Tag Archives: Japan

Pepper mild mottle virus as a surrogate of human enteric viruses

Shirasaki N, Matsushita T, Matsui Y, Yamashita R. Evaluation of the suitability of a plant virus, pepper mild mottle virus, as a surrogate of human enteric viruses for assessment of the efficacy of coagulation-rapid sand filtration to remove those viruses. Water Research. 2017 Nov 21;129:460-469. doi: 10.1016/j.watres.2017.11.043.

Here, we evaluated the removal of three representative human enteric viruses – adenovirus (AdV) type 40, coxsackievirus (CV) B5, and hepatitis A virus (HAV) IB – and one surrogate of human caliciviruses – murine norovirus (MNV) type 1 – by coagulation-rapid sand filtration, using water samples from eight water sources for drinking water treatment plants in Japan. The removal ratios of a plant virus (pepper mild mottle virus; PMMoV) and two bacteriophages (MS2 and φX174) were compared with the removal ratios of human enteric viruses to assess the suitability of PMMoV, MS2, and φX174 as surrogates for human enteric viruses. The removal ratios of AdV, CV, HAV, and MNV, evaluated via the real-time polymerase chain reaction (PCR) method, were 0.8-2.5-log10 when commercially available polyaluminum chloride (PACl, basicity 1.5) and virgin silica sand were used as the coagulant and filter medium, respectively. The type of coagulant affected the virus removal efficiency, but the age of silica sand used in the rapid sand filtration did not. Coagulation-rapid sand filtration with non-sulfated, high-basicity PACls (basicity 2.1 or 2.5) removed viruses more efficiently than the other aluminum-based coagulants. The removal ratios of MS2 were sometimes higher than those of the three human enteric viruses and MNV, whereas the removal ratios of φX174 tended to be smaller than those of the three human enteric viruses and MNV. In contrast, the removal ratios of PMMoV were similar to and strongly correlated with those of the three human enteric viruses and MNV. Thus, PMMoV appears to be a suitable surrogate for human enteric viruses for the assessment of the efficacy of coagulation-rapid sand filtration to remove viruses.

Japan Moves Toward Coal-Fired Power Plants

“Japan is continuing to re-embrace coal to make up for its lack of nuclear energy, with plans for another power station released Thursday bringing the number of new coal-fired plants announced this year to seven.” click here

Lessons from Fukushima; Nuclear Power Safer than Thought

A different point of view than that of the popular press. But a point of view well justified indeed.

“So what were the lessons learned from Fukushima? Quite simply they are that nuclear power has been proven to be much safer than anyone previously imagined.

The nuclear fraternity worldwide should have celebrated after the Fukushima drama. The world watched the entire saga, second by second…and what was the outcome?

Answer: total people killed by radiation, zero. Total injured, zero. Total private property damaged by radiation, zero. Expected long term effects on people; zero.” – Dr. Kelvin Kemm (click here)

San Diego will Soon be Washed Away in 0.67 ft of Sea Level Rise!

If one eyeballs the data since about 1980 there looks to be no rise in sea level of any significance.

san diego sea level rise

The mean sea level trend is 2.04 millimeters/year with a 95% confidence
interval of +/- 0.18 mm/yr based on monthly mean sea level data from
1906 to 2013 which is equivalent to a change of 0.67 feet in 100 years.

But San Diego should be concerned about rapid sea level rise, such as this (click here).

happy-bouncing-smilie

Fukushima Radiation Levels do not Represent a Threat to Human Health or the Environment

John N. Smitha, Robin M. Brown, William J. Williams, Marie Robert, Richard Nelson, and S. Bradley Moran. Arrival of the Fukushima radioactivity plume in North American continental waters PNAS Dec 29 2014 Early Edition

The large discharge of radioactivity into the northwest Pacific Ocean from the 2011 Fukushima Dai-ichi nuclear reactor accident has generated considerable concern about the spread of this material across the ocean to North America. We report here the first systematic study to our knowledge of the transport of the Fukushima marine radioactivity signal to the eastern North Pacific. Time series measurements of 134Cs and 137Cs in seawater revealed the initial arrival of the Fukushima signal by ocean current transport at a location 1,500 km west of British Columbia, Canada, in June 2012, about 1.3 y after the accident. By June 2013, the Fukushima signal had spread onto the Canadian continental shelf, and by February 2014, it had increased to a value of 2 Bq/m3 throughout the upper 150 m of the water column, resulting in an overall doubling of the fallout background from atmospheric nuclear weapons tests. Ocean circulation model estimates that are in reasonable agreement with our measured values indicate that future total levels of 137Cs (Fukushima-derived plus fallout 137Cs) off the North American coast will likely attain maximum values in the 3–5 Bq/m3 range by 2015–2016 before declining to levels closer to the fallout background of about 1 Bq/m3 by 2021. The increase in 137Cs levels in the eastern North Pacific from Fukushima inputs will probably return eastern North Pacific concentrations to the fallout levels that prevailed during the 1980s but does not represent a threat to human health or the environment.

Click here for full paper (Open Access).

Lifestyle, household Environment Affect Dental Caries at Age 3 in Japan

This study concludes the following:

“The present study examined how lifestyle, household environment, and caries activity test score of Japanese children at age 1.5 affected their dental caries incidence at age 3. The findings support a positive association of dental caries incidence with the following factors: consumption of sugar-sweetened beverages and snacks, living with family members who smoke, and also suggest late bedtime is one of the major risk factors for dental caries in children. Further investigation is needed to examine whether the short duration or the irregularity of the sleep-wake cycle affects early childhood oral health and whether there is a relationship between a late bedtime and late snack intake.”

Watanabe M, Wang DH, Ijichi A, Shirai C, Zou Y, Kubo M, Takemoto K, Masatomi C, Ogino K. The Influence of Lifestyle on the Incidence of Dental Caries among 3-Year-Old Japanese Children. International journal of environmental research and public health. 2014 Dec 5;11(12):12611-12622.

The present cohort study examined how lifestyle, household environment, and caries activity test score of Japanese children at age 1.5 years affected their dental caries incidence at age 3. Inclusion criteria were 1.5-year-old children with no dental caries. Dental examinations were performed for 33,655 children who participated in routine dental examinations at 1.5 years of age, and the exam was repeated approximately 21 months later (at age 3) at the Kobe City Public Health Center in Japan. After excluding 622 children who had caries at age 1.5 and 1831 children with missing lifestyle and household environment data in the questionnaires, the final data analysis was performed on a total of 31,202 children (16,052 boys, 15,150 girls).The multivariate logistic regression analysis indicated a strong association of the consumption of sugar-sweetened beverages/snacks, less frequent tooth brushing by the parents, lack of fluoride varnish, family history of smoking, with the risk of developing dental caries. A child’s late bedtime is also one of the major risk factors for dental caries development. Further investigation is needed to examine whether the short duration or the irregularity of the sleep-wake cycle would affect early childhood oral health and whether there is a relationship between late bedtime and late night snack intake.

Click here for full paper (Open Access).

Fukushima Radionuclide Emssions

Georg Steinhauser. Fukushima’s Forgotten Radionuclides: A Review of the Understudied Radioactive Emissions. Environ. Sci. Technol. DOI: 10.1021/es405654c

In environmental monitoring campaigns for anthropogenic radionuclides released in the course of the Fukushima nuclear accident (2011), most focus had been on gamma-emitting radionuclides. More than 99% of the released activity was due to radionuclides of the elements Kr, Te, I, Xe, and Cs. However, little work had been done on the monitoring of radionuclides other than 131I, 132Te, 134Cs, 136Cs, and 137Cs. Radionuclides such as those of less volatile elements (e.g., 89Sr, 90Sr, 103Ru, 106Ru, plutonium), pure beta-emitters (3H, 14C, 35S), gaseous radionuclides (85Kr, 133Xe, 135Xe) or radionuclides with very long half-lives (e.g., 36Cl, 99Tc, 129I, some actinides such as 236U) have been understudied by comparison. In this review, we summarize previous monitoring work on these “orphan” radionuclides in various environmental media and outline further challenges for future monitoring campaigns. Some of the understudied radionuclides are of radiological concern, others are promising tracers for environmental, geochemical processes such as oceanic mixing. Unfortunately, the shorter-lived nuclides of radioxenon, 103Ru, 89Sr and 35S will no longer exhibit detectable activities in the environment. Activity concentrations of other radionuclides such as tritium, 14C, or 85Kr will become blurred in the significant background of previous releases (nuclear explosions and previous accidents). Isotope ratios such as 240Pu/239Pu will allow for the identification of Fukushima plutonium despite the plutonium background.

Click here for full article (fee).