This paper reviews published research results on the levels of PCDD/DF in organisms in the environment. Though biota samples from densely populated/industrialized areas had higher contents of PCDD/DF, the temporal variation generally had declining tendency. Levels and isomer/homologue patterns of PCDD/DF of individual biota depended on not only emission sources, such as combustion, byproducts of pesticide, chlorine breaching and so on, but also diet, uptake, metabolism or elimination. The observations suggest that only toxic, low chlorine substituted 2, 3, 7, 8-congener of PCDD/DF revealed the food-chain accumulation as reflection of the species-related selectivity of isomer/homologue. Coplanar polychlorinated biphenyls (Co-PCB) which have dioxin-like toxicity showed markedly higher accumulation than PCDD/DF, therefore levels and ratios of Co-PCB in fish, fish-eating birds and mammals were higher than those of PCDD/DF.

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In this study, the effects of space velocity (SV) and gas temperature on the removal rate of Dioxins (polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans=PCDD/DF) in exhaust gas of incinerator by fly ash-derived artificial zeolite were investigated. The highest removal rate calculated by TEQ value (98.7%) of vapor PCDD/DF in exhaust gas of small size incinerator was found at 150°C and 10000h^-1 as SV value. Removal rate decreased with the increase of gas temperature and/or with the increase of SV value, and also relatively low removal rate of vapor PCDD/DF was found in low chlorinated PCDD/DF-congeners and -isomers. These results suggested that the adsorption mechanism of PCDD/DF by artificial zeolite was mainly due to physical adsorption. However, rapid increase of vapor PCDD/DF concentration was found at 300°C. It was considered due to new synthesis of PCDD/DF, so called de-novo synthesis. Furthermore, considering these observations, the removal method of PCDD/DF by artificial zeolite will be effective in small size incinerator.

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Soil samples with high total zinc concentrations (41 to 15200mg kg^-1), collected near a mine, were investigated for Zn speciation after taking the extracts from water-saturated soil samples, (described below as“soil solution”), in order to clarify the forms of Zn adversely affecting soil bacteria. The zinc speciation was estimated using an equilibrium thermodynamic computer model, SOILCHEM. The effects of Zn on soil bacteria were evaluated by an indicator: the Zn tolerance level of the bacterial community, shown as IC₅₀. In all samples, more than 80% of total Zn was present as free ion in the soil solutions. The Zn tolerance levels of the bacterial community were dependent on the Zn ion activities with the high square of correlation coefficients (γ²=0.610, p<0.01), but had no relationship with the total zinc concentrations in the soils. The results showed that the high Zn ion activities in the soils led to the development of the Zn tolerance levels of the bacterial community. IC₅₀ was also correlated with the amounts of chloride, nitrate, and sulfate complexes of Zn in the soil solutions.

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The surface and subterranean waters of Hazaribagh industrial area, the western part of Dhaka city of Bangladesh are heavily contaminated with chromium, inorganic and organic matters. In this study, exposure assessment of chromium, pH value, alkalinity, calcium and dissolved organic carbon in tannery effluents, surface water and groundwater has been done. The samples were collected from ten different sites in two seasons (spring and winter) according to a well-planned monitoring scheme that can represent the entire area and the instant analysis was done. The pH values of waste water flowing through main outflows and groundwater varied from 8.90 to 11.00 that is higher than the acceptable limit proposed by Bangladesh drinking water standard, very harmful for aquatic animals and unfavorable for microbiological growth for waste treatment. The calcium content of the samples (560.0-1600.0ppm) was also very high to disrupt sewerage system by deposition of calcium carbonate inside it. The high content of dissolved organic carbon (DOC) from 338.98 to 361.13ppm is depleting the dissolved oxygen (DO) in the river Buriganga making the water ecosystem uninhabitable for fish. The chromium content of the chrome tan liquor and waste water ranged from 5.19 to 72.80ppm. This higher concentration can interfere with biological oxidation by tying up the enzymes essentially required for microbial growth and exceeded all of the national and international standards for safe disposal and drinking. The chromium concentration in surface water (5.19ppm) on the low-lying lands discharged from main outflows showed identical value with that of groundwater (5.19ppm) contributing to dietary intake. The daily intake of chromium, 377.45μg/kg/d for the residents of that area, that is higher than maximum limits proposed by USA, NRC (0.71-2.90μg/kg/d) and FDA (120.00μg/d), arises health concern among the population and they are at risk of health hazards.

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Suspended particulate matter (SPM) in the ambient air had been measured with using the two methods, i.e., a β attenuation method (β-ray absorption method; particles larger than 10μm were removed by a cyclon type separator) and a gravimetric high-volume (HV) method (the exposed filters were kept in 50% relative humidity for more than one day before weighing), at two monitoring stations (Ohta and Minato) in Tokyo for a decade (1984-1993) . The measurements were run for 24-hours on randomly selected non-consecutive two days per month.
1) High correlation between the two data sets was observed on the SPM concentrations in each station, [Ohta Sta.; r (correlation coef.) =0.690 (0.529, 0.879) ], [Minato Sta.; r = 0.857 (0.807, 0.907) ], where; the numbers in the parentheses mean the correlation coef. for the periods before and after March in 1991 (when the instruments for a β method were changed) . 2) Linear relationships between the SPM concentrations by an HV and a β method after April in 1991 were;
Ohta Sta.; HV = [1.2-1.4-1.7] ·β+ [10-27-34] ………………… (1)
Minato Sta.; HV = [0.9-1.1-1.6] ·β+ [3-26-36] …………………… (2)
Where; HV = [α₁-α-α₂] ·β+ [γ₁-γ-γ₂],
α&γ: slope & intercept of the line by principal component analysis.
α₁-α₂ & γ₁-γ₂: 95% confidence interval for slope & intercept estimated by a Bootstrap method.
3) The variation patterns of SPM concentration at the two sites were very similar in spite of 8 km distance. 4) SPM concentration was increased under the weather conditions of higher relative humidity and/or weak wind. 5) The difference of values between HV and β was decreased with higher relative humidity (>80%) and/or lower HV value.
In addition, the SPM concentration for HV induced from the relationship showing in eq. (1) and (2) were compared with the HV values in 12 mega-cities in the world.

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A comparison of the solid-phase extraction disks and the solid-phase extraction cartridges for Ames mutagenicity test of river water was conducted. Acetone and ethyl acetate were suitable solvents for extracting mutagen from the disk and the cartridge after the passage of river water.
Mutagenicity, towards test strain S. typhimurium TA98, of the extracts obtained from disks was almost similar to that of the extracts obtained from cartridges. Thus, the use of solidphase extraction disk was useful as an extraction procedure for the Ames mutagenicity test of river water. This extraction procedure was applied to seven rivers in Kanagawa Prefecture and their Ames mutagenic activities were evaluated.

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Among organochlorines in adipose tissues of Korean people, DDTs concentrations were found to be the highest in the range of 118 to 7800ng·g^-1, with a mean value of 828ng·g^-1 on a lipid weight basis. Regarding DDTs, p, p'-DDE was the major component in human adipose tissues, accounting for more than 90%. On the other hand, p, p'-DDT and p, p'-DDD amounted to 5.8% and 0.7%, respectively. Relatively higher ratio of p, p'-DDE to p, p'-DDT suggests that fairly long time has passed since stop of usage of DDTs in Korea. The mean concentration of HCHs was 143ng·g^-1 (43-1100ng·g^-1) . β-HCH was the predominant isomer occupying 98.6% of total HCHs. α- and γ -HCH occupied only 0.9% and 0.4% of total HCHs, respectively. Average concentration of HCB was 19ng·g^-1 (7.3-86ng·g^-1) . PCBs concentrations varied from 61 to 810ng·g^-1, with an average of 325ng·g^-1 on a lipid weight basis. The concentrations of HCHs and DDTs in samples from Jinju were significantly higher than in those from Seoul. However, this is probably due to a fact that the former group was relatively older than the latter. Furthermore, there was no characteristic difference in HCB and PCB residues in the geographic population. The lack of regional differences of organochlorine compounds in Koreans was estimated to be probably due to the uniform food supply.
The residue levels of organochlorine compounds in human milk samples from Masan were found in the order of a magnitude of DDTs (mean; 287ng·g^-1), PCBs (220ng·g^-1), HCHs (57ng·g^-1) and HCB (12ng·g^-1) . A similar tendency was seen in the concentrations of these compounds in the adipose samples. The average daily intake of organochlorines via human milk by a baby weighing 5kg was calculated based on the analytical data and assuming a daily consumption of 800ml breast milk with 3% fat. The amounts of organochlorine pesticides and PCBs were all lower than the acceptable daily intakes proposed by FAO/WHO which for lindane, HCB and DDT are 12.5, 5 and 0.6g/kg body weight/day, respectively.

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Non-conjugated natural and synthetic estrogens (estrone: E1, alpha-estradiol: a-E2, betaestradiol: b-E2, ethynylestradiol: EE2, mestranol: Me, estriol: E3) in discharge of sewage plant (DSP) and river water were preconcentrated by solid-phase extraction using a reversed-phase C18 disk, and cleaned up by silica-gel cartridge. They were derivatized with TMS, and the products were analyzed by GC/MS used widely. The products were stable for 30 days at 25°C. Range of mean recoveries of six estrogens from eight samples (six DSP samples and two river water samples) were 76.9-111% and range of RSD as repeatability from one DSP sample were 0.9-8.9% at spiking levels of 105 (E1) and 5 (others) ng/l. Range of recovery of E2-d4 as surrogate from twenty samples was 53.6-120% (average: 84.5%) . These estrogens can be detected in concentrations below 0.5ng/l. This method has been successfully applied to the analysis of DSP and river water. E1, a-E2, b-E2, EE2 and E3 were detected in river water. E1, a-E2, b-E2 and E3 were detected in DSP, a maximum concentration was found for E1 with 89ng/l. No Me was detected in all investigated samples.

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The heating decomposition (120°C, 30min) with peroxodisulfate is often used for the determination of total nitrogen and total phosphorus in environmental water. Potassium peroxodisulfate can oxidize water under UV irradiation even at room temperature and this oxidation condition was applied to the pretreatment for the determination of total nitrogen and total phosphorus in water in stead of the heating decomposition. The UV irradiation time for total nitrogen were 20minutes for inland water and 40minutes for seawater.
The difference of yield percentage of nitrate ion for the five nitrogen-containing compounds by both decomposition methods were within 8%.
The determinatin of total phosphorus in seawater was also studied by using the UV irradiation decomposition method.

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A simple method using liquid chromatography with tandem mass spectrometry (LC/MS/MS) has been developed for the determination of individual nonylphenol polyethoxylate surfactants (NPnEO) in river waters and discharges of sewage treatment plants. Quantification limits of individual NPnEO (n=2-17) were less than 2ng/l and 10ng/l in river waters and discharges of sewage treatment plants, respectively. The recoveries of NPnEO were 70.7-86.2% in river water and 40.0-67.0% in the discharge of sewage treatment plant.
This method was applied for determination of NPnEO in Tamagawa river water and discharges of sewage treatment plants. Over 95% of total NPnEO (n=2-17) in discharges of sewage treatment plants were found as NPnEO (n=2-6) . On the other hand, the NP9EO constituted the most abundant NPnEO in Tamagawa river water. These results suggested that the discharges of sewage treatment plants were unlikely major source of NPnEO in Tamagawa river water.

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