Martin Nygren

Overview on environmental fate of chlorinated dioxins and dibenzofurans. Sources, levels and isomeric pattern in various matrices

Abstract Polychlorinated dioxins and dibenzofurans have been identified in technical products and pesticides, most of which are not very widely used today. Other sources are incinerators of various types like MSW incinerators, but also hazardous waste incinerators and industrial incinerators. PCDDs and PCDFs have also been identified in exhausts from cars running on leaded gasoline with halogenated additives. Background levels of PCDDs and PCDFs have been identified in fish and other aquatic organisms from the Great Lakes and the Baltic Sea, and also in human adipose tissue samples from USA, Canada, Sweden, Japan and Viet Nam as well as in samples of breast milk from Sweden, Denmark, West Germany, the Netherlands, Yugoslavia and Viet Nam. The isomeric pattern in all these biological samples is very similar.

Polychlorinated biphenyls, dibenzofurans and quaterphenyls in toxic rice-bran oil and in the blood and tissues of patients with PCB poisoning (Yu-Cheng) in Taiwan.

A mass outbreak of poisoning occurred in central Taiwan in 1979 due to the ingestion of rice-bran oil contaminated with polychlorinated biphenyls (PCBs), dibenzofurans (PCDFs) and quaterphenyls (PCQs). The incident was called PCB poisoning or Yu-Cheng in Taiwan. The major PCB and PCDF congeners in the toxic oil and in the blood and tissues of the poisoned patients were characterized by gas chromatography and gas chromatography-mass spectrometry using highly efficient glass capillary columns. The levels of toxic agents in the rice oil samples collected from the factory and school cafeterias and the families of the poisoned patients are in the range of 53 to 99 ppm, 0.18 to 0.40 ppm and 25 to 53 ppm for PCBs, PCDFs, and PCQs, respectively. The blood samples of 165 patients collected 9 to 18 months after the onset of poisoning contained 10 to 720 ppb of PCBs, with a mean value of 38 ppb. The blood samples of 10 patients collected 9 to 27 months after poisoning contained 0.02 to 0.20 ppb of PCDFs. Comparative rates of elimination of some PCB congeners from the blood of patients were studied. Various tissues from a patient who died 2 years after poisoning were analyzed for PCBs, PCDFs and PCQs. The intestinal fat contains the highest level of PCBs, while the liver contains the highest concentration of PCDFs. The PCB congeners retained in the tissues either do not have adjacent unsubstituted carbon atoms or have a pair at ortho-meta positions of the biphenyl ring. The major PCDF congeners retained in the tissues were 1,2,3,4,7,8-hexachloro-DF, 2,3,4,7,8-pentachloro-DF and 1,2,4,7,8-pentachloro-DF. The former two congeners, especially 2,3,4,7,8-pentachloro-DF, are very toxic PCDFs; they may play important roles in the etiology of Yu-Cheng.

Development and validation of a method for determination of PCDDs and PCDFs in human blood plasma. A multivariate comparison of blood and adipose tissue levels between Viet Nam veterans and matched controls

Abstract A method which allows measurements of low levels (fg/g) of PCDDs and PCDFs in blood plasma, has been developed and validated at four fortified levels between 0.027 ppt and 0.9 ppt. The procedure involves extraction with organic solvents, multiple cleanup using various absorbents and finally detection and quantification by multiple-ion-mode high resolution gas chromato graphy/high resolution mass spectrometry. This method has been found to have a limit of detection of 0.003 to 0.02 ppt depending on the isomer studied. Using this method, samples of blood plasma have been analyzed for PCDDs and PCDFs from Viet Nam veterans from The United States, and from matched controls, and have been compared with the results of the analyses of adipose tissue. Exposed Vietnam Veterans could be separated from matched controls using a multivariate data analysis.

Sources and Relative Importance of PCDD and PCDF Emissions

Polychlorinated dioxins (PCDD) and dibenzofurans (PCDF) have been identified in technical products and pesticides, most of which are not very widely used today. Other sources are incinerators of various types like MSW incinerators, hazardous waste incinerators and industrial incinerators. PCDDs and PCDFs have also been identified in exhausts from cars running on leaded gasoline with halogenated additives. Background levels of PCDDs and PCDFs have been identified in fish and other aquatic organisms from the Great Lakes and the Baltic Sea, and also in human adipose tissue samples from U.S.A., Canada, Sweden, Japan and Vietnam as well as in samples of breast milk from Sweden, Denmark, West Germany, the Netherlands, Yugoslavia and Vietnam. The isomeric pattern in all these biological samples is very similar. The relative importance of different sources to the general background is difficult to estimate although the contribution of direct inhalation from point sources like MSW incinerators is small.

Identification of Polychlorinated Dioxins (PCDDs) and Dibenzofurans (PCDFs) in Human Samples, Occupational Exposure and Yusho Patients

A number of PCDDs and PCDFs have been identified in human samples. The analytical technique used allows the identification and quantification of individual isomers. The detection levels were in the pg/g region (ppt). The samples analyzed include blood plasma from occupationally exposed workers and also various samples from the Yusho episodes in Japan in 1968 and in Taiwan in 1979.

Isomer specific measurement of polychlorinated dibenzodioxin and dibenzofuran isomers in human blood from American Vietnam veterans two decades after exposure to Agent Orange

Abstract In an attempt to develop a quantitative biological marker of intake of 2,3,7,8-TCDD from Agent Orange in American Vietnam veterans, 28 participants in a Commonwealth of Massachusetts study volunteered to submit one unit (450 mL) of blood for polychlorinated dibenzodioxin (PCDD) and polychlorinated dibenzofuran (PCDF) analysis. Analysis was performed for all the currently measurable PCDD/Fs in the plasma lipid. It is concluded that measurement of all detectable PCDD/Fs in body tissue is a preferable way to detect intake of a specific isomer some time in the past. It is also concluded that blood, in addition to adipose tissue, is a promising tissue to use for detecting such elevations.

Correlation of adipose and blood levels of several dioxin and dibenzofuran congeners in Agent Orange exposed Viet Nam veterans

Abstract Most of the 13 dioxins and dibenzofurans analyzed in blood and fat of Viet Nam veterans were positively correlated. TCDD showed the highest correlation (r = +0.89). Other correlations ranged from −0.27 to +0.70.

Quality assurance of multivariate analytical measurements by principal components analysis

Abstract The use of principal components analysis for the quality control of a mass spectrometer is demonstrated and commented upon.

SOURCES AND RELATIVE IMPORTANCE OF PCDD AND PCDF EMISSIONS

Polychlorinated dioxins (PCDD) and dibenzofurans (PCDF) have been identified in technical products and pesticides, most of which are not very widely used today. Other sources are incinerators of various types like MSW incinerators, hazardous waste incinerators and industrial incinerators. PCDDs and PCDFs have also been identified in exhausts from cars running on leaded gasoline with halogenated additives. Background levels of PCDDs and PCDFs have been identified in fish and other aquatic organisms from the Great Lakes and the Baltic Sea, and also in human adipose tissue samples from U.S.A., Canada, Sweden, Japan and Vietnam as well as in samples of breast milk from Sweden, Denmark, West Germany, the Netherlands, Yugoslavia and Vietnam. The isomeric pattern in all these biological samples is very similar. The relative importance of different sources to the general background is difficult to estimate although the contribution of direct inhalation from point sources like MSW incinerators is small.

Analysis of Polychlorinated Dibenzo-P-Dioxins and Dibenzofurans

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are two series of tricyclic aromatic compounds with similar physical and toxicological properties. The chemical structures and the numbering are given below.