Suchergebnisse

In order to investigate the seasonal variation in chemical characteristics of VOCs in the urban and suburban areas of southwest China, we used SUMMA canister sampling in Jinghong city from October 2016 to June 2017. Forty-eight VOC species concentrations were analyzed using atmospheric preconcentration gas chromatography–mass spectrometry (GC–MS), Then, regional VOC pollution characteristics, ozone formation potentials (OFP), source identity, and health risk assessments were studied. The results showed that the average concentration of total mass was 144.34 μg·m−3 in the urban area and 47.81 μg·m−3 in the suburban area. Alkanes accounted for the highest proportion of VOC groups at 38.11%, followed by olefins (36.60%) and aromatic hydrocarbons (25.28%). Propane and isoprene were the species with the highest mass concentrations in urban and suburban sampling sites. The calculation of OFP showed that the contributions of olefins and aromatic hydrocarbons were higher than those of alkanes. Through the ratio of specific species, the VOCs were mainly affected by motor vehicle exhaust emissions, fuel volatilization, vegetation emissions, and biomass combustion. Combined with the analysis of the backward trajectory model, biomass burning activities in Myanmar influenced the concentration of VOCs in Jinghong. Health risk assessments have shown that the noncarcinogenic risk and hazard index of atmospheric VOCs in Jinghong were low (less than 1). However, the value of the benzene cancer risk to the human body was higher than the safety threshold of 1 × 10−6, showing that benzene has carcinogenic risk. This study provides effective support for local governments formulating air pollution control policies.

Flyktige organiske forbindelser (VOC-er) er en gruppe av organiske kjemikalier som lett fordamper ved omgivelsestemperaturer, bl.a. fra byggematerialer. Dette gjør at de kan påvirke inneluftkvaliteten. Det finnes mange ulike typer VOC-er, i første rekke er det type materiale som bestemmer hvilke VOCer frigjøres til inneluften. Deretter vil materialbehandling og fysiske forhold bestemme konsentrasjonen og sammensetningen av disse forbindelsene. De siste årene har det blitt et økt fokus på VOC-emisjoner, ettersom konsentrasjoner fra disse forbindelsene er ofte høyere innendørs enn utendørs. Dette kan ha en effekt på menneskehelse, spesielt med tanke på at befolkningen i Skandinavia tilbringer over 90% av tiden sin innendørs. Derfor setter stadig flere reguleringer og lovverk krav til VOCkonsentrasjoner fra byggematerialer bl.a. trematerialer, og nivået av VOC-er innendørs. Et modellsystem, med bakgrunn i kravene for den europeiske standarden for vurdering av frigjøring av farlige stoffer til inneluft (EN 16516) ble utviklet. Dette ble gjort for å sammenligne VOC-emisjoner fra to forskjellige typer av interiørpanel fra furu (Pinus Sylvestris). De mest vanligst forekommende VOC-ene fra furu ble analysert fra disse prøvene, ved bruk av termodesorpsjon-gasskromatografi (ATD GC-MS). Emisjonene fra tre prøver av ubehandlet interiørpanel, og tre prøver av beiset interiørpanel ble analysert i forhold til kravene i den europeiske byggevareforordningen (EU-LCI). Målene med dette studiet var å utvikle et modellsystem for analyse av VOC-er, og utforske resultater i forhold til tidligere undersøkelser. Deretter var det et mål å utforske hvordan materialbehandling eventuelt påvirker VOC-emisjoner, samt finne ut om disse materialene oppfyller kravene satt i EU-LCI. Modellsystemet klarte å kvantifisere seks av de mest forekommende forbindelsene i bartrær, heksanal, α-pinene, β-pinene, β-myrcene, camphene og 3-carene. Det ble ikke funnet noen statistisk signifikant forskjell mellom de ubehandlede og behandlede materialene, til tross for at det ubehandlede materialet hadde langt høyere konsentrasjoner enn det ubehandlede materialet. Ingen av prøvene klarte å oppfylle EU-LCI kravene etter 28 dager, men dette kan også skyldes modellsystemet. Det er derfor viktig å utvikle dette systemet videre, spesielt med tanke på at målinger av emisjoner fra VOC-er vil bli et stadig større krav i forskjellige reguleringer og lovverk. ; Volatile organic compounds (VOCs) are a diverse group of organic chemicals that easily evaporate at ambient temperatures, e.g. from building materials. This makes them likely to affect indoor air quality (IAQ). There are many different types of VOCs, and their concentration and composition depend on a number of different factors. Primary, the type of material determines which VOCs will be present in a given environment. Then other factors, such as the material treatment and physical conditions decide the concentration and composition of these compounds in an environment. There has been an increasing focus on VOC-emissions indoors over the last years, as the concentrations of these compounds are higher indoors than outdoors. VOCs can also have an effect on human health. This has led to an increasing number of regulations establishing requirements for VOC emissions from different types of materials, e.g. wood materials, and the level of VOCs in indoors. A model system was developed to compare VOC emissions from two different types of Scots Pine interior panelling (Pinus Sylvestris). The model system was based on the requirements of the European standard for the assessment of the release of hazardous substances for indoor air (EN 16516). The most common VOCs in Scots Pine were analysed using thermo-desorption gas chromatography (ATD GC-MS). Overall, the emissions from three samples of untreated interior panel, and three samples of stained interior panel were analysed in accordance to the requirements of the Construction Products Regulation (EU-LCI). The objectives of this study were to develop a model system for the analysis of VOCs, and to compare the analysis from this model system in relation to previous studies. Other objectives were to explore how material treatment might affect VOC emissions, as well as find out if these materials meet the requirements set in EU-LCI. The model system was able to quantify six of the most abundant compounds in conifers, i.e. hexanal, α-pinene, β-pinene, β-myrcene, camphene and 3-carene. No statistically significant difference was found between the untreated and treated materials, even though the untreated material had substantially higher concentrations than the untreated material. None of the samples met the EU-LCI requirements after 28 days, but this could also be due to the model system. It is therefore important to further develop this system, especially as testing of emissions from VOCs will become an increasingly important requirement in various regulations and legislations. ; M-SF