As lifestyles continue to change toward a more convenient and affluent life, we are exposed to many hazards and risks every day, such as unregulated compounds, radioactive substances due to nuclear power plant accidents, non-ionizing radiation due to the spread of 5G systems, and food poisoning accidents caused by bacteria and viruses contained in daily necessities and encountered in living environments. In recent years, although the use of known highly toxic substances has been banned or regulated, risks of natural disasters related to abnormal weather and infectious diseases such as the novel coronavirus have exerted huge impacts on our lives. Regarding the contribution of these risk factors to major diseases, the World Health Organization (WHO) has indicated the Disability-adjusted life year (DALY) as an index, and has also presented environmental risks as indices for disease prevention. Based on the philosophy of regulatory science, risk assessments based on scientific knowledge through environmental surveys including environmental epidemiological studies, and efforts for safety management through the implementation of regulations and practical measures are becoming increasingly necessary. Furthermore, environmental risks in the world range from man-made factors such as industry and industrial activities, to natural disasters such as earthquakes and volcanic eruptions, as well as cross-border problems such as cross-border pollution and marine pollution. At the same time, complex and uncertain problems that are difficult to deal with have been emerging in succession. For this reason, Japan needs to contribute to measures to reduce environmental risks based on our experience in responding to natural disasters, both as a developed country, and with a shared international understanding. In dealing with solutions, it will become increasingly necessary to promote cross-disciplinary research such as in chemistry, physics, biology, and medicine, and to collaborate with experts from industry, academia including the social sciences, and government.

Outbreaks of food poisoning in Japan have been on a continuous downward trend over the past quarter century. On the other hand, outbreaks due to Anisakis have increased in the last decade, probably because doctors did not recognize these outbreaks as food poisoning, and did not report them to the public health department before that time. As a result, they were not included in the statistics. This may be related to the passive surveillance system, in which doctors notify the health department when they recognize a patient with food poisoning.

Therefore, if a cause is not included in the etiological agents section of the report form, it may not be recognized as a causative agent of food poisoning. In such a case, not only would it not be reported as food poisoning and recorded in the statistics, but food safety measures against the causative agent might also not be adequately taken.

If the administrative authorities in charge of food safety do not receive reports of cases of these original foodborne illnesses, there is a risk that the administrative authorities will not take measures such as providing guidance to food-related businesses, and that no progress will be made in improving their foodborne illness countermeasures.

Other than anisakiasis, for example, histamines are also not included in the list of etiologic agents in its reporting form, and may be underreported by medical institutions.

Non-proteolytic Clostridium botulinum has the potential to grow and produce toxins under refrigeration. However, due to improved and diversified food packaging technologies, the shelf life of fish and shellfish products that may contain the bacteria tends to be extended. There are concerns about whether the risk assessment is sufficient to meet the actual conditions of these products.

In addition, although the number of hepatitis E cases has increased over the past 10 years, only a few cases are reported as food poisoning. There are concerns about whether the outbreaks are being investigated sufficiently to pursue the causative foods, etc., and whether measures to prevent their occurrence are being adequately considered.

Per- and polyfluoroalkyl compounds (PFAS), pesticides, and haloacetic acids were introduced as recent topics on chemicals in drinking water. As for PFAS, PFOS (perfluorooctanesulfonic acid) and PFOA (perfluorooctanoic acid) were selected as complementary items for water quality management in 2020, after which time monitoring data for these substances in the water supply system across Japan have been tallied in the Statistics on Water Supply by the Japan Water Works Association. However, as the number of these monitoring data is smaller than those for other items, more monitoring points for PFOS and PFOA are needed. Drinking water treatment processes have been applied for the purpose of PFAS removal in overseas countries. However, most of these processes, which involve activated carbon treatment, which has been applied in many cases, are applied for the purpose of removal of the substances other than PFAS in Japan. Therefore, it is important to study the operating conditions for PFAS removal at drinking water treatment plants, including cost considerations. Since there are many types of pesticides and the timing of their use depends upon the application, it is necessary to set the timing and frequency of the measurement of pesticides for their detection. However, there are currently cases where the monitoring plans for pesticides are inappropriate (e.g., all pesticides complementary items for water quality management are measured once a year at many water supply systems). The types and guideline values of pesticides that have been selected as complementary items for water quality management are continuously revised under a rolling revision system of drinking water quality regulation. As the detection of some pesticides that have been newly added as complementary items (e.g., tefuryltrione and ipfencarbazone) has been reported, countermeasures for these new pesticides are also required. Three chlorinated haloacetic acids have been selected as standard items in drinking water, and trichloroacetic acid, in particular, became one of the items most likely to exceed its standard value after a significant tightening of the value in 2015. Among the brominated haloacetic acids selected as items for further study, proposed guideline values for bromochloroacetic acid and bromodichloroacetic acid were introduced, and the acids were found in tap water at an excess of 50% over their proposed guideline values. Thus, it is considered that water quality management involving brominated species is needed for haloacetic acids.

Since the accident at the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Company in 2011, we have been faced with radiation risks. Through the efforts of all involved parties, both the radiation risks and secondary risks have been reduced. However, social conflicts continue to occur, and relations with neighboring countries are also a challenge.

The medical field is also faced with the challenge of dealing with radiation risks. The Enforcement Regulations of the Medical Service Act and the Regulations for Prevention of Ionizing Radiation Hazards have been revised, and public health centers are also required to take appropriate measures.

Overseas member states that have joined the international organization have begun to recognize not only radioactive materials in drinking water and indoor radon, but also naturally radioactive materials in common consumer goods as a public health issue, and have begun to take action.

With regard to the above issues, this report follows up on the handling of radiation risks in response to the nuclear power plant accident that have been discussed in this journal, including a social science perspective, and also outlines radiation issues in the medical and industrial fields that local governments are expected to address, as well as natural radiation issues that Japan will be required to deal with in the future. This report also outlines the issues of radiation in the medical and industrial fields that public health centers are expected to address, as well as the issues of natural radiation that need to be addressed in Japan in the near future.

In recent years, society has been engaged in the process of implementing a digital transformation. To achieve this social infrastructure, communication using wireless radio waves is an important basis. In Japan, the 5th generation communication standard (5G), which enables high-speed and high-capacity communication, was introduced in 2020 and is currently being deployed nationwide. The speed of 5G communications will be 10 times faster than that of the 4th generation, and it is expected that technologies that could drastically change our lives, such as self-driving technologies for automobiles and telemedicine (remote surgery) will be introduced in the future.

Extremely low frequency electromagnetic fields from electric power facilities, high frequency electromagnetic fields from TV, and radio transmissions also contribute to the electromagnetic environment. In recent years, induction heating (IH) cookers have become widespread, and wireless power transfer system, which uses electromagnetic fields to transmit electrical energy, has also entered commercial use. Since these technological innovations mean that our living environment will be increasingly flooded with radio waves and electromagnetic fields, there is a certain degree of concern among the public regarding the health effects of these electromagnetic fields. On the other hand, there is also the practical situation that the strength of the electromagnetic fields in our living environment is controlled based on scientific evidence. In this article, the current scientific evidence and the health risks of electromagnetic environments are outlined.

It has now been more than 20 years since the establishment of the MHLW Guidelines (1997-2002) and the revised Building Code (2003) came into force, and there has been a dramatic improvement in indoor air quality since that time. In addition, guideline valnes on the concentrations of three substances were revised and strengthened in the MHLW guidelines in April 2019. The issue of shifting to alternative substances to avoid these regulations is an ongoing challenge that needs to be addressed.

Possible pollutants that will continue to be discussed include benzene, 2E1H, texanol, TXIB, terpenes such as pinene and limonene, which are components emitted from natural woods, plasticizers and flame retardants, insect repellents and insecticides, fragrance components in air fresheners, deodorants, and detergents.

It is impossible to live without contacting chemicals in modern society. While not all chemicals are harmful, we need to deal with them rationally, making efforts to keep concentrations as low as possible, and to live with them wisely.

In recent years, there have been concerns regarding an increase in allergic diseases among children and the effects of chemical substances on the stages of development, and the possibility of exposure to chemical substances through familiar daily necessities and the environment has been pointed out [1]. Children come into contact with toys containing various chemical substances such as paints and plasticizers very frequently in their daily lives. In particular, plasticizers such as phthalates, which have been pointed out to be harmful to the reproductive functions and fertility of adults, and to have reproductive toxicity such as developmental toxicity for offspring [2], are subject to the standards of the Food Sanitation Law. Safety control measures have been taken, such as the use of concentration limits in toy products in Japan. However, along with the changing times, the types of toys have diversified, and there is a tendency towards an increase due to the distribution of imported goods from overseas and recycled products in the market. Furthermore, in recent years, new products such as tablet devices have become popular among people in a wide range of generations, as familiar daily necessities.

On the other hand, based on the results of research on exposure assessments of chemical substances using biological samples, a relatively large number of regulated substances are actually detected as metabolites in products, and new substances with similar structures can be used as substitutes for regulated substances. It has been suggested that the use of such chemicals is increasing. Therefore, in order to maintain a safe life, it can be said that safety management of chemical substances that corresponds to the changing times is necessary.

Objectives: This study aimed to assess the incidence of aspiration pneumonia in Nagasaki Prefecture and clarify the characteristics of aspiration pneumonia.

Methods: Cases of aspiration pneumonia that occurred in Nagasaki Prefecture between 2005 and 2019 were analyzed using emergency transportation records. The number of occurrences and incidence were analyzed according to age, sex, season, day of the week, and time of emergency call to clarify the actual situation of aspiration pneumonia.

Results: The total number of new aspiration pneumonia cases was 8,321, at a mean age of 83.0 years. Annual incidence per 100,000 population increased from 12.4 in 2005 to 65.1 in 2019, with the most prominent increase in the ≥ 80-year-old stratum. Males (55.1%) were relatively more commonly affected than females (44.9%) and 82.2% of cases involved patients ≥ 70 years old. No significant correlations were seen between incidence of aspiration pneumonia and season, month, or day of the week. Aspiration pneumonia occurred more frequently in the home (39.8%) and facilities for the elderly (40.8%). Seven days after admission, 80.9% of patients had been hospitalized and 6.5% had died.

Conclusion: Information on actual situations and valid preventive measures relevant to aspiration pneumonia are urgently needed.

Objective: The Revised Child Welfare Act was introduced in 2018 and mandated the placement of doctors and public health nurses at child guidance centers in Japan. The act became effective in April 1, 2022, with reports showing that professional officers needed to enhance their expertise. But there are no reports showing differences in recognition and perspectives between officers working in child guidance centers. This study aimed to identify current and future role recognition and perspectives on maltreatment of professional officers when making an assessment.

Method: The study group included child welfare officers, child psychologists, and public health nurses employed at 214 child guidance centers throughout Japan. The respondents completed an anonymous, written questionnaire that collected personal information and information about current role recognition, role recognition that should be performed in the future, and perspectives on maltreatment when making an assessment. Descriptive statistics were performed on the items analyzed, and in order to confirm differences in response trends between occupations, Kruskal-Wallis tests were conducted for items with three options or more, and multiple comparisons were made with Dunn-Bonferroni tests for items that showed a significant difference. For items with two options, the χ2 test was performed, and multiple comparisons were made by calculating adjusted standardized residuals.

Results: Of the 395 responses, 381 (96.5%) were eligible for analysis. Child welfare officers, child psychologists and public health nurses represented 44.1%, 44.4%, and 11.5%, of the study population, respectively. Child welfare officers were significantly higher than other professionals in 4 out of 20 items, including “observation, confirmation, and risk assessment in initial investigation,” and significantly higher than other professionals in only “operational support to the Regional Council for Children in Need of Protection” out of 20 items in the tasks/roles they should take on in the future. In implementation of consultation and guidance, public health nurses were lower than other occupations in 6 out of 12 items, but significantly higher than other occupations in 4 out of 24 items from the perspective of assessment, including residential environment and relationship with the local community.

Conclusion: Current role recognition, future role recognition, and perspectives on maltreatment when making an assessment were identified in professional officers. Most roles were concentrated mainly in child welfare officers, while public health nurses were not able to play their role adequately using their knowledge, abilities, and experiences. The results of this study are helpful for functional enhancement of child guidance centers by facilitating a mutual understanding of one another's expertise, and considering these three kinds of professional officer's expertise.

Objective: To calculate the fatality rate of the new coronavirus wave 6 Omicron strain positive persons aged 40 years or older in Japan and compare this with the wave 5 Delta strain positive persons.

Method: In January 2022, 21,821 people over the age of 40 who were diagnosed with a new type of coronavirus infection (COVID-19) in 7 prefectures, 3 core cities, 3 public health centers and notified were selected based on the mutation epidemic situation in Japan at that time. They were considered to be Omicron strain positive and used as subjects. A passive follow-up method based on the death notification based on the Infectious Diseases Control Law was used to ascertain the fact of death. 16,320 people diagnosed with COVID-19 in August-September 2021 were considered to be Delta strain positive due to the mutation epidemic situation in Japan at that time, and compared with the fatality rate calculated by the same method.

Result: The 30-day fatality rates for Omicron strain positive patients were 0.026% in their 40s (95% confidence interval: 0.00% to 0.061%), 0.021% in their 50s (0.00% to 0.061%), 0.14% in their 60s (0.00% to 0.27%), 0.74% in their 70s (0.37% to 1.12%), 2.77% in their 80s (1.84% to 3.70%), and 5.18% in their 90s or older (3.38% to 6.99%). The age group ratios to the fatality rate of the Delta strain in age 40s to 80s were 0.21, 0.079, 0.18, 0.36 and 0.49, which were significantly lower than unity. The age-adjusted fatality rate ratio between positives with Omicron and Delta variant was 0.42(95% confidence interval:0.40-0.45), based on the Japanese population in 2020, showing significantly lower rate in Omicron variant.

Conclusion: The fatality rate of COVID-19 wave 6 Omicron strain-positive people aged 50 to 90 years in Japan was significantly lower than that of wave 5 Delta strain-positive people.