Takashi Kashimoto

Polybrominated biphenyl ethers in marine fish, shellfish and river and marine sediments in Japan

Abstract The presence of polybrominated biphenyl ethers (PBBEs), commonly used as flame retardants, was confirmed in marine fish, shellfish and river and marine sediments in Japan. These compounds were detected in seven out of 17 marine fish and shellfish, though at low levels. Tetrabrominated biphenyl ether was a major component in marine organisms. However, sediment pollution by PBBEs, particularly that by decabrominated biphenyl ether, pose a serious problem in the rivers of Osaka but not in marine areas.

Polycyclic aromatic hydrocarbons in human fat and liver

Nine polycyclic aromatic hydrocarbons (PAH) were determined in human fat and liver by high pressure liquid column chromatography without complex pretreatment prior to analysis. Fat and liver tissue were obtained from autopsies. Smoking habits, occupations, and residence of the persons were unknown. The tissues were free from cancer. Differences of sex and age did not affect PAH content in the tissues. Pyrene averaged 1100 ppT in the fat and 380 ppT in the liver. The next highest level was that of anthracene (260 ppT in the fat and 170 ppT in the liver). The known carcinogens, benzanthracene and dibenzanthracene, were not detected in either tissue, but benzo(a)pyrene was present at a rather low level (20 ppT in both tissues). (RJC)

Rate of decrease and half-life of polychlorinated biphenyls (PCBs) in the blood of mothers and their children occupationally exposed to PCBs

Long-term studies on the concentrations of polychlorinated biphenyls (PCBs) in the blood of children and their mothers occupationally exposed to PCBs were made during the period 1975 to 1979. This report deals in particular with the rates of decrease and half-lives of PCB concentrations in the blood. Rates of decrease of the concentration of PCBs in the blood of both mothers and their children were relatively constant and independent of PCB concentrations. Therefore, a one-compartment model equation was sufficient to represent the decrease of the concentrations of PCB in the blood. The mean rate constant of the decrease of PCB concentration for the children was approximately 2.6 times higher than that of the mothers.The dilution effect due to the increase of body weight was the most important factor which affected the reduction of the PCB concentrations in the children. Since the rate of the body weight gain is very high during the two years after birth, the half-life of the PCB concentration was extremely shortened during this period. The natural excretion of PCBs from children was estimated to be about 10%, which was obtained by subtracting the rate of decrease of PCB concentration by the dilution effect, due to the gain of body weight from the total rate of decrease per year. This rate constant relates favorably to that of the mothers.

Hexabromobenzene and its debrominated compounds in river and estuary sediments in Japan.

HBB has been found in estuary sediments collected at Tokyo, Japan, though at extremely low levels. It has not been found in any river, estuary or marine sediments collected outside the Tokyo area. A peak having the same retention time as HBB was found in the gas chromatogram of an extract of the river sediment collected at Osaka, Japan. The shake extraction method for HBB in sediment using organic solvents such as acetone and benzene was found less efficient. This paper describes a method for the extraction of HBB from sediment, and an attempt has been made to determine more accurately HBB in sediments in Japan. Also an examination has been made of the decomposition products of HBB in the environment.

Levels of PCDDS and PCDFS in human tissues and various foodstuffs in Japan

Abstract In preserved breast milk fat samples from 505 persons gathered over a period of seven years, from 1978 to 1984. We found that TCDD was 37 ppt, PenCDD 15 ppt, HexCDD 76 ppt, HepCDD 150 ppt and OCDD 789 ppt in primiparas milk fat. On the other hand, in multiparas, TCDD was 19 ppt, PenCDD 10 ppt, HexCDD 98 ppt, HepCDD 73 ppt and OCDD 518 ppt as an average amount. In regard to TCDD isomers, 2,3,7,8-TCDD was detected only in primiparas with the value of 13 ppt. It was found that OCDD was a major component in primiparas milk fat and its component ratio was 71%. Similar observations were seen in multiparas milk fat, human adipose tissues and human livers, but in absolute amounts, there were differences among these four groups. In our results from various foodstuffs which are easily obtained in daily life, we can find that most of animal foodstuffs have already been contaminated by very small amount of these contaminants in our environment. The trend that TCDDs were major components in shellfish was seen and their component ratios were 34 to 80%. The data of chicken and porker seems to show the tendency that PenCDD is lower while HexCDD is higher, whereas in cattle, the tendencies are not similar.

PCDDs, PCDFs, PCBs, coplanar PCBs and organochlorinated pesticides in human adipose tissue in Japan

Abstract Thirty-nine samples of human adipose tissue from three prefectures with large differences in population densities and industrial and commercial activities were analyzed for PCDDs, PCDFs, PCBs, coplanar PCBs, DDT, DDE, DDD, HCHs, hexachlor epoxide, chlordanes and hexachlorobenzene. The residue levels of PCDDs and PCDFs were related closely to the human activity. It was found that the residue levels of chlordanes and HCHs vary in different regions in a manner apparently related to the extent of their dispersion in the past. Other chlorinated compounds showed no significant regional difference in their residue levels.

Levels of PCBS, PCDDS and PCDFS in soil samples from incineration sites for metal reclamation in Taiwan

Abstract Surface soil samples from six sites at which waste electric wires and/or magnetic cards are incinerated for metal reclamation in Taiwan, Republic of China, were analyzed for polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). All samples analyzed were contaminated with PCBs at a level of 0.45 to 77 ug/g dry weight, PCDDs at n.d. to 540 ng/g and PCDFs at 1.8 to 310 ng/g. The samples from the incineration sites only with waste electric wire were heavily polluted by these chlorinated chemicals.

Levels of PCDDs, coplanar PCBs and PCDFs in patients with Yusho disease and in the Yusho oil

Abstract Yusho victims tissues and Yusho oil samples were analysed by using a recently developed analytical method. Consequently, non-ortho chlorine substituted PCBs (coplanar PCBs) and PCDDs were newly found in both of them. Moreover, the profiles of PCDFs were revealed to be fairly different from those previously reported by us and other investigators.

Average daily intake of pesticides and polychlorinated biphenyls in total diet samples in Osaka, Japan.

Total diet studies (also referred to as Market Basket Programs) have been conducted by the US Food and Drug Administration (FDA) since 1964. In Japan, similar studies have been carried out since 1977 by the National Institute of Hygienic Sciences in combination with some Prefectural Institutes of Public Health. This study was done to obtain fundamental data concerning the safety of foods; (1) the chemical contaminants in the foods eaten in selected areas in Japan were analyzed and their content determined, and (2) the problems and trends in the intake of these chemical and the sources of unusual residues were identified. The authors carried out these studies seven times between the fiscal year 1977 and 1985 in Osaka Prefectural (relatively urbanized district in comparison with a rural area in Japan). Daily dietary intake of organic contaminants was obtained and the means of these were calculated from the data.

Polychlorinated dibenzo-p-dioxins in blue mussel from marine coastal water in Japan

Polychlorinated dibenzo-p-dioxins (PCDDs) are tricyclic aromatic compounds containing 75 specific isomers. Some of the isomers with chlorine substitutions at 2, 3, 7 and 8 positions in their molecules have been reported to be extraordinary toxic. In this paper, the pollution degree of PCDDs in marine coastal water in our country was examined by using blue mussel as a biological indicator because it provided an effective trapping mechanism for many environmental pollutants.