[Adsorption of Airbone Organophosphorus Flame Retardants on Polished Rice Stored in a House].

In order to clarify the actual situation of indoor pollution to polished rice with organophosphorus flame retardants (PFRs) which are ubiquitous in the indoor environment, the pollution of PFRs to polished rice stored in a house for a week was investigated. The survey covered 64 ordinary families in the Osaka region. We analyzed six typical PFRs in 37 rice samples in 2015, and ten typical PFRs in 27 rice samples in 2016. Polished rice was homogenized with acetone-hexane and defatted by hexane-acetonitrile partition. Quantitative analysis for PFRs was performed by GC-FPD. The detection frequency of PFRs in the rice samples was 35/37 in 2015 and 27/27 in 2016. The highest values were 160 ng/g for TCEP, 500 ng/g for TCIPP and 430 ng/g for TBEP. The concentration ratio of each detected PFR in the polished rice samples was different in each house. In the analysis of 16 polished rice samples which were stored in the home, PFRs were detected in ten samples regardless of the storage methods. PFRs were detected from 12 out of 16 commercial brown rice samples. This result suggested that they were polluted during distribution and storage process of them.

[Chlorpyrifos-Methyl, Pirimiphos-Methyl and Fenitrothion Residues in Commercial Wheat Products].

We measured the concentrations of organophosphorus pesticide （chlorpyrifos-methyl, pirimiphos-methyl and fenitrothion） residues in domestic and imported commercial wheat products （flour, noodles, cookies） collected from 2008 to 2016. Chlorpyrifos-methyl and fenitrothion in domestic flour samples were detected in 16 out of 34 samples at levels of ＜0.001 to 0.016 ppm, and in 14 out of 34 samples at levels of ＜0.001 to 0.004 ppm. Chlorpyrifos-methyl was detected in 22 out of 38 domestic cookies at levels of ＜0.001 to 0.054 ppm （median: 0.001 ppm）. Relatively high concentrations of chlorpyrifos-methyl （0.005 to 0.054 ppm） were found in six domestic cookies containing wheat bran. Pirimiphos-methyl was detected in 32 out of 68 cookies from foreign countries at levels of ＜0.001 to 0.11 ppm. Pirimiphos-methyl was detected frequently in products imported from Europe.

[Determination of S-421 in Commercial Fish and Shellfish].

S-421 is a synergist of pyrethroid and organophosphorus pesticides, which are used as termiticides or household insecticides. S-421 is stable and ubiquitous in the environment. Here we describe the concentrations of S-421 in domestic and imported commercial fish collected from 2009 to 2016. Samples were extracted with acetone/hexane and S-421 was purified on a silica gel column. Quantitative analysis was performed by GC-ECD. S-421 was detected in 78 of 116 samples of domestic fish and shellfish at levels of <0.2 to 2.6 ng/g (mean: 0.4 ng/g), and in 69 of 102 imported samples at a level of <0.2 to 1.5 ng/g (mean: 0.4 ng/g). The concentrations of S-421 in fish were lower than those of p,p'-DDE and similar to those of ß-HCH.