34 research outputs found
Air pollution exposure estimation using dispersion modelling and continuous monitoring data in a prospective birth cohort study in the Netherlands
Previous studies suggest that pregnant women and children are particularly vulnerable to the adverse effects of air pollution. A prospective cohort study in pregnant women and their children enables identification of the specific effects and critical periods. This paper describes the design of air pollution exposure assessment for participants of the Generation R Study, a population-based prospective cohort study from early pregnancy onwards in 9778 women in the Netherlands. Individual exposures to PM10 and NO2 levels at the home address were estimated for mothers and children, using a combination of advanced dispersion modelling and continuous monitoring data, taking into account the spatial and temporal variation in air pollution concentrations. Full residential history was considered. We observed substantial spatial and temporal variation in air pollution exposure levels. The Generation R Study provides unique possibilities to examine effects of short- and long-term air pollution exposure on various maternal and childhood outcomes and to identify potential critical windows of exposure
Validation of the AERIUS air quality model
De luchtkwaliteit in Nederland wordt gemonitord in het Nationaal Samenwerkingsprogramma Luchtkwaliteit (NSL). De luchtkwaliteit wordt berekend met behulp van technische rekenregels die voldoen aan de wettelijk voorgeschreven standaard rekenmethoden voor luchtkwaliteit. Het gaat hierbij specifiek om de rekenmethoden voor de luchtkwaliteit langs wegen in stedelijk gebied en rond snelwegen. Het rekenmodel voor het NSL is nu vervangen door AERIUS lucht en is gevalideerd als rekenmodel luchtkwaliteit. In dit rapport wordt de validatie van AERIUS lucht toegelicht. Een nieuw rekenmodel luchtkwaliteit wordt standaard gevalideerd door het RIVM. Dat gebeurt door de resultaten te vergelijken met die van het rekenmodel van het RIVM (TREDM). Het rekenmodel van het RIVM werkt ook met de wettelijk voorgeschreven standaardrekenmethoden. Om mogelijke discussies over de werkwijze te voorkomen heeft een onafhankelijke organisatie het validatieproces gecontroleerd. Volgens hen is de validatie goed uitgevoerd. Zie rapport: https://vito.be/sites/vito.be/files/rapport_rivm2.pdf De oude NSL-rekenmethode is van 2010 tot en met 2019 gebruikt. Het nieuwe model sluit aan bij de laatste ontwikkelingen in de wetenschap en ict. Het nieuwe model is in opdracht van het ministerie van Infrastructuur en Waterstaat (IenW) gebouwd. Zie ook rapport: Actualisering en addenda SRM-1 en SRM-2 https://www.rivm.nl/bibliotheek/rapporten/2020-0118.pdfThe air quality in the Netherlands is monitored in the National Air Quality Cooperation Program (NAQCP). The air quality is calculated with the help of technical calculation rules that comply with the legally mandated calculation methods for air quality. More specifically, we are talking here about the air quality alongside roads in urban areas and near motorways. The NAQCP calculation model has now been replaced by AERIUS air, which has been validated as an air quality calculation model. This report explains how AERIUS air has been validated. A new calculation model for air quality is, as a rule, validated by RIVM. This is done by comparing the results of the new model with the results of the RIVM calculation model (TREDM). The RIVM calculation model also complies with the legally mandated standard calculation methods. In order to avoid potential discussions about the working procedure, an independent organisation checked the validation process. According to them, the validation process was sound. See report: https://vito.be/sites/vito.be/files/rapport_rivm2.pdf The older NAQCP calculation method was used from 2010 up to and including 2019. The new model is in line with the latest developments in science and ICT. The new model was commissioned by the Ministry of Infrastructure and Water Management. See also report: Updating addenda SRM-1 and SRM-2 https://www.rivm.nl/bibliotheek/rapporten/2020-0118.pdfMinisterie van I&
Measurements and calculations of ultrafine particles originating from air traffic around Schiphol : For research into the health of local residents
Het RIVM heeft het rekenmodel verbeterd waarmee de jaargemiddelde concentratie ultrafijn stof van vliegverkeer rond Schiphol wordt bepaald. Ultrafijn stof is het aantal zeer kleine deeltjes in de lucht (kleiner dan 0,1 micrometer). De nieuwe berekeningen zijn vergeleken met metingen gedurende een half jaar op tien locaties rond Schiphol. Het is voor het eerst dat dit in Nederland op deze schaal is gedaan. Het rekenmodel is op twee punten aangepast. Taxiënde vliegtuigen zijn als bron toegevoegd. Daarnaast zijn extra gegevens over de uitstoot van ultrafijn stof van vliegverkeer uit de wetenschappelijke literatuur gebruikt. Vervolgens zijn de rekenresultaten afgestemd op de meetwaarden. Het aangepaste rekenmodel blijkt op deze manier goed in staat te zijn om gemiddelde concentraties over een langere tijd te bepalen. Locaties met lagere en hogere concentraties worden goed van elkaar onderscheiden. Daarmee zijn we erin geslaagd om het rekenmodel geschikt te maken voor onderzoek naar effecten op de gezondheid als mensen langdurig aan ultrafijn stof van vliegverkeer van Schiphol blootstaan. Volgens de berekeningen is de jaargemiddelde blootstelling van omwonenden aan ultrafijn stof van vliegverkeer op Schiphol in 2017 en 2018 het hoogst op woonlocaties vlak bij de luchthaven en neemt deze af naarmate ze verder weg wonen. Wel zijn er van jaar tot jaar kleine verschillen die onder andere veroorzaakt worden door variatie in weersomstandigheden en baangebruik. Een volgend onderdeel van het onderzoeksprogramma is onderzoek naar de gezondheidseffecten van langdurige blootstelling aan ultrafijn stof van vliegverkeer. Hiervoor is informatie nodig over de mate waarin mensen die in de omgeving van Schiphol wonen aan ultrafijn stof worden blootgesteld. Om de blootstelling te kunnen bepalen, is inzicht in de concentratie ultrafijn stof in de lucht nodig. Het rekenmodel maakt het mogelijk om die informatie te verkrijgen. Metingen kennen beperkingen: het is onmogelijk om op alle locaties waar mensen wonen de concentratie van ultrafijn stof te meten. Ook zijn de metingen erg afhankelijk van de weersomstandigheden en het baangebruik. Het rekenmodel vertaalt metingen naar alle overige locaties en andere (langere) perioden.RIVM has improved the model used to calculate the annual average concentration of ultrafine particles originating from air traffic around Schiphol. Ultrafine particles are very small particles in the air (smaller than 0.1 micrometres). The new calculations were compared with measurements taken for a period of six months at ten locations around Schiphol. This is the first time that this has been carried out in The Netherlands on this scale. The calculation model has been adjusted in two ways. Taxiing aircraft have been added to the list of sources. Furthermore, additional data from the scientific literature has been used concerning the emission of ultrafine particles originating from air traffic. The calculation results were then adjusted to the measured values. It shows that in this way, the adjusted calculation model is well able to determine average concentrations over a longer period. Locations with lower and higher concentrations are well distinguished, making the model suitable for research into the effects on people's health of long-term exposure to ultrafine particles originating from air traffic at Schiphol. According to the calculations, the annual average exposure of local residents to ultrafine particles from air traffic at Schiphol in 2017 and 2018 is the highest near the airport, and decreases as they live farther away. There are, however, small differences from year to year. They are caused by, among other things, variations in weather conditions and runway use. The next part of the broader program is research into the effects on people's health of long-term exposure to ultrafine particles originating from air traffic at Schiphol. To this end, information is needed about the degree to which people who live in the vicinity of Schiphol are exposed to ultrafine particles. In order to determine the exposure, insight into the concentration of ultrafine particles in the air is needed. The calculation model makes it possible to obtain that information. Measurements have limitations: the concentration of ultrafine particles can only be determined at a few locations and only under the weather and flight conditions at the times in question. The calculation model translates the measurements to all other locations and other (longer) periods.Ministerie van I&
Degassing of ships transporting MTBE
Bij het ontgassen van binnenvaartschepen die de stof MTBE (methyltert- butylether) vervoeren, kunnen restanten MTBE vrijkomen. Het ontgassen gebeurt als de schepen varen, in principe buiten woonwijken. Van MTBE is bekend dat het een hinderlijke geur verspreidt die klachten als hoofdpijn kan veroorzaken. Mensen aan wal kunnen last hebben van de geur, die al bij lage concentraties optreedt. Vanwege de korte blootstellingsduur wordt de kans klein geacht dat bij hen andere directe gezondheidseffecten optreden. Dit blijkt uit een kleinschalig onderzoek van het RIVM dat in samenwerking met TNO is uitgevoerd. Hiervoor is de berekende blootstelling vergeleken met de grenswaarden voor MTBE. Bij de berekeningen die voor dit onderzoek zijn uitgevoerd, is telkens uitgegaan van worst case-scenario's. Daarbinnen zijn de grenswaarden zelden overschreden. Het onderzoek is gestart naar aanleiding van Kamervragen die in 2013 zijn gesteld over de (geur)overlast bij mensen die in de regio Rijnmond aan de wal wonen. De Tweede Kamer wilde ook weten of het ontgassen van MTBEvervoerende schepen de oorzaak is van de verhoogde MTBEconcentraties die in Nederlands oppervlaktewater zijn aangetroffen. Dat blijkt niet het geval te zijn. MTBE is een stof die wordt toegevoegd aan benzine om de kwaliteit ervan te verbeteren ('antiklopmiddel'). In Nederland vervoeren binnenvaartschepen ongeveer 600 scheepsladingen MTBE per jaar. Wanneer een schip overgaat op een andere scheepslading, wordt het schip gereinigd en ontgast.During degassing at inland waterways of vessels transporting MTBE (methyl-tert-butyl ether), some of the MTBE is released to the atmosphere. Degassing occurs when the vessel is sailing, basically outside residential areas. MTBE is known to spread an odour which can cause symptoms such as headaches. People ashore can suffer from the smell, which may already occur at low concentrations. Because of the short duration of exposure, the risk of other direct health effects is expected to be small. This is shown in study which RIVM carried out in cooperation with TNO. For this, the calculated exposure is compared with the air quality limit values for MTBE. Calculations were consistently based on worst case scenarios. The results show that MTBE exposure limits are rarely exceeded. The investigation was initiated in response to questions from the Dutch Parliament in 2013 about the (odour) nuisance for people who live on the shore in the Rijnmond region. The parliament also wanted to know whether the degassing of MTBE ships are the cause of the elevated MTBE concentrations detected in Dutch surface water. This appeared not to be the case. MTBE is a substance that is added to gasoline in order to improve its quality. In the Netherlands, about 600 cargoes of MTBE per year are transported. When another good is to be shipped, the ship is cleaned and degassed.Ministerie van I&
Target of rapamycin signalling mediates the lifespan-extending effects of dietary restriction by essential amino acid alteration
Dietary restriction (DR), defined as a moderate reduction in food intake short of malnutrition, has been shown to extend healthy lifespan in a diverse range of organisms, from yeast to primates. Reduced signalling through the insulin/IGF-like (IIS) and Target of Rapamycin (TOR) signalling pathways also extend lifespan. In Drosophila melanogaster the lifespan benefits of DR can be reproduced by modulating only the essential amino acids in yeast based food. Here, we show that pharmacological downregulation of TOR signalling, but not reduced IIS, modulates the lifespan response to DR by amino acid alteration. Of the physiological responses flies exhibit upon DR, only increased body fat and decreased heat stress resistance phenotypes correlated with longevity via reduced TOR signalling. These data indicate that lowered dietary amino acids promote longevity via TOR, not by enhanced resistance to molecular damage, but through modified physiological conditions that favour fat accumulation
Comparison of the performances of land use regression modelling and dispersion modelling in estimating small-scale variations in long-term air pollution concentrations in a Dutch urban area.
The performance of a Land Use Regression (LUR) model and a dispersion model (URBIS - URBis Information System) was compared in a Dutch urban area. For the Rijnmond area, i.e. Rotterdam and surroundings, nitrogen dioxide (NO2) concentrations for 2001 were estimated for nearly 70 000 centroids of a regular grid of 100 Ă— 100 m. A LUR model based upon measurements carried out on 44 sites from the Dutch national monitoring network and upon Geographic Information System (GIS) predictor variables including traffic intensity, industry, population and residential land use was developed. Interpolation of regional background concentration measurements was used to obtain the regional background. The URBIS system was used to estimate NO2 concentrations using dispersion modelling. URBIS includes the CAR model (Calculation of Air pollution from Road traffic) to calculate concentrations of air pollutants near urban roads and Gaussian plume models to calculate air pollution levels near motorways and industrial sources. Background concentrations were accounted for using 1 Ă— 1 km maps derived from monitoring and model calculations. Moderate agreement was found between the URBIS and LUR in calculating NO2 concentrations (R = 0.55). The predictions agreed well for the central part of the concentration distribution but differed substantially for the highest and lowest concentrations. The URBIS dispersion model performed better than the LUR model (R = 0.77 versus R = 0.47 respectively) in the comparison between measured and calculated concentrations on 18 validation sites. Differences can be understood because of the use of different regional background concentrations, inclusion of rather coarse land use category industry as a predictor variable in the LUR model and different treatment of conversion of NO to NO2. Moderate agreement was found between a dispersion model and a land use regression model in calculating annual average NO2 concentrations in an area with multiple sources. The dispersion model explained concentrations at validation sites better
Both overlapping and independent mechanisms determine how diet and insulin-ligand knockouts extend lifespan of Drosophila melanogaster
Lifespan in many organisms, including Drosophila melanogaster, can be increased by reduced insulin-IGF-like signaling (IIS) or by changes in diet. Most studies testing whether IIS is involved in diet-mediated lifespan extension employ only a few diets, but recent data shows that a broad range of nutritional environments is required. Here, we present lifespan data of long-lived Drosophila, lacking three of the eight insulin-like peptides [Drosophila insulin-like peptides 2,3,5 (dilp2-3,5)] on nine different diets that surround the optimum for lifespan. Their nutritional content was varied by manipulating sugar and yeast concentrations independently, and thus incorporated changes in both diet restriction and nutrient balance. The mutants were substantially longer-lived than controls on every diet, but the effects on the lifespan response to sugar and yeast differed. Our data illustrates how a greater coverage of diet balance (DB) and restriction can unify differing interpretations of how IIS might be involved in the response of lifespan to diet.</p
Assessment of the applicability of a model for aviation-related ultrafine particle concentrations for use in epidemiological studies
Growing more positive with age: The relationship between reproduction and survival in aging flies
Both overlapping and independent mechanisms determine how diet and insulin-ligand knockouts extend lifespan of Drosophila melanogaster
Lifespan in many organisms, including Drosophila melanogaster, can be increased by reduced insulin-IGF-like signaling (IIS) or by changes in diet. Most studies testing whether IIS is involved in diet-mediated lifespan extension employ only a few diets, but recent data shows that a broad range of nutritional environments is required. Here, we present lifespan data of long-lived Drosophila, lacking three of the eight insulin-like peptides [Drosophila insulin-like peptides 2,3,5 (dilp2-3,5)] on nine different diets that surround the optimum for lifespan. Their nutritional content was varied by manipulating sugar and yeast concentrations independently, and thus incorporated changes in both diet restriction and nutrient balance. The mutants were substantially longer-lived than controls on every diet, but the effects on the lifespan response to sugar and yeast differed. Our data illustrates how a greater coverage of diet balance (DB) and restriction can unify differing interpretations of how IIS might be involved in the response of lifespan to diet.</p