Estimation of β-ray dose in air and soil from Fukushima Daiichi Power Plant accident

Following the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident of 2011, which deposited radionuclides across Tohoku and northern Kanto, β-ray dose evaluation has been performed to estimate radiation exposure for small creatures like insects as well as human skin. Using the Monte Carlo radiation transport code MCNP-4C, we calculated the β-ray dose for ^129mTe, ¹²⁹Te, ¹³¹I, ¹³²Te, ¹³²I, ¹³⁴Cs and ¹³⁷Cs in air as a function of altitude and in soil. These calculations of β-dose rate for each radionuclide were conducted for the conditions following the FDNPP accident, with ¹³⁷Cs deposition assumed to be 1000 kBq/m². Beta-ray dose rate was found to be ∼10-fold (resp. 5-fold) higher than the γ-ray dose rate in the soil (resp. on the ground surface) at ∼20 days after deposition, and ∼4-fold (resp. 1.7-fold) higher after 6 months or more. For convenience, the height dependence of the ratio for 0, 10, 30, 90, 180 and 365 days after deposition was obtained by a fitting function. The cumulative 70 µm β-ray dose at 30, 60 and 90 days after deposition was estimated to be 35, 45 and 53 mGy for the ground surface, and 61, 79 and 92 mGy in the soil, respectively. These results can be used to estimate the external β-ray exposure for small creatures as well as for human skin.     

Reconstruction of the ingestion doses received by the population evacuated from the settlements in the 30-km zone around the Chernobyl reactor.

As a consequence of the Chernobyl accident, about 50,000 people were evacuated from the settlements in the 30-km zone around the reactor in the period 3-11 d after the accident. As no countermeasures were implemented in the early phase, people continued to consume milk and some leafy vegetables. In this paper, average effective ingestion doses are modeled for evacuees. Input data for the assessment are the 137Cs activity per unit area, the ratios of the radionuclides relative to 137Cs, the mean day of evacuation, and intake rates for milk and green vegetables. The transfer of radionuclides from deposition to humans is estimated by modeling radionuclide interception by vegetation, weathering, and the time-dependent transfer of radionuclides to milk taking into account site-specific agricultural practices. Depending on the evacuation day and site, the estimated ingestion doses for the settlements are in the range of 20 to 1,300 mSv and 3 to 180 mSv for infants and adults, respectively. 131I is by far the most important isotope, the ingestion dose due to 133I is more than one order of magnitude lower. The most exposed organ is the thyroid, inducing more than 80% and 50% of the ingestion dose for infants and adults. The ingestion doses are compared to the doses due to inhalation and external exposure. The internal dose exceeds the external by a factor of about 2-10 for adults and 2-40 for 1-y-old infants depending on site and evacuation day. The thyroid doses assessed for the evacuees are consistent with results achieved in studies performed in areas outside the 30-km zone.     

Preliminary assessment of ecological exposure of adult residents in Fukushima Prefecture to radioactive cesium through ingestion and inhalation

Objective

This study aims to estimate the ecological exposure of adult residents of Fukushima Prefecture to ¹³⁴cesium (Cs) and ¹³⁷Cs through ingestion and inhalation between July 2 and July 8, 2011.

Methods

Fifty-five sets of meals with tap water, each representing one person’s daily intake, were purchased in local towns in Fukushima Prefecture. Locally produced cow’s milk (21 samples) and vegetables (43 samples) were also purchased. In parallel, air sampling was conducted at 12 different sites using a high-volume sampler. Nineteen sets of control meals were collected in Kyoto in July 2011. ¹³⁴Cs and ¹³⁷Cs levels in the samples were measured using a germanium detector.

Results

Radioactivity was detected in 36 of the 55 sample meals from Fukushima, compared with one of 19 controls from Kyoto. The median estimated dose level (μSv/year) was 3.0, ranging from not detectable to 83.1. None of the cow’s milk (21) or vegetable (49) samples showed levels of contamination above the current recommended limits (Bq/kg) of 200 for milk and 500 for vegetables. The total effective dose levels by inhalation were estimated to be <3 μSv/year at nine locations, but samples at three other locations close to the edge of the 20-km radius from the crippled nuclear power plant showed higher levels of contamination (μSv/year): 14.7 at Iitate, 76.9 at Namie, and 27.7 at Katsurao.

Conclusions

Levels of exposure to ¹³⁴Cs and ¹³⁷Cs in Fukushima by ingestion and inhalation are discernible, but generally within recommended limits.

Electronic supplementary material

The online version of this article (doi:10.1007/s12199-011-0251-9) contains supplementary material, which is available to authorized users.     

High body mass index and cancer risk—a Mendelian randomisation study

High body mass index (BMI) has been associated with increased risk of some cancer. Whether these reflect causal associations is unknown. We examined this issue. Using a Mendelian randomisation approach, we studied 108,812 individuals from the general population. During a median of 4.7 years of follow-up (range 0–37), 8002 developed non-skin cancer, 3347 non-melanoma skin cancer, 1396 lung cancer, 637 other smoking related cancers, 1203 colon cancer, 159 kidney cancer, 1402 breast cancer, 1062 prostate cancer, and 2804 other cancers. Participants were genotyped for five genetic variants associated with BMI. Two Danish general population studies, the Copenhagen General Population and the Copenhagen City Heart Study. In observational analyses, overall risk of non-melanoma skin cancer was 35 % (95 % confidence interval 28–42 %) lower and risk of lung cancer 32 % (19–43 %) lower in individuals with a BMI ≥ 30 versus 18.5–24.9 kg/m². Corresponding risk of breast cancer was 20 % (0–44 %) higher in postmenopausal women. BMI was not associated with risk of colon, kidney, other smoking related cancers, prostate cancer, or other cancers. In genetic analyses, carrying 7–10 versus 0–4 BMI increasing alleles was associated with a 3 % higher BMI (P < 0.001), but not with risk of cancer. In instrumental variable analysis for a 10 kg/m² higher genetically determined BMI the odds ratio for any non-skin cancer was 1.16 (0.64–2.09), with a corresponding observational estimate of 0.94 (0.88–1.01). Using 108,812 individuals from the general population, we found that observationally high BMI was associated with lower risk of lung and skin cancer overall and with higher risk of breast cancer in postmenopausal women, but not with other types of cancer. BMI increasing alleles were not associated with risk of cancer, and results do not support causal associations. Power to test associations for some cancer sites was low.     

Measuring the external exposure dose in the contaminated area near the Chernobyl nuclear power station using the thermoluminescence of quartz in bricks

We collected bricks from buildings in the heavily contaminated evacuated area of Belarus in a 30-km zone around the Chernobyl nuclear power station and the Gomel-Bryansk area of 150-250 km from Chernobyl and estimated the cumulative radiation dose caused by the reactor accident by measuring the thermoluminescence (TL) of the bricks. The annual dose at each location was measured using glass dosimeters and thermoluminescence dosimeters (TLD). The dose rate was measured using an energy-compensated NaI scintillation survey meter. The soil contamination near the location of each brick was measured using a germanium semiconductor detector. The main purpose of the project was to extrapolate the relation between the cumulative external dose and the present dose rate or contamination level to the lower contaminated areas. The results of the glass dosimeter, TLD, and survey meter determinations were almost identical. For a determination of the annual dose higher than 10 mGy y(-1), the cumulative dose by TL (TL dose) was roughly proportional to the annual dose and about 1.5 times larger than the cumulative dose calculated from the annual dose and 137Cs half life. The difference is expected due to the contribution of short-lived nuclides immediately after the accident or localized heavy contamination of the ground surface with 137Cs that migrated afterwards. For annual dose smaller than 10 mGy y(-1), the proportionality was not observed and most of the locations facing indoors showed TL doses very much larger than that expected from the proportionality. The cumulative dose outdoors by TL was also roughly proportional to the regional 137Cs contamination level and the proportional constant is about 10(-1) mGy per GBq km(-2), and is about 250 times larger than the present annual internal dose derived from published results. The correlation between the present dose rate where the brick was sampled and the average 137Cs concentration in the ground soil near the point is not clear, possibly because of the large spatial fluctuation in the 137Cs concentration in the soil.     

Establishment of the central radiation dose registration system for decontamination work involving radioactive fallout emitted by the Fukushima Daiichi APP accident

With respect to radiation protection for decontamination efforts involving radioactive fallout emitted by the accident at the Fukushima Daiichi Atomic Power Plant, new regulations were established and obligated employers to monitor, record, and store of workers' dose records, and to check their past dose records at the time of employment. However, cumulative doses may not be properly maintained if a worker declares incorrect values for past doses. In response, with facilitation from the Ministry of Health, Labour and Welfare, primary contractors of decontamination works decided to establish a central dose registration system. There are four major issues in the design of the system to be resolved, included the following: primary contractors (a) do not have a legal responsibility to perform dose control for subcontractors, (b) do not have the right to control decontamination sites, (c) often organize joint ventures, and (d) correspond to a wide range of ambient dose rates. To resolve the issues, requirements of the system included the following: (a) centralize the operation of radiation passbooks, which records past doses and the results of medical examinations to each worker; (b) develop a database system that could register all dose data and accept inquiry from primary contractors; (c) establish a permanent data storage system for transferred records; and (d) provide graded type of services that are appropriate to the risk of radiation exposure. The system started its operation in December 2013 and provided dose distributions in April and July 2015. The average yearly dose in 2014 was 0.7 mSv, which increased by 0.2 mSv from 0.5 mSv in 2012 and 2013. However, no cumulative dose from 2012–2014 exceeded 20 mSv, which was far below than the dose limits (100 mSv/5 years and 50 mSv/year). Although current dose distributions of decontamination workers were within appropriate levels, careful monitoring of dose distribution is necessary for preserving the proper implementation of radiation protection prescribed in the regulations.     

Reconstruction of the inhalation dose in the 30-km zone after the Chernobyl accident.

Due to lack of measurements of activity concentrations in air, the assessment of the inhalation dose of the population evacuated from the 30-km zone after the Chernobyl accident is not possible from continuous filter measurements. Since the evaluation of the inhalation dose in each settlement of the zone is of great interest for epidemiological purposes, an approach was chosen that utilizes the available data on ground deposition of 137Cs, a recently performed best estimate of the radionuclide vector and its spatial distribution as well as the radionuclide dependent deposition velocity. The derived inhalation dose values in the 30-km zone range between 3 mSv to 150 mSv effective dose for adults depending on the distance to the reactor site and the day of evacuation. For 1-y-old infants the values range between 10 to 700 mSv. In Chernobyl town, an effective inhalation dose of 25 mSv until evacuation day was assessed. Thyroid doses due to inhalation ranged from 0.02 to 1 Sv for adults, for 1-y-old infants from 0.02 to 6 Sv. The inhalation dose in each settlement of the 30-km zone is approximately 8-13 times higher than the external exposure in each settlement if evacuation of the settlement occurred at an early stage. For settlements with evacuation at a later stage (day 10 or later) the inhalation dose was about 50-70% higher than the external dose. The dominant contribution to the effective inhalation dose comes from 131I (about 40%) and tellurium and rubidium isotopes (about 20-30%). Despite high zirconium and cerium ground depositions, zirconium and cerium isotopes contribute rather little to the inhalation dose which is mainly due to the great particle sizes to which they are attached. The relative contribution of short-lived radionuclides is, despite higher activities than at greater distances, less than 5%.     

Dependence of radiation dose on the behavioral patterns among school children: a retrospective analysis 18 to 20 months following the 2011 Fukushima nuclear incident in Japan

After radioactive incidents, the exposure risk in daily activities among children is a major public concern. However, there are limited methods available for evaluation of this risk, which is essential to future health risk management. To this end, this study assessed the relationship between behavioral patterns of school children and radiation exposure for a period of 18–20 months following the 2011 Fukushima nuclear incident. The assessed population comprised 520 school children from Minamisoma city, located 20 km north of the nuclear plant. Data for the doses were obtained using individual dosimeters and from results of a behavior survey administered by the City Office. The mean value of the doses in the study period was 0.34 mSv, with a standard deviation of 0.14 mSv, indicating an annual dose of ∼1.36 mSv, which includes doses from natural sources. Our results showed that behavior with respect to outdoor activities had no statistically significant relationship to the dose. A 0.1 μSv/h increase in the air dose rate at home was associated with a 10% increase in the dose; however, a 0.01 μSv/h increase in the air dose rate on the school grounds was associated with a 2% increase in the dose. This study indicates that the air contamination levels at the places where children spend most of their day are the significant predictors of the dose, as opposed to the levels at those outdoor locations in which short periods of time spent.     

The peripheral dose outside the applicator in electron beams of an Elekta linear accelerator

Peripheral doses out of field could have short and long terms biological effects on patients treated with electron beams. In this study, peripheral dose outside the applicator was measured using the 6, 10 and 18 MeV beams of an Elekta synergy linac. For these beams dose profiles were measured using EBT3 film at various depths within a solid water phantom. Measurements were performed using 6?×?6, 10?×?10, 14?×?14 and 20?×?20 cm² applicators at gantryangles of 0°, 10° and 20° and depths of 0, 0.5, 1 cm and depth of Dmax (maximum dose) for each energy. The peripheral dose profiles were normalized to the distance of 2 cm from the edge of each field. The largest peak of the peripheral dose was observed for 18 MeV 3 cm from the outer edge of the applicator. Peak dose increased with increasing energy. Peak dose at 18 MeV electron beam was 1.6% at the surface of phantom and at the distance of 2 cm from the outer edge of the applicator when the applicator of 20?×?20 cm² was used. Peak dose at 6 MeV electron beam was 1.15% at the same distance in the same applicator size. It was found that the peak dose decreased with increasing depth and increased with increase in field size. Also, the peak dose moved towards CAX with increase in gantry angle.In general dose to tissue out of field could be reduced using appropriate shielding for each applicator and beam energy.     

Occupational radiation exposure and risk of cataract incidence in a cohort of US radiologic technologists

It has long been known that relatively high-dose ionising radiation exposure (>?1 Gy) can induce cataract, but there has been no evidence that this occurs at low doses (<?100 mGy). To assess low-dose risk, participants from the US Radiologic Technologists Study, a large, prospective cohort, were followed from date of mailed questionnaire survey completed during 1994–1998 to the earliest of self-reported diagnosis of cataract/cataract surgery, cancer other than non-melanoma skin, or date of last survey (up to end 2014). Cox proportional hazards models with age as timescale were used, adjusted for a priori selected cataract risk factors (diabetes, body mass index, smoking history, race, sex, birth year, cumulative UVB radiant exposure). 12,336 out of 67,246 eligible technologists reported a history of diagnosis of cataract during 832,479 person years of follow-up, and 5509 from 67,709 eligible technologists reported undergoing cataract surgery with 888,420 person years of follow-up. The mean cumulative estimated 5-year lagged eye-lens absorbed dose from occupational radiation exposures was 55.7 mGy (interquartile range 23.6–69.0 mGy). Five-year lagged occupational radiation exposure was strongly associated with self-reported cataract, with an excess hazard ratio/mGy of 0.69?×?10^?3 (95% CI 0.27 ×?10^?3 to 1.16 ×?10^?3, p?<?0.001). Cataract risk remained statistically significant (p?=?0.030) when analysis was restricted to?<?100 mGy cumulative occupational radiation exposure to the eye lens. A non-significantly increased excess hazard ratio/mGy of 0.34?×?10^?3 (95% CI ??0.19?×?10^?3 to 0.97?×?10^?3, p?=?0.221) was observed for cataract surgery. Our results suggest that there is excess risk for cataract associated with radiation exposure from low-dose and low dose-rate occupational exposures.     

Water equivalence evaluation of PRESAGE® formulations for megavoltage electron beams: a Monte Carlo study

To investigate the radiological water equivalency of three different formulations of the radiochromic, polyurethane based dosimeter PRESAGE^® for three dimensional (3D) dosimetry of electron beams. The EGSnrc/BEAMnrc Monte Carlo package was used to model 6–20 MeV electron beams and calculate the corresponding doses delivered in the three different PRESAGE^® formulations and water. The depth of 50 % dose and practical range of electron beams were determined from the depth dose calculations and scaling factors were calculated for these electron beams. In the buildup region, a 1.0 % difference in dose was found for all PRESAGE^® formulations relative to water for 6 and 9 MeV electron beams while the difference was negligible for the higher energy electron beams. Beyond the buildup region (at a depth range of 22–26 mm for the 6 MeV beam and 38 mm for the 9 MeV beam), the discrepancy from water was found to be 5.0 % for the PRESAGE^® formulations with lower halogen content than the original formulation, which was found to have a discrepancy of up to 14 % relative to water. For a 16 MeV electron beam, the dose discrepancy from water increases and reaches about 7.0 % at 70 mm depth for the lower halogen content PRESAGE^® formulations and 20 % at 66 mm depth for the original formulation. For the 20 MeV electron beam, the discrepancy drops to 6.0 % at 90 mm depth for the lower halogen content formulations and 18 % at 85 mm depth for the original formulation. For the lower halogen content PRESAGE^®, the depth of 50 % dose and practical range of electrons differ from water by up to 3.0 %, while the range of differences from water is between 6.5 and 8.0 % for the original PRESAGE^® formulation. The water equivalent depth scaling factor required for the original formulation of PRESAGE^® was determined to be 1.07–1.08, which is larger than that determined for the lower halogen content formulations (1.03) over the entire beam energy range of electrons. All three of the PRESAGE^® formulations studied require a depth scaling factor to convert depth in PRESAGE^® to water equivalent depth for megavoltage electron beam dosimetry. Compared to the original PRESAGE^® formulation, the lower halogen content formulations require a significantly smaller scaling factor and are thus recommended over the original PRESAGE^® formulation for electron beam dosimetry.     

Persistence Behaviour of Fungicide Tebuconazole in a Viticulture Application

Dissipation pattern and risk assessment of tebuconazole in grapes was studied following two application rates (250 and 500 mL ha^?1) under tropical humid climatic condition of West Bengal during 2009–2010. Residues of tebuconazole were confirmed by liquid chromatography–mass spectrometry. The average recoveries were found 87.53 % and 89.67 % for grapes and cropped soil respectively. Following the first order kinetics the fungicide dissipates in grapes with a half-life (T_1/2) value ranges between 2.62 and 2.86 days irrespective of seasons and doses. No residues of tebuconazole were detected in harvest grapes and soil samples which refers that, tebuconazole does not possess any background contamination property in grapes. So it may be concluded from the study that tebuconazole does not possess any toxicological property when applied at the recommended dose.     

Body mass index,abdominal fatness,weight gain and the risk of psoriasis: a systematic review and dose–response meta-analysis of prospective studies

Greater body mass index (BMI) has been associated with increased risk of psoriasis in case–control and cross-sectional studies, however, the evidence from prospective studies has been limited. We conducted a systematic review and dose–response meta-analysis of different adiposity measures and the risk of psoriasis to provide a more robust summary of the evidence based on data from prospective studies. PubMed and Embase databases were searched for relevant studies up to August 8th 2017. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using a random effects model. The summary relative risk (RR) for a 5 unit increment in BMI was 1.19 (95% CI 1.10–1.28, I² = 83%, n = 7). The association appeared to be stronger at higher compared to lower levels of BMI, p_nonlinearity < 0.0001, and the lowest risk was observed at a BMI around 20. The summary RR was 1.24 (95% CI 1.17–1.31, I² = 0%, p_{heterogeneity} = 0.72, n = 3) per 10 cm increase in waist circumference, 1.37 (95% CI 1.23–1.53, I² = 0%, p_{heterogeneity} = 0.93, n = 3) per 0.1 unit increase in waist-to-hip ratio, and 1.11 (95% CI 1.07–1.16, I² = 47%, p_{heterogeneity} = 0.15, n = 3) per 5 kg of weight gain. Adiposity as measured by BMI, waist circumference, waist-to-hip ratio, and weight gain is associated with increased risk of psoriasis.     

The effect of grid resolution on estimates of the burden of ozone and fine particulate matter on premature mortality in the USA

Assessments of human health impacts associated with outdoor air pollution often use air quality models to represent exposure, but involve uncertainties due to coarse model resolution. Here, we quantify how estimates of mortality in the USA attributable to ozone (O₃) and fine particulate matter (PM_2.5) at coarse resolution differ from those at finer resolution. Using the finest modeled concentrations (12 km), we estimate that 66,000 (95 % CI, 39,300–84,500) all-cause and 21,400 (5,600–34,200) respiratory deaths per year are attributable to PM_2.5 and O₃ concentrations above low-concentration thresholds, respectively. Using model results at 36 km resolution gives mortality burdens that are 11 % higher for PM_2.5 and 12 % higher for O₃ than the 12-km estimates, suggesting a modest positive bias. We also scale modeled concentrations at 12 km to coarser resolutions by simple averaging and repeat the mortality assessment at multiple resolutions from 24 to 408 km, including the resolutions of global models; in doing so, we account for the effect of resolution on population exposure. Coarse grid resolutions produce mortality estimates that are substantially biased low for PM_2.5 (30–40 % lower than the 12-km estimate at >250 km resolution), but less than 6 % higher for O₃ at any resolution. Mortality estimates for primary PM_2.5 species show greater bias at coarse resolution than secondary species. These results suggest that coarse resolution global models (>100 km) are likely biased low for PM_2.5 health effects. For ozone, biases due to coarse resolution may be much smaller, and the effect on modeled chemistry likely dominates.     

Respiratory deposition and health risk of inhalation of particle-bound heavy metals in the carbon black feeding area of a tire manufacturer

The health effects of metal-containing carbon black (CB) particles obtained from the CB feeding area of a tire manufacturing plant were investigated. Atmospheric samples were collected over 24 h for 20 working days in 2016 using the 12 impaction stages of micro-orifice uniform deposit impactor, and metal-containing particles were analyzed using an inductively coupled plasma optical emission spectrometer. The concentration of total particulate matter in the CB feeding area was 944.8 ± 456.4 μg/m³, and the most abundant elements in the samples include Zn (8622.0 ± 5679.0 ng/m³), Al (3113.3 ± 2017.1 ng/m³), and Fe (1519.1 ± 875.0 ng/m³). Carcinogenic metals (Cd, Co, Cr, and Ni) with the mass median diameter were incorporated in submicron particles. The mean total deposition flux in the head airway (HA) region was approximately 16–30 times higher than that in the tracheobronchial (TB) region and alveolar region (AR). The most abundant deposition flux of heavy metals in the AR and TB region was distributed in particles of less than 3.2 μm. The cancer risk presented by carcinogenic metals (Cd, Co, Cr, and Ni) in total particles to CB feeding workers ranged from 5.52 × 10^?4 to 5.65 × 10^?2, which is substantially higher than the acceptable cancer risk range 10^?6–10^?4. In particular, the cancer risk presented by these four metals in ultrafine particles (UFPs) exceeded the 10^?6 benchmark level. These results demonstrate the high health risk presented by particle-bound heavy metals to workers in a CB feeding area via inhalation exposure.     

Observations of Fallout from the Fukushima Reactor Accident in Cienfuegos,Cuba

Following the recent accident at the Fukushima Daiichi nuclear power plant in Japan, radioactive contamination was observed near the reactor site. As a contribution towards the understanding of the worldwide impact of the accident, we collected fallout samples in Cienfuegos, Cuba, and examined them for the presence of above normal amounts of radioactivity. Gamma ray spectra measured from these samples showed clear evidence of fission products (131)I and (137)Cs. However, the fallout levels measured for these isotopes (135 ± 4.78 mBq m(-2) day(-1) for (131)I and 10.7 ± 0.38 mBq m(-2) day(-1)for (137)Cs) were very low and posed no health risk to the public. The doses received as consequence to the Fukushima fallout by the Cienfuegos population's (0.002 mSv per year) don't overcome the limit of dose (1 mSv per year) fixed for the public in Cuba.     

YouTube Videos Related to the Fukushima Nuclear Disaster: Content Analysis

BackgroundYouTube (Alphabet Incorporated) has become the most popular video-sharing platform in the world. The Fukushima Daiichi Nuclear Power Plant (FDNPP) disaster resulted in public anxiety toward nuclear power and radiation worldwide. YouTube is an important source of information about the FDNPP disaster for the world.ObjectiveThis study''s objectives were to examine the characteristics of YouTube videos related to the FDNPP disaster, analyze the content and comments of videos with a quantitative method, and determine which features contribute to making a video popular with audiences. This study is the first to examine FDNPP disaster–related videos on YouTube.MethodsWe searched for the term “Fukushima nuclear disaster” on YouTube on November 2, 2019. The first 60 eligible videos in the relevance, upload date, view count, and rating categories were recorded. Videos that were irrelevant, were non-English, had inappropriate words, were machine synthesized, and were <3 minutes long were excluded. In total, 111 videos met the inclusion criteria. Parameters of the videos, including the number of subscribers, length, the number of days since the video was uploaded, region, video popularity (views, views/day, likes, likes/day, dislikes, dislikes/day, comments, comments/day), the tone of the videos, the top ten comments, affiliation, whether Japanese people participated in the video, whether the video recorder visited Fukushima, whether the video contained theoretical knowledge, and whether the video contained information about the recent situation in Fukushima, were recorded. By using criteria for content and technical design, two evaluators scored videos and grouped them into the useful (score: 11-14), slightly useful (score: 6-10), and useless (score: 0-5) video categories.ResultsOf the 111 videos, 43 (38.7%) videos were useful, 43 (38.7%) were slightly useful, and 25 (22.5%) were useless. Useful videos had good visual and aural effects, provided vivid information on the Fukushima disaster, and had a mean score of 12 (SD 0.9). Useful videos had more views per day (P<.001), likes per day (P<.001), and comments per day (P=.02) than useless and slightly useful videos. The popularity of videos had a significant correlation with clear sounds (likes/day: P=.001; comments/day: P=.02), vivid information (likes/day: P<.001; comments/day: P=.007), understanding content (likes/day: P=.001; comments/day: P=.04). There was no significant difference in likes per day (P=.72) and comments per day (P=.11) between negative and neutral- and mixed-tone videos. Videos about the recent situation in Fukushima had more likes and comments per day. Video recorders who personally visited Fukushima Prefecture had more subscribers and received more views and likes.ConclusionsThe possible features that made videos popular to the public included video quality, videos made in Fukushima, and information on the recent situation in Fukushima. During risk communication on new forms of media, health institutes should increase publicity and be more approachable to resonate with international audiences.     

Milk and dairy consumption and risk of cardiovascular diseases and all-cause mortality: dose–response meta-analysis of prospective cohort studies

With a growing number of prospective cohort studies, an updated dose–response meta-analysis of milk and dairy products with all-cause mortality, coronary heart disease (CHD) or cardiovascular disease (CVD) have been conducted. PubMed, Embase and Scopus were searched for articles published up to September 2016. Random-effect meta-analyses with summarised dose–response data were performed for total (high-fat/low-fat) dairy, milk, fermented dairy, cheese and yogurt. Non-linear associations were investigated using the spine models and heterogeneity by subgroup analyses. A total of 29 cohort studies were available for meta-analysis, with 938,465 participants and 93,158 mortality, 28,419 CHD and 25,416 CVD cases. No associations were found for total (high-fat/low-fat) dairy, and milk with the health outcomes of mortality, CHD or CVD. Inverse associations were found between total fermented dairy (included sour milk products, cheese or yogurt; per 20 g/day) with mortality (RR 0.98, 95% CI 0.97–0.99; I² = 94.4%) and CVD risk (RR 0.98, 95% CI 0.97–0.99; I² = 87.5%). Further analyses of individual fermented dairy of cheese and yogurt showed cheese to have a 2% lower risk of CVD (RR 0.98, 95% CI 0.95–1.00; I² = 82.6%) per 10 g/day, but not yogurt. All of these marginally inverse associations of totally fermented dairy and cheese were attenuated in sensitivity analyses by removing one large Swedish study. This meta-analysis combining data from 29 prospective cohort studies demonstrated neutral associations between dairy products and cardiovascular and all-cause mortality. For future studies it is important to investigate in more detail how dairy products can be replaced by other foods.     

Combined effect of tobacco smoking and alcohol drinking in the risk of head and neck cancers: a re-analysis of case–control studies using bi-dimensional spline models

The synergistic effect of tobacco smoking and alcohol consumption on the risk of head and neck cancers has been mainly investigated as a cross-product of categorical exposure, thus leading to loss of information. We propose a bi-dimensional logistic spline model to investigate the interacting dose–response relationship of two continuous exposures (i.e., ethanol intake and tobacco smoking) on the risk of head and neck cancers, representing results through three-dimensional graphs. This model was applied to a pool of hospital-based case–control studies on head and neck cancers conducted in Italy and in the Vaud Swiss Canton between 1982 and 2000, including 1569 cases and 3147 controls. Among never drinkers and for all levels of ethanol intake, the risk of head and neck cancers steeply increased with increasing smoking intensity, starting from 1 cigarette/day. The risk associated to ethanol intake increased with incrementing exposure among smokers, and a threshold effect at approximately 50 g/day emerged among never smokers. Compared to abstainers from both tobacco and alcohol consumption, the combined exposure to ethanol and/or cigarettes led to a steep increase of cancer risk up to a 35-fold higher risk (95 % confidence interval 27.30–43.61) among people consuming 84 g/day of ethanol and 10 cigarettes/day. The highest risk was observed at the highest levels of alcohol and tobacco consumption. Our findings confirmed a combined effect of tobacco smoking and alcohol drinking on head and neck cancers risk, providing evidence that bi-dimensional spline models could be a feasible and flexible method to explore the pattern of risks associated to two interacting continuous-exposure variables.