 - 10,000 mug/m3 are estimated in the centres of large cities. Concentrations of heavy metals in this dust were low. Other compounds, such as nitrogen oxides, sulphur dioxide and carbon monoxide, did not noticeably increase after the fireworks. The air pollution may have caused acute health effects. Visibility in or near domestic areas, was reduced to several tens of meters. Locally, further visibility reductions, due to fire works, are expected. These extreme concentrations, due to various meteorological conditions, may occur once in a decade.

A sharp increase of atmospheric pollutants was observed during the festivities at the turn of the year 1992. Concentrations of fine particles (PM10) over the first day of the new year were more than 200 mug/m3. During the first hour of 1993, concentrations of 1,000 - 10,000 mug/m3 are estimated in the centres of large cities. Concentrations of heavy metals in this dust were low. Other compounds, such as nitrogen oxides, sulphur dioxide and carbon monoxide, did not noticeably increase after the fireworks. The air pollution may have caused acute health effects. Visibility in or near domestic areas, was reduced to several tens of meters. Locally, further visibility reductions, due to fire works, are expected. These extreme concentrations, due to various meteorological conditions, may occur once in a decade.

Concerns research on emission data used as input for atmospheric dispersion modelling in the framework of the RIVM project "Air Pollution and Health" and the Netherlands Environmental Outlook 4. The data collected apply to primary particulate matter, SO2, NOX and NH3 for Europe and the Netherlands for base and future years. Economic developments and abatement measures used to calculate future emission trends are explained. A first analysis has been made of the uncertainties involved in the estimates of particulate matter emissions. On the basis of these reported emission data we recommend focusing future emission research on: i) closer analysis of the uncertainties in present emission estimates, ii) the subsequent effect of uncertainties in emission estimates on dispersion modelling, and iii) increasing the insight into the quality of present emission data and probable missing sources of data. This can be achieved through measurements at emission sources and a stronger linking of emission inventories to air quality monitoring in general.

This report presents a halfway score of the research project "Winter smog and Traffic", one of the themes of the research programme "Air Pollution and Health". A state of the art is presented of the health effects associated with exposure to winter smog and of the toxicological effects caused by the inhalation of particles. A summary of the assessment of air quality and the results of epidemiological research is presented. Some policy questions are answered as far as possible at this stage of the project. Finally, an outline of a plan of activities is presented which is based on the policy needs and the most serious gaps in knowledge.

This report is based on reports from provinces and municipalities on exceedances of the air quality standards for the compounds sulphur dioxide, suspended particles (black smoke), nitrogen dioxide, carbon monoxide, lead and benzene. No exceedances of air quality standards were reported for industrial areas. By seven municipalities exceedances were reported: thirteen times of nitrogen dioxide and nine times of benzene.

The EUROS model is an air-quality model used at the Air Research Laborotory of RIVM for short (day) to long term (year) for simulations of the (chemical) dispersion of gaseous and/or airborne particulate matter on European scale. This report describes a part of ongoing development and validation work on the model to improve the models generic applicability which is one of the objectives of the RIVM project compartimental models (now: integration of regional models S711002). It focusses on the representation of dispersion processes, with the goal to improve and evaluate these processes. As such it forms a first step in the revision towards a complete three dimensional description of the transport module in the EUROS model. The work is performed within the framework of a collaboration between the Flemish institute for technological research (VITO) and RIVM. In EUROS the representation of the mixing layer and horizontal advection is improved. The new EUROS version is extensively tested and mixing layer height values are evaluated with lidar measurements. Model results for ozone concentrations and accumulated exposure (AOT) are evaluated in terms of the different mixing layer representations. The revised calculation of the mixing layer gives a much better representation of the land-sea contrast, with lower mixing heights over sea than over land, during the daytime. An important outcome is that the mixing layer concept, used in EUROS, hinders the validation of modelled concentration levels. Because, in spite of the applied scientific model improvements, modelled AOT40 levels for ozone do not show significant improvement in respect to observations. The main concern in this context is the value of the reservoir layer height in the model, which is interlaced with the mixing layer concept. Therefore, it is anticipated that a more realistic representation of the vertical exchange processes, by describing explicitly three-dimensional advection and diffusion, will improve the EUROS model results significantly, both quantitatively and qualitatively.

The EUROS model is an air-quality model used at the Air Research Laborotory of RIVM for short (day) to long term (year) for simulations of the (chemical) dispersion of gaseous and/or airborne particulate matter on European scale. This report describes a part of ongoing development and validation work on the model to improve the models generic applicability which is one of the objectives of the RIVM project compartimental models (now: integration of regional models S711002). It focusses on the representation of dispersion processes, with the goal to improve and evaluate these processes. As such it forms a first step in the revision towards a complete three dimensional description of the transport module in the EUROS model. The work is performed within the framework of a collaboration between the Flemish institute for technological research (VITO) and RIVM. In EUROS the representation of the mixing layer and horizontal advection is improved. The new EUROS version is extensively tested and mixing layer height values are evaluated with lidar measurements. Model results for ozone concentrations and accumulated exposure (AOT) are evaluated in terms of the different mixing layer representations. The revised calculation of the mixing layer gives a much better representation of the land-sea contrast, with lower mixing heights over sea than over land, during the daytime. An important outcome is that the mixing layer concept, used in EUROS, hinders the validation of modelled concentration levels. Because, in spite of the applied scientific model improvements, modelled AOT40 levels for ozone do not show significant improvement in respect to observations. The main concern in this context is the value of the reservoir layer height in the model, which is interlaced with the mixing layer concept. Therefore, it is anticipated that a more realistic representation of the vertical exchange processes, by describing explicitly three-dimensional advection and diffusion, will improve the EUROS model results significantly, both quantitatively and qualitatively.

A study commissioned by the Inspectorate of the Netherlands Ministry of Spatial Planning, Housing and the Environment and the municipality of Zaltbommel was conducted by RIVM on the living environment in the surroundings of the Van Voorden Gieterij BV foundry in the city of Zaltbommel in 2003. The measurements collected were used to study both the exposure of residents to compounds emitted from the foundry and the health effects and annoyance experienced by the residents. This was done through air quality measurements, determination of the particle and heavy-metal deposition, and analyses of grass and soil samples taken in the surroundings of the foundry. The results showed that concentrations of several compounds were enhanced during working hours, with peak values up to 10-50 times above the background level. Annoyance due to bad odours was also thought to occur, particularly in winter. The long-term average rural and urban background concentrations in this area did not, however, exceed the normal levels, except for isopropyl alcohol and heavy metals, for which the average concentrations were 2 to 5 times the normal level. The deposition of heavy metals in the surroundings of the foundry was also found to have increased. Further, elevated levels of some heavy metals, particularly copper, were found in the grass samples. The exposure of residents through inhalation of toxic compounds in the air did not exceed the tolerable limit values. Furthermore, oral exposure to heavy metals was below the Tolerable Daily Intake, provided that residents did not intensively consume produce from their own gardens, i.e. on a daily basis. Daily consumption of self-grown vegetables implies a risk of exposure to lead and barium at levels above the Tolerable Daily Intake, particularly for young children.

Tijdens de internationale conferentie DustConf 2007 te Maasticht (23 en 24 april) presenteerden wetenschappers uit diverse landen hun nieuwste manieren om de uitstoot van fijn stof te verminderen

In het kader van het Arboconvenant grondstofallergie is onderzoek gedaan naar de stof- en allergeenblootstelling (tarweallergeen en schimmel a-amylase) in industriële bakkerijen, de maalindustrie en bakkerijgrondstoffenindustrie. De resultaten zijn vergeleken met metingen uit 2000-2001. Er wordt geconcludeerd dat de doelstellingen voor wat betreft de introductie van de arbeidshygiënische strategie en werkwijze zijn gehaald. Ook de reductie van piekblootstelling voor diverse taken en handelingen is gerealiseerd. De reductie van de totale blootstelling is tot op zekere hoogte gerealiseerd met duidelijke verschillen per branche en functie. In industriële bakkerijen is de gemiddelde stof- en tarweallergeenbelasting niet of nauwelijks afgenomen. Maar blootstelling aan de schimmel a-amylase is daar duidelijk afgenomen. In de maalindustrie is de stof- en tarweallergeenbelasting afgenomen, het duidelijkst voor de stofbelasting. De schimmel a-amylase blootstelling is in de maalindustrie voor een paar functies afgenomen. In de bakkerijgrondstoffenindustrie is de stof- en tarweallergeenbelasting in beperkte mate afgenomen. De blootstelling aan schimmel a-amylase is in deze indusrtie over het geheel genomen gelijk gebleven of gestegen.

In het kader van het Arboconvenant grondstofallergie is onderzoek gedaan naar de stof- en allergeenblootstelling (tarweallergeen en schimmel a-amylase) in industriële bakkerijen, de maalindustrie en bakkerijgrondstoffenindustrie. De resultaten zijn vergeleken met metingen uit 2000-2001. Er wordt geconcludeerd dat de doelstellingen voor wat betreft de introductie van de arbeidshygiënische strategie en werkwijze zijn gehaald. Ook de reductie van piekblootstelling voor diverse taken en handelingen is gerealiseerd. De reductie van de totale blootstelling is tot op zekere hoogte gerealiseerd met duidelijke verschillen per branche en functie. In industriële bakkerijen is de gemiddelde stof- en tarweallergeenbelasting niet of nauwelijks afgenomen. Maar blootstelling aan de schimmel a-amylase is daar duidelijk afgenomen. In de maalindustrie is de stof- en tarweallergeenbelasting afgenomen, het duidelijkst voor de stofbelasting. De schimmel a-amylase blootstelling is in de maalindustrie voor een paar functies afgenomen. In de bakkerijgrondstoffenindustrie is de stof- en tarweallergeenbelasting in beperkte mate afgenomen. De blootstelling aan schimmel a-amylase is in deze indusrtie over het geheel genomen gelijk gebleven of gestegen.

In de eendenhouderij wordt veelal tarwestro gebruikt als bodembedekking, al dan niet gehakseld. Regelmatig bijstrooien is van belang om verentrekkerij en vervuiling van de eenden te voorkomen. Bij het hakselen en verspreiden van stro komt echter veel stof vrij en soms kunnen er veel schimmelsporen in stro aanwezig zijn. Het is van belang om hiermee rekening te houden, want eenden zijn hier zeer gevoelig voor.