Feasible conditions for Japanese woody biomass utilization

Environmental Science and Pollution Research - There is an abundance of woody biomass in Japan. However, its economic feasibility is limited. There have been several discussions on whether...     

Detection of Rotavirus Strains in Freshwater Clams in Japan

Bivalve molluscan shellfish like clams and oysters, etc., are capable to bioaccumulate surrounding contaminants from waters into their digestive systems and posing serious threats of food poisoning. Detection of rotaviruses (RVs) in shellfish is of particular importance because RVs are prone to genome reassortment resulting in the emergence of new RV variants that may compromise vaccine safety. Herein, we have detected the wild-type RVs and Rotarix/RotaTeq vaccine strains in freshwater clams collected on the riverside, Kawasaki city, from July 2019 to January 2020 and correlated the detected genotypes with that of gastroenteritis cases of nearby clinics to understand the transmission of RVs in the environment. The wild-type RVs were detected in 62 (64.6%) out of 96 freshwater clams in every study month: July, September, November, and January that are considered as off-season for RV infections. The most frequent genotypes were G2 (42.9%), G8 (28.6%), G3 (14.3%), G1 (7.1%), and G10 (7.1%), which remained comparable with genotypic distribution found in the clinical samples over the last few years indicating that these RVs may accumulate in clams since a long time. However, G10 genotype was detected in clam but not in clinical samples suggesting the presence of asymptomatic infection or RVs could be carried out from a long distance. Importantly, vaccine strains, RotaTeq (1%) but not Rotarix (0%), were also detected in a clam. Attention must be paid to monitoring the potential transmission of wild-type and vaccine RV strains in the environment to prevent the emergence of new variants generated from genome reassortment with vaccine strains.

     

Temporal trends in organophosphorus pesticides use and concentrations in river water in Japan, and risk assessment

We reviewed organophosphorus pesticide use in Japan between 1982 and 2016 using data from the National Institute of Environmental Studies. Organophosphorus pesticide concentrations in river water throughout Japan were taken from the literature, and risk assessments were performed for some organophosphorus pesticides based on risk quotients and hazard quotients. Assessments were performed for 20 common pesticides, including insecticides, fungicides, and herbicides. The amounts used decreased in the order: insecticides?>?herbicides?>?fungicides. Organophosphorus insecticide and fungicide use have decreased over the last four decades, but organophosphorus herbicide use has increased. During this period, annual organophosphorus pesticide use was the highest for chlorpyrifos (105,263?tons/year) and the lowest for glyphosate-sodium (8?tons/year). The ecotoxicological risk assessment indicated that diazinon and fenitrothion posed strong risks to the Japanese aquatic environment, and chlorpyrifos and malathion have moderate risks. None of the pesticides that were assessed posed significant risks to humans. Continued use of organophosphorus pesticides in Japan may cause strong risks to aquatic environments. These risks should be reassessed periodically.     

The effects of current water management practices on methane emissions in Japanese rice cultivation

Cultivated wetland rice fields are a source of methane (CH₄) emissions. To estimate CH₄ emissions and develop policies to reduce such emissions, information on water management at the farm level is crucial. It is known that farmers implement midseason drainage (MD) to increase rice yields and save water. However, little is known about whether MD is carried out in soils where CH₄ emissions are high and how part-time status will influence management. The objective of this study is to identify factors that determine MD implementation using a binomial logistic regression model based on a farm-level survey in Japan and to indicate possible changes in estimates of CH₄ emissions, accounting for current water management practices. The implementation rates were significantly higher where the soil types were classified as having the potential for high CH₄ emissions. Under current water management practices, the duration of MD and the percentage of continuous flooding were 5 to 7 days longer and approximately 7 % higher, respectively, than the values used by the Greenhouse Gas Inventory Office of Japan, which in turn are used to report greenhouse gas emissions to the United Nations Framework Convention on Climate Change. By accounting for current water conditions with the Tier 2 method, this study indicates that national estimates of CH₄ emissions from rice straw application areas could be lowered by 12.7 %. These results may contribute to the development of a mitigation policy that will help to further reduce CH₄ emissions.     

Stagnant surface water bodies (SSWBs) as an alternative water resource for the Chittagong metropolitan area of Bangladesh: physicochemical characterization in terms of water quality indices

The concern over ensuing freshwater scarcity has forced the developing countries to delve for alternative water resources. In this study, we examined the potential of stagnant surface water bodies (SSWBs) as alternative freshwater resources in the densely populated Chittagong metropolitan area (CMPA) of Bangladesh??where there is an acute shortage of urban freshwater supply. Water samples were collected at 1-month intervals for a period of 1 year from 12 stations distributed over the whole metropolis. Samples were analyzed for pH, water temperature (WTemp), turbidity, electrical conductivity (EC), total dissolved solids, total solids, total hardness, dissolved oxygen (DO), chloride, orthophosphates, ammonia, total coliforms (TC), and trace metal (Cd, Cr, Cu, Pb, As, and Fe) concentrations. Based on these parameters, different types of water quality indices (WQIs) were deduced. WQIs showed most of CMPA-SSWBs as good or medium quality water bodies, while none were categorized as bad. Moreover, it was observed that the minimal water quality index (WQI_m), computed using five parameters: WTemp, pH, DO, EC, and turbidity, gave a reliable estimate of water quality. The WQI_m gave similar results in 72% of the cases compared with other WQIs that were based on larger set of parameters. Based on our finding, we suggest the wider use WQI_m in developing countries for assessing health of SSWBs, as it will minimize the analytical cost to overcome the budget constraints involved in this kind of evaluations. It was observed that except turbidity and TC content, all other quality parameters fluctuated within the limit of the World Health Organization suggested standards for drinking water. From our findings, we concluded that if the turbidity and TC content of water from SSWBs in CMPA are taken care of, they will become good candidates as alternative water resources all round the year.     

Investigation of perfluoroalkyl carboxylic and sulfonic acids in leachates from industrial and municipal solid waste landfills,and their treated waters and effluents from their closest leachate treatment plants

Journal of Material Cycles and Waste Management - Per- and polyfluoroalkyl substances (PFASs) are used in products, such as aqueous film-forming foam and fluorochemical surfactants, because of...     

Relationship between the growth and survival of larval Pacific bluefin tuna, Thunnus orientalis

We tested the hypothesis that a large body size and rapid growth rate affect the survival of larval Pacific bluefin tuna, Thunnus orientalis (PBT), and analyzed larval growth in relation to environmental conditions. Seven high density larval patches of PBT were tracked with reference buoys in the northwestern Pacific Ocean for 28–171 h in May–June from 2004 to 2008. The otolith radii and daily growth rates of the survivor larvae (collected on later tracking days of each tracking session) tended to be larger and more rapid, respectively, than those of original larvae (collected on earlier tracking days). A large body size was found to positively affect the survival of larval PBT, as did a rapid growth rate, even at an early larval stage (7 days after hatching). Generalized linear modeling showed that the otolith radius was influenced positively by the sea temperature, stratification parameter and food density, while the growth rate was influenced positively by the sea temperature and food density.     

Serial variations of trace metal concentrations in aquatic insect Stenopsyche marmorata

Caddisfly larvae (Stenopsyche marmorata) instar V, periphyton, sediment and river water at a non‐contaminated upstream site, a metallic contaminated downstream site, and industrial wasterwater which caused the metallic contamination were collected once a month for 21 months. Nickel (Ni), copper (Cu), zinc (Zn), and lead (Pb) concentrations in these samples were measured. Significant serial variations of the 4 metal concentrations in the larvae showed a seasonal tendency at the upstream site but not at the downstream site. The larvae more clearly indicated the influence of industrial wastewater than periphyton. As the larvae of Stenopsyche marmorata could be collected throughout the year, this larva is useful for monitoring trace metal contamination in rivers.     

Assessment of biological effects and harm to Japanese medaka due to carbonized carbon fibers generated by a pyrolysis carbon fiber recycling process

Journal of Material Cycles and Waste Management - Carbon-fiber-reinforced plastics (CFRPs) are used as structural materials in the aircraft and automotive industries owing to their lightweight and...