Measurements of neutrino oscillation parameters from the T2K experiment using 3.6×1021 protons on target.

The T2K experiment presents new measurements of neutrino oscillation parameters using 19.7(16.3)×1020 protons on target (POT) in (anti-)neutrino mode at the far detector (FD). Compared to the previous analysis, an additional 4.7×1020 POT neutrino data was collected at the FD. Significant improvements were made to the analysis methodology, with the near-detector analysis introducing new selections and using more than double the data. Additionally, this is the first T2K oscillation analysis to use NA61/SHINE data on a replica of the T2K target to tune the neutrino flux model, and the neutrino interaction model was improved to include new nuclear effects and calculations. Frequentist and Bayesian analyses are presented, including results on sin2θ13 and the impact of priors on the δCP measurement. Both analyses prefer the normal mass ordering and upper octant of sin2θ23 with a nearly maximally CP-violating phase. Assuming the normal ordering and using the constraint on sin2θ13 from reactors, sin2θ23=0.561-0.032+0.021 using Feldman-Cousins corrected intervals, and Δm322=2.494-0.058+0.041×10-3eV2 using constant Δχ2 intervals. The CP-violating phase is constrained to δCP=-1.97-0.70+0.97 using Feldman-Cousins corrected intervals, and δCP=0,π is excluded at more than 90% confidence level. A Jarlskog invariant of zero is excluded at more than 2σ credible level using a flat prior in δCP, and just below 2σ using a flat prior in sinδCP. When the external constraint on sin2θ13 is removed, sin2θ13=28.0-6.5+2.8×10-3, in agreement with measurements from reactor experiments. These results are consistent with previous T2K analyses.

Search for Electron Antineutrino Appearance in a Long-Baseline Muon Antineutrino Beam.

Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40σ and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.

APPLICATION OF PTTL METHOD FOR DOSE REASSESSMENT IN EXTREMITY DOSIMETRY.

Wide and common applications of ionising radiation require continuous improvement of radiation safety and dosimetry methods. The thermoluminescent (TL) method is well known and very popular. Apart from its advantages, it also carries certain disadvantages. The erasure of the TL signal on detector readout and the resulting impossibility of post-readout dose reassessment is one of them. At the Institute of Nuclear Physics, Polish Academy of Sciences (IFJ PAN), a method for dose reassessment based on phototransferred thermoluminescence (PTTL) has been developed. This method has been applied for dose reassessment to MTS-N (LiF:Mg, Ti) detectors used in individual whole-body dosemeters and adjusted to an automatic reader used in routine measurements. The next step was to extend and adapt this method for extremity dosemeters. With the use of the PTTL method, it is possible to reassess relatively high doses measured on individual whole-body and extremity dosemeters collected from our customers after routine use. The influence of PTTL background has greater impact in extremity dosemeters where it is only one and thinner MTS-N detector compared with four MTS-N detectors in whole-body dosemeters. The minimum dose was determined as 5 mSv for extremity dosimetry. Below 5 mSv, the impact of PTTL background is comparable to the signal, and the estimated uncertainty of reassessed dose is at the level of reassessed dose.

The effect of coal stoves and environmental tobacco smoke on the level of urinary 1-hydroxypyrene.

The objective of this study was to investigate a relationship between indoor air pollution from heating and cooking with coal-burning stoves and from environmental tobacco smoke (ETS), and the level of urinary 1-hydroxypyrene (1-OH-PY). 1-OH-PY was analysed in children living in three areas of Silesia, a province in Poland. Urine samples were collected in winter, (1) from children exposed to ETS and smoke resulting from indoor coal-burning and (2) from control children. Airborne particulates had been sampled by use of stationary samplers by the Regional Sanitary-Epidemiological Station, Katowice throughout 12 months prior to the urine sampling. The urinary level of 1-OH-PY tended to increase in children exposed to ETS, but the increase was not significant. The concentrations of 1-OH-PY in urine of passive smokers were significantly elevated only in Bytom where an index of smoking parents of the studied children was highest as compared to other areas. Exposure to polycyclic aromatic hydrocarbons (PAH) due to domestic heating and cooking with coal-burning stoves resulted in significantly increased levels of 1-OH-PY. The results of this study indicate that the uptake of PAH due to indoor air pollution strongly affected the level of 1-OH-PY and that the main source of PAH in indoor air was the household use of coal for heating and/or cooking. When the results associated with this kind of exposure were excluded, median 1-OH-PY levels from the three examined areas assumed a pattern more similar to that of the benzo(a)pyrene (BaP) concentrations in ambient air.

Evaluation of intra- and interindividual variation of urinary 1-hydroxypyrene, a biomarker of exposure to polycyclic aromatic hydrocarbons.

The study was performed on 30, 8-year-old children living in an industrial town of the Upper Silesia region. Morning urine samples were collected on 6 consecutive days. Intraindividual variation of urinary 1-hydroxypyrene concentrations, calculated as a coefficient of variance (CV), ranged from 14 to 109% whereas inter-individual variation ranged from 69 to 109%. Three-way analysis of variance disclosed a significant effect of sex, exposure to environmental tobacco smoke and day of examination on 1-hydroxypyrene concentrations not corrected for creatinine. The appropriate sample size for population studies and the minimum number of observations for the individual assessment of environmental exposure to PAHs calculated on the basis of inter- and intraindividual variability of 1-hydroxypyrene concentrations in urine amounted to 164 and 99, respectively. Urinary 1-hydroxypyrene may be considered a good indicator of environmental exposure to PAHs at the group level.

Exposure of coke-oven workers to polycyclic aromatic hydrocarbons based on biological monitoring results.

This study assessed the exposure of coke-oven workers to polycyclic aromatic hydrocarbons (PAH) based on two methods of biological monitoring (urinary mutagenicity by Ames test and urinary 1-hydroxypyrene) and concentrations of benzo(a)pyrene in the air collected by personal sampling. The coke-oven workers were classified into four job categories. There was no significant correlation among three methods applied. According to all methods, the workers most exposed to PAH were those working at the topside area of the coke plant, Coke-oven workers excreted significantly more mutagenic substances and 1-hydroxypyrene (HpU) in urine than the controls. Mutagenic substances in urine of coke-oven workers and the control group were detected only with TA98 after metabolic activation. Median HpU levels of coke-oven workers classified into three job categories (A, B, C) exceeded the biological exposure limit. The effect of smoking on urinary mutagenicity and urinary 1-hydroxypyrene was statistically significant.

Can we detect mutagenic activity of urinary sediment by the Ames test?

Using the Salmonella typhimurium strain TA98 we tested the mutagenicity of filtrate and sediment of urine collected from children and coke-oven workers living in the town of Dabrowa Górnicza. Mutagenic substances were detected in samples of urinary filtrate taken either from environmentally exposed children or from occupationally exposed coke-oven workers. The mutagenic effect was found only in acetone extracts of urinary filtrate in the presence of promutagenic activating fraction S9. Beta-glucuronidase/arylsulphatase treatment hydrolysed the conjugates contained urinary filtrate into compounds that were toxic towards tester strain. The mutagenic effect of urine should be tested only in urinary filtrate as we have never detected mutagenic substances in urinary sediment.

[Test for the effects of mutagenic toxic fungal metabolites originating from municipal landfill sites]. / Badanie efektu mutagennego metabolitów grzybów toksynotwórczych pochodzacych z wysypiska odpadów komunalnych.

The purpose of the study is to assess the mutagenic effect of mycotoxins produced by moulds growing on municipal landfill sites. Mutagenicity of toxic fungal metabolites was determined by the Salmonella plate incorporation assay with two strains of bacteria: TA98 and TA100, with and without metabolic activation. The results obtained indicate that there is a severe hazard caused by these mycotoxins detected main by TA98 with metabolic activation. The most mutagenic mixture of mycotoxins acting directly on both strains was produced by Aspergillus nidulans. The highest mutagenic effect detected by TA98 with metabolic activation was found in the mixture of mycotoxins produced by one of three isolated Aspergillus fumigatus varieties.