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Biomedical subjects

J Paasivirta

Publications and source records attributed to J Paasivirta.

13 recordsLinked to original sources
PubMed2001

Trends of organochlorine compounds in Finnish inland waters. Results of mussel incubation monitoring 1984-1998.

Caged common lake mussels (Anodonta piscinalis) have been used in the monitoring of organochlorine compounds in pulp and paper mill recipient watercourses of Finland annually from 1984 to 1998. Statistically significant decreasing trends of chlorophenols and chloroguaiacols originating from chlorobleaching were observed in all recipients in parallel with the decreasing discharges from the mills. Metabolites of chlorophenols, chloroanisoles and chloroveratroles had no or slightly increasing trends. Elevated PCB concentrations were measured in four watercourses. In two areas, PCBs were found to be significantly increasing, in two other cases they showed no trend. A mill producing recycled paper was apparently responsible for an increase of PCBs and DDE in recipient watercourses. Overall decreases were observed for other chlorohydrocarbons except for DDT. Material flows of chlorohydrocarbons were positively correlated with waterflows (Q) in some cases.

Animals↗
PubMed2000

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.

Animals↗
PubMed1997

Polychlorinated diphenyl ethers, dibenzo-p-dioxins, dibenzofurans and biphenyls in seals and sediment from the Gulf of Finland.

Polychlorinated diphenyl ethers (PCDEs), 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) were analyzed in seals from the Gulf of Finland and in sediments from the Gulf of Finland and near Gotland. The sediments included one surface core from both sampling sites. The seal material consisted of 14 ringed seals and 6 grey seals that all were found dead and examined for pathology. The main aims were to scrutinize levels and patterns of PCDEs for the first time in seals from the Baltic Sea and to estimate whether chlorinated compounds mentioned have an influence on an exceptional high mortality that occurred among ringed seals in the Gulf of Finland in late 1991. The concentrations of 50 congeners of tetra- through deca-CDEs analyzed ranged from < 0.3 to 62 ng/g lipid weight (lw) in seal blubber, but in the sediments PCDEs were non-detectable (tetra- through hepta-CDEs < 0.1 ng/g dry weight (dw)). In ringed seals with good nutritional status, the concentrations of almost all PCDE congeners were greater in two adult females than in specimens of younger age groups. The concentrations of PCDDs and PCDFs as TCDD-equivalents exceeded those of the coplanar (non-ortho) PCBs in sediments, whereas non- and monoortho PCBs constituted greater toxic loads as those calculated for PCDDs and PCDFs in seals. However, the levels revealed do not explain the high mortality of ringed seals.

Adipose Tissue↗
PubMed1995

Polychlorinated diphenyl ethers, dibenzo-P-dioxins and dibenzofurans in Finnish human tissues compared to environmental samples.

Finnish human samples from the Helsinki area and Arctic cod samples from Vestertana Fjord (Norway) were analyzed for polychlorinated diphenyl ethers (PCDE) and 2,3,7,8-chloro substituted dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF). The PCDE, PCDD and PCDF contents in human and animal samples from Finland and elsewhere were briefly reviewed. PCDEs were non-detectable in human liver and testis, but some PCDE congeners were identified in human adipose tissue and fat of boiled Arctic cod liver composite. The contents of PCDEs in Finnish human samples were similar to those reported in the literature for human tissues from North America. The estimated concentrations of PCDEs 99, 147 + 153 (coeluting) and 206 ranged between 2 and 8 ng/g lipid weight (lw) in one Finnish human adipose tissue. The concentrations of PCDE congeners identified in the cod liver fat were between 0.4 and 5 ng/g lw. Of toxic PCDDs and PCDFs, hepta- and octa-CDDs dominated in human. The concentrations of PCDD and PCDF congeners varied from < 2 to 7700 pg/g lw in human. In Arctic cod samples analyzed (muscle tissues of an air dried cod and cod liver fat), 2,3,7,8-tetra-CDF was nearly the only congener of PCDD/PCDFs detected.

Adipose Tissue↗
PubMed1993

Chemical ecotoxicology--general aspects.

Chemical ecotoxicology is defined as application of methods of chemistry to the study of the occurrence and adverse effects of anthropogenic chemicals and their transformation products in the biosphere. Examples of methods and their applications are given.

Dioxins↗
PubMed1985

Pyrolysis products of PCBs.

Model compound studies which were previously done for impurities and environmental residues of chlorophenols and for wastes of chlorination processes were extended to the impurities and pyrolysis products of polychlorinated biphenyls (PCBs). Model compounds were commercial products or synthesized and their structures proven by spectroscopic methods. These models were used as analytical reference substances in GC/ECD and GC/MS studies of the pyrolyzed PCB samples. In addition to previously known neutral components like polychlorinated dibenzofurans (PCDFs), chlorophenolic substances, especially polychlorophenols (PCPs) and polychlorinated biphenylols (PCB-OHs) were observed as major pyrolysis products of PCBs. Capacitor fires are suggested to produce in many cases chlorophenols which are major toxic hazards to people.

Chromatography, Gas↗
PubMed1980

Alkylation products of DNA bases by simple epoxides.

The reaction products of a series of epoxides with deoxyribonucleosides were characterized using ultraviolet, and NMR spectroscopy. The epoxides included structural analogues which are known to differ extensively in their mutagenic potency: propylene oxide, glycidol, epichlorohydrin, trichloropropylene oxide and styrene oxide. Trichloropropylene oxide, epichlorohydrin and glycidol reacted with deoxyguanosine producing a major adduct of 1,7-(or 1,9-)dialkylguanine. All of the epoxides produced a 7-alkylguanine adduct, with the possible exception of styrene oxide. Propylene oxide, glycidol and epichlorohydrin reacted with deoxyadenosine at N-6. Glycidol, trichloropropylene oxide and styrene oxide reacted with deoxycytidine at N-3. It was concluded that the structurally related epoxides tend to react largely in a uniform way with nucleic acid bases. Thus, the reaction rates rather than the major adducts explain the differential mutagenicity of the epoxides.

Alkylation↗
PubMed1977

Thin-layer chromatography of chlorinated catechols.

The thin-layer chromatography of catechol and six chlorinated catechols has been studied on five adsorbents. Acetic acid in the developing solvent was essential for the production of sharp zones. The best separation of the individual compounds occurred on alumina, whereas silica gel appeared to be good for group separation (clean-up) from other compounds.

Catechols↗
PubMedDate not supplied

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.

Benzofurans↗