Kiwao Kadokami

Monitoring of 1300 organic micro-pollutants in surface waters from Tianjin, North China

In spite of the quantities and species of chemicals dramatically increased with rapid economic growth in China in the last decade, the focus of environmental research was mainly on limited number of priority pollutants. Therefore, to elucidate environmental pollution by organic micro-pollutants, this work was conducted as the first systematic survey on the occurrence of 1300 substances in 20 surface water samples of Tianjin, North China, selected as a representative area of China. The results showed the presence of 227 chemicals. The most relevant compounds in terms of frequency of detection and median concentration were bis(2-ethylhexyl) phthalate (100%; 0.26μgL(-1)), siduron (100%; 0.20μgL(-1)), lidocaine (100%; 96ngL(-1)), antipyrine (100%; 76ngL(-1)), caffeine (95%; 0.28μgL(-1)), cotinine (95%; 0.20μgL(-1)), phenanthrene (95%; 0.17μgL(-1)), metformin (90%; 0.61μgL(-1)), diethyl phthalate (90%; 0.19μgL(-1)), quinoxaline-2-carboxylic acid (90%; 0.14μgL(-1)), 2-(methylthio)-benzothiazole (85%; 0.11μgL(-1)) and anthraquinone (85%; 54ngL(-1)). Cluster analysis discriminated three highly polluted sites from others based on data similarity. Principle component analysis identified four factors, corresponding to industrial wastewater, domestic discharge, tire production and atmospheric deposition, accounting for 78% of the total variance in the water monitoring data set. This work provides a wide reconnaissance on broad spectrum of organic micro-contaminants in surface waters in China, which indicates that the aquatic environment in China has been polluted by a large number of chemicals.

Determination of organotin compounds in water by bonded-phase extraction and high-performance liquid chromatography with long-tube atomic absorption spectrometric detection

A method for the simple and rapid determination of monomethyl-, dimethyl-, trimethyl-, monobutyl-, dibutyl-, tributyl-, diphenyl- and triphenyltin in water has been developed by using high-performance liquid chromatography (HPLC) with atomic absorption spectrometry (AAS) for the selective and sensitive detection of tin. A water sample was passed through a silica gel C18 disposable column, and organotin compounds were recovered with tetrahydrofuran-acetic acid containing 0.5%m/V tropolone. The HPLC- AAS system consisted of a flame atomic absorption spectrometer with a long absorption tube connected directly to the high-performance liquid chromatograph which was fitted with a reversed-phase column. Recoveries of the above mentioned eight tin compounds spiked in water at 0.1 µg l–1 as tin ranged from 63 to 96% and their relative standard deviations ranged from 6 to 12%. The detection limit recorded for these compounds (as tin) by this method was 0.03 µg l–1.

Screening analysis of hundreds of sediment pollutants and evaluation of their effects on benthic organisms in Dokai Bay, Japan

Dokai Bay in Kitakyushu, Japan, is polluted with complex mixtures of micro-pollutants originating from the extensive industry and urbanization. In order to evaluate effects of these micro-pollutants on benthic organisms in this almost completely enclosed bay, we screened for the occurrence of approximately 900 organic chemicals and heavy metals, and in addition quantified the density and biomass of benthic animals. For the chemical analysis, we used a newly developed comprehensive analytical method using an automated identification and quantification system with a GC-MS database. We detected 184 organic chemicals in the sediments. Since their concentrations, as well as those of metals, increased with proximity to the innermost part of the bay, their source seem to be factories and a sewage treatment plant located in this area. Confirming this, the identified pollutants in this area are characteristic of industrial chemicals and residues, as well as household chemicals, fecal matter and sewage effluent. Several polycyclic aromatic hydrocarbons (PAHs) and metals had concentrations higher than the effects range-median of the sediment quality guidelines of National Oceanic and Atmospheric Administration. The species richness and abundance of benthic animals were lowest in areas where concentrations of metals, PAHs and other organic pollutants were high, suggesting that these contaminants are having an adverse effect on benthic animals in the bay.

RELATIONSHIP BETWEEN MUTAGENICITY AND REACTIVITY OR BIODEGRADABILITY FOR NITROAROMATIC COMPOUNDS

Although many studies have reported that nitroaromatics such as 2,4,6-trinitrotoluene (TNT) have strong mutagenicity, the mechanism of mutagenic activity in these compounds has not yet been reported. We examined the mutagenicity versus reactivity and biodegradation by bacteria using TNT and its analogs (1,3,5-trinitrobenzene [TNB], 2,4,6-trinitroaniline [TNA], 2,4,6-trinitro-phenol [TNP], N,2,4,6-tetranitro-N-methyl-aniline [tetryl], 2,4-dinitrotoluene [24DNT], and 2,6-dinitrotoluene [26DNT]). Aromatic compounds harboring three nitro groups (except TNP) have high mutagenicity, judging from the results of the umu test using luminescent bacteria (Salmonella typhimurium strain TA1535/pTL210). Single-electron reduction potentials for these chemicals were -530, -555, -565, -575, -640, -674, and -764 mV for TNA, tetyl, TNT, TNB, 24DNT, 26DNT, and TNP, respectively, indicating that trinitro-aromatics (except TNP) were more reducible than other compounds. Pseudomonas sp. strain TM15, which was isolated from TNT-contaminated soils in the Yamada Green Zone, Kitakyushu City, Japan, could efficiently biotransform TNT, TNB, TNA, and tetryl; 24DNT, 26DNT, and TNP were less biodegradable. This strain converted all TNT analogs into reduction products; nitro groups were reduced to amino groups. We revealed that the mutagenicity of nitroaromatics correlate with reactivity and biodegradability. This finding may contribute to the elucidation of mutagenic expression of nitroaromatic compounds in organisms.

Target and screening analysis of 940 micro-pollutants in sediments in Tokyo Bay, Japan.

Urban societies are using an increasingly diverse array of chemicals, many of which ultimately end up accumulating in urban harbors, where they can act as contaminants alone or as part of a mixture. In attempt to grasp a more complete picture of anthropogenic chemicals in an urban harbor, we analyzed 940 organic chemicals in sediments in Tokyo Bay, one of the most densely populated and modernized areas in the world. For the chemical analysis, we used targeted analytical methods using a GC-MS-MS and a GC-MS-SIM, and a screening analysis using an automated identification and quantification system with a GC-MS database. We detected 195 organic chemicals in the sediments; the sum of concentrations of compounds detected varied from 6095 to 39140μgkg(-1)dry wt. Since their concentrations increased with proximity to the innermost part of the bay, their sources seem to be mainly sewage treatment plants (STPs) and rivers flowing to this area. Additional confirmation comes from the nature of the identified pollutants, which are characteristic of chemicals used in households as well as fecal matter, business activities and urban run-off. From these results, it was confirmed that sediments in Tokyo Bay are still polluted with a wide range of chemicals, particularly domestic chemicals, despite nearly 100% of wastewater from household and business activities being treated by STPs.

A Rapid Method, Combining Microwave-Assisted Extraction and Gas Chromatography-Mass Spectrometry with a Database, for Determining Organochlorine Pesticides and Polycyclic Aromatic Hydrocarbons in Soils and Sediments

ABSTRACT A rapid method for determining organochlorine pesticides and polycyclic aromatic hydrocarbons in soils and sediments was developed to allow pollution surveys to be performed in emergencies. The method involves microwave-assisted extraction and uses an automated identification/quantification system with a gas chromatography mass spectrometry database. A sample (3 g) is extracted with a 3:2 v/v hexane:water mixture (10 mL) for 30 min using a microwave-assisted extraction system at 120°C. The hexane extract is then cleaned using silica gel, then analyzed by gas chromatography mass spectrometry. The total analysis time is approximately 4 h. The precision of the quantitative results and accuracy of the analyte identification were determined. The total analyte concentrations were generally comparable to (61%–110% of) the concentrations determined using a Soxhlet extraction method, but the concentrations of individual high-molecular-weight polycyclic aromatic hydrocarbons were unacceptably low compared with the concentrations determined using the Soxhlet method. However, these compounds (e.g., benzo(ghi)perylene and indeno(1,2,3-cd)pyrene) were subsequently efficiently extracted using a hexane:water:ethanol mixture. The accuracy of identification was evaluated using accurate masses determined by gas chromatography time-of-flight mass spectrometry, and the mass error was 2 ppm for 21 of the 22 compounds identified using the new method.

Wastewater recycling in Antarctica: Performance assessment of an advanced water treatment plant in removing trace organic chemicals

The Australian Antarctic Division (AAD) operates Australias Davis Station in the Antarctic. In 2005, Davis Stations wastewater treatment plant failed and since then untreated, macerated effluent has been discharged to the ocean. The objectives of this study were to determine whether an advanced water treatment plant (AWTP) commissioned by the AAD and featuring a multi-barrier process involving ozonation, ceramic microfiltration, biologically activated carbon filtration, reverse osmosis, ultraviolet disinfection and chlorination was capable of producing potable water and a non-toxic brine concentrate that can be discharged with minimal environmental impact. The AWTP was tested using water from a municipal wastewater treatment plant in Tasmania, Australia. We used spot water and passive sampling combined with two multi-residue chromatographic-mass spectrometric methods and a range of recombinant receptor-reporter gene bioassays to screen trace organic chemicals (TrOCs), toxicity and receptor activity in the Feed water, in the environmental discharge (reject water), and product water from the AWTP for six months during 2014-15, and then again for three months in 2016. Across the two surveys we unambiguously detected 109 different TrOCs in the feed water, 39 chemicals in the reject water, and 34 chemicals in the product water. Sample toxicity and receptor activity in the feed water samples was almost totally removed in both testing periods, confirming that the vast majority of the receptor active TrOCs were removed by the treatment process. All the NDMA entering the AWTP in the feed and/or produced in the plant (typically < 50 ng/L), was retained into the reject water with no NDMA observed in the product water. In conclusion, the AWTP was working to design, and releases of TrOCs at the concentrations observed in this study would be unlikely cause adverse effects on populations of aquatic organisms in the receiving environment or users of the potable product water.

Survey on the micro-pollutants presence in surface water system of northern Serbia and environmental and health risk assessment

ABSTRACT This study demonstrates the occurrence of 940 organic micro‐pollutants in surface water of four rivers, one irrigation canal system, and two lakes in Vojvodina Province, the northern part of Serbia, summing in total eighteen samples. The number of detected chemicals ranged from 22 to 84, with 127 micro‐pollutants detected at least once, representing 13% of the studied substances. The targeted compounds include n‐alkanes, sterols, polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides polychlorinated biphenyls, pesticides, pharmaceutical active compounds, industrial chemicals, plasticizers, etc. Among the analysed compounds, sterols were the most dominant with maximum quantified concentrations. The substances which were quantified with frequency over 50% were two PAHs (2‐methylnaphthalene, benzo(ghi)perylene), five sterols (cholesterol, cholestanol, stigmasterol, fucosterol, beta‐sitosterol), three pharmaceuticals and personal care products (L‐menthol, diethyltoluamide, caffeine), and ten household chemicals (4‐tert‐octylphenol, dimethyl phthalate, methyl palmitate, phenylethyl alcohol, 1‐nonanol, alpha‐terpineol, 2‐phenoxy‐ethanol, methyl myristate, acetophenone, and 2‐ethyl‐1‐hexanol). The list of priority substances under the European Union Directive 2013/39/EU includes 49 priority substances (PSs) out of which 34 were analysed. Among these, eleven PSs were quantified, and only two compounds (fluoranthene and benzo (a) pyrene) exceeded EU Environmental Quality Standards targeted values. The obtained results were compared with the previously published data that dealt with the same targeted number of micro‐pollutants in sediment samples. This revealed connections between the same sampling locations. Environmental risk assessment showed the existence of potential ecological risk as 72% of the obtained values for the ecological hazard index (HI) at investigated locations were higher that the targeted value (HI > 1). Estimated values for hazard quotient (HQ) and hazard index (HI) for non‐carcinogenic risk were lower than the targeted value, indicating no non‐carcinogenic risk through dermal contact and non‐intentional ingestion of water. Estimated values for cancer risk were all below 1 × 10−6, which is not considered to pose significant human health risk. HighlightsFirst survey on the occurrence of 940 substances in the middle part of the Danube Basin.Micro‐pollutants from canals water had higher abundance of contaminants that from river.High level of sterols indicated dominant effect of untreated domestic wastewater.Correlations among the groups of micro‐pollutants indicated their common origin.Ecological risk suggesting a potential for adverse effects on fish.

Determination of trace n-alkanes in seawater by gas chromatography mass spectrometry using deuterated internal standards.

海水中に存在するバックグラウンドレベルのn-アルカンを重水素化n-アルカンを内標準として海水に添加した後,XAD-2樹脂を用いて抽出,濃縮し,ガスクロマトグラフ質量分析計により定量する方法を検討した。重水素化n-アルカンは全操作を通じてn-アルカンと同一の挙動をするため,抽出,濃縮及び測定時の誤差を最小限に抑えることができ,XAD-2樹脂による回収率が低い炭素数13から18のn-アルカンについても精度よく定量することができた。本法を用いて実際の海水中の炭素数13から32のn-アルカンを定量した。