Yuichi Miyake

• Doctor of Engineering
• Professor (Associate) at Yokohama National University

Isocyanates are used as raw materials for polyurethane foams, paints, and building materials. The isocyanates can cause acute adverse health effects such as irritation of the respiratory tract, skin, and eyes, and induce asthma and sick house syndrome. However, investigations into the potential sources and risk assessments of indoor isocyanates are...

Passive smoking poses a major hazard to the health of non-smokers. Cigarette combustion emits environmental tobacco smoke (ETS) that contains various pollutants, including volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons, and particulate matter with particles < 2.5 μm in aerodynamic diameter (PM2.5). Therefore, to assess the risk...

Tightening of environmental regulations against long-chain perfluoroalkyl acids (PFAAs) since the 2000s may have led to significant increases in the occurrence of short-chain PFAAs in the environment. Understanding the impact of the regulations on composition of durable water repellents (DWRs) is imperative to guide implementation of pragmatic acti...

Chemical exposures should be measured to assess the health risks from chemicals in the work environment to workers. Passive air samplers (PAS) that do not require a power source are useful for assessing individual exposure to chemicals. Therefore, the International Organization for Standardization has determined ISO 16107 as the standard method for...

Polycyclic aromatic hydrocarbons (PAHs) and their halogenated derivatives (XPAHs) have been a concern because of their high toxicity. Monitoring indoor PAHs and XPAHs concentrations is important for risk assessment because humans typically spend >90 % of their time indoors. However, the background levels of indoor PAHs and XPAHs concentrations are...

The Industrial Safety and Health Act in Japan has established guideline values for volatile organic compounds (VOCs) in indoor workplace air; however, because the physicochemical properties of these VOCs are diverse, appropriate analytical methods have not yet been developed. Here we performed recovery tests to simultaneously measure VOCs and to op...

Because of their unintentional formation and low vapor pressure, polycyclic aromatic hydrocarbons (PAHs) and their halogenated derivatives (XPAHs) in the atmosphere are distributed primarily to aerosolized particles with an aerodynamic diameter less than 2.5 μm (PM2.5). However, no information is available regarding the occurrence of PM2.5-bound PA...

Polycyclic aromatic hydrocarbons (PAHs) and their halogenated derivatives (XPAHs) are ubiquitous in various environmental media. Analytical problems, however, make it difficult to accurately determine their concentrations. To develop a satisfactory analytical method suitable for a diversity of PAHs and XPAHs in multiple environmental samples, we ev...

Cooking exhaust gas includes polycyclic aromatic hydrocarbons (PAHs) that are unintentionally generated during cooking, which exposes the cook and others in the vicinity to these toxic compounds. However, information on the occurrence of PAHs, particularly their chlorinated derivatives (ClPAHs), in cooking exhaust gas is limited. Here, we determine...

A sensitive method for the quantification of brominated polycyclic aromatic hydrocarbons (BrPAHs) in environmental samples is yet to be developed. Here, we optimized the analytical conditions for liquid chromatography tandem mass spectrometry with atmospheric pressure photoionization and post-column infusion of dopant (LC-DA-APPI-MS/MS). We then co...

Co-existing substances (substances not targeted for degradation) can negatively affect wastewater treatment process performance. Here, we quantitatively evaluated the effects of propanal, a common co-existing substance, on the degradation of the azo-dye Orange II, a common pollutant, by the Fenton process to provide data for the development of meas...

Parabens (p-hydroxybenzoic acids) are commonly used as preservatives in personal care products. Although the rate of exposure to a single product may be small, it is possible for an individual to have marked exposure to parabens through the use of multiple personal care products (aggregate exposure). To assess the risks associated with aggregate ex...

Polycyclic aromatic hydrocarbons (PAHs) are unintentionally generated in foods that are cooked, and dietary ingestion of these PAHs is regarded as the dominant route of exposure to PAHs. Some chlorinated PAHs (ClPAHs) are more toxic than their corresponding parent PAHs and can also be generated in food during cooking. Knowledge of the concentration...

Acid gases generated during the thermal treatment of waste are neutralized using devices, such as bag filters coated with slaked lime. However, residual trace organic substances can react with the highly reactive slaked lime. This study investigates the dynamics of organic substances generated in the bag filter when slaked lime is used in the exhau...

In this study, the pathways for migration of phosphorus flame retardants (PFRs), tris(1,3-dichloroisopropyl) phosphate (TDCPP) and tricresyl phosphate (TCsP) which were detected from curtains often, from flame-re-tardant-treated polyester curtains to indoor dust were investigated. Two possible migration pathways were compared quantitatively: (1) an...

Phosphorus-based compounds are used as plasticizers in the manufacture of many products found in the indoor environment. Here we quantitatively investigated dermal exposure to phosphorus-based compounds contained in 45 nail polishes purchased in Japan. The alternative plasticizer triphenyl phosphate (TPhP) was detected in some samples of the nail p...

An analytical method was developed for screening and identifying novel flame retardants in curtains purchased in Japan in 2014 by use of a liquid chromatograph interfaced with a hybrid quadrupole Orbitrap mass spectrometer (LC–Orbitrap-MS; Q Exactive Plus). To enable complete extraction of flame retardants in curtains, we used an extraction method...

Organophosphorus flame retardants (PFRs) are extensively used as alternatives to banned polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD). In this study, we analyzed 14 PFRs by means of four mass-spectrometry-based methods: gas chromatography combined with electron-impact mass spectrometry (GC-EI-MS) or negative-chemical-ioni...

We determined the concentrations of halogenated polycyclic aromatic hydrocarbons (XPAHs), some of which are carcinogenic and/or mutagenic compounds, in fly and bottom ashes and stack gas collected from waste incinerators in Japan. The dominant XPAHs in stack gas were consistent with those in the urban atmosphere. The dioxin-like toxic equivalent (T...

The use of novel brominated flame retardants (BFRs) and phosphate-based flame retardants (PFRs) has increased as substitutes for hexabromocyclododecane (HBCD) in many consumer products. To facilitate collection of data on chemicals used as flame retardants in textiles and fabrics, we developed an analytical method using liquid chromatography interf...

The annual emission rates of 34 halogenated polycyclic aromatic hydrocarbons (XPAHs) from 40 industrial/municipal waste incinerators in Saitama, Japan were determined. The sum of annual emission rates for 34 XPAHs from 40 waste incinerators was 810 g/year. The sum of annual emission rates for 34 XPAHs from each waste incinerator ranged 0.0074‒240 g...

Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) are an emerging class of environmental contaminants, but the sources of ClPAHs in the environment are not well known. In this study, we developed a kinetic model describing the chlorination of PAHs to observe the mechanism of formation of ClPAHs during the combustion of organic waste containing...

The Industrial Safety and Health Law in Japan established administrative levels for volatile organic compounds (VOCs) in indoor air. In the present study, these 49 VOCs were extracted from the absorbents of commercial active samplers from Sibata Scientific Technology (carbon-bead active sampler), SKC Inc. (Anasorb CSC sorbent tube), and Gastec (bea...

Here, we examined the incineration of extruded polystyrene containing hexabromocyclododecane (HBCD) in a pilot-scale incinerator under various combustion temperatures (800–950°C) and flue gas residence times (2–8 sec). Rates of HBCD decomposition ranged from 99.996% (800°C, 2 sec) to 99.9999% (950°C, 8 sec); the decomposition of HBCD, except during...

An ion chromatography with post-column derivatization with 1,5-diphenylcarbazide (IC-DPC) analytical method was modified to enable measurement of trace-level hexavalent chromium (Cr(VI)) in air. One of the difficulties in determining trace levels of Cr(VI) in air with conventional IC-DPC methods is co-elution of the solvent and ion peaks due to hig...

The passive sampler is a simple device for collecting gaseous compounds. It is affected by environmental conditions such as relative humidity, but a dehumidification system (DHS) has not been developed for it. We have developed a dehumidification device for the passive sampler for determining 1,3-butadiene. It consists of a passive sampler surround...

We have determined halogenated polycyclic aromatic hydrocarbons (XPAHs) in 40 samples of surface soil (n = 32) and river sediment (n = 8) collected around the E-waste recycling area in Bui Dau, northern Vietnam. Thirty-one target compounds including 21 chlorinated PAHs (ClPAHs) and 10 brominated PAHs (BrPAHs) were quantified by gas chromatography-h...

To measure nicotine personal exposure in our daily life, we have developed a determination method of personal exposure to nicotine. The method consisted of passive sampling of nicotine, simple solvent extraction and high performance liquid chromatography (HPLC) determination. The passive sampler was badge type and collection media was sodium bisulf...

Terpenes such as α-pinene and β-pinene are emitted from wooden building materials. They have been reported to be relatively high concentration in the indoor environment. In this study, concentrations of α-pinene and β-pinene in indoor and outdoor air in 30 houses in Shizuoka, Japan were determined using a passive sampler. The individual exposures o...

Perfluorooctane sulfonate (PFOS) was quantified in seawater and sediment samples collected from Tokyo Bay, Japan, ranging from 2.0 to 7.3 ng/L for surface seawater, 2.2 to 5.7 ng/L for intermediate seawater, 1.5 to 5.7 ng/L for bottom seawater, and 0.3 to 0.9 ng/g dry wt. for sediment. In addition, a 3-D chemical fate prediction model (National Ins...

We have developed a simple and reliable passive-sampling method for determining outdoor 1,3-butadiene concentrations in air. In this method, 1,3-butadiene is adsorbed on Carboxen 1000 uniformly packed in a porous polytetrafluoroethylene tube and then analyzed by thermal desorption-gas chromatography/mass spectrometry. The amounts of 1,3-butadiene a...

In the regulation concerning the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH), the supplier of a substance or a preparation is required to ensure that exposure to these substances throughout the entire life-cycle is below the threshold level beyond which adverse effects may occur. Although scenarios of exposure to ch...

Topsoil along the altitudinal gradient (2086-4487m above sea level) and yak samples, collected from Wolong high mountain area of Sichuan Province, western China, were analyzed for polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs) and polychlorinated naphthalenes (PCNs) using HRGC-HRMS. The to...

There are several methods for determining personal exposure to PM2.5. Among these methods, the gravimetric method that include collection of PM2.5 on the filter and measurement of the filter weight have the advantage of measuring weight of PM2.5 directly. We have developed a low-noise personal pump for collecting PM2.5, and found that this can be u...

In this study, it was attempted to identify the mutagen produced by chlorination of insecticide fenitrothion using a quadrupole GC-MS and a high-resolution GC-MS. From the mass spectra obtained by the GC-MS, the chemical structures of two unidentified compounds were extrapolated: one was identified as 2-chloro-5-methyl-4-nitrophenol by comparison t...

The mutagens produced through chemical reaction between chlorine and the insecticide fenitrothion were studied by using a quadrupole GC-MS. The mutagenicity and the mutagen formation potential (MFP) of the identified by-products were evaluated by the Ames assay (preincubation method) using Salmonella typhimurium TA100 without exogenous activation b...

The concentrations of toluene and dichloromethane in the vicinity of factories that emitted a large amount of toluene or dichloromethane into the atmosphere were determined for the comparison of observed and estimated concentrations using a Gaussian dispersion model (METI-LIS model). Greater concentrations of toluene and dichloromethane than the gu...

The widespread occurrence and environmental persistence of perfluorinated compounds (PFCs) received worldwide attention recently. Exhaustive analysis of all fluorinated compounds in an environmental sample can be daunting because of the constraints in the availability of analytical standards and extraction methods. Combustion ion chromatographic te...

An improved extraction (ion pairing) and cleanup (ENVI-carb and solid phase extraction) method was developed for analysis of perfluorinated compounds (PFCs) in human whole blood samples from China. Ten PFCs including PFOS, PFHxS, PFOSA, PFDoDA, PFUnDA, PFDA, PFNA, PFOA, PFHpA, and PFHxA were detected in the blood samples (n=30) from five cities (Ji...

The concentrations of 10 PFCs (perfluorinated compounds: PFOS, PFHxS, PFOSA, N-EtFOSA, PFDoDA, PFUnDA, PFDA, PFNA, PFOA, and PFHpA) were measured in liver samples of Indo-Pacific humpback dolphins (Sousa chinensis) (n=10) and finless porpoises (Neophocaena phocaenoides) (n=10) stranded in Hong Kong between 2003 and 2007. PFOS was the dominant PFC i...

Dietary intake is one of the important routes of human exposure to brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs). The use of PBDEs may also result in exposure to polybrominated dibenzo-p-dioxins and dibenzofurans (PBDDs/DFs), as these compounds are impurities in technical mixtures of BFRs and can also be formed u...

A total of 14 perfluorinated compounds (PFCs) were quantified in river water samples collected from tributaries of the Pearl River (Guangzhou Province, south China) and the Yangtze River (central China). Among the PFCs analyzed, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the two compounds with the highest concentrations...

This study determined the concentrations of organochlorine contaminants in common seafood in two Chinese coastal cities (Guangzhou and Zhoushan), and assessed the health risk due to the daily consumption of contaminated seafood. Twenty-six pooled samples, belonging to five food categories (fish, bivalves, shrimp, crab, and cephalopods), were purcha...

The number of perfluorochemicals (PFCs) that have been found in biological and environmental matrices is increasing as analytical standards and methods evolve. Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) constitute only a fraction of the total suite of PFCs found in environmental and biological matrices. A robust method and approa...

Perfluorinated compounds (PFCs) such as perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) have received worldwide attention because of their environmental persistence and widespread distribution. Because of the lack of robust analytical methods and standards to detect all of the PFCs, and their precursors and metabolic intermediates, a...

Recent studies have shown that various semi- and non-volatile organohalogen compounds are ubiquitous in the environment: these include halogenated dioxins including chlorinated dioxins, other persistent organic pollutants (POPs), brominated flame retardants (BFRs), and perfluorooctane sulfonate (PFOS). However, monitoring and assessment of these co...

The objective of this study was to determine the concentrations and compositions of polybrominated biphenyls (PBBs), polybrominated dibenzo-p-dioxins (PBDDs), and polybrominated dibenzofurans (PBDFs) as contaminants in the commercial polybrominated diphenyl ether (PBDE) mixtures DE-71, DE-79, and DE-83 and to ascertain the lot-to-lot variations in...

The method enables congener-specific determination not only of polychlorinated dioxins but also of polybrominated diphenyl ethers (PBDEs), -biphenyls (PBBs), -dibenzo-p-dioxins (PBDDs) and -dibenzofurans (PBDFs) using two dimensional high performance liquid chromatograph (HPLC) with graphitized carbon and pyrenyl silica columns cleanup, and high re...

廃棄物焼却排ガスからは塩素のみが結合したダイオキシン類のほかに, フッ素, 塩素, 臭素, ヨウ素が混合して結合したダイオキシン類などの半・難揮発性有機ハロゲン化合物が排出されている可能性がある。しかし, これらの化合物の排出実態はほとんどわかっていない。そこで, 実際の廃棄物焼却施設10施設の排ガスについて半・難揮発性有機ハロゲン (SNVOXs) 濃度を測定し, 半・難揮発性有機ハロゲン化合物の排出実態を調査した。その結果, 半・難揮発性有機臭素 (SNVOBr) や半・難揮発性有機ヨウ素 (SNVOI) が半・難揮発性有機塩素 (SNVOCI) の0.02～1.4倍存在していた。このことより, 塩素のみが結合している化合物だけでなく, 塩素, 臭素, ヨウ素が混合して結合している半・難...