Seija Sinkkonen

Degradation half-life times of PCDDs, PCDFs and PCBs for environmental fate modeling

Literature search of the knowledge on the degradation of persistent organic pollutants (POPs) in environmental compartments air, water, soil and sediment was done in purpose to find properties of POPs of interest for modeling. One degradation process, hydrolysis (chemical degradation), was omitted as negligibly slow for POPs studied. The other two, photolysis and biodegradation processes, were considered separately in purpose to develop estimation procedures. The estimates can be given as pseudo first-order rate constants kP for photolysis and kB for biodegradation. For each compartment, an overall degradation rate is k(tot) = kP + kB and lifetime t(1/2) = ln 2/k(tot). The latter values, lifetimes in each compartment, will be used as input parameters to the Baltic Sea model.

Estimation of vapor pressures, solubilities and Henry's law constants of selected persistent organic pollutants as functions of temperature

Abstract An internally consistent set of temperature dependent physical-chemical property data was derived for 73 persistent organic pollutants, including polychlorinated biphenyls, diphenylethers, dibenzo-p-dioxins, and dibenzofurans, organochlorinated pesticides and polycyclic aromatic hydrocarbons. Measured data reported in the literature were expanded by different estimation and regression methods. Temperature dependent vapor pressures were estimated from relative gas chromatographic retention times and by a modified Watson equation. Temperature dependent water solubilities were estimated by equations based on mobile order theory modified from Ruelle and Kesselring. The temperature dependence of Henrys law constants was estimated from the temperature dependence of both the vapor pressure and water solubility. The results are presented as intercepts A and slopes B of log-linear relationships of the type log property = A - B / T. Octanol-water partition coefficients of the same compounds at 25°C were also compiled and estimated. A comparison of the estimated data with literature values showed fair agreement. The estimated property values may serve as interim input values to models of the fate of persistent organic pollutants under variable climatic conditions.

Polychlorinated organic compounds in the Arctic cod liver: trends and profiles.

Polychlorinated organic compounds (POCs) have been measured in Arctic cod liver from Vestertana Fjord for a period of 1987-1998. Significant decrease was observed for DDD (p = 0.043), alpha-HCH (p = 0.001), and gamma-HCH (lindane; p = 0.001). Contents of DDE, 2,3,7,8-tetrachlorodibenzofuran, PCBs, chlordanes, chloronaphthalenes, hexachlorobenzene and polychlorodiphenyl ethers had no significant trend. Contents of three hexa- and two heptachlorodibenzofurans and octachlorodibenzofuran increased slightly from 1987 to 1994, but then at very high rate from 1994 to 1998. Trends of HCHs, profiles of PCBs and levels of chlordanes are in accordance with atmospheric long range transport. The hexa-, hepta- and octachlorodibenzofurans observed are major impurities in chlorophenol formulation Ky-5, which has been used as wood preservative and as fungicide/slimicide in industrial processes. Their profile in Vestertana cod was similar to that observed in Ky-5 contaminated fish.

Formation of chloroaromatics at a metal reclamation plant and efficiency of stack filter in their removal from emission

Abstract Sampling and analyses of chloroaromatic compounds emitted from the metal reclamation plant of Kuusakoski Ltd in Heinola, South Finland, were continued in order to find out formation pathways and to follow the impact of process improvements done in 1991–1992. Especially, process gas cleaning by baghouse filter at aluminum smelter plant (ALS) and by scrubber at car schredding (CSH) were successful in emission control. At ALS, reductions of polychlorinated dioxins, furans, planar PCBs and dibenzothiophenes were better that 90, naphthalenes 78, other PCBs 73, chlorobenzenes 51 and chlorophenols 43 per cent. CSH scrubber gave similar results.

Tetra- and pentachlorodibenzothiophenes are formed in waste combustion

Abstract Two different waste combustion samples have been analyzed for tetra- and pentachlorodibenzothiophenes. HRGC/HRMS with a resolution of 20 000 was used for identification. By resolution of 10 000 chlorinated dibenzo-p-dioxins and some unknown compounds gave GC/SIM peaks at the exact masses of the chlorinated dibenzothiophenes. These peaks were no more present by resolution 20 000. Several tetra- and pentachlorodibenzothiophenes were found in both samples. In the other one of the samples the concentrations were seemingly high although exact quantitative determination could not be done.

Metal reclamation produces sulphur analogues of toxic dioxins and furans

Abstract Polychlorinated dibenzothiophenes (PCDBTs), polychlorinated thianthrenes (PCTAs) and polychlorinated diphenylsulphides (PCDPSs) which are sulphur analogues for polychlorinated dibenzofurans (PCDFs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated diphenyl ethers (PCDEs), were analyzed by HRGC/HRMS in different samples from a metal reclamation plant. The samples were gas phase samples from an aluminium smelter and a car shredder and ash and slag from processes where different temperatures (300–850 °C) were used. Tri-, tetra-and pentaCDBTs were most abundant sulphur chloroaromatics at amounts comparable to PCDDs and PCDFs in emissions and wastes. Small amounts of tri- and tetraCTAs were identified in car shredder samples. Occurence of PCDPSs remained uncertain due to interferences even in GC/HRMS analyses.

Temperature dependent properties of environmentally important synthetic musks

Environmental fate determining physical properties including their temperature dependence for five nitro musks and for seven polycyclic musks were estimated. The properties evaluated were vapor pressure in a solid and liquid state (PS and PLsolubility in water (S), Henry’s law coefficient (H = PL/S) and log octanol-water partition coefficient (log Kow). Gas chromatography for starting values of vapor pressure estimation and HPLC experiments at 5–20°C for comparison of the theoretical versus experimental solubilities in water were performed. The values of temperature (T) dependence coefficients (Ai and Bi) in equations: log (Property)i = Ai − Bi / T were determined. Values of properties were compared with literature-based data, and an example of their use in environmental hazard estimation by fate modeling was given.

Chlorinated and methylated dibenzothiophenes: Preparation of the model compounds and their analysis from some environmental samples

Abstract Polychlorinated and polymethylated dibenzothiophenes if occuring in the environment can cause environmental hazards and problems like chlorinated dibenzodioxins and dibenzofurans. Some chlorinated and methylated dibenzothiophenes have been synthesized to serve as model compounds in environmental and toxicological analysis. The synthesis mixtures and some environmental samples have been analyzed by high resolution GC/low resolution MS. This investigation showed that the concentrations of these compounds in environmental samples were below ppb level but it did not exclude the occurence of these compounds in our environment. More investigation is needed.

Chlorohydrocarbons, PCB congeners, polychlorodioxins, furans and dibenzothiophenes in pine needles in the vicinity of a metal reclamation plant

Abstract Chlorohydrocarbons, PCB congeners, polychlorodioxins, furans and dibenzothiophenes in pine needles in the vicinity of a metal reclamation plant were analyzed by GC/ECD and GC/MS. Wax and the rest of the needles were analyzed separately. As a rule the concentrations of α-HCH (0.5–13.6 ng/g), γ-HCH (0.4–7.3 ng/g), HCB (0.2–3.4 ng/g), PCB congeners (0.2–67 ng/g), PCDDs and PCDFs were higher in the older needles. The ratio of the concentration in the wax to the concentration in the rest of the needles was higher in the younger needles. The concentrations of PCB congeners, TeCDDs and TeCDFs were higher in the needles collected in the area nearest to the plant. The samples, obviously, contained tri- and tetrachlorodibenzothiophenes but these were not determined quantitatively due to interfering peaks in GC/MS.

Oil residues in Baltic sediment, mussel and fish. I. Development of the analysis methods

Abstract Sediment, sediment trap, Mytilus, Macoma and flounder samples from Northern Baltic (Finnish archipelago) have been analyzed for their contents of aliphatic and aromatic hydrocarbons. Androstane and hexaethylbenzene were used as internal standards. The analysis procedure consisted of alkaline degradation of fat, column fractionation of the two residue groups and final determination by glass capillary gas chromatography with FID for aliphatic hydrocarbon group and with mass spectrometry for non-polar aromatic residue group. The latter group was also determined by high pressure liquid chromatography. The residues due to oil pollution were distinguished from compounds of pure natural origin on the basis of statistical treatment of the determination results.