Gunther Umlauf

Determination of the Principal Pathways of Polychlorinated Dibenzo-p-dioxins and Dibenzofurans to Lolium multiflorum (Welsh Ray Grass).

This study presents experimental evidence that dry gaseous deposition is the dominant pathway of relatively involatile organic contaminants like polychlorinated dibenzo-p-dioxins and dibenzofurans to Welsh ray grass, an important species in agricultural food chains. The uptake pathways of these compounds to Welsh ray grass were studied under near natural conditions using a system of greenhouses and outdoor plots. Dry gaseous deposition was found to be the principal pathway of Cl 4 -Cl 6 DD/F to the grass leaves. The contribution of dry deposition of small particles (<2.9μm)to the grass levels was negligible for all compounds studied. There was some evidence that the deposition of large particles was an important pathway for the uptake of Cl 7 DD and Cl 8 DD, particularly during the autumn period when the particle-bound concentrations of these compounds were higher. Soil-related pathways did not measurably influence the substance levels in the grass.

Uptake of Gaseous DDE in Spruce Needles.

The accumulation and desorption of gaseous DDE in spruce needles was investigated in two chamber experiments using Picea omorika and in a third using Picea abies. The P. omorika needles were divided into two fractions for analysis: the soluble cuticular lipids and the remaining needle. The data were used to parameterize a one-compartment (complete needle) and a two-compartment (surface, reservoir) plant model. The one-compartment model performed poorly, whereas the uptake and clearance behavior of the complete needle was described very well with the two-compartment model. However, the two model compartments did not correspond to the two needle fractions that were analyzed for P. omorika (...)

The distribution of semivolatile organic compounds in conifer needles following gas phase contamination

Abstract Spruce needles (Picea abies) which had been exposed for 6 hours to elevated concentrations of gaseous SOC were immersed in dichloromethane for up to 100 minutes. It was found that compounds with higher molecular weights (PCBs, DDT and DDE) were completely removed from the needles after washing for several minutes. Large fractions of the compounds with lower molecular weight (chlorobenzenes and hexachlorocyclohexanes) could not be extracted by this method, even after immersion for 100 minutes. These results are attributed to differences in the diffusion behavior of the two substance groups. For the SOC with higher molecular weights the cuticular lipids act both as a sink and as a diffusion barrier, whereas the SOC with lower molecular weight can readily penetrate into the interior of the needle. These results question contaminant models which assume that the leaf is a single, well mixed compartment. The solvent immersion extraction may be useful when employing needles as biomonitors, possibly circumventing the problem of very slow kinetic behavior in the whole needle.

Deposition of semivolatile organic compounds to spruce needles

The deposition of atmospheric tetrachlorobenzene, pentachlorobenzene, hexachlorobenzene, α-HCH, γ-HCH, DDT, DDE and the PCB congeners 52, 101, 138, 153 and 180 to spruce needles (Picea abies) was estimated for a period of 9 months. Accumulation in spruce as a result of dry gaseous deposition, particle bound deposition and wet deposition was calculated on the basis of the corresponding deposition rates and the compounds’ concentrations in the different atmospheric compartments. The comparison of the calculated values with the concentrations of the compounds measured in 9-month-old spruce needles showed that for many compounds each deposition pathway could explain a large part of the concentrations found in the needles.

Gene biomarkers in diatom Thalassiosira pseudonana exposed to polycyclic aromatic hydrocarbons from contaminated marine surface sediments

Marine diatoms have a key role in the global carbon fixation and therefore in the ecosystem. We used Thalassiosira pseudonana as a model organism to assess the effects of exposure to environmental pollutants at the gene expression level. Diatoms were exposed to polycyclic aromatic hydrocarbons mixture (PAH) from surface sediments collected at a highly PAH contaminated area of the Mediterranean Sea (Genoa, Italy), due to intense industrial and harbor activities. The gene expression data for exposure to the sediment-derived PAH mixture was compared with gene expression data for in vitro exposure to specific polycyclic aromatic hydrocarbons. The data shows that genes involved in stress response, silica uptake, and metabolism were regulated both upon exposure to the sediment-derived PAH mixture and to the single component. Complementary monitoring of silica in the diatom cultures provide further evidence of a reduced cellular uptake of silica as an end-point for benzo[a]pyrene exposure that could be linked with the reduced gene and protein expression of the silicon transporter protein. However some genes showed differences in regulation indicating that mixtures of structurally related chemical compounds can elicit a slightly different gene expression response compared to that of a single component. The paper provides indications on the specific pathways affected by PAH exposure and shows that selected genes (silicon transporter, and silaffin 3) involved in silica uptake and metabolism could be suitable molecular biomarkers of exposure to PAHs.

Deposition of semivolatile organic compounds to spruce needles : II. Experimental evaluation of the relative importance of different pathways.

The accumulation of atmospheric HCB, Lindane, DDT, DDE and the PCB congeners 52, 101, 138, 153 and 180 in spruce needles (Picea abies) was investigated at outdoor locations and in greenhouses supplied with ambient air. The air supply of the greenhouses was modified to dinstinguish between gaseous and particle-associated deposition of the compounds. Accumulation of the compounds occurred in all spruce except those grown in the greenhouse where the gaseous concentration of the compounds was reduced. Spruce grown in the greenhouse supplied with particle-free ambient air behaved similarity to those grown outdoors. Protecting the spruce located outdoors from rain did not affect the accumulation. The results show that under spring and summer conditions at a typical central European rural environment dry gaseous deposition is the dominant pathway of these compounds to needles.

Deposition of semivolatile organic compounds to spruce needles : I. Calculation of dry and wet fluxes.

The deposition of atmospheric tetrachlorobenzene, pentachlorobenzene, hexachlorobenzene,α-HCH,gg-HCH, DDT, DDE and the PCB congeners 52, 101, 138, 153 and 180 to spruce needles (Picea abies) was estimated for a period of 9 months. Accumulation in spruce as a result of dry gaseous deposition, particle-bound deposition and wet deposition was calculated on the basis of the corresponding deposition rates and the compounds’ concentrations in the different atmospheric compartments. The comparison of the calculated values with the concentrations of the compounds measured in 9-month-old spruce needles showed that for many compounds each deposition pathway could explain a large pan of the concentrations found in the needles.

Analysis of emerging organic contaminants in water, fish and suspended particulate matter (SPM) in the Joint Danube Survey using solid-phase extraction followed by UHPLC-MS-MS and GC–MS analysis

Highlights • 71 water samples from the Danube River and its tributaries were analysed.• Most relevant micropollutants were benzotriazoles, pharmaceuticals, organophosphorus compounds, and PFOS/A.• PFOS concentrations exceed its environmental quality standard (EQS).• Concentrations and loads are similar for the years 2007 and 2013.

Spatial gradients of OCPs in European butter—integrating environmental and exposure information

The Stockholm Convention and the Global Monitoring Plan encourage the production of monitoring data to effectively evaluate the presence of the persistent organic pollutants (POPs) in all regions, in order to identify changes in levels over time, as well as to provide information on their regional and global environmental transport. Here, we report the first step of two to investigate whether butter is a feasible matrix to screen with the purpose to reflect regional ambient atmospheric air levels of POPs. The first step described here is to generate monitoring data; the second is to investigate the relationship between the two matrixes, i.e., POP concentrations in air and butter, which will be reported in another article published in this journal. Here, the 27 organochlorine pesticides listed under the Stockholm Convention have been analyzed in 75 butter samples from Europe. The general conclusions were as follows: Total organochlorine pesticide concentration is lower in butter from northern and central Europe. The spatial gradient of 1,1,1-trichloro-2,2-di(4-chlorophenyl)ethane and hexachlorocyclohexane is increasing in the eastern region of Europe (Romania, Bulgaria, and Ukraine), dieldrin towards France, and endosulfan levels were elevated on the Azores Island in the Atlantic Ocean. One butter sample from Romania exceeded the European Maximum Residue Limit value for lindane, but the other butter pesticide levels were all below the limit values. The dataset reported here can be used for the calibration of the air–grass–dairy products model, which would support the feasibility to use butter as biomonitor for measuring POP levels in ambient air.

Semivolatile Organic Compounds in Water, Suspended Particulate Matter, Sediments and Biota in the Danube

During the second joint Danube survey (JDS 2) in autumn 2007, water, sediment, suspended particulate matter and mussel samples were collected from 23 sites covering the River Danube and important tributaries from Germany until the Black Sea. The compound classes investigated were polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs) and polyaromatic hydrocarbons (PAHs).