[Show abstract][Hide abstract] ABSTRACT: The atmospheric concentrations of both gas-phase and particulate-phase polycyclic aromatic hydrocarbons (PAHs) including 16 US Environmental Protection Agency priority PAHs (16 PAHs) were measured in eleven cities across Japan. Using the measured average concentrations and toxic equivalency factors (TEF) of the 16 PAHs, the benzo[a]pyrene (BaP)-toxic equivalent for eight major PAHs was obtained: the ratio of BaP to the eight major PAH toxicities ranged from 0.23 to 0.47. Among the target PAHs, from the viewpoint of carcinogenicity, we focused on benzo[c]fluorene (BcFE), which was detected in both the gas and particulate phase in contrast to BaP. The relative potency factor (RPF) of BcFE was evaluated as 6.46 based on its cancer slope factor relative to that of BaP determined in the benchmark dose calculations for mice. The relative carcinogenic risk of BcFE to BaP was obtained by multiplying the averaged concentrations of BaP and BcFE by the RPF value: the risk of BcFE was 6.8 and 5.1 times higher than that of BaP in summer and winter, respectively. These results show that the collection of atmospheric samples including the gas phase is important when assessing the carcinogenic risk of atmospheric PAHs.
Preview · Article · May 2015 · Atmospheric Environment
[Show abstract][Hide abstract] ABSTRACT: There are fewer studies on the degradation of polyaromatic hydrocarbons (PAHs) by fungi than those by bacteria. Three fungi (strains A, B, and C), which could grow on pyrene as the sole source of carbon, were isolated from soils at the side of a freeway, a gas station, and a lake in Japan. Strain A was tentatively classified as members of the Trichoderma/Hypocrea genus, and both strains B and C were classified as belonging to the Fusarium genus on the basis of their base sequence of 18S ribosomal DNA and morphological characteristics. After an incubation period of 7 and 14 days at 28°C in an inorganic Czapek-Dox medium with PAHs as the substrate, both strains A and B assimilated anthracene and fluoranthene, whereas strain C assimilated neither of them. The pyrene-degrading activity and the growth of strain A improved by adding 0.02% yeast extract, 0.1% sucrose, or 0.1% lactose. The pyrene-degrading activity was also found to be more effective at pH 4 rather than at pH 6.5.
No preview · Article · Nov 2014 · Polycyclic Aromatic Compounds
[Show abstract][Hide abstract] ABSTRACT: We used a high-volume air sampler in the summer of 2007 and the winter of 2008 at ten Japanese sites (Sapporo, Sendai, Maebashi, Tsukuba, Shinjuku, Sagamihara, Shizuoka, Touhaku, Kitakyushu, and Kagoshima) to collect total suspended particulate (TSP) and gaseous matter for evaluation. We evaluated the transformation frequency at the tumor promotion stage of these samples in a cell transformation assay using Bhas 42 cells, which were established from BALB/c 3T3 cells transfected with the v-Ha-ras oncogene. All samples collected from the gaseous matter were negative for transformed foci. There were several patterns of transformation frequency at the tumor promotion stage by area for the TSP samples. At Sapporo, the transformation frequency at the tumor promotion stage was remarkably higher in winter than in summer as well as in winter at the other sites. At six urban cities from Sendai to Shizuoka, the levels of transformed frequencies per μg of suspended particulates in winter were almost the same, and were higher than those of the remaining three sites. At three sites, Touhaku, Kitakyushu and Kagoshima, the transformation results in winter were judged as negative. The characteristics of the transformed frequencies of the compounds adsorbed on particulate matter at the sampling sites were significant in winter. We also studied the correlation between the transformation frequency at the tumor promotion stage of the TSP samples and the results of quantitative analysis of 16 polyaromatic hydrocarbons (PAHs) at the ten sites. We found that the transformation frequency at the tumor promotion stage of airborne samples could not be predicted based on the quantitative results of the PAHs in those samples. These data suggest that direct risk assessment of air samples with a bioassay is more valuable than quantitative analysis of compounds such as PAHs for predicting carcinogenicity.
No preview · Article · Apr 2013 · Environmental Sciences: Processes and Impacts
[Show abstract][Hide abstract] ABSTRACT: In 2007, samples of treated effluent were collected at point of discharge to the environment from 39 wastewater treatment plants (WWTPs) located across Victoria, Australia grouped by treatment type. Sample genotoxicity was assessed with a high-throughput luminescent umu test method using Salmonella typhimurium TL210 strain, with and without addition of a commercially available metabolic activation system. Samples were also screened using a gas chromatographic-mass spectrometric mass-structure database recognition method. A genotoxic response was observed in half of the samples tested without metabolic activation system (<LOR - 0.19 μg/L 4-nitroquinoline-N-oxide equivalents). On addition of metabolic activation system, 75% of samples elicited a genotoxic response, the majority of responses were stronger than without metabolic activation (<LOR - 2.97 μg/L benzo[a]pyrene equivalents). The type of WWTP had no effect on genotoxicity. A large number of chemicals were identified in the effluents, although none could be unambiguously tied to the genotoxicity observed. Chemicals observed in one or more effluents included food additives (e.g. dibenzylether), various alkyl phenols, tyre leachates (e.g. 2(3H)-benzothiazolone), antioxidants, flame retardants (e.g. tris(2-chloroethyl)phosphate), insect repellents (e.g. diethyltoluamide), stimulants (e.g. caffeine) and anticonvulsants (e.g. carbamazepine). Of the 451 pesticides screened, carbamate insecticides (e.g. bendiocarb, propoxur), plant growth regulators (e.g. propham) and herbicides (e.g. atrazine, metolachlor, simazine) were amongst the compounds observed.
[Show abstract][Hide abstract] ABSTRACT: Abstract The genotoxic effects of multi-walled carbon nanotubes (MWCNTs) were examined by using in vitro and in vivo assays. MWCNTs significantly induced micronuclei in A549 cells and enhanced the frequency of sister chromatid exchange (SCE) in CHO AA8 cells. When ICR mice were intratracheally instilled with a single dose (0.05 or 0.2 mg/animal) of MWCNTs, DNA damage of the lungs, analysed by comet assay, increased in a dose-dependent manner. Moreover, DNA oxidative damage, indicated by 8-oxo-7,8-dihydro-2'-deoxyguanosine and heptanone etheno-deoxyribonucleosides, occurred in the lungs of MWCNT-exposed mice. The gpt mutation frequencies significantly increased in the lungs of MWCNT-treated gpt delta transgenic mice. Transversions were predominant, and G:C to C:G was clearly increased by MWCNTs. Moreover, many regions immunohistochemically stained for inducible NO synthase and nitrotyrosine were observed in the lungs of MWCNT-exposed mice. Overall, MWCNTs were shown to be genotoxic both in in vitro and in vivo tests; the mechanisms probably involve oxidative stress and inflammatory responses.
[Show abstract][Hide abstract] ABSTRACT: As part of research on the method of collecting soil samples for mutagenicity measurement, a map of the former Sagamihara City was divided into a square mesh by drawing lines along every latitudinal minute and longitudinal minute. 40 surface soil samples were collected at the intersection points on the map, and the mutagenicity of the samples was examined by the Ames preincubation method using Salmonella typhimurium TA98 and TA100 strains. It was found that the average mutagenicity was 47 rev/g of soil when TA98 was used without S9mix, 87 rev/g of soil when TA98 was used with S9mix, 11 rev/g of soil when TA100 was used without S9mix, and 152 rev/g of soil when TA100 was used with S9mix, all of which were lower than the values reported in past documents, and were approximately the same as values obtained in the countryside. To provide an overview, the geographical distribution of specific mutagenic activity was examined. As a result, mutagenic substances easily detectable with TA98 strain (inducing frame shift type mutations) were found mostly in the center of the former Sagamihara City, whereas mutagenic substances easily detectable with TA100 strain (inducing base pair substitution type mutations) were found to have spread over the whole of Sagamihara City. In order to look for hot spots, and in order to understand the distribution of mutagenicity, a sampling plan using non-arbitrary selection of sites as in the present study was effective.
[Show abstract][Hide abstract] ABSTRACT: A pilot study was initiated to provide the first information on the recombinant receptor-reporter gene bioassay (hormonal) activity of freshwaters in Victoria. The project involved the collection of water samples from six stations on the main stem of the Yarra River in and upstream of the city of Melbourne, Australia in April 2008 and April 2009. Samples were prepared for measurement of sample toxicity using a modified photobacterium test, genotoxicity using a high-throughput luminescent umu test method, and human and medaka estrogen receptor (hERα and medERα), retinoic acid receptor (RAR), aryl hydrocarbon receptor (AhR) and thyroid receptor (TR) assay activity using the relevant yeast-based bioassays. Most samples were only weakly or moderately toxic, with no relationship observed to location along the river. The data for 2008 suggests that at that time the Yarra River samples contained few compounds that were, in and of themselves, genotoxic. No estrogenic or thyroid, and <1 ng/L retinoic acid receptor activity was observed. AhR activity increased with progressed downstream. AhR activity was higher in April 2009 than at the same time in 2008, perhaps as a result of extensive bush fires in the catchment in the months immediately prior to sampling. About 24% of the total AhR activity observed was associated with suspended solids.
Full-text · Article · Sep 2011 · Bulletin of Environmental Contamination and Toxicology
[Show abstract][Hide abstract] ABSTRACT: Nanomaterials are being utilized for many kinds of industrial products, and the assessment of genotoxicity and safety of nanomaterials is therefore of concern. In the present study, we examined the genotoxic effects of fullerene (C60) and kaolin using in vitro and in vivo genotoxicity systems. Both nanomaterials significantly induced micronuclei and enhanced frequency of sister chromatid exchange (SCE) in cultured mammalian cells. When ICR mice were intratracheally instilled with these nanomaterials, DNA damage of the lungs increased significantly that of the vehicle control. Formation of DNA adducts in the lungs of mice exposed to nanomaterials were also analyzed by stable isotope dilution LC-MS/MS. 8-Oxodeoxyguanosine and other lipid peroxide related adducts were increased by 2- to 5-fold in the nanomaterial-exposed mice. Moreover, multiple (four consecutive doses of 0.2 mg per animal per week) instillations of C60 or kaolin, increased gpt mutant frequencies in the lungs of gpt delta transgenic mice. As the result of mutation spectrum analysis, G:C to C:G transversions were commonly increased in the lungs of mice exposed to both nanomaterials. In addition, G:C to A:T was increased in kaolin-exposed mice. In immunohistochemical analysis, many regions of the lungs that stained positively for nitrotyrosine (NT) were observed in mice exposed to nanomaterials. From these observations, it is suggested that oxidative stress and inflammatory responses are probably involved in the genotoxicity induced by C60 and kaolin.
No preview · Article · Jan 2011 · Genes and Environment
[Show abstract][Hide abstract] ABSTRACT: There are many gaseous air pollutants found in indoor air. It is very important to precisely measure the concentration of these compounds in order to evaluate the risk to human health and to reduce their concentrations. A diffusive sampling device is suitable for measurement of indoor air, because these are small, light, and can be used without a power supply for the pump. In this study, representative gaseous air pollutants in winter indoor and outdoor air were measured using diffusive sampling devices. Furthermore, the relationship between gaseous air pollutants, secondary formation mechanism, and the outbreak source were examined. The indoor concentrations of aldehydes, nitrogen dioxide and ammonia were higher than outdoor concentrations. By contrast, indoor concentrations of ozone were lower than outdoor concentrations. The indoor concentrations of nitrogen dioxide in 43% houses exceeded the maximum limit stated by environmental law (60 ppb). It was suggested that the main emission sources of nitrogen dioxide are kerosene and gas stoves. In addition, it was suggested that carbonyl compounds are formed by interactions between volatile organic compounds (VOCs) and ozone from outdoor air. Formic acid was estimated to be formed by the oxidation of formaldehyde with ozone, because a positive correlation between formaldehyde and formic acid, and an inverse correlation between formaldehyde and ozone, were observed in indoor air.
[Show abstract][Hide abstract] ABSTRACT: By using an Andersen sampler equipped with a low-pressure impactor, samples of 12 size-classified (>0.13 μm to <12 μm) airborne particles and samples of gaseous components were taken from the air in Tokyo for continuous periods of 19 weeks in the summer of 2001 and 17 weeks in the winter of 2001–2. The sampling filters were changed weekly. The concentrations of eight polycyclic aromatic hydrocarbons (PAHs) in the particulate and gas-phase samples were measured by reverse-phase high performance liquid chromatography (HPLC) with fluorescence detection. Pyrene was detected in the gas phase in both summer and winter: 59% of the total pyrene detected was present in the gas phase in summer, but this fraction decreased to 40% in winter. In the particle fractions, the summer levels of benzo[k]fluoranthene (BkF), dibenz[a,h]anthracene (dBahA), and benzo[a]anthracene (BaA) peaked in particles of diameter 1.25 μm, and benzo[ghi]perylene (BghiP), benzo[a]pyrene, benzo[b]chrysene (BbC), and dibenzo[a,e]pyrene (dBaeP) peaked in particles of diameter 0.76 μm. In winter, BkF, BghiP, BaA, BbC, and dBaeP levels peaked in particles of diameter 0.52 μm, whereas dBahA peaked in particles of diameter 0.76 μm.
No preview · Article · Aug 2010 · Polycyclic Aromatic Compounds
[Show abstract][Hide abstract] ABSTRACT: To estimate human exposure to hazardous chemicals, it is important to measure the annual trends regarding the concentrations of these compounds in the environment. Airborne particulate samples were collected over the past 20 years (1980–2001) from ambient air using a quartz fiber filter with the help of a high-volume air sampler placed on the top of the National Institute of the Public Health building, Minato-ku, Tokyo, Japan. In the present study, portions of these filter samples were analyzed to investigate the trends regarding the concentration of PAHs in urban air over the sampling period. The concentrations of various PAHs per unit air volume were determined. The concentrations of seven PAHs decreased within the sampling periods, especially in the late 1980s, and slowly decreased from the middle 1990s. The concentrations of seven PAHs were higher in autumn and winter than in the spring and summer.
No preview · Article · Aug 2010 · Polycyclic Aromatic Compounds
[Show abstract][Hide abstract] ABSTRACT: Poly aromatic hydrocarbons (PAHs) and mutagenic compounds were adsorbed on Blue Rayon (BR) to monitor the pollution level of the surface seawater of the East and South China Seas by continuous sampling of seawater along the ship lane of our research and training vessel Umitaka-Maru. Eluted PAHs from BR were quantitatively determined by HPLC and their total amount in each sample ranged between 30.40 and 120.29 ng per liter of seawater, showing a difference of about 4 times among 8 samples. Acenaphthylene, naphthalene, and benz(a)anthracene were the most common PAHs found in the East and South China Seas, however, no big difference was observed in the concentrations of PAHs distributed throughout those two closed seas. Mutagenicity was detected as pseudo-positive from three samples. Among them, one sample collected along the east edge of the East China Sea showed a strong direct cytotoxicity which interrupted the mutagenicity test.
Full-text · Article · Feb 2010 · Estuarine Coastal and Shelf Science
[Show abstract][Hide abstract] ABSTRACT: To clarify the effect of indoor air pollutants on nerve growth factor (NGF) production in lung, male C3H/HeN mice were exposed to filtered air (control) or toluene at levels of 0.9 ppm, 9 ppm, or 90 ppm for 30 min via nose-only inhalation on days 0, 1, 2, 7, 14, 21, 28, 35, 42, 49 and 56. As an allergic mouse model, some mice (n=24) were immunized with ovalbumin. Lungs from each mouse were collected to determine NGF and related receptor expressions using real-time reverse transcription polymerase chain reaction (RT-PCR) analysis. NGF and TrkA mRNAs were increased in the lungs of the immunized mice following exposure to 9 ppm toluene (n=6) (P<0.05 ppm vs. 0 ppm). Remarkably increased NGF-positive bronchiolus and alveolar epithelium cells were observed in 9 ppm toluene-exposed, immunized mice. To determine NGF mediating signaling, we also examined mRNA expression of neurotrophin receptor p75 (p75(NTR)) and oxidative stress marker, heme oxygenase (HO)-1 in the lung. There is no difference in the expressions of p75(NTR) and HO-1 between toluene-exposed and control mice. The expression of CCL2 and CCL3 mRNAs was significantly elevated in 9 ppm toluene-exposed, immunized mice. These findings suggest that the exposure with volatile organic compounds enhanced NGF expression and airway inflammation stronger in allergic individuals than in healthy individuals.
No preview · Article · Sep 2009 · Toxicology Letters
[Show abstract][Hide abstract] ABSTRACT: 3,6-Dinitrobenzo[e]pyrene (3,6-DNBeP) is an extremely strong bacterial mutagen, and was recently identi-fied in highly mutagenic surface soil samples. In a previous study, a sensitive analytical method was developed using high-performance liquid chromatography (HPLC) and fluorescence detection. In this study, we analyzed 3,6-DNBeP in surface soil, airborne particles, diesel particles, and incinerator dusts using this analytical method to reveal the distribution of 3,6-DNBeP in the environment. 3,6-DNBeP was detected in all surface soil samples, and the mutagenic contribution ratio of 3,6-DNBeP to the mutagenicity of the soil extracts toward Salmonella (S.) typhimurium TA98 was 17.3% on average. A positive correlation was observed between the mutagenicity of sur-face soil and the amount of 3,6-DNBeP (r = 0.8653). 3,6-DNBeP was detected in airborne particles in the range of 19–76 fg/m 3 . The particle-size-distribution ratios of 3,6-DNBeP in <1.1, 1.1–2.0, 2.0–3.3, 3.3–7, and >7 µm of airborne particles were 13.1%, 13.8%, 37.0%, 19.1%, and 17.0%, respectively. 3,6-DNBeP was detected in diesel particles from general automobiles and industrial forklifts, and incinerator dusts. These results suggested that 3,6-DNBeP was a major mutagen in surface soil, and diesel engines and incinerators were possible sources of 3,6-DNBeP distributed in surface soil and air. This is the first report on the detection of 3,6-DNBeP in diesel particles and incinerator dusts.
Preview · Article · Aug 2009 · Journal of health science
[Show abstract][Hide abstract] ABSTRACT: We investigated the behavior of mutagenic substances in the soil of forests or planted areas. Mutagenicity and concentration was examined for 16 types of PAHs in soil samples collected at a depth of 1 m in 10 forests in Iwate, Ibaraki, Tokyo, Kanagawa, Yamanashi and Shizuoka prefectures in Japan. Mutagenicity and PAHs were detected mostly in soil from the surface to a depth of 30 cm when strains TA100, TA98 and YG1024 were used. In addition, a significant correlation was not found between the concentration of BaP, and specific mutagenic activity (TA98 without S9mix, r = 0.285).
No preview · Article · Aug 2009 · Bulletin of Environmental Contamination and Toxicology
[Show abstract][Hide abstract] ABSTRACT: Based upon the Framework Convention on Tobacco Control (FCTC), the World Health Organization (WHO) ha sr ecommended that health authorities disclose toxicological properties of cigarette mainstream smoke (MSS) obtained not only according to US Federal Trade Commission (FTC)/International Organization for Standardization (ISO) conditions but also by more intense conditions such as the Health Canada Intense (HCI) condition. This is because smokers are believed to smoke more intensely than machine smoking under the ISO regimen. Because there are no previous reports on the toxicological properties of MSS of Japanese cigarettes under the HCI condition, we determined nicotine and water contents by gas chromatography (GC-MS and GC/Thermal Conductivity Detector (TCD)) for three product lots each of the ten bestselling brands of Japanese cigarettes following the WHO protocol. One of the three lots of each MSS condensate was also resolved in dimethylsulfoxide and investigated by Ames preincubation assay using Salmonella typhimurium TA100, TA98, and YG1024 strains with and without metabolic activation (rat liver S9 mix). Nicotine and tar yields with the HCI regimen were higher than those with ISO, the latter being very close to the values described on the packages of each cigarette brand. Mutagenicity was mainly observed in TA98 and YG1024 with metabolic activation. Mutagenic activity of MSS with the HCI regimen was 1.4-9 times higher than that with the ISO regimen. Based on YG1024 with activation, high activities were observed in several "low yield" brands. The activity of "low-yield" brands with the HCI regimen was not always lower than that of regular-yield brands with the ISO regimen. These results suggest that "low yield" cigarettes do not result in reduced exposure or reduced risk to humans.
Preview · Article · Jun 2009 · Journal of health science