Factors associated with prehospital death among traffic accident patients in Osaka City,Japan: A population-based study

Objective: Although it is important to assess the factors associated with traffic accident fatalities to decrease them as a matter of public health, such factors have not been fully identified.

Methods: Using a large-scale data set of ambulance records in Osaka City, Japan, we retrospectively analyzed all traffic accident patients transported to hospitals by emergency medical service personnel from 2013 to 2014. In this study, prehospital death was defined as that occurring at the scene or in the emergency department immediately after hospital arrival. We assessed prehospital factors associated with prehospital death due to traffic accidents by logistic regression models.

Results: This study enrolled 28,903 emergency patients involved in traffic accidents, of whom 68 died prehospital. In a multivariate model, elderly patients aged ≥75 years (adjusted odds ratio [AOR] = 4.34; 95% confidence interval [CI], 2.29–8.23), nighttime (AOR = 2.75; 95% CI, 1.65–4.70), and type of injured person compared to bicyclists such as pedestrians (AOR = 9.58; 95% CI, 5.07–17.99), motorcyclists (AOR = 2.75; 95% CI, 1.21–6.24), and car occupants (AOR = 2.98; 95% CI, 1.39–6.40) were significantly associated with prehospital death due to traffic accidents. In addition, the AOR for automobile versus nonautomobile as the collision opponent was 4.76 (95% CI, 2.30–9.88).

Conclusions: In this population, the factors associated with prehospital death due to traffic accidents were elderly people, nighttime, and pedestrian as the type of patient. The proportion of prehospital deaths due to traffic accidents was also high when the collision component was an automobile.     

Relationship of urinary arsenic metabolites to intake estimates in residents of the Red River Delta, Vietnam

This study investigated the status of arsenic (As) exposure from groundwater and rice, and its methylation capacity in residents from the Red River Delta, Vietnam. Arsenic levels in groundwater ranged from <1.8 to 486 μg/L. Remarkably, 86% of groundwater samples exceeded WHO drinking water guideline of 10 μg/L. Also, estimated inorganic As intake from groundwater and rice were over Provisional Tolerable Weekly Intake (15 μg/week/kg body wt.) by FAO/WHO for 92% of the residents examined. Inorganic As and its metabolite (monomethylarsonic acid and dimethylarsinic acid) concentrations in human urine were positively correlated with estimated inorganic As intake. These results suggest that residents in these areas are exposed to As through consumption of groundwater and rice, and potential health risk of As is of great concern for these people. Urinary concentration ratios of dimethylarsinic acid to monomethylarsonic acid in children were higher than those in adults, especially among men, indicating greater As methylation capacity in children.     

Concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls in blood and breast milk collected from 60 mothers in Sapporo City, Japan

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho polychlorinated biphenyls (non-ortho PCBs), and mono-ortho polychlorinated biphenyls (mono-ortho PCBs) in paired samples of blood and breast milk collected from 60 mothers in Sapporo City, Hokkaido Prefecture, Japan. The present study is one of the few studies in which PCDDs, PCDFs, and dioxin-like PCBs have been measured in blood and breast milk collected from 60 same mothers. Of these 60 mothers, 30 were primipara (mean: 30.1 years, median: 28.0 years) and 30 were multipara (mean: 32.2 years, median: 32.5 years). The arithmetic mean TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk of the primiparous mothers were 9.0, 3.3, 5.7, and 0.4 pg TEQ g(-1) lipid, respectively, and 5.2, 2.2, 4.5, and 0.4 pg TEQ g(-1) lipid, respectively, with the total TEQ concentrations of these dioxin-like compounds being 9.3-42.9 (mean: 18.4, median: 17.3) and 7.0-41.1 (mean: 12.3, median: 11.4) pg TEQ g(-1) lipid, respectively. In the case of multiparous mothers, the arithmetic mean TEQ concentrations of these dioxin-like compounds in blood and breast milk were 7.1, 2.7, 5.3, and 0.4 pg TEQ g(-1) lipid, respectively, and 3.9, 1.7, 3.8, and 0.4 pg TEQ g(-1) lipid, respectively, with the total TEQ concentrations being 3.4-28.1 (mean: 15.5, median: 13.9) and 2.7-20.0 (mean: 9.8, median: 9.2)pg TEQ g(-1) lipid, respectively. The total TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk of primiparous mothers in Sapporo City appeared to be generally lower than those recently surveyed throughout the greater area of Japan. Significant correlations were observed between age and the total TEQ concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in the blood of primiparae and multiparae, and significant correlations were also observed between age and the total TEQ concentrations of these dioxin-like compounds in the breast milk of primiparae and multiparae. The total TEQ concentrations of PCDDs, PCDFs, and dioxin-like PCBs in the blood of primiparous mothers showed a close correlation to those in their breast milk and also showed good correlations between the total TEQ concentrations of these dioxin-like compounds in the blood of multiparous mothers and those in their breast milk. The result of a comparison of the arithmetic mean concentrations of each congener of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in blood and breast milk indicated that the transfer of octachlorodibenzo-p-dioxin (OCDD) from the blood to the breast milk was lower than those of other congeners. In contrast, among mono-ortho PCBs congeners, the arithmetic mean concentrations of 2,3',4,4',5-pentachlorobiphenyl (PentaCB) (#118) and 2,3,3',4,4'-PentaCB (#105) in the breast milk were slightly higher than those in the blood, which suggested that breast-fed infants may be at higher risk from mono-ortho PCBs.     

Congener-specific analysis of non-dioxin-like polychlorinated biphenyls in blood collected from 195 pregnant women in Sapporo City, Japan

We conducted a congener-specific analysis of non-dioxin-like polychlorinated biphenyls (non-dioxin-like PCBs) in blood collected between July 2002 and July 2004 from 195 pregnant women living in Sapporo City of Hokkaido Prefecture, Japan. The present study is one of the few studies in which full congener concentrations of non-dioxin-like PCBs have been measured in the blood of pregnant women. Of the 195 pregnant women, 101 were primipara (mean: 28.8 years, median: 28.0 years) and 94 were multipara (mean: 32.3 years, median: 33.0 years). Among the 197 non-dioxin-like PCB congeners, 58 congeners were identified in the blood of pregnant women. The arithmetic mean total concentrations of 58 non-dioxin-like PCB congeners in the blood of primiparous and multiparous mothers in Sapporo City were 42.2-329.3 (mean: 114.5, median: 98.6) and 31.5-258.0 (mean: 100.3, median: 91.4)ngg(-1)lipid, respectively. The results show that the contamination of non-dioxin-like PCBs in the blood of women has decreased compared to past levels in other domestic areas, in which the subject age was similar to that in this study. The results of the present study indicate that current levels of non-dioxin-like PCBs in the blood of Japanese women and can be used as baseline data for future temporal trends. The sums of the ratios of the concentrations of hexaCBs and heptaCBs to the total concentrations of 58 non-dioxin-like PCB congeners in the blood of primiparous and multiparous mothers were 78.5% and 77.7%, respectively. The hexaCBs ratios in the blood of primiparous and multiparous mothers were 45.4% and 44.7%, respectively. HexaCB-153 among hexaCBs congeners, the most abundant congener in the blood of primiparous and multiparous mothers, contributed approximately 22.0% and 21.8% to the total concentrations of 58 non-dioxin-like PCBs congeners that were measured in the blood, respectively. Among the non-dioxin-like PCB congeners measured in the present study, hexaCB-138, heptaCB-170, heptaCB-180, and heptaCB-182/heptaCB-187 also showed high ratios to total concentrations of 58 non-dioxin-like PCB congeners detected in the blood of primiparous and multiparous mothers. With regard to the relationship between the total concentrations of 58 non-dioxin-like PCB congeners in maternal blood and the number of deliveries or the age of primiparous and multifarious mothers, the total levels of these PCB congeners tended to decreases with increases in the number of deliveries and significantly increased with increasing maternal age in both groups. Furthermore, significant correlations were observed between the total concentrations of these PCB congeners in blood and the age of primiparae and multiparae. The concentrations of hexaCB-153 in the blood of primiparous and multiparous mothers showed a close correlation to the total concentrations of these PCBs, suggesting that hexaCB-153 could be an indicator of total concentrations of non-dioxin-like PCB congeners in the blood of pregnant women.     

Concentrations of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and non-ortho and mono-ortho polychlorinated biphenyls in blood of Yusho patients

We measured the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), non-ortho polychlorinated biphenyls (non-ortho PCBs) and mono-ortho polychlorinated biphenyls (mono-ortho PCBs) in blood collected from 279 Yusho patients living in Japan, 92 Yusho-suspected persons living in Japan and 127 normal controls living in Fukuoka Prefecture, and compared among the groups in terms the concentrations of these compounds. The total toxic equivalents (TEQ) concentrations of PCDDs, PCDFs, non-ortho PCBs, and mono-ortho PCBs in the bloods of Yusho patients and Yusho-suspected persons were 161.4 and 51.2 pg TEQ/g lipid, respectively and were about 3.5 and 1.1 times higher than those of normal controls, respectively. Although the TEQ concentrations of PCDDs, non-ortho PCBs, and mono-ortho PCBs among Yusho patients, Yusho-suspected persons and normal controls were nearly the same, the PCDFs levels of Yusho patients were significantly higher than those of Yusho-suspected persons and about 10.3 times higher than those of normal controls. In Yusho patients, PCDFs contributed about 65% to the total TEQ concentration. Among the PCDFs congeners for Yusho patients, the concentration of 2,3,4,7,8-pentachlorodibenzofuran (PeCDF) was about 11.3 times higher than that of normal controls. These findings indicated that Yusho patients even now, more than 34 years after the outbreak of Yusho, have much higher blood levels of 2,3,4,7,8-PeCDF in general than do unaffected persons.     

PCB decomposition and formation in thermal treatment plant equipment

In this study we investigated both the decomposition and unintentional formation of polychlorinated biphenyl congeners during combustion experiments of refuse-derived fuel (RDF) and automobile shredder residue (ASR) at several stages in thermal treatment plant equipment composed of a primary combustion chamber, a secondary combustion chamber, and other equipments for flue gas treatment. In both experiments, the unintentional formation of PCB occurred in the primary combustion chamber at the same time as the decomposition of PCB in input samples. By combusting RDF, non-ortho-PCB predominantly formed, whereas ortho-PCB and symmetric chlorinated biphenyls (e.g., #52/69, #87/108, and #151) tended to be decomposed. ASR formed the higher chlorinated biphenyls more than RDF. These by-products from ASR had no structural relation with ortho-chlorine. Lower chlorinated biphenyls appeared as predominant homologues at the final exit site, while all congeners from lower to higher chlorinated PCB were unintentionally formed as by-products in the primary combustion chamber. This result showed that the flue gas treatment equipments effectively removed higher chlorinated PCB. Input marker congeners of RDF were #11, #39, and #68, while those for ASR were #11, #101, #110/120, and #118. Otherwise, combustion marker congeners of RDF were #13/12, #35, #77, and #126, while those for ASR were #170, #194, #206, and #209. While the concentration of PCB increased significantly in the primary combustion chamber, the value of toxicity equivalency quantity for dioxin-like PCB decreased in the secondary combustion chamber and the flue gas treatment equipments.     

Recycling process for yttria-stabilized tetragonal zirconia ceramics using a hydrothermal treatment

The recycling process for 3 mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP) sintered at 1450°–1550°C was examined by applying low-temperature degradation of zirconia ceramics under hydrothermal conditions. Hydrothermal treatment at a temperature from 200° to 240°C can lead to the spontaneous disintegration of 3Y-TZP sintered bodies into powdery particles. The hydrothermally obtained zirconia powder was found to consist of primary particles and aggregated particles. Detailed X-ray diffraction measurement revealed the formation of a cubic zirconia phase in the 3Y-TZP sintered bodies, which seemed to inhibit the disintegration of aggregated particles toward the primary particle level. The reclaimed 3Y-TZP powder was sintered again through a conventional powder processing route. The mechanical properties and microstructure of recycled 3Y-TZP sintered specimens were examined by comparison with those of the original 3Y-TZP sintered bodies. Dense recycled 3Y-TZP sintered at a higher temperature exhibited higher fracture toughness to some degree than the original 3Y-TZP.     

Paper fibers as a carbon source for the de novo formation of polychlorinated dioxins and furans

The formation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/Fs) from carbon that was produced by the pyrolysis of paper fibers and from wood charcoal was investigated experimentally. Fibers obtained from filter paper were pyrolyzed at 300° and 800°C to produce low- and high-temperature carbon samples. The two types of carbon and wood charcoal were mixed with silica (SiO₂) and trace copper oxide to produce three synthetic fly ash samples. Experiments to measure the formation of PCCDs/Fs from the three ash samples were conducted using a bench-scale reactor. The two carbon samples derived from paper fibers generated more PCDDs/Fs than was generated by the wood charcoal. The PCDDs/Fs generated by the low-temperature carbon and by the wood charcoal were dominated by the lower-chlorinated PCDFs. Such unique homologue distribution patterns are very similar to those generated by the open burning of household waste. The high-temperature carbon generated more highly chlorinated PCDDs/Fs. The effect of pyrolysis temperature on the de novo formation of PCDDs/Fs from residual carbon is discussed. Paper and paper products contained in household waste are likely to be the source of unburned carbon that contributes to high PCDD/F emissions in the open burning of household waste.