We examined the possibility of analysis of Dechlorane Plus (DP) and related compounds in ambient air by using High Volume Air Sampler (HVAS) installing quartz fiber filter (QFF) and polyurethane foam (PUF), which is usually used for ambient-air-dioxin analysis. Results of recovery test showed that the QFF and PUF can trap most of targets including anti-DP, syn-DP, Dechlorane 601, Dechlorane 602 (Dec-602), Dechlorane 603 (Dec-603), Dechlorane 604, Dechlorane 604 Component B, Chlordene Plus (CP), Dibromoaldrin, Dibromochlordene, and Hexachloro(phenyl)norbornene. In addition, we analyzed 24 stock extracts of ambient air samples collected by using the HVAS in Kazo, Saitama in fiscal year 2013. Two DP isomers (anti and syn) were detected in all 24 samples. Concentrations of ΣDP (anti-DP+syn-DP) ranged from 1.2 to 6.7 pg/m³ (average: 3.9±1.3 pg/m³). No seasonal variation of ΣDP concentrations was found. f_anti (anti-DP/ΣDP) values were substantially constant at the value of technical DP composition, suggesting the DP in the air samples was originated from DP products in the neighborhood. As for the DP related compounds, only Dec-602, Dec-603 and CP were detected in the range of ND (not detected) ~0.09, ND~0.05 and ND~0.13 pg/m³, respectively. To the best of our knowledge, this is the first study to report Dec-602, Dec-603 and CP in the environment in Japan.

Several types of chemicals are added to resins for enhancement of their physicochemical properties. Among added chemicals, halogenated flame retardants (FRs) including tetrabromobisphenol A (TBBPA) were major additives. Recently, Dechlorane Plus (DP), that was used in commercial applications, has been paid attention as not only FRs but also environmental pollutants, though few information of DP are available. Consequently, we prepared resin samples [acrylonitrilebutadiene-styrene (ABS) and polycarbonate (PC) resins] containing DP at 500 mg/kg as plastic disks, and evaluated the change in concentration of DP on the disks exposed by accelerated weathering tests which were performed in accordance with the JIS K7350-2. As a result of the weathering tests assumed to be similar to the sunlight exposure of approximately half a year, the concentration of DP in ABS resin decreased approximately 10 % despite the fact that the concentration of DP in PC resin did not change. On the other hand, the concentration of TBBPA added to the disks as a reference changed and decreased approximately 30 to 40 % in both resins. For element analyses, there were no significant differences in chlorine concentration based on DP and bromine concentration based on TBBPA between original and weathered resins. Therefore, it seemed that DP, TBBPA, and occurred degradation products did stay in the disks in spite of performing the weathering tests. From the results in this study, a possibility of release to the environment on DP and TBBPA in resins may be not considerable, while it is necessary to perform additional studies in order to evaluate the possibilities of elution to the hydrosphere of fine particles of the resin and of release to the atmospheric environment by incineration processes.

Dechlorane Plus (DP), a chlorinated flame retardant, was determined in the sediment samples collected in twentynine sampling sites in the northern Shikoku Island along the coast of the Seto Inland Sea, from 2012 to 2013. Dechlorane(Mirex) and PCBs were also measured in this study comparing with the concentrations of DP in the same samples. Concentrations of DP detected in the sediment samples were significantly higher than those of Mirex. On the other hand, statistically slight difference was found between the concentrations of DP and PCBs, indicating significant environmental load and residue of DP in coastal sediments of this region. Principal component analysis based on the analytical results indicated that the chemical manufacture facility, E-waste recycling facility and the waste dumping site would be potential contamination sources of DP. To our knowledge, this is the first paper on DP accumulation in coastal sediments, which showed PCB residues at comparable concentrations, in the northern Shikoku Island.

Dechlorane Plus (DP) is a chlorinated flame retardant developed as an alternative for Mirex (Dechlorane) in the1960s, and was detected by Hoh et al. in the environment for the first time in 2006. Thereafter DP as an emerging substance began to be investigated around the world, but the data was not available in Japan until 2011. We investigated contamination levels of DP in the various environmental media in Japan using a high-resolution gas chromatograph/mass spectrometer (HRGC/HRMS). The DP concentrations detected in Japan were 0.24-230 ng/g-dry in sediments, 1.7 ng/g-dry in soil, 74-270 ng/g-dry in outdoor dust (deposits adhering to windows and road sediments), 2.9-42 ng/g-dry in indoor dust, 0.082-1.2 ng/g-dry in plant leaves, and 5.5-8.0 pg/g-wet in vegetables. These results of our investigation indicated that various environmental matrices had been contaminated with DP, which was detected in high concentrations in deposits adhering to the outside of windows in Japan. In this study, it was found that DP concentrations of sediments in Japan were higher than in foreign countries, but levels in other media were comparable to other countries. DP concentrations in outdoor dust were higher than indoor dust, and it is suggested that DP mostly exists in outdoor environments in Japan. Mirex was present at low levels in most of the samples. Mirex was not used as a pesticide in Japan; therefore it may have been used as a flame retardant, Dechlorane. In outdoor samples (dust, soil and sediments), the ratio of an anti isomer of DP (f_anti) was slightly higher than in commercial DP. Furthermore, f_anti in indoor dust, plant leaves, and vegetables were lower than in outdoor samples, and were varied significantly.

The particle size distributions of dechloranes were determined. For collecting PM, an Andersen air sampler equipped with five-stage quartz fiber filters and a PM_0.1 air sampler equipped with six-stage Teflon and inertial SUS fiber filters were used. Particulate matter (PM) was collected in April 2014 by Andersen air sampler and October 2014 and January 2015 by PM_0.1 air sampler. The samples were analyzed for Dechlorane Plus (DP), Dechlorane602, Dechlorane603, and Dechlorane604 Component A using gas chromatography high-resolution mass spectrometry. The almost all nanoparticles smaller than 100 nm are reported to reach and deposit in lung periphery, so it is important to reveal the concentration of these dechloranes in nanoparticles. In our study, only DP was detected in PM. DP was detected from all the filter samples. In this study, the particle size distribution of DP was revealed for the first time and the approximately 70 ％ of DP exist in ＜2.5 µm fractions and 10 ％ of DP exist in ＜0.1 µm fractions of PM samples.

We examined measurement methods of Dechlorane Plus (DP) for HRMS-EI and LRMS-NCI in this report. Both linearity of the calibration curves were excellent. IDL towards the LRMS-NCI and air samples towards the HRMS-EI were sensitive, respectively. The results of DP analysis for ambient air, syn-DP: 0.46-7.7 pg/m³, anti-DP: 1.5-16 pg/m³ and Total DP: 2.0-24 pg/m³ were detected, by two of the measurement method. The difference of the measured values had within permissible range. Surrogate recoveries obtained ranged from 90 to 120%. DP concentrations detected in this study was not a particular high value when compared to the concentrations of such POPs that have been literature reports. However, there were detected at a higher concentration than brominated flame retardants.