Enzyme activity of the white rot fungus Phaneroeheate chrysosporium and the degradation activity for refractory organic compounds was studied. Experiments were conducted under ligninolytic (low-nitrogen) and non-ligninolytic (high-nitrogen) culture conditions with Basal III medium containing glucose as a carbon source and ammonium tartrate as a nitrogen source. Under both high-nitrogen and low-nitrogen conditions, lignin peroxidase (LiP) activity was sufficiently produced. The level of LiP activity reached the peak and was decreased more slowly by added matter such as veratryl alcohol (VA) and nonionic surfactant (Tween-80) than nitrogen and oxygen level. However, the formation of manganese-dependent peroxidase (MnP) activity was more affected by the nitrogen level than that of LiP activity. Degradation activities for three organochlorine compounds, one organochlorine pesticide and two PAH were observed under ligninolytic and non-ligninolytic conditions. For example, the degradation of phenanthrene and γ-BHC was observed under ligninolytic as well as non-ligninolytic conditions. This indicates that LiP and MnP are not essential for the degradation of the compounds by this fungi. It is also demonstrated that the potential of P. chysosporium for degradation of certain environmental pollutants is more affected by added matters than limited nutrient starvation conditions.

View full abstract

The application of cherry tree leaves (Cerasus yedoensis) as a indicator for air pollution by PCDD/Fs was investigated. Adsorption and desorption rates of PCDD/Fs were in equilibrium between cherry tree leaves and ambient air during growing periods of cherry tree leaves. However, the concentrations of cherry tree leaves also varied slightly in the periods. This may be caused by the several conditions such as the temperature of ambient air. Consequently, the mean values of PCDD/Fs in the leaves determined in a long term (one month) was used in order to reduced the fluctuation of the concentration affected by the atmospheric conditions. As the results, high relationships between the concentration of PCDD/Fs in cherry tree leaves and in ambient air were obtained. Those results indicated that the concentrations of PCDD/Fs in cherry tree leaves reflected the ambient air concentration during growing periods of cherry tree leaves and cherry tree leaves are a useful indicator for air pollution monitoring of PCDD/Fs.

View full abstract

Leachate samples from 2 adjacent municipal waste disposal sites (n=7 each), water samples from a stream which runs nearby the sites (n=7), and precipitation (n=12) of the area were collected over 15 months period beginning from November 1997. Boron concentrations in the water samples were measured by ICP atomic emission spectrometry and ICP mass spectrometry to estimate input and output of boron at the sites. Median boron concentration in the leachates (1.3 mg/l for both of the sites) was 600 times higher than that in precipitate (0.0021 mg/l) indicating leaching of boron from the waste disposed. Median concentration in the stream water was intermediate (0.062 mg/l) and it indicated that boron from natural origin alone can increase the concentration by a factor of 30. Annual input of boron to the sites was estimated by the median boron concentration in the precipitate and the site area. The output was by boron concentration in the leachates and annual leachate treatment volume. Annual input of 350 g and output of 62000 g was obtained and the output input ratio was calculated to be 180 being less than that of alkali metals (>3000), and similar to that of alkaline earths. These results indicate that the disposed waste does release boron into the leachate but the magnitude of the release is similar to, or less than, that of other elements.

View full abstract

Analytical accuracy and storage stability on both passive sampling and pressurized sampling into canisters for volatile organic compounds (VOCs) in air are described in this paper. Forty four kinds of VOCs including polar volatile organic compounds (PVOCs) were examined. The VOCs except a few polar chemicals were relatively stable in canisters and had high analytical accuracy and precision. Compared with these two sampling methods in chamber tests and field measurements, both results derived from the passive sampling and pressurized sampling methods were in fair agreement for non-polar chemicals. However, the PVOCs did not give concordant results in both duplicated measurements and parallel measurements and showed high variability. These results may be due to adsorption of the PVOCs to flow path in the sampling apparatus.

View full abstract

We analyzed the occurrence and effects of endocrine-disrupting chemicals in 2 species of frog, Yama-aka-gaeru (Rang ornativentris) and Nihon-aka-gaeru (Rang japonica), and in water and soil samples. Our aim was to determine the cause of malformation in Yama-aka-gaeru frogs that had been found with extra forelimbs. Frogs, not including malformed ones, and soil samples were collected at 3 sites: the study site where the malformed frogs had been found, and 2 reference sites where only normal individuals of both frog species were observed. We also performed a histological examination of the gonads of the frogs. We found significant levels of DDTs and oxychlordane in both species and soils collected at the study site. These chemicals are persistent and bioaccumulative. We did not detect less-stable chemicals such as simazine and atrazine. High concentrations of benzo (a) pyrene were detected in the soil samples at the study site, but not in the frogs. In both species the chemicals we detected occurred at significantly higher concentrations in males than in females; this difference was probably caused by transference of chemicals to the eggs. The chemical concentrations that we detected in the frogs were lower than the lowest levels reported to cause adverse effects. However, there was a significant negative correlation between DDT concentrations and testis size, and aspermatogenesis was demonstrated in some of the Nihon-aka-gaeru frogs. We suspect that endocrine-disrupting chemicals present in the eggs affect early embryogenesis.

View full abstract

Toxic level of chemical contamination in the river waters in Tokyo was bioassayed using Microtox test, Ames Salmonella mutation test, Daphnia immobilization test and algal growth inhibition test over a period of 3 years. Though no serious toxicity was found, 60% of river water samples reached positive response level of toxicity. The Microtox test and the Ames test are useful to assess the total acute/geno-toxicity level of river water. The Daphnia immobilization test and the algal growth inhibition test indicate whether the chemical contamination in river water reaches toxic level for crustaceans and algae, respectively. And adaptation of river water to the guideline value is evaluated using both bioassays without chemical analysis. The combination of these bioassays, which have individual specific detection spectrum, is effective for the assessment and evaluation of chemical contaminants.

View full abstract

A rapid, and simple operational estrogenicity assay system using the yeast two-hybrid system was developed. The original agonist test was modified and implemented by two additional tests, metabolic activation test using rat liver S9 and antagonist test. Background signal was greatly reduced by using modified SD medium containing 0.2% dextrose. Simple semi-automatic “one plate” operation was realized became possible by adapting the 96-wells plate culture method and the chemiluminescent reporter gene assay method.
Agonist activity was evaluated by EC_x10, which was defined as the concentration where the ratio of the chemiluminescent signal of sample to that of blank control was 10-fold. Five steroidal hormones and diethylstilbestrol showed clear dose-response on agonist (-S9) test, and the lowest EC_x10 value was found to be 0.085nM on ethynylestradiol. The agonist test (+S9) of methoxychlor also showed clear dose-response with EC_x10 of 3, 000nM. The agonist activities were found in p-t-octylphenol (EC_x10: 67nM), p-nonylphenol (550nM) and bisphenol A (3, 500nM), and the metabolites of benzo (a) pyrene (1, 800nM), pyrene (5, 100nM), and 1-nitropyrene (12, 000nM) . IC₅₀, which is defined as 50% inhibition of 17 β-estradiol (b-E2) activity, was calculated on antagonist test, and 4-hydoxy-tamoxifen showed IC₅₀ of 2, 400nM. The antagonist activities of tetrabromobisphenol A (IC₅₀: 820nM) and pretilachlor (41, 000nM) were also suggested.
This system was successively applied to the samples such as environmental waters and waste landfill leachate. It was shown that the estrogenic activity of Lake Kasumigaura water could be detected as low as sub ppt levels (as b-E2) by agonist (-S9) test. In addition, quality control guideline using microtox test was proposed.

View full abstract

We examined test condition in the yeast two-hybrid based estrogen assay, and established a simplified method using a microtiter plate. We also discussed the quantification of estrogenic activity evaluation. Incubation for 18 hours without shaking was adequate for this assay. The cell wall of the yeast was broken more readily by treatment with zymolyase than with chloroform and SDS, the former treatment producing high sensitivity and reproducibility. A simplified assay method using a microtiter plate and requiring no operations such as centrifugation was established. We found that the dose response curve between the estrogenic chemicals and activity was regressed by Hill's equation, and proposed a quantitative evaluation system for estrogenic activity based on the activity of 17-β-estradiol.

View full abstract

Twenty-two plastic films for food-wrapping were investigated for elution of nonylphenols (NPs) and bisphenol A (BPA) with distilled water. The plastic films investigated were seven polyethylene films, one polyethylene polypropylene film, two polyolefin films, one polypropylene nylon film, two polymethylpentene films, three polyvinylidene chloride films and six polyvinyl chloride films. Significant amounts of NPs were eluted in the range of 98-120ng/cm² from five polyvinyl chloride films, BPA of 30ng/cm² were also eluted from one of the five films. On the other hand, no NPs and BPA were eluted from the other plastic films investigated. Further more, the six polyvinyl chloride films were eluted with n-heptane for NPs and BPA. Although NPs amounts of 480-610ng/cm² eluted by n-heptane from the five polyvinyl chloride films were higher than those by distilled water, BPA amounts eluted were almost same to those by distilled water.

View full abstract