Application of biological safety index in two Japanese watersheds using a bioassay battery

Self Cite

The objective of this study was to assess the biological safety and river health in an actual river and to clarify their relationship. In this study, "biological safety" meant safety level of contaminants in river water to aquatic creatures, which was evaluated by performing various bioassays. "River health" meant conditions of water quality and biodiversity from a viewpoint of benthic macroinvertebrate assemblages, which was desired by humans. At nine sites on the Sakawa River system (Japan), biological safety was evaluated as a toxicity score and bio-safety rank (BSR) using an algae growth inhibition test, a daphnia immobilization test, and a larval medaka assay. According to the result, the biological safety was found to be completely different among the sampling sites and the test species. River health was evaluated according to the Ministry of the Environment (MOE) of Japan water quality and biodiversity (taxa number) at the nine sites. According to the result, the number of taxa were found to be completely different among the sites. The results of the bioassays and macroinvertebrate collections were compared and indicated that the number of taxa and BSR described similar behavior when going downstream, although no clear correlation was found between BSR and MOE-water quality class. Therefore, biodiversity tended to deteriorate as the intensity of toxicity became more severe.

Section: Preparation Of River Water Samples For Toxicity Testingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Evaluation of Relationship Between Biological Safety and Benthic Macroinvertebrate Assemblages in the Sakawa River System, Japan

Kubo

Wei

Kisuno

et al. 2011

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“…The sample water was adjusted to pH 2.0 ± 0.2, and 1,500 mL of sample water was loaded into the pre-conditioned Sep-Pak ® Plus PS-2 (Nihon Waters K.K., Tokyo, Japan) cartridge at an upflow rate of 20 mL/min. This cartridge adsorbs various organic micropollutants in water (Ishii et al, 2000) and has been widely used to recover chemicals from complex environmental water samples (Liu et al, 2007;Wei et al, 2008;Kubo et al, 2011). Air was injected into the cartridge with a syringe to drive out the water.…”

Section: Sample Preparationmentioning

confidence: 99%

Quantitative Evaluation of the Genotoxic Activity of Japanese Tap Water Using the Umu Test

Kubo

Wang

Kameya

et al. 2015

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The genotoxicity of Japanese tap water was investigated using the umu test in order to clarify the relative and absolute genotoxic levels. Samples were collected at 25 sites in Japan and the umu test was carried out with concentrated solutions. The values of genotoxic activity (GA) varied significantly from less than 72 to 670 ng 4NQO/L depending on the site location and/or sampling period. Typical GA value among the tested tap water samples was around 200 ng 4NQO/L. According to a roughly estimated safety level, it was shown that the genotoxicity level of the tested tap water was not negligible. A comparison of the results of the present study with those of a previous investigation using Ames mutagenicity test indicates that the genotoxic level of Japanese tap water did not decrease significantly between the two investigations. In addition, it was shown that there was a weak positive correlation between the genotoxicity of the tap water and the value of the total organic carbon content.

“…These values of the concentration factors were established by statistically comparing the values of the data set for acute and chronic ecotoxicity at 80% or higher confidence level (Wei et al, 2006). If no adverse ecotoxicity effects were observed for all the three tests at each concentration factor, the water sample could be considered harmless for the aquatic ecosystem in the site (Wei et al, 2008). …”

Section: Preparation Of Samples For Analysismentioning

confidence: 99%

Ecological Assessment of Water Quality by Three-species Acute Toxicity Test and GC/MS Analysis - A Case Study of Agricultural Drains -

Kameya

Yamazaki

Kobayashi

et al. 2010

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The water quality of environmental waters from the viewpoint of aquatic ecotoxicity was investigated using a three-species ecotoxicity test (algae, daphnia and fish). Water samples were collected, concentrated with a solid-phase extraction technique and exposed to each test species. The growth inhibition, immobilization (swimming inhibition) and mortality ratios in acute toxicity tests for algae, daphnia and fish, respectively, were used as water quality indexes. For the river waters, 38% of the monitoring sites showed good water quality from the viewpoint of long-term ecotoxicity for all the three test species because no toxicity effects were observed at the concentration factors of 10, 50 and 50 for algae, daphnia and fish, respectively. For the agricultural drains, the ecotoxicity level responded sensitively especially when agricultural chemicals were applied. The GC/MS analysis also confirmed that the detection index (DI) in the agricultural drains was often raised significantly by the agricultural chemicals, but the period with high ecotoxicity did not continue for long.