dissertation
Klemen Teran (Author), Gorazd Žibret (Mentor), Mattia Fanetti (Mentor)

Abstract

Household dust (HD) and road dust (RD) are widespread and easily accessible urban sediments, which are influenced by deposition of airborne particulate matter (PM). Since airborne PM is considered to be one of the most important pollutants in urban areas, with significant adverse effects on human health, a better understanding of its elemental composition and dispersion mechanisms is needed. The present study examines whether the HD and RD elemental composition can be used as a quick alternative method for the determination of corresponding PM elemental composition over a selected area. In summer 2016, HD, RD, and topsoil samples were collected from 249 sampling locations distributed across rural, urban, and industrial areas in Slovenia. The collected samples were sieved for particle diameters below 63 μm and analysed for 53 elements with ICP-MS after aqua regia digestion. SEM/EDS analyses were applied for the determination of characteristic particles at the microlevel. Finally, the elemental composition of HD and RD was compared with the PM10 elemental composition obtained from National Network for Ambient Air Quality Monitoring governed by Slovenian Environmental Agency (ARSO) to determine any potential connection between them. The results show that HD and RD are considerably enriched with a large set of elements compared to the topsoil. Correlations and factor analyses show that spatial distribution of factor scores in RD revealed strong regional trends, connected with soil resuspension (Al, Ce, Ga, K, La, Li, P, Rb, Sc and Y) or with anthropogenic sources such as traffic (Ag, Bi, Cu, Sb and Sn), steel mill emissions (Cr, Mo, Mn, Ni and W) and construction material decomposition (Ca and Sr). In contrast, HD elemental composition was highly variable between sampling locations. Variability was probably caused by indoor sources, such as smoking (Ce and La), biomass combustion (K, P and Rb), construction material decomposition (Ca and Sr) and residents’ professional occupation: dental care employees (Ag, Au, Pd) and employees in the metal-processing industry (Cr, Mo, Ni). Among deposited particles in RD, urbanization processes, such as fossil fuel combustion and traffic emissions, including brake pad abrasion and tyre wear, contributed the largest share of particles with anomalous elemental composition. Brake pad abrasion, for instance, contributed Ba-, Cu-, Sn-, and Zn-enriched irregular, angular and tabular particles, while tyre wear produced elongated rubber particles with traces of Ba, Cu, and Zn. RD from urban areas showed significantly higher elemental levels of Ag, Bi, Ca, Cd, Cr, Cu, Hg, Fe, Mo, Nb, Pb, Pt, Sb, Sn, Sr, Ti, Zn, and W in comparison to the rural environment, indicating the strong impact of urbanization on RD elemental composition. Another important anthropogenic source of deposited particles in RD were steel mills. Strong anomalies of Cr, Mo and Ni were detected in their vicinity. Their elemental levels decreased with distancing from the plan location, reaching urban background levels between 15 and 20 km from the mills. SEM/EDS analyses identified enrichments of Cr, Mn, Mo, Ni, V, and W in spherical particles and particles with partially melted surfaces, which were found only in the proximity of steel mills, indicating their influence of the PM deposition. Comparison of RD and the corresponding PM10 elemental composition showed that the RD fraction with particle diameters below 63 μm reflects PM10 elemental composition for the last 30 to 90 days for Cr, Cu, Mo and Zn and can be used as a predictor for PM10 elemental levels. This is not true for HD, as indoor particle sources prevail over the deposition of ambient PM10.

Keywords

household dust;road dust;particulate matter;PM10;pollution;steel mills;topsoil;traffic;urbanization;dissertations;

Data

Language: English
Year of publishing:
Typology: 2.08 - Doctoral Dissertation
Organization: UNG FPŠ - Graduate School
Publisher: [K. Teran]
UDC: 502.3:543.275(043.3)
COBISS: 40548867 Link will open in a new window
Views: 2701
Downloads: 146
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Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary language: Slovenian
Secondary title: Hišni in cestni prah kot indikatorja elementne sestave trdnih delcev v zraku.
Secondary abstract: Atmosferski trdni delci (PM) so eno izmed najbolj razširjenih onesnaževal moderne dobe in predvsem v urbanih območjih negativno vplivajo na zdravje ljudi. Boljše poznavanje njihove elementne sestave in transportnih mehanizmov je nujno za omejevanje škodljivih učinkov na okolje in zdravje ljudi. Hišni prah (HP) ter cestni prah (CP) sta med najbolj razširjenimi in lahko dostopnimi urbanimi sedimenti, na katere vpliva odlaganje PM iz atmosfere. Študij elementne sestave HP in CP bi zato lahko služil kot hiter alternativen pristop k poznavanju sestave PM. Na območju Republike Slovenije so bili med poletjem leta 2016 zbrani vzorci HP, CP in tal na 249 vzorčnih lokacijah, ki so bile razporejene v mestnem in podeželskem okolju, kakor tudi v okolici večjih industrijskih obratov. Vzorci so bili ročno presejani na frakcijo pod 63 μm in poslani na kemijsko analizo. Vsebnosti 53 elementov so bile določene z uporabo ICP-MS na vzorcih raztopljenih v zlatotopki. Z uporabo SEM/EDS so bili določeni najbolj značilni delci v HP in CP ter njihova elementna sestava. Vpliv usedanja atmosferskih trdnih delcev v HP in CP je bil preučen s primerjavo elementne sestave HP in CP s podatki o elementni sestavi PM10 na isti vzorčni točki. Podatki o sestavi PM10 so bili pridobljeni z vzorčnih točk vključenih v državno merilno mrežo za spremljanje kakovosti zunanjega zraka, ki jo upravlja Agencija Republike Slovenije za okolje. Tako HP kakor tudi CP sta v primerjavi s tlemi pokazala precejšnje obogatitve za večino kemijskih elementov. Na sestavo CP so najbolj vplivali prašenje tal (Al, Ce, Ga, K, La, Li, P, Rb, Sc in Y), izpusti povezani s prometom (Ag, Bi, Cu, Sb in Sn), jeklarski izpusti (Cr, Mo, Mn, Ni in W) in razpadanje gradbenega materiala (Ca in Sr), ki so imeli lepo razvite prostorske trende. Elementna sestava HP med vzorčnimi lokacijami je bila za razliko od CP zelo variabilna, saj so na sestavo HP verjetno prevladujoče vplivali notranji viri delcev, med katerimi so bili prepoznani kajenje (Ce in La), zgorevanje biomase (K, P in Rb), razpadanje gradbenega materiala (Ca in Sr) ter poklic stanovalcev – zaposleni v zobozdravstvu (Ag, Au, Pd) in zaposleni v kovino-predelovalni industriji (Cr, Mo in Ni). Največji delež trdnih delcev s povišanimi vsebnosti potencialno strupenih elementov, ki so bili odloženi v CP, je bil sproščen med urbanimi procesi kot so npr. zgorevanje fosilnih goriv, obraba avtomobilskih zavor ter abrazija pnevmatik. Obraba avtomobilskih zavor je tako prispevala nepravilne, koničaste in ploščaste delce obogatene z Ba, Cu, Sn in Zn. Produkt obrabe pnevmatik so bili podolgovati nitkasti delci gume, ki so vsebovali sledi Ba, Cu in Zn. Na splošno je v primerjavi s podeželjem CP v urbanih območjih vseboval višje vsebnosti Ag, Bi, Ca, Cd, Cr, Cu, Hg, Fe, Mo, Nb, Pb, Pt, Sb, Sn, Sr, Ti, Zn and W. Pomemben vir delcev odloženih v CP so bili tudi jeklarski izpusti. V vzorcih CP, zbranih v neposredni bližini jeklarn, so bile zaznane močno povišane vsebnosti Cr, Mo in Ni. Njihova vsebnost v CP je nato padala z oddaljevanjem od lokacije jeklarne ter po 15 do 20 km dosegla raven urbanega ozadja. SEM/EDS analiza CP iz bližine jeklarn je pokazala prisotnost kroglastih in nepravilnih delno nataljenih delcev, ki so vsebovali Cr, Mn, Mo, Ni, V in W. Našteti elementi so pogosti legirni elementi v jeklarstvu, poleg tega pa so bili tovrstni delci zaznani le v bližini jeklarn, zato so bili najverjetneje v CP odloženi z usedanjem PM. Primerjava elementne sestave CP in PM10 z iste lokacije je pokazala, da frakcija CP s premerom delcev manjšim od 63 µm dobro odraža vsebnosti Cr, Cu, Mo in Zn v PM10 za obdobje zadnjih 30 do 90 dni. Elementna sestava CP tako lahko služi za oceno vsebnosti nekaterih elementov v PM10 na določenem območju. Slednje ne velja za HP, saj delci, sproščeni iz notranjih virov, prekrijejo vpliv sedimentacije trdnih delcev iz zunanjega zraka.
Secondary keywords: atmosferski trdni delci;onesnaženje;hišni prah;cestni prah;jeklarne;PM10;promet;Slovenija;tla;disertacije;Ozračje;Disertacije;Prah;
URN: URN:SI:UNG
Type (COBISS): Doctoral dissertation
Thesis comment: Univ. v Novi Gorici, Fak. za podiplomski študij
Pages: XXVI, 155 str., [22] str. pril.
ID: 12212746