Carp (Cyprinus carpio L.) was exposed to perfluorinated compounds (PFCs)-perfluoroalkyl carboxylic acids (number of carbon atoms, C = 8, 11, 12, 14, 16, and 18) and perfluorooctane sulfonate (PFOS)-in bioconcentration tests to compare the bioconcentration factors (BCFs) and physicochemical properties of each specific compound. Despite having the same number of carbon atoms (C = 8), the BCFs of perfulorooctanoic acid (PFOA) and PFOS differed by more than two orders of magnitude (PFOA BCF = < 5.1 to 9.4; PFOS BCF = 720 to 1300). The highest BCFs were obtained from perfluorododecanoic acid (BCF = 10,000 to 16,000) and perfluorotetradecanoic acid (BCF = 16,000 to 17,000). The longest observed depuration half-lives were for perfluorohexadecanoic acid (48 to 54 days) and PFOS (45 to 52 days). The concentrations of PFCs were highest in the viscera, followed by the head, integument, and remaining parts of the test fish. PFCs concentrations in the integument, which was in direct contact with the test substances, were relatively greater than that of other lipophilic substance (hexachlorobenzene). It is likely that Clog P would be a better parameter than log K (ow) for the prediction of BCFs for PFCs. Threshold values for PFCs bioaccumulation potential (molecular weight = 700, maximum diameter = 2 nm) seemed to deviate from those generally reported because of the specific steric bulk effect of molecule size.

Existing regulatory criteria for bioaccumulation assessment of chemicals are mainly based on a bioconcentration factors (BCF) not a biomagnification factors (BMF). We performed dietary exposure tests for nine poorly water-soluble chemicals and developed a linear regression between the 5 % lipid normalized BCF (BCF(L)) and the lipid-corrected BMF (BMF(L)). The BMF(L) of substances with BCF(L) = 5,000 was 0.31 (95 % CI 0.11-0.87), whereas the BCF(L) of substances with BMF(L) = 1 was 13,000 (95 % CI 5,600-30,000). Five substances can be considered very bioaccumulative (vB) according to the BCF end point (BCF > 5,000), but only two substances were recognized to biomagnify according to the BMF end point (BMF ≥ 1). Although our results are highly suggestive of a relationship between BCF and BMF, additional BMF and trophic magnification factor data for chemicals are required to support this relationship, and new techniques (e.g., fugacity approach) may help in resolving the apparent contradiction in hazard categorization.

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CBA/J and CBA/Ca mice are the recommended strains for local lymph node assays (LLNAs). Here, we report quantitative and qualitative comparisons between both mouse strains to provide useful information for the strain selection of sensitization testing. LLNA was conducted, in accordance with Organisation for Economic Co-operation and Development Test Guideline No. 429, with CBA/J and CBA/Ca mice using five chemicals including typical contact sensitizers and non-sensitizers: 2,4-dinitrochlorobenzene (DNCB), isoeugenol, α-hexylcinnamic aldehyde (HCA), propylene glycol (PG), and hexane; then outcomes were compared based on the raw data (disintegrations per minute, DPM), stimulation index (SI) values, EC3 values and positive/negative decisions. Although a significant difference was noted between DPM values derived from each strain of mice, SI values exhibited no considerable difference. The EC3 values for DNCB in CBA/J and CBA/Ca mice were 0.04 and 0.03, those for isoeugenol were 1.4 and 0.9, and those for HCA were 7.7 and 6.0, respectively. All EC values derived from each test system were almost equivalent and were within the range of acceptance criteria of the ICCVAM performance standard for LLNA. Positive/negative outcomes for all test chemicals were consistent. In conclusion, no considerable differences were observed in the final outcomes derived from CBA/J and CBA/Ca mice in LLNA. Copyright © 2015 John Wiley & Sons, Ltd.

Tetramethylammonium hydroxide (TMAH) , which is mainly used in the manufacturing process of semiconductors and liquid-crystal panels, is not subject to effluent regulation under the Water Pollution Control Law. Therefore, the possibility is not excluded that some portion of TMAH used is released into the environment, and the effects of TMAH on aquatic organisms are of concern. In this study, we conducted reproduction tests with Ceriodaphnia dubia and short-term toxicity tests on embryonic and sac-fry stages of zebrafish to set a management target value of TMAH concentration in wastewater. As a result, the concentrations yielding no observed effect on Ceriodaphnia dubia and zebrafish were 0.0158 and 500 mg L-1 , respectively, indicating a high sensitivity of Ceriodaphnia dubia to TMAH. Therefore, given that the dilution ratio of wastewater in public water bodies is 10 times, the TMAH concentration in wastewater discharged directly from a factory site to public waters should be managed to be below 0.158 mg L-1 in consideration of the protection of aquatic organisms.

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