Search

Contains fulltext : 235792.pdf (Publisher’s version ) (Closed access) BACKGROUND: Residential exposure to pesticides may occur via inhalation of airborne pesticides, direct skin contacts with pesticide-contaminated surfaces, and consumption of food containing pesticide residues. The aim was to study the association of dermal exposure to pesticides between the use and non-use periods, between farmer and non-farmer families and between dermal exposure and the excretion of metabolites from urine in residents living close to treated agricultural fields. METHODS: In total, 112 hand wipes and 206 spot urine samples were collected from 16 farmer and 38 non-farmer participants living within 50 m from an agricultural field in the Netherlands. The study took place from May 2016 to December 2017 during the use as well as the non-use periods of pesticides. Hand wipes were analysed for the parent compound and urines samples for the corresponding urinary metabolite of five applied pesticides: asulam, carbendazim (applied as thiophanate-methyl), chlorpropham, prochloraz and tebuconazole. Questionnaire data was used to study potential determinants of occurrence and levels of pesticides in hand wipes according to univariate and multivariate analysis. RESULTS: Carbendazim and tebuconazole concentrations in hand wipes were statistically significantly higher in the pesticide-use period compared to the non-use period. In addition, especially during the use periods, concentrations were statistically significantly higher in farmer families compared to non-farmer families. For asulam, chlorpropham and prochloraz, the frequency of non-detects was too high (57-85%) to be included in this analysis. The carbendazim contents in urine samples and hand wipes were correlated on the first and second day after taking the hand wipe, whereas chlorpropham was only observed to be related on the second day following the spray event. CONCLUSIONS: Concentrations in hand wipes were overall higher in pesticide use periods compared to non-use periods and higher in farmer families compared to non-farmer families. Only for carbendazim a strong correlation between concentrations in hand wipes and its main metabolite in urine was observed, indicating dermal exposure via contaminated indoor surfaces. We expect this to be related to the lower vapour pressure and longer environmental lifetime of carbendazim compared to the other pesticides studies.

Methods for the determination of ship fuel sulphur content and NOx emission factors based on remote measurements have been compared in the harbour of Rotterdam and compared to direct stack emission measurements on the ferry Stena Hollandica. The methods were selected based on a review of the available literature on ship emission measurements. They were either optical (LIDAR, Differential Optical Absorption Spectroscopy (DOAS), UV camera), combined with model-based estimates of fuel consumption, or based on the so called "sniffer" principle, where SO2 or NOx emission factors are determined from simultaneous measurement of the increase of CO2 and SO2 or NOx concentrations in the plume of the ship compared to the background. The measurements were performed from stations at land, from a boat and from a helicopter. Mobile measurement platforms were found to have important advantages compared to the land-based ones because they allow optimizing the sampling conditions and sampling from ships on the open sea. Although optical methods can provide reliable results it was found that at the state of the art level, the "sniffer" approach is the most convenient technique for determining both SO2 and NOx emission factors remotely. The average random error on the determination of SO2 emission factors comparing two identical instrumental set-ups was 6%. However, it was found that apparently minor differences in the instrumental characteristics, such as response time, could cause significant differences between the emission factors determined. Direct stack measurements showed that about 14% of the fuel sulphur content was not emitted as SO2. This was supported by the remote measurements and is in agreement with the results of other field studies.

Methods for the determination of ship fuel sulphur content and NOx emission factors based on remote measurements have been compared in the harbour of Rotterdam and compared to direct stack emission measurements on the ferry Stena Hollandica. The methods were selected based on a review of the available literature on ship emission measurements. They were either optical (LIDAR, DOAS, UV camera), combined with model based estimates of fuel consumption, or based on the so called ‘sniffer’ principle, where SO2 or NOx emission factors are determined from simultaneous measurement of the increase of CO2 and SO2 or NOx concentrations in the plume of the ship compared to the background. The measurements were performed from stations at land, from a boat and from a helicopter. Mobile measurement platforms were found to have important advantages compared to the landbased ones because they allow to optimize the sampling conditions and to sample from ships on the open sea. Although optical methods can provide reliable results it was found that at the state of the art, the “sniffer” approach is the most convenient technique for determining both SO2 and NOx emission factors remotely. The average random error on the determination of SO2 emission factors comparing two identical instrumental set-ups was 6%. However, it was found that apparently minor differences in the instrumental characteristics, such as response time, could cause significant differences between the emission factors determined. Direct stack measurements showed that about 14% of the fuel sulphur content was not emitted as SO2. This was supported by the remote measurements and is in agreement with the results of other field studies., JRC.H.2-Air and Climate

In het Stikstof Onderzoeks Programma (STOP) is door KEMA, IMAG, LEI-DLO, LUW, TNO, ECN en RIVM gewerkt aan het valideren en verbeteren van modellen voor de emissie - concentratie - depositie van stikstofverbindingen (NHx, NOx) op lokale schaal. Hiertoe zijn een tweetal kortdurende veldexperimenten uitgevoerd in het proefgebied De Driesprong bij Ede waarbij de emissie en de verspreiding van ammoniak zijn gemeten bij het aanwenden van mest. Daarnaast zijn de emissies van een drietal bedrijven gemeten gedurende enkele maanden en is de ammoniak-concentratie gemeten op een 17-tal plaatsen in het proefgebied van ca. 2 x 2 km. Dit rapport legt de verbinding tussen de gemeten (en overige) emissies en de gemeten concentraties en deposities via bestaande en nieuw ontwikkelde/gemodificeerde verspreidingsmodellen. Voor de lange-termijn gemiddelde concentraties is het OPS-LT model toegepast. Op basis van dit model is een korte termijn versie ontwikkeld (OPS-KT) met als doel de verbinding te leggen tussen kortdurende (detail)metingen en het OPS-LT model. Daarnaast is een numeriek K-diffusiemodel (verder) ontwikkeld om het horizontale transport en de verticale dispersie vanuit zeer lage bronnen te kunnen kwantificeren. Dit model fungeert daarmee als een referentie voor het testen van procesbenaderingen in het OPS-KT/LT model. Uit vergelijking van het OPS-KT model met resultaten van het 'Prairie Grass' experiment blijken geen belangrijke systematische afwijkingen, maar wel flinke spreidingen in uurlijkse uitkomsten. Het huidige OPS-LT model blijkt de ruimtelijke verdeling van de gemeten (9 maandsgemiddelde) concentraties binnen het proefgebied voor ongeveer 50% te verklaren. De gemiddelde concentratie wordt door het model echter met ongeveer 15% onderschat. Toepassing van het korte termijn model op de gemeten emissies bij de aanwendingsproeven laat zien dat dit model de tijdreeks van lokaal gemeten concentraties redelijk volgt maar in absolute zin met ongeveer een factor 2 overschat. Het aantal uitgevoerde experimenten is te beperkt om hieraan duidelijke conclusies te verbinden. De gevonden afwijkingen liggen wel binnen de range welke internationaal met moderne korte termijn modellen bij vergelijking met metingen worden gevonden. Op basis van de goede simulatie van gemiddelde ruimtelijke verschillen in het proefgebied kan worden geconcludeerd dat met het huidige modelinstrumentarium het bedrijfsvestigings- en bedrijfsverplaatsingsbeleid redelijk tot goed kan worden ondersteund.

In dit rapport is een vergelijking gemaakt tussen berekende en gemeten concentraties van ammoniak, waarbij voor de gemeten concentraties de passieve monsternemingsmethode is toegepast. Op 184 locaties in drie ROM gebieden (Zuid-Oost Friesland, de Gelderse Vallei en Noord-Oost Brabant) zijn ammoniak concentratiemetingen verricht in de periode van februari 1996 tot en met januari 1997. Voor de berekening van de concentraties is gebruik gemaakt van het OPS-model en emissies afkomstig van verschillende bronnen. De gebruikte emissies verschillen van elkaar wat betreft het beschouwde gebied, de resolutie en het onderliggende aggregatieniveau. De gemeten concentraties zijn een factor 2 hoger dan de berekende concentraties. De onderschatting van de metingen is voor alle drie de studiegebieden ongeveer even groot. Rekening houdend met de onzekerheidsmarges in de berekeningen kan gesteld worden dat de berekeningen maximaal 60 a 65% van de gemeten concentraties kunnen verklaren. Op basis van vergelijkende meetstudies is het uitermate onwaarschijnlijk dat het verschil tussen gemeten en berekende concentratie verklaard kan worden door een overschatting van de gemeten concentraties. Indien men het resterende verschil, in de genoemde gebieden, wil verklaren door verandering van de emissieniveaus, zullen de huidige emissies met 50 a 70% verhoogd moeten worden. De vergelijking van de metingen met de modelberekeningen laat zien dat het OPS-model in staat is de ruimtelijke variatie in de gemeten concentraties goed weer te geven, wanneer zowel metingen als berekeningen worden gemiddeld per 5x5 km gridcel. Op basis van emissies met een resolutie van 5x5 km kan ongeveer 80% van de ruimtelijke variatie op 5x5 km schaal worden verklaard. Binnen een 5x5 km grid komen echter grote ruimtelijke variaties van concentratie- en depositiewaarden voor (tot een factor 10). Voor berekeningen van concentraties en deposities op ecosysteemniveau leveren emissiegegevens met een hoger ruimtelijk detail (bijv. 500x500 m en individuele stal- en opslagemissies als puntbron) realistischer schattingen.

Omdat Nederland geen megasteden kent, zou men verwachten dat het aantal stedelijke hitte-eilanden gering is. Satellietbeelden van de oppervlaktetemperatuur in Nederland laten echter een ander beeld zien. Deze beelden opgenomen tijdens de hittegolfperiode in 2006, laten zien dat bijna elke stad in Nederland te maken heeft met een hitte-eiland effect

De uitwisseling van broeikasgassen tussen het landschap en de atmosfeer laat zich niet zo gemakkelijk bepalen als de emissie uit een schoorsteen. Verschillende meetinstrumenten en technieken worden ingezet om de dynamiek van deze uitwisseling in ruimte en tijd in beeld te krijgen. De metingen moeten vertellen wat de netto broeikasgasbalans van het landschap is en hoe deze zal reageren op een veranderend klimaat.

Greenhouse gas emissions are highly variable in spaceand time. This variability hampers measurements ofgreenhouse gas emissions and hinders the use of landuse and management as mitigation options. We give anoverview of explaining factors of temporal and spatialvariability of greenhouse gas emissions from Dutchlandscapes.CO2 fluxes have a regular annual temporal variability.Temporal variability of N2O emission is characterizedby low background emissions and high peaks that arerelated to precipitation and manure application, whiletemporal variability of CH4 fluxes is very irregular. Spatialvariability of CO2 can be explained using the croptype in agricultural land or the tree species in forests.Spatial variability of N2O and CH4 is strongly influencedby groundwater and management intensity. Additionally,at the landscape scale there is a significant greenhousegas emission from ditches and open water. Thetemporal variability has to be considered in the designof measurement campaigns, while the insight in factorsexplaining the spatial variability of greenhouse gasemissions can help to improve landscape scale estimatesof greenhouse gas emissions and guide managementdecisions for mitigation. De uitstoot van broeikasgassen door het landschap varieert enorm in tijd en ruimte doordat landschappelijke omstandigheden als bodem, grondwater, vegetatie en weer ook enorm variëren in tijd en ruimte. Gebrek aan inzicht hierin beperkt de betrouwbaarheid van emissieschattingen en maakt kwantificering van migratie via ingrepen in het landschap tot een hachelijke zaak. Wat is bekend over de variabiliteit van de broeikasgasfluxen binnen en tussen verschillende landschapselementen, en wat gebeurt er bij veranderingen in het landgebruik?

International audience; Soil emissions of NO and N2O were measured continuously at high frequency for more than one year at 15 European forest sites as part of the EU-funded project NOFRETETE. The locations represent different forest types (coniferous/deciduous) and different nitrogen loads. Geographically they range from Finland in the north to Italy in the south and from Hungary in the east to Scotland in the west. The highest NO emissions were observed from coniferous forests, whereas the lowest NO emissions were observed from deciduous forests. The NO emissions from coniferous forests were highly correlated with N-deposition. The site with the highest average annual emission (82 ?g NO-Nm?2 h?1) was a spruce forest in South-Germany (Höglwald) receiving an annual N-deposition of 2.9 gm?2. NO emissions close to the detection limit were observed from a pine forest in Finland where the N-deposition was 0.2 g N m?2 y?1. No significant correlation between N2O emission and N-deposition was found. The highest average annual N2O emission (20 ?g N2O-Nm?2 h?1) was found in an oak forest in the Mátra mountains (Hungary) receiving an annual N-deposition of 1.6 gm?2. N2O emission was significantly negatively correlated with the C/N ratio. The difference in N-oxide emissions from soils of coniferous and deciduous forests may partly be explained by differences in N-deposition rates and partly by difference in characteristics of the litter layer and soil. NO was mainly derived from nitrification whereas N2O was mainly derived from denitrification. In general, soil moisture is lower at coniferous sites (at least during spring time) and the litter layer of coniferous forests is thick and well aerated favouring nitrification and thus release of NO. Conversely, the higher rates of denitrification in deciduous forests due to a compact and moist litter layer lead to N2O production and NO consumption in the soil. The two factors soil moisture and soil temperature are often explaining most of the temporal variation within a site. When comparing annual emissions on a regional scale, however, factors such as nitrogen deposition and forest and soil type become much more important.

The factors used to estimate emissions of sea going ships to air (so called emission factors) are based upon critical evaluation of the literature. Current estimates of emission factors of sea going ships are based upon a limited number of laboratory experiments and information on fuel usage and engine power. Especially emissions of nitrogen oxides (NOx) are reported in literature, measurements of particulate matter (PM2) are scarcer. It is important to realize that large variations in results are observed especially in emissions of particulate matter by engines using HFO (Heavy Fuel Oil). These are therefore rather uncertain. In the process of developing scenarios to improve local air quality and decrease atmospheric deposition accurate data on emissions are essential.

International audience; Forest soils are a significant source for the primary and secondary greenhouse gases N2O and NO. However, current estimates are still uncertain due to the still limited number of field measurements and the herein observed pronounced variability of N trace gas fluxes in space and time, which are due to the variation of environmental factors such as soil and vegetation properties or meteorological conditions. To overcome these problems we further developed a process-oriented model, the PnET-N-DNDC model, which simulates the N trace gas exchange on the basis of the processes involved in production, consumption and emission of N trace gases. This model was validated against field observations of N trace gas fluxes from 19 sites obtained within the EU project NOFRETETE, and shown to perform well for N2O (r=0.68, slope=0.76) and NO (r2=0.78, slope=0.73). For the calculation of a European-wide emission inventory we linked the model to a detailed, regionally and temporally resolved database, comprising climatic properties (daily resolution), and soil parameters, and information on forest areas and types for the years 1990, 1995 and 2000. Our calculations show that N trace gas fluxes from forest soils may vary substantial from year to year and that distinct regional patterns can be observed. Our central estimate of NO emissions from forest soils in the EU amounts to 98.4, 84.9 and 99.2 kt N yr-1, using meteorology from 1990, 1995 and year 2000, respectively. This is x emissions. For N2O emissions the central estimates were 86.8, 77.6 and 81.6 kt N yr-1, respectively, which is approx. 14.5% of the source strength coming from agricultural soils. An extensive sensitivity analysis was conducted which showed a range in NO emissions from 44.4 to 254.0 kt N yr-1 for NO and 50.7 to 96.9 kt N yr-1 for N2O, for year 2000 meteorology. The results show that process-oriented models coupled to a GIS are useful tools for the calculation of regional, national, or global inventories of biogenic N-trace gas emissions from soils. This work represents the most comprehensive effort to date to simulate NO and N2O emissions from European forest soils.

Studie naar de invloed van groenelementen (bomen, struiken) op de luchtkwaliteit rond wegen en in steden

Air is an important transport medium for persistent chemicals in general. Heavy metals and persistent organic pollutants (POPs) were included in EMEP’ s monitoring programme in 1999. However, by 1995, co-operation concerning heavy metals and POPs between EMEP and other international programs was extended. This co-operation included the establishment of a database and collection of already available data on POPs among the participants. A number of countries have been reporting POPs within the EMEP area in connection with different national and international programmes such as HELCOM, AMAP, OSPARCOM, MEDPOP.

Gekeken is naar wat de inspanningen om de emissie van zwaveldioxiden, stikstofoxiden en ammoniak terug te brengen hebben opgeleverd, verder in welke mate de depositie is afgenomen, en of er herstel van kwaliteit van bodem, grondwater en ecosystemen heeft plaatsgevonden

De beoordeling van milieurisico's en de effectiviteit van emissiereducerende methoden worden onderbouwd via onderzoek, zodat op EU niveau beoordelingsprocedures ontwikkeld worden die consistent zijn