Mental health and natural land cover: a global analysis based on random forest with geographical consideration.

Natural features in living environments can help to reduce stress and improve mental health. Different land types have disproportionate impacts on mental health. However, the relationships between mental health and land cover are inconclusive. In this study, we aim to accurately fit the relationships, estimate the impacts of land cover change on mental health, and demonstrate the global spatial variability of impacts. In the analysis, we show the complex relationships between mental health and eight land types based on the random forest method and Shapley additive explanations. The accuracy of our model is 67.59%, while the accuracy of the models used in previous studies is usually no more than 20%. According to the analysis results, we estimate the average effects of eight land types. Due to their scarcity in living environments, shrubland, wetland, and bare land have larger impacts on mental health. Cropland, forest, and water could improve mental health in high-population-density areas. The impacts of urban land and grassland are mainly negative. The current land cover composition influences people's attitudes toward a specific land type. Our research is the first study that analyzes data with geographical information by random forest and explains the results geographically. This paper provides a novel machine learning explanation method and insights to formulate better land-use policies to improve mental health.

Effects of bathing in different hot spring types on Japanese gut microbiota.

Hot springs have been used for a variety of purposes, including the treatment and amelioration of illness and recreation. Japan has ten different types of therapeutic springs (described here as spa types), which are traditionally believed to have different efficacy. However, more research must be conducted to determine how they affect healthy people. Therefore, this study focused on the gut microbiota and aimed to investigate changes in the gut microbiota in healthy people after bathing in different spa types. Using Beppu's hot springs (simple, chloride, bicarbonate, sulfur, and sulfate types), 136 healthy Japanese adults living in the Kyushu area participated in the study and bathed in the same hot spring for seven days. Fecal samples were collected before and after the 7-day bathing period, and the relative abundance of the gut microbiota was determined by 16S rRNA sequencing. The results showed that the relative abundance of Bifidobacterium bifidum increased significantly after seven consecutive days of bathing in the bicarbonate spring. Significant increases in other gut microbiota were also observed after bathing in simple, bicarbonate, and sulfur springs. These results suggest that bathing in different hot springs may affect the gut microbiota in healthy individuals differently.

Forest carbon removal potential and sustainable development in Japan.

Forests play a crucial role in mitigating climate change and reducing emissions as a major carbon sink. However, its value in removing carbon dioxide (CO2) from the atmosphere is always underestimated in natural capital (NC) accounting and sustainability assessments. This study predicted Japan's forest CO2 removal by afforestation and forest management and its monetary value until 2042 from national to gridded level, with statistical data and complementary satellite data products, and explored how that CO2 removal will contribute to sustainable development under the inclusive wealth (IW) framework. The results show that: (1) the annual CO2 removal by forests has the potential to offset 15.3% of the emission and increase NC by 6.8% in Japan, significantly contributing to carbon neutrality and IW growth; (2) the total CO2 removal in exiting forests will peak at around 2030 and then decrease, but expanding afforestation could offset that decrease in later years; (3) the spatial distribution patterns of IW and forest CO2 removal are opposite. This indicates a national carbon trading market could create new wealth for rural communities where vast forests exist, and then effectively balance the inequal urban-rural development in Japan. The explicit spatial information of this study could provide valuable information for differentiating policy priorities of forestry planning and sustainable development in different local communities.

Hot spring bathing practices have a positive effect on mental health in Japan.

Hot springs have long been used for medical purposes throughout the world. Recently, the positive effects of hot spa-bathing on circulatory diseases have been reported, while there are few reports on the mental effects of hot spa-bathing. Therefore, the purpose of this study was to clarify the relationship between hot spa-bathing habits and mental health throughout Japan. We conducted a nationwide online survey, including questions on bathing behavior, subjective satisfaction, lifestyle, and illness. The results showed a significant positive correlation between hot spa-bathing habits and multiple subjective satisfaction levels regarding mental health effects. The factor analysis results indicated that hot spa-bathing habits tended to be associated with good mental health, high health consciousness, and disease. Our study revealed that subjective satisfaction was higher among individuals with hot spa-bathing habits, suggesting that the hot spring spa-bathing habit may have a positive influence on mental health.

Inappropriate nighttime light reduces living comfort.

Living comfort is an important aspect of human well-being and a critical index of sustainable environments. Many environmental factors are associated with living comfort. Nighttime light (NTL) is remote sensing data that is widely used to reflect development level and economic status, and it also represents the lighting intensity in living environments. However, the relationship between NTL and living comfort is poorly understood. Here, we employ linear regression and a random forest model to investigate the direct impact of NTL on living comfort. Our results show that increased NTL is negatively associated with living comfort, but this relationship may be obscured by other factors, such as infrastructure. According to the nonlinear relationship, when the NTL is approximately 10 nW/cm2∙sr, there is a peak in living comfort. Hence, ensuring a reasonable level of lighting is a key to promoting sustainable development. Our research offers crucial insights that can aid in developing sustainable development policies to enhance livability.

Effects of information provision on willingness to pay for conservation of alpine plants in Japan.

Information provision is essential for obtaining the cooperation of the general public for the conservation of unfamiliar ecosystems towards a sustainable (e.g. carbon-neutral and nature-positive) society. The purpose of this study is to identify effective ways of raising public awareness for ecosystem conservation. We explored the interaction between the manner of information provision (i.e. the medium through which and how much information is provided) and the personal attributes (e.g. environmental attitude) of the recipients on their willingness to pay (WTP) for conservation using Japanese alpine plants as the subject. Discrete choice experiments using an online survey were conducted with public citizens aged 20-69 years across Japan, and data from 8457 respondents were analysed. The data analysis was performed in two steps: 1) estimating individual WTP and 2) exploring factors affecting WTP. The results demonstrated that individual WTP was 135,798 ± 82,840 (mean ± standard deviation) JPY per person for a lifetime. The WTP increased when information was provided in the form of short texts and graphics for those proactive about nature conservation, but increased more when video information was provided to those reactive about nature conservation. The study shows that ecosystem conservation groups need to adapt the amount and format of information for target audiences (e.g. Generation Z youth, who are more sustainability-oriented and prefer to accomplish more in less time).

Lessons on the COVID-19 pandemic: who are the most affected.

The COVID-19 pandemic has led to significant changes in work and lifestyle, impacting occupational mental health. This study examines the time and individual heterogeneity in the pandemic's effects on occupational mental health using panel data from job stress checks spanning 2018 to 2021. On average, there was an initial alleviation of high-stress risk in 2020, followed by a deterioration in 2021. Based on the job demand-resource theory, we identify the group of employees most affected by the pandemic. The findings highlight that employees in unfavorable workplace conditions are more likely to experience substantial adverse impacts. Adequate workplace support, including factors like interpersonal relationships, managerial support, job meaning, control, and work-life balance, is crucial for mitigating high-stress risk. Additionally, during the early phase of the pandemic, engaged employees experienced a slight decline in occupational mental health, while those lacking job resources at their worksite faced higher levels of occupational stress in the subsequent year. These findings offer practical suggestions for person-centered coping strategies to mitigate the pandemic's adverse impact.

The international role of education in sustainable lifestyles and economic development.

Improved economic growth and environmental protection are necessary to achieve the United Nations' Sustainable Development Goals. This study examines the relationship between people's education levels and sustainable lifestyles in protecting the environment and economic growth, as expressed by the increase in household equivalent income. We conducted an original cross-sectional survey, which yielded 100,956 valid observations in 37 countries. The factors included educational level, sustainable lifestyle with natural resource consumption, and household equivalent income for economic development. We used logit and ordered logit model and applied an ordinary linear regression model after confirming the association between education and income. Our analyses found that higher educational levels were associated with an increase in specific environmentally friendly behaviors and sustainable energy consumption. Individuals in the higher educational level group tended to consume recycled goods, purchase energy-saving household products, conserve electricity, and separate their waste. Additionally, higher levels of education were positively associated with equivalent household income in all 37 countries, indicating better economic development. Thus, our study underscores the importance of improving education at the broad population level to promote economic development and establish cooperative human behaviors necessary to sustain the environment.

Income raises human well-being indefinitely, but age consistently slashes it.

The relationships among human well-being, income, and age have long been debated. The association between human well-being and income is believed to be U-shaped, although the reasons remain elusive. A recent study shows a turning point in the link between human well-being and income; that is, increased income does not always improve well-being. However, the mechanisms of the effects of income and age on human well-being are unknown. Here, we illustrate the total cumulative effects of income and age on evaluated well-being through all observed causal pathways based on a 1.6-million-observation global dataset and the structural causal model. This is the first study to investigate those casual relationships globally. We find that an increase in age always reduces evaluated well-being, and the adverse effects are aggravated with age. Furthermore, increased income continuously improves human well-being, but the impacts gradually become marginal with higher income. Our results demonstrate that physical health improvement in older people is the most effective way to intervene against the harmful effects of age on well-being. Moreover, increased income may dramatically enhance the well-being of people living close to the poverty line.

Natural land cover positively correlates with COVID-19 health outcomes.

BACKGROUND: The coronavirus disease 2019 (COVID-19) poses special challenges for societies, as the disease causes millions of deaths. Although the direct prevention measures affect the prevalence and mortality the most, the other indirect factors, including natural environments and economics, could not be neglected. Evaluating the effect of natural land cover on COVID-19 health outcomes is an urgent and crucial public health topic. METHODS: Here, we examine the relationships between natural land cover and the prevalence and mortality of COVID-19 in the United States. To probe the effects of long-term living with natural land cover, we extract county-level land cover data from 2001 to 2019. Based on statistically spatial tests, we employ the Spatial Simultaneous Autoregressive (SAC) Model to estimate natural land cover's impact and monetary values on COVID-19 health outcomes. To examine the short-term effects of natural environments, we build a seasonal panel data set about the greenery index and COVID-19 health outcomes. The panel SAC model is used to detect the relationship between the greenery index and seasonal COVID-19 health outcomes. RESULTS: A 1% increase in open water or deciduous forest is associated with a 0.004-death and 0.163-conformed-case, or 0.006-death and 0.099-confirmed-case decrease in every 1,000 people. Converting them into monetary value, for the mortality, a 1% increase in open water, deciduous forest, or evergreen forest in a county is equivalent to a 212-, 313-, or 219-USD increase in household income in the long term. Moreover, for the prevalence, a 1% change in open water, deciduous forest, or mixed forest is worth a 382-, 230-, or 650-USD increase in household income. Furthermore, a rational development intensity is also critical to reduce the risk of the COVID-19 pandemic. More greenery in the short term is also linked to lower prevalence and mortality. CONCLUSIONS: Our study underscores the importance of incorporating natural land cover as a means of mitigating the risks and negative consequences of future pandemics like COVID-19 and promoting overall public health.

Gridded Datasets for Japan: Total, Male, and Female Populations from 2001-2020.

Japan is a highly urbanized and severely aging society. In an aging society, chronic disease and disability are prevalent, and the population is sensitive to environmental issues and climate change. To identify the effects of population changes, formulate population and public health policies, and assist environmental projects, a high-resolution and accurate gridded population dataset is highly desirable. To provide basic data for research in these areas, we created an open access annual dataset from 2001 to 2020 containing the total, male, and female population counts in each grid at a resolution of 500 m. A random forest method was employed to fill the gaps in Japan's nationwide census data collected in 2005, 2010, 2015, and 2020. The yearly population dataset was based on the 4th-level mesh data from the Statistics Bureau of Japan to make it easy to use. The dataset is provided here along with descriptions of the data and methods used in the fitting, cross-validation, and prediction processes.

Household energy-saving behavior, its consumption, and life satisfaction in 37 countries.

Since energy consumption became an important contributor to climate change owing to carbon emissions, energy-saving behavior and expenditure at the household level have been attracting scholars' and policymakers' attention. This study identified whether greenhouse gas emissions at the household level can be reduced through purchase of energy-saving goods and whether the energy-saving behavior enhanced with household income increase. We conducted a large-scale survey across 37 nations using internet-based and face-to-face approaches, collecting 100,956 observations. The wealth effect on energy consumption expenditure at the household level was found to be positive across countries, confirming that energy consumption increases with household wealth improvement. Furthermore, households show a positive association between household energy expenditure and life satisfaction in 27 out of 37 countries, including China, India, the United States, and Germany. Additionally, the favorable effects of household energy-saving behavior are confirmed. However, purchase of household energy-saving products has a limited effect on energy consumption expenditure, compared with that of energy-curtailment behavior. In conclusion, achieving a carbon-neutral household by reducing energy consumption expenditure at the household level is challenging; thus, along with the use of energy-saving goods, alternative energy sources, such as renewable energies, are recommended.

Assessing the United Nations sustainable development goals from the inclusive wealth perspective.

The statement of sustainability in the sustainable development goals (SDGs) framework needs to be supplemented by a formal proof that intergenerational well-being also improves. This is the first study that aims to provide empirical evidence that links the progress of the SDGs and the changes in well-being, which are proxied by the SDG Index and the Inclusive Wealth (IW) Index, respectively. We propose an SDGs-wealth model which was analyzed using a machine learning method involving a balanced panel of 147 countries for 2000-2019. We find a strong correlation between wealth and the SDGs, with Goals 12, 13, and 7 being the most significant predictors of wealth. In contrast to Goals 12 and 13, we find a positive correlation between Goal 7 and the per capita IW Index, suggesting that promoting affordable and clean energy is beneficial for wealth accumulation. Quite the opposite, fostering responsible consumption and production and climate actions might be detrimental to wealth. We also find an alarming result for 50 countries in our study since they have deviated from the sustainable development trajectories either in the short or long run. Our study suggests that to achieve sustainable development, instead of focusing on the complex interactions among the SDGs, policymakers should put a stronger focus on improving IW.

COVID-19, stigma, and habituation: evidence from mobility data.

BACKGROUND: The Japanese government has restricted people's going-out behavior by declaring a non-punitive state of emergency several times under COVID-19. This study aims to analyze how multiple policy interventions that impose non-legally binding restrictions on behavior associate with people's going-out. THEORY: This study models the stigma model of self-restraint behavior under the pandemic with habituation effects. The theoretical result indicates that the state of emergency's self-restraint effects weaken with the number of times. METHODS: The empirical analysis examines the impact of emergency declarations on going-out behavior using a prefecture-level daily panel dataset. The dataset includes Google's going-out behavior data, the Japanese government's policy interventions based on emergency declarations, and covariates that affect going-out behavior, such as weather and holidays. RESULTS: First, for multiple emergency declarations from the beginning of the pandemic to 2021, the negative association between emergency declarations and mobility was confirmed in a model that did not distinguish the number of emergency declarations. Second, in the model that considers the number of declarations, the negative association was found to decrease with the number of declarations. CONCLUSION: These empirical analyses are consistent with the results of theoretical analyses, which show that the negative association between people's going-out behavior and emergency declarations decreases in magnitude as the number of declarations increases.

Improvement impact of nudges incorporated in environmental education on students' environmental knowledge, attitudes, and behaviors.

This study conducted randomized controlled trials to evaluate the effectiveness of an environmental education class and the impacts of nudges and boosts implemented in this program on high school students' basic knowledge, attitudes, and behaviors regarding environmental issues in Japan. This environmental education class consisted of a lecture on reducing the use of plastic products for energy conservation in daily life, a board game for learning how to reduce plastic waste, and a worksheet for reflection. Four types of worksheets were randomly distributed: nudges, in which students were asked to set a goal regarding their level of effort in not throwing away plastic products such as plastic bags, wet wipes, and plastic bottles; boosts, in which participants were asked to write an essay to help increase their empathy for the parties impacted by environmental issues; both nudges and boosts; and none (neither nudges nor boosts). After environmental education, an end-line survey was conducted to evaluate the effectiveness of this class. This study found that the environmental education class significantly improved students' basic environmental knowledge and promoted their concerns about plastic waste. Although there was no evidence that nudges and boosts amplify the effects of the environmental education class on the students' knowledge, nudges were successful in making them more concerned about plastic waste. The results showed that students who received nudges or boosts were more likely to refuse free wet wipes offered at convenience stores but were not more likely to refuse plastic bottles. These results also indicated that interventions through environmental education can change students' pro-environmental behaviors only if the cost of behavioral change is low. The environmental education class not only increased students' environmental knowledge and attitudes, but the use of worksheets in administering nudges and boosts ensured the effectiveness of environmental education.

Identifying the impact of rainfall variability on conflicts at the monthly level.

Research on the relationship between rainfall variability and conflicts has yielded contradictory results. This study is the first to show that the significance of the impact of rainfall variability on conflicts depends on the temporal unit of analysis. We prove this point by comparing the statistical significance of the linkages between georeferenced conflicts and rainfall variabilities at the monthly and annual levels with panel data analyses from 1989 to 2020. We find that a 10 percent increase in monthly rainfall decreases the risk of conflict incidence by 0.0298 percent, but annual rainfall variability is not statistically linked to conflict outbreaks. These statistically significant disparities result from the aggregation of data dispersion and the disregard for the timing of the impact of rainfall on conflicts. These findings highlight the importance of information on monthly rainfall variation when estimating the impact of rainfall on conflicts.

Fluctuations in Intestinal Microbiota Following Ingestion of Natto Powder Containing Bacillus subtilis var. natto SONOMONO Spores: Considerations Using a Large-Scale Intestinal Microflora Database.

Improving the intestinal microbiota using probiotics, prebiotics, and synbiotics has attracted attention as a method of disease prevention and treatment. This is the first study to discuss the effects of food intake on the intestinal microbiota using a large Japanese intestinal microbiota database. Here, as a case study, we determined changes in the intestinal microbiota caused by ingestion of a processed natto food containing B. subtilisvar. natto SONOMONO spores, SONOMONO NATTO POWDER CAPSULESTM, by analyzing 16S rRNA sequence data generated using next-generation sequencing techniques. The results showed that the relative abundance of Bifidobacterium and Blautia as well as the relative abundance of Bifidobacterium were increased in males and females in the ingesting group, respectively. Additionally, the effects of SONOMONO NATTO POWDER CAPSULESTM intake on Bifidobacterium and Blautia abundance depended on the relative abundance of Bifidobacterium at baseline. Finally, analysis of a large Japanese intestinal microbiota database suggested that the bacterial genera that fluctuated with the ingestion of SONOMONO NATTO POWDER CAPSULESTM may be associated with lifestyle-related diseases such as diabetes.

Children mirror adults for the worse: evidence of suicide rates due to air pollution and unemployment.

BACKGROUND: Every year, more than 700,000 people die due to suicide, one of the most common reasons for youth death. While many studies have revealed two main factors for suicidal behavior: impulsive suicidal behavior due to mental illness and financial stress, it is not clear what happens if individuals face deterioration of mental health and economic recession. This paper attempts to answer this question and how suicide rates are correlated with these factors. METHODS: We empirically investigate whether economic recessions and air pollution trigger suicides by examining Japan, a country with one of the highest suicide rates, from 2014 to 2021. We take advantage of the characteristics of the COVID-19 pandemic and the periods before the pandemic, when both economic recessions and reductions in air pollution occurred simultaneously. Using monthly and municipal- level data, we construct a triple difference model that takes air pollution and unemployment as treatments. RESULTS: Our findings show that high (upper half of each period) levels of air pollution and unemployment have substantial impacts on the suicide rates of adults (22.9% in the short term) and children (42.7% in the short term, 36.0% in the long term), indicating that the increase in suicide rates among children is almost twice as high as that among adults. Our study finds that unemployment and air pollution alone are not associated with increased suicide rates but their simultaneous occurrence triggers suicides during the pandemic. CONCLUSIONS: Our study urges suicide prevention, particularly among children, as an essential consideration for public health. Furthermore, our results indicate the need for the government to allocate resources to recover air quality and the economy simultaneously during a recession to reduce suicide mortality of both child and adults.

Global malaria infection risk from climate change.

As a long-standing public health issue, malaria still severely affects many parts of the world, especially Africa. With greenhouse gas emissions, temperatures continue to rise. Based on diverse shared socioeconomic pathways (SSPs), future temperatures can be estimated. However, the impacts of climate change on malaria infection rates in all epidemic regions are unknown. Here, we estimate the differences in global malaria infection rates predicted under different SSPs during several periods as well as malaria infection case changes (MICCs) resulting from those differences. Our results indicate that the global MICCs resulting from the conversion from SSP1-2.6 to SSP2-4.5, to SSP3-7.0, and to SSP5-8.5 are 6.506 (with a 95% uncertainty interval [UI] of 6.150-6.861) million, 3.655 (3.416-3.894) million, and 2.823 (2.635-3.012) million, respectively, from 2021 to 2040; these values represent increases of 2.699%, 1.517%, and 1.171%, respectively, compared to the 241 million infection cases reported in 2020. Temperatures increases will adversely affect malaria the most in Africa during the 2021-2040 period. From 2081 to 2100, the MICCs obtained for the three scenario shifts listed above are -79.109 (-83.626 to -74.591) million, -238.337 (-251.920 to -0.141) million, and -162.692 (-174.628 to -150.757) million, corresponding to increases of -32.825%, -98.895%, and -67.507%, respectively. Climate change will increase the danger and risks associated with malaria in the most vulnerable regions in the near term, thus aggravating the difficulty of eliminating malaria. Reducing GHG emissions is a potential pathway to protecting people from malaria.