Frakcionacija in biodosegljivost Pb iz onesnaženih tal otroškega igrišča

Ivanović, Anja (author), Grčman, Helena (mentor)

Za preučevanje smo izbrali tla otroškega igrišča, ki so bila onesnažena s svincem. Povprečna koncentracija Pb v tleh na globini 0 – 20 cm je bila 516 mg/kg. Posamezni točkovni vzorci so presegali koncentracijo 10 000 mg/kg. Zanimalo nas je kaj je izvor onesnaženja ter kakšne bi lahko bile posledice za zdravje otrok. Iz talnih profilov ter neenakomernih koncentracij Pb v horizontalni in vertikalni smeri je bilo razvidno, da onesnaženje ni posledica imisij iz zraka (promet, industrija), temveč je bila zemljina pomešana z ostanki gradbenega materiala ter ostanki avtomobilskih akumulatorjev. Izvedli smo osnovne pedološke analize: vsebnost karbonatov, kislost tal, teksturni razred, vsebnost organske snovi, kationsko izmenjalno kapaciteto ter dostopnost fosforja. Z metodo sekvenčnih ekstrakcij po Tessierju smo ugotovili, da je največji delež svinca vezan na organsko snov (od 30,61 % do 67,48 %) ter karbonate (od 12,22 % do 62,86 %). Biodostopnost svinca smo določali z in vitro metodo, ki jo je določila U.S. EPA. Absolutna biodostopnost je bila med 25,18 in 56,92 %. Z modelom IEUBK, smo želeli napovedati koncentracijo svinca v krvi otrok, nato pa smo rezultat primerjali z izmerjeno koncentracijo Pb v krvi otrok. Napovedana ter izmerjena koncentracija se nista ujemali. Eden od razlogov je lahko točkovna, neenakomerna onesnaženost, pri čemer smo za analize izbrali vzorce z visoko koncentracijo Pb. Predvidevamo tudi, da je bil zaradi zatravljenosti onesnaženega dela igrišča stik otrok s tlemi zmanjšan.

• Language: Slovenian
• Keywords: biodostopnost/onesnaženost tal/svinec/ sekvenčna ekstrakcija/in vitro/IEUBK
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [A. Ivanović]
• Year: 2017
• PID: 20.500.12556/RUL-94270
• UDC: 631.453:504.5:546.81(043.2)
• COBISS.SI-ID: 8758393
• Publication date in RUL: 23.07.2017

Secondary language

• Language: English
• Title: FRACTIONATION AND BIOAVAILABILITY OF Pb CONTAMINATED SOIL AT CHILDREN'S PLAYGROUND

Abstract

For the study we chose the soil from the playground, which was contaminated with lead. Average Pb concentration in soil at the depth of 0 – 20 cm was 516 mg/kg. Some point samples exceeded concentration of 10 000 mg/kg. The aim was to identify the source of contamination and the negative effects on children's health. From the soil profiles and the heterogeneous concentration of Pb in the horizontal and vertical direction, was evident, that the contamination is not a result of immissions from air, but the result of the soil mixing with the remains of building materials, and residues of car batteries. We carried out the basic soil analysis: content of carbonates, soil acidity, texture class, the organic matter content, the cation exchange capacity, and the availability of phosphorus. The method of sequential extractions, according to Tessier, showed that the largest proportion of lead is bonded to the organic substance (from 30.61 % to 67.48 %) and carbonates (from 12.22 % to 62.86 %). Bioavailability of lead was determined by the in vitro method, established by the U.S. EPA. The absolute bioavailability was between 25.18 and 56.92%. With the IEUBK model, we wanted to predict the PbB concentration, and then compare the results to the measured concentration of Pb in the blood of children. The predicted and measured concentrations do not match, since the pollution was uneven and we chose samples with high concentration of Pb for our analysis. We assume that the intake of lead was minimized since contaminated part of playground was covered with grass.

• Keywords: bioaccessability/soil contamination/lead/sequential extraction/in vitro/IEUBK