The objective of this study is to characterize changes in the fate, behaviour and bioavailability of four conazole fungicides - CFs (prochloraz - PRO, tebuconazole - TEB, epoxiconazole - EPO, flusilazole - FLU) in 12 diverse agricultural soils in complex microcosm systems consisting of agriculturally-used fluvisols, plants (Lactuca sativa), earthworms (Eisenia fetida) and passive samplers (SPME, Empore™ discs, silicone rubber). Due to great variability of the data and other methodological problems, the in-matrix passive samplers failed to be indicators of pore-water concentration and (bio)availability/(bio)accessibility of CFs. A dissipation of all CFs followed the first order kinetics (usually after initial lag phase) with large span of resulting half-lives (7-670 d) depending on soils and compounds. In many soils, the model revealed the ending plateau, which indicates the non-degradable or slowly-degradable residues. The half-lives and the residues were generally higher for EPO and FLU, than for PRO and TEB. Greater but slower total dissipation of CFs was observed in soils with higher percentage of organic matter. Earthworm concentrations were highest at first sampling time (14 days) and considerably decreased afterwards often resulting in PRO concentration below LOQ. Earthworm uptake was influenced by amount of organic matter and soil texture. Accumulation to lettuce roots was generally higher than to leaves and differed greatly among CFs. Concentration shoot to root ratios were generally the lowest for FLU (0.04) and highest for TEB (0.37). PRO was not detected in lettuce leaves during experiment. The study brings new results on fate and bioavailability of CFs in soils.
The presented study investigates the use of passive sampling, i.e. solid phase microextraction with polydimethylsiloxane fibers (PDMS-SPME), to assess the bioavailability of fiver neutral organic chemicals (phenanthrene, pyrene, lindane, p,p'-DDT, and PCB 153) spiked to natural and artificial soils after different aging times. Contaminant bioavailability was assessed by comparing PDMS concentrations with results from a 10 day bioaccumulation test with earthworms (Eisenia fetida). The hypotheses tested were (i) organic carbon (OC) normalization, which is commonly used to account for sorption and bioavailability of hydrophobic organic chemicals in soil risk assessment, has limitations due to differences in sorptive properties of OC and aging processes (i.e. sequestration and biodegradation) and (ii) PDMS-SPME provides a more reliable measure of soil contaminant bioavailability than OC normalized soil concentrations. The above stated hypotheses were confirmed since the results showed that: (i) the PDMS/soil organic carbon partition ratio (R) accounting for the role that OC plays in partitioning significantly differed between soils and aging times and (ii) the correlation with earthworm concentrations was better using porewater concentrations derived from PDMS concentrations than when organic normalized soil concentrations were used. Capsule: Sorption of organic compounds measured by SPME method and their bioavailability to earthworms cannot be reliably predicted using OC content.
- MeSH
- látky znečišťující půdu chemie metabolismus MeSH
- mikroextrakce na pevné fázi * MeSH
- monitorování životního prostředí MeSH
- Oligochaeta chemie metabolismus MeSH
- organické látky analýza metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The close relationship between soil organic matter and the bioavailability of POPs in soils suggests the possibility of using it for the extrapolation between different soils. The aim of this study was to prove that TOC content is not a single factor affecting the bioavailability of POPs and that TOC based extrapolation might be incorrect, especially when comparing natural and artificial soils. Three natural soils with increasing TOC and three artificial soils with TOC comparable to these natural soils were spiked with phenanthrene, pyrene, lindane, p,p'-DDT, and PCB 153 and studied after 0, 14, 28, and 56 days. At each sampling point, total soil concentration and bioaccumulation in earthworms Eisenia fetida were measured. The results showed different behavior and bioavailability of POPs in natural and artificial soils and apparent effects of aging on these differences. Hence, direct TOC based extrapolation between various soils seems to be limited.
- MeSH
- látky znečišťující půdu chemie metabolismus toxicita MeSH
- Oligochaeta chemie účinky léků metabolismus MeSH
- organické látky chemie metabolismus toxicita MeSH
- půda chemie MeSH
- uhlík analýza MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
Závěrečná zpráva o řešení grantu Interní grantové agentury MZ ČR
117 l. : tab., grafy ; 30 cm
The hazard identification of chemical mixtures is an objective of the project. The hazard calculated as a sum of hazards of individual chemicals in a mixture can significantly deviate from a real one. This may cause a bad risk assessment. An expresstestof acute toxicity using Tubifex worms, techniques of mathematical statistics (QSAR, ANN) and physicochemical properties of components of a mixture (partition coefficients) will be used to prove the (non) additivity.
Předmětem projektu je určení nebezpečnosti (hazardu) směsí chemikálií. Mezi nebezpečností chemických směsí a jeho výpočtem z nebezpečnosti jednotlivých složek za předpokladu aditivity může být významný rozdíl. To může vést ke špatnému stanovení rizika. Kprůkazu (ne)aditivity bude použito rychlého testu toxicity pomocí červů Tubifex , matematicko-statistických technik (QSAR, ANN) a fyzikálně chemických vlastností složek směsi (rozdělovací koeficienty).
- MeSH
- hodnocení rizik statistika a číselné údaje normy MeSH
- interpretace statistických dat MeSH
- kvantitativní vztahy mezi strukturou a aktivitou MeSH
- matematické výpočty počítačové MeSH
- nebezpečné látky toxicita MeSH
- oktanoly chemie MeSH
- Oligochaeta chemie MeSH
- testy akutní toxicity metody normy využití MeSH
- testy toxicity metody statistika a číselné údaje normy MeSH
- vystavení vlivu životního prostředí MeSH
- Konspekt
- Farmacie. Farmakologie
- NLK Obory
- toxikologie
- chemie, klinická chemie
- přírodní vědy
- NLK Publikační typ
- závěrečné zprávy o řešení grantu IGA MZ ČR
