Environmental Monitoring and Contaminants Research
Online ISSN : 2435-7685
2 巻
選択された号の論文の12件中1~12を表示しています
Articles
  • Mahiro GOMI, Kaoruko MIZUKAWA, Hideshige TAKADA
    原稿種別: Article
    2022 年 2 巻 p. 1-13
    発行日: 2022年
    公開日: 2022/01/26
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    To analyze a wide range of phenolic endocrine disrupting chemicals, including alkylphenols, bisphenol A (BPA) and its analogues, triclosan (TCS), thymol, and phenolic UV filters, a direct acetylation method has been developed and applied to 116 river water samples and 40 sewage treatment plant (STP) effluent samples collected in 2016–2019 in Tokyo, Japan. This method can simultaneously derivatize a range of target chemicals to inert acetylates at an early stage in the analytical procedure. In this study, nonylphenol concentrations in the Tamagawa River (median 5.7 ng/L) and the Sumidagawa River (median 13.4 ng/L) were one order of magnitude lower than those 20 years ago. Similarly, the TCS and BPA concentrations (median 27.0 ng/L and 11.0 ng/L, respectively) decreased by ~80% compared to the values obtained in studies conducted ~20 years ago. These decreases can be attributed to reduced production due to the establishment of environmental standards and industrial self-regulation. Most target chemicals had higher concentrations in the STP effluents than in river water, indicating that STP effluents are major sources of the chemicals. However, BPA in the Tamagawa River exhibited a different spatial pattern. Namely, BPA concentrations in the STP effluents (~5 ng/L) in the middle and lower reaches were lower than those in the receiving water (~15 ng/L). Meanwhile, effluents from two upstream STPs had extremely high BPA concentrations of up to 158 ng/L, revealing effluents from these STPs as major sources of BPA in the Tamagawa River. There are several landfills in the upstream STP catchment area, and their leachate is likely to contribute to the high concentrations of BPA in the STP effluents and river water. This is consistent with the composition of BPA and its alternatives, including BPAP, BPZ, BPS, BPB, BPE, BPF, BPAF, in the effluents from the STPs. The upstream STPs showed a predominance of BPA, whereas the alternatives, such as BPS and BPF, were dominant in the STPs in the middle and lower reaches. The compositional difference can be ascribed to the recent replacement of BPA with alternatives and BPA leaching from plastic products dumped in the 1980s and 1990s.

Letters
  • Bee Geok YEO, Kaoruko MIZUKAWA, Hideshige TAKADA, Heidi TAIT, Jeanette ...
    原稿種別: Letter
    2022 年 2 巻 p. 14-21
    発行日: 2022年
    公開日: 2022/01/27
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    Among the plastic debris surveyed in the marine environment, a large quantity in terms of volume was found to be expanded polystyrene foam (EPS). This is due to its light weight and popularity as a packaging material. In this study, 28 compounds of polycyclic aromatic hydrocarbon (PAHs) were analyzed in both new and beached EPS collected in California, USA. In beached EPS, a variation in total PAH concentrations of up to 2 orders of magnitude was observed in the 337 to 11,800 ng/g-EPS range. Meanwhile, new EPS showed less variation in total PAH concentrations ranging from 282 to 1,194 ng/g-EPS. Most PAH species were shown to have higher concentrations in beached EPS than in new EPS, suggesting the ability of EPS to sorb PAHs from surrounding seawater. However, with anthracene, there was a significant depletion in beached EPS compared to new EPS. The fact that significant PAH concentrations were found in new unexposed EPS, including food packaging, highlights EPS as an exposure source of toxic chemicals to human food stocks upon migration, as well as to marine wildlife upon disposal. PAH concentrations and composition in new and beached EPS were consistent with those of samples from Japan, Malaysia and Australia, suggesting that the problems associated with EPS is a global issue.

Articles
  • Huiho JEONG, Teruhiko KUSANO, Sylvester ADDAI-ARHIN, Willy Cahya NUGRA ...
    原稿種別: Article
    2022 年 2 巻 p. 22-34
    発行日: 2022年
    公開日: 2022/03/03
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    Microplastics have recently been considered anthropogenic pollutants. Of the arguments to describe microplastic distributions is what mesh size should be employed. Many researchers have reported that the use of different mesh sizes causes naturally generated microplastic quantity differences. However, studies on how much specific microplastic distribution is overlooked in a large mesh remain insufficient in the aquatic environment, particularly in freshwater. Therefore, this study demonstrated qualitative and quantitative differences in microplastic distributions between 100– and 355– μm meshes from five perspectives: numerical/mass abundances, distributions along the flow direction, and microplastic features (size, shape, and polymer type). As observed, median values of numerical and mass abundances were 13.9 particles/m3 and 6.0 μg/m3, respectively, in the 100 μm mesh, then 0.4 particles/m3 and 1.0 μg/m3, respectively, in the 355 μm mesh. Although differences in mass abundances were six times between both meshes, for pristine river characteristics, the difference was ignored in this study. Results also showed that accidental irregularities discovered in the sampling analysis step affected the distribution tendency along the flow direction using the 355 μm mesh. Moreover, the 100 μm mesh showed the highest abundances in the lower sampling station, thereby reflecting the adjacent urban and its tributaries. A gradual increase in numerical fragment abundance toward a smaller size was observed with the 100 μm mesh. Additionally, results showed that cumulative probabilities relating to the minimum Feret diameter of films and fragments were divided into three parts. This division showed a 97% and 67% potential underestimation in the 355– and 100–μm meshes, respectively. Besides, although films, fibers, and fragments having seven polymers were observed in the 100 μm mesh, few shapes and polymer types were revealed in the 355 μm mesh. This finding made it was challenging to trace microplastic origins and presume bioaccumulation potentials using the 355 μm mesh. In conclusion, since the 100 μm mesh revealed completely different distributions from the 355 μm mesh, it was recommended in this study. However, viewpoints that the 355 μm mesh has an advantage in clogging the mesh exist. Therefore, a proper sampling method should be employed by establishing strategic research plans.

  • Yukio AOKI, Akihiro TOKAI, Naoya KOJIMA, Sosuke HANAI
    原稿種別: Article
    2022 年 2 巻 p. 35-44
    発行日: 2022年
    公開日: 2022/03/09
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    This study evaluated the effects of reducing the exposure concentration and the human health damage of alternative plasticizers to di(2-ethylhexyl) phthalate (DEHP) by a novel relative and quantitative risk assessment framework. The framework combines semivolatile organic compounds (SVOC) consumer exposure tools and damage functions. The used exposure tools were the consumer exposure models (CEM) of the US Environmental Protection Agency (US EPA) and DustEx of the Dutch National Institute for Public Health and the Environment (RIVM). These were used in the chemical substance management systems of the Toxic Substances Control Act (TSCA) and the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH). Concerning plasticizers, we determined the rational values for the main parameters and estimation accuracy which have not been informed sufficiently to users. We also identified the key parameters for operating the exposure tools. The indoor concentrations of DEHP were predicted using a simple box model, and the estimation accuracies of CEM and DustEx were evaluated by comparing predicted DEHP concentrations with actual measured values. For the DEHP concentration in house dust, both CEM and DustEx had an estimation accuracy of Factor 3−1–3. In particular, in the region of LogKoa <12, DustEx tended to provide higher estimations of the dust phase concentration compared with CEM. The material/air partition coefficient Kma was the most sensitive and crucial parameter for both exposure tools. Compared with DEHP, the predictions of both exposure tools showed that the alternative plasticizers had lower exposure concentrations of 86.8%–4.5% in air and 75.5%–4.4% in dust. In addition, the damage functions for nonphthalates were newly determined, and the human health damage amount was calculated by multiplying the determined damage function by the estimated exposure concentration. The total amount of human health damage of alternative plasticizers was 59−1–655−1 compared with DEHP, indicating that the nonphthalate di(2-ethylhexyl) terephthalate (DEHT) had the highest risk reduction effect.

Status Reports
  • Mitsugu SAITO, Tatsuya HATTORI, Keisuke UCHIDA, Go SUZUKI, Yoshinobu W ...
    原稿種別: Status Report
    2022 年 2 巻 p. 45-53
    発行日: 2022年
    公開日: 2022/05/10
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    Open dumping and burning of waste contaminated with mercury are known mercury emission sources in the environment, especially in developing countries. However, little data are available to understand the actual situation. The results of a survey—implemented by the Ministry of the Environment, Japan—were analysed to examine the effectiveness and challenges of the survey methodologies. Mercury levels in ambient air, solid waste, emission flux, leachate water and human hair at waste disposal facilities in Cameroon, Indonesia, Kenya, Myanmar and Nigeria were analysed.

    Ambient mercury levels at waste disposal facilities, where spontaneous waste combustion was observed, fluctuated significantly, although the average with the continuous monitoring was below 50 ng m−3. The factors for these fluctuations might be waste conditions, wind directions, distance from the waste combustion point, and others. The level was well below the guideline value for the workplace environment of the World Health Organization. Thus, it is unlikely for the site workers to develop adverse health effects caused by inhaling the ambient air.

    The proportion of mercury emitted from waste disposal facilities, the quotient of daily mercury emission from the surface and daily mercury input to the facility were calculated. The results are 0.075%–1.32%, which indicated that less percentage of mercury input was emitted to the atmosphere and that the remaining will be accumulated in the facilities.

    The methylmercury levels in hair were mostly below 1 μg g−1, which is below the equivalent to tolerable intake both for adults (4.4 μg g−1) and pregnant women (2.2 μg g−1). Thus, it is of no special concern for onsite workers regarding dietary mercury intake. Total mercury levels for most samples were also sufficiently low, but a few samples showed elevated mercury. The elevated levels might have been caused due to the application of personal care products containing mercury or accidental contact with other products containing mercury.

    The survey has provided some useful insights into the mercury situation in waste landfill facilities in developing countries. The enhancement of mercury levels when and where open burning of waste is occurring needs further evaluation.

    Mercury concentrations in ambient air at solid waste landfill facilities in developing countries with and without spontaneous waste combustion Fullsize Image
Articles
Letters
  • Masahiro SAKATA, Tatsumaru KIMURA, Ryuji NAKAMURA
    原稿種別: Letter
    2022 年 2 巻 p. 60-66
    発行日: 2022年
    公開日: 2022/07/15
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    In Japan, the amount of freshwater and short-neck clams imported from countries, such as China, South Korea, and North Korea, has increased with the decrease in their domestic production. This calls attention to the contamination of marketed clams with toxic substances, such as heavy metals in aquatic environments, from the viewpoint of food safety and security, because their origin has been falsely indicated. Herein, first, we measured the concentrations of Cd, Cu, Pb, and Zn in marketed freshwater and short-neck clam samples to clarify the extent of their contamination. Consequently, we found that some of the freshwater clam samples were contaminated with both Cd and Pb at concentrations comparable to their maximum concentrations in bivalve mollusks imposed by the Commission of the European Communities. Further, we evaluated the sources of Pb in the contaminated clams on the basis of Pb isotope ratios. The result supported the hypothesis that the Pb in the contaminated freshwater clam samples originates predominantly from effluent and exhaust from mining or smelting, which is associated with old Pb ores formed in some countries, such as China and North Korea. On the contrary, it appears that the contamination of freshwater clam samples with Cd is attributable to the Cd contained as an impurity in effluent and exhaust from the mining or smelting.

Articles
  • Yuki OYA, Hideshige TAKADA, Kaoruko MIZUKAWA, Madoka OHJI, Izumi WATAN ...
    原稿種別: Article
    2022 年 2 巻 p. 67-87
    発行日: 2022年
    公開日: 2022/09/02
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    Three bivalves, Cyclina sinensis (n=6), Crassostrea gigas (n=7), and Mactra veneriformis (n=6), and three crustaceans, Hemigrapsus penicillatus (n=5), Macrophthalmus japonicus (n=5), and Pyrhila pisum (n=5), were collected at Haneda in June 2019. In July 2019, M. veneriformis (n=5) and M. japonicus (n=3) were collected at Kasai. Concentrations of 34 trace elements were analyzed in muscles and internal organs: Li, Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Y, Mo, Cd, In, Sn, Sb, Cs, Ba, La, Ce, Gd, Pt, Tl, Pb, and Bi. C. sinensis and M. veneriformis accumulate elements higher in internal organs than muscles. But C. gigas indicates a different accumulation from other bivalves. The strength of hypoxia tolerance may be related to the difference in element distribution among the tissues because C. gigas is exposed to air at low tide, but the other bivalves are not. Moreover, C. sinensis and M. veneriformis accumulated the elements abundant in sediment such as rare earth elements. However, C. gigas accumulated different elements from other bivalves: Cu, Zn, Cd, and Pb. The effect of habitat, in or above the sediment, seemed related to the accumulated element composition. While crustaceans accumulated elements higher in the hepatopancreas than in muscles. In crustaceans, detritus-eating or carnivorous feeding may have affected the accumulated element composition. Most elements, except Mg, K, Ca, and Sr, in the hepatopancreas of H. penicillatus and M. japonicus had higher concentrations than in P. pisum. The detritus-eating in crustaceans was likely to result in accumulating elements with microplastics as one of their origins, e.g., Al, Mn, Co, Cu, Ba, and Pb. Moreover, all invertebrates in Haneda accumulated higher concentrations of Zn than in other studies—likely due to industrial wastes and tires disposed of in Haneda. Additionally, most high-toxicity element concentrations in Kasai were at similar or higher levels than in Haneda. Thallium was only detected in Kasai and was higher than in other studies. Thus, different trace element distributions were suggested among sites in Tokyo Bay.

  • Heesoo EUN, Kodai SHIMAMURA, Takuya ASANO, Eriko YAMAZAKI, Sachi TANIY ...
    原稿種別: Article
    2022 年 2 巻 p. 88-93
    発行日: 2022年
    公開日: 2022/09/02
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    Poly- and perfluoroalkyl substances (PFAS) are environmentally persistent organic compounds of industrial origin and harmful to human health and ecosystems. Perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) remain the most common PFAS in aquatic environments despite recent regulations on their use. In the water purification process, selection of materials such as activated carbon (AC) to efficiently adsorb and remove PFOS and PFOA remains a major challenge from the viewpoints of cost, efficiency of organic pollutant removal and disposal of used adsorbents. For efficient water purification, here we aimed to identify effective and low-cost carbon-based adsorbents (granular AC [GAC] and powdered AC [PAC]) with good physiochemical properties for removing PFOS and PFOA. The conventional GAC removed 12% of PFOA but could not remove PFOS. Alternatively, PAC #1, #2 and #3 removed >90% of PFOS and PFOA in 72 h at 25°C. Moreover, only a marginal difference in adsorption performance was observed among coconut husk, coal and wood. The removal rate of PFOS and PFOA by PAC #3 (at 1 mg/L) was 100% and 98%, respectively, rendering it the most effective water purification adsorbent. PAC #1, #2 and #3 had a significant adsorption effect compared with PAC #4 and GAC and are more cost-effective than conventional GAC, thereby making them ideal for water purification. This study presents a feasible water purification method involving PFOS and PFOA removal.

Status Reports
  • Hokuto NAKATA, Shouta M. M. NAKAYAMA, John YABE, Kaampwe MUZANDU, Andr ...
    原稿種別: Status Report
    2022 年 2 巻 p. 94-111
    発行日: 2022年
    公開日: 2022/09/08
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    Industrial development and economic growth have made human life more convenient. However, the accompanying environmental pollution is a serious problem. The same situation that developed countries have experienced in the past is now being repeated in developing countries, especially in Asia and Africa. Although lead has long been a useful metal in supporting human life, it is highly toxic to living organisms and affects various biological functions, including the kidneys and nervous system. Lead is one of the substances symbolizing the trade-off between industrial and economic development and environmental pollution. Kabwe in the Republic of Zambia, a town that grew out of the discovery and development of lead-zinc deposits, is now known as one of the most lead-polluted areas in the world. While Kabwe is a classic example of the trade-off described above, it is distinct from other polluted areas in that it has been the site of diverse academic research. These include geological survey of the mine, the characterization of mine wastes, monitoring of environmental and animal samples, human health impact studies, understanding of lead dispersion pathways, and development of remediation technologies for contaminated environments. In environmental monitoring, several studies have reported lead concentrations in soil of up to tens of thousands of mg/kg, and lead concentrations in crops exceed international standards by up to 770 times. Extremely high concentrations of lead have also been detected in wildlife, livestock, and humans. Various toxicological studies have been conducted on humans in particular. These studies reveal the contamination status and its effects. However, the elucidation of the diffusion pathways and the development of environmental remediation methods using materials that can be procured locally at low cost pave the way to solving the problem. This review comprehensively outlines these studies in chronological order, as well as the efforts of the Zambian government and future perspectives. This report also provides some guidance on how to promote academic research and problem solving in other polluted areas.

Articles
  • Ei Ei MON, Thant Zin TUN, Tetsuro AGUSA, Hsin-Ming YEH, Ching-Huei HUA ...
    原稿種別: Article
    2022 年 2 巻 p. 112-119
    発行日: 2022年
    公開日: 2022/10/14
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    Microplastics (MPs) are ubiquitous pollutants in various environmental matrices. In this study, 82 road dust samples collected from Myanmar and Taiwan between 2014 and 2018 were analyzed to investigate the status of MPs pollution and distribution. In Myanmar, the mean abundances of MPs in road dust were high in cities, such as Nay Pyi Taw (285 pieces/kg dry weight), Mandalay (79 pieces/kg), and Yangon (63 pieces/kg). Alternatively, no MPs were found in samples from the rural areas, Wundwin and Bagan. The mean MP abundance was 555 pieces/kg in road dust from Taiwan, which was two to nine times that of road dust from Myanmar. Polyethylene and polypropylene were the dominant polymers detected in road dust from Myanmar, whereas polyvinyl chloride was a major component in road dust from Taiwan. These results suggest that differences in economic and industrial activities and population densities are related to MP profiles in road dust. The plastic additives butylated hydroxytoluene, diethyl phthalate, and di-n-octyl phthalate were identified in a polyvinyl chloride MP in the road dust. These MPs originate from plastic products in the environment and lead to extensive pollution with hazardous chemicals. To our knowledge, this is the first study to report the occurrence of MPs in road dust from Myanmar.

  • Yuko ISHIBASHI, Manabu KASHIWABARA
    原稿種別: Article
    2022 年 2 巻 p. 120-127
    発行日: 2022年
    公開日: 2022/11/22
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    To purify groundwater contaminated with nitrate (NO3-N) from manure and fertilizer used in tea fields, six anion exchange resins made with trimethylamine (1), triethylamine (2), tributylamine (3), trihexylamine (4), trioctylamine (5), or tridecylamine (6) were synthesized, and their performance was evaluated. The NO3-N removal rates of resins 1–4 were very similar and were higher than those of resins 5 and 6. The nitrate adsorption by all resins was satisfactorily described by the Langmuir adsorption isotherm model. The groundwater originating from tea fields contains high concentrations of SO42- in addition to NO3-N. Resin 4 had the highest selectivity for NO3-N adsorption in solutions containing SO42−. Therefore, resin 4 was selected for denitrification experiments, which demonstrated that NO3-N adsorbed on resin 4 was denitrified and that resin 4 may be reusable. Biological denitrification was confirmed by measuring nitrous oxide (N2O) in the headspace of the vial bottle containing 20 mL of the soil solution with NO3-N removed, 0.1 g of glucose, and 0.1 g of NO3-N-saturated resin 4. The denitrifying nitrogen calculated from the N2O concentration was only 0.04% of the NO3-N adsorbed on the NO3-N-saturated resin 4. Moreover, when 1 g or more of glucose was added, approximately 10% of the NO3-N in 10 mL of NO3-N solution (100 mg-N/L) was absorbed on 0.05 g of resin 4 after denitrification. Further improvements in the efficiency of denitrification are necessary for their application in tea fields.

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