미세플라스틱의 건강 피해 저감 연구(Ⅲ) = A Study on Reduction of Health Damage caused by Microplastics (Ⅲ)

다국어 초록 (Multilingual Abstract)

Ⅰ. Background and Objectives
□ [Background] Since the 1970s, humans have been struggling to solve the problem of marine pollution caused by plastic waste, but no clear solution has been reached. While this journey is still ongoing, microplastics have been identified worldwide, and it is difficult to accurately estimate the number of existing and potential microplastics (waste plastics); as such, policy management is required evidently.
□ [Purpose] Policy research has been conducted for three years from 2019 to 2021 to respond to environmental problems caused by microplastics and identify the pending domestic policy issues based on relevant scientific knowledge and issues.
□ [Definition of health damage] The purpose of this study is to define ‘health damage’ regarding the wide range of microplastic problems affecting the health of living organisms and environmental systems, and to prepare policies to reduce the impact on ecosystems, species, and human health resulting from such problems.
Ⅱ. Research and Analysis of Environmental Pollution by Medium
□ If all of the studies conducted on microplastics related to environmental pollution are integrated, we can deduce that microplastics have become pollutants distributed across the Earth. Although nearly 50 years of research have been conducted, it is still difficult to predict how concentrations change in different regions, countries, seasons, and years, and how the distribution characteristics differ.
□ Although the number of individual research cases in specific locations, ecosystems, regions, or countries is gradually increasing, studies involving long-term monitoring of a single region are rare. Furthermore, research generality is difficult to guarantee, as even studies conducted in the same region have large deviations in the analytical techniques, such as research methodology and identification, and statistical processing.
□ To date, most of the mainstream research involved the ocean, but various studies on freshwater on land are becoming popular. However, research on soil and the atmosphere remains lacking. China is showing the most activity in water and soil research, while insufficient research is being conducted in Africa, Southeast Asia, and Korea.
□ Owing to the lack of a conceptual and methodological basis for research on environmental pollution, quantitative comparisons should only be conducted in studies with similar research methods and analysis units. Furthermore, it is necessary to avoid using these comparisons as an absolute indicator to interpret policies or evaluate pollution levels.
Ⅲ. Analysis of the Effects of Microplastics
□ Exposure and effects of microplastics
○ Size of microplastics
- Recently, there has been a tendency to regard those having a size of 1 to 5,000 μm as microplastics as defined by the International Organization for Standardization (ISO).
○ Research trends in exposure and the effects of microplastics
- We reviewed the following studies conducted in Korea on exposure to microplastics: Distribution Characteristics of Microplastics in Southern Sea of Korea (Min et al., 2021) and Measurement of Microplastics Concentration in the Atmosphere (Seoul Research Institute of Public Health and Environment, 2021).
- Recent papers on the effect of microplastics that should be noted include research on microplastics dissolved in disposable paper cups, microplastics exposure in infants and newborns, in vivo biological behavior of microplastics and microplastics in connection with COVID-19.
Ⅳ. Review of Risk Assessment Methods for Microplastics
□ Ecological risk assessments
○ Qualitative ecological risk assessment methodology
- Based on the results of research on the distribution of microplastics on the coasts of Korea, qualitative ecological risk assessments are conducted, and the results are mapped.
○ Preliminary probabilistic ecological risk assessment methodology
- Preliminary probabilistic ecological risk assessments are conducted based on the results of research on the distribution of microplastics in freshwater areas in Korea.
- The results confirmed that the risk was not high at the current distribution level. However, due to the lack of data on exposure and toxicity in freshwater, a re-evaluation was deemed necessary once sufficient data are secured.
□ Human risk assessment
○ Human risk assessment methodology
- Owing to the lack of research on techniques to evaluate human risk, we identified the overall status while referring to literature on exposure levels and pathways in which microplastics are detected, such as drinking water intake.
○ Review of the application of human exposure assessments in Korea
- We investigated the current status of people drinking water from disposable paper cups through a survey.
- Microplastic intake through disposable paper cups was estimated as an example by applying previous research and survey results.
□ Diagnosis of the current risk assessment status and aspects to be improved
○ Consideration points for risk assessment and management
- Both qualitative and quantitative risk assessment methods should be considered for ecological risks due to the limitations of the target media and biological data. Data obtained from monitoring the concentrations of each type of microplastic in water systems on land, such as rivers, must be acquired.
- Both qualitative and quantitative risk assessment methods should be developed for human risk due to the limitations of the data on different exposure pathways. Acquiring data from monitoring exposure for different exposure pathways must be prioritized.
- For accurate quantitative risk assessment, research on developing the risk assessment methods which take into account the size and characteristics of microplastics by type should be conducted.
□ Implications for policy coordination in risk assessment
○ Seeking methods to review regulations that consider the limitations of risk research
- Considering the current limitations of human risk assessments, ways to review regulations based on emission size and ecological risks must be identified, as demonstrated in the EU.
- Before conducting risk assessment, methods to designate management priorities based on the concerned areas and high-risk product ranges derived through periodic monitoring and screening of environmental media and exposure pathways must be prepared.
- Methods that can persuade consumers to refrain from using plastic containers, such as public education and campaigns on products that are likely to be exposed to the human body, must be identified. Synergistic effects are expected if such methods are conducted in conjunction with carbon neutrality policies.
Ⅴ. Preparation of Measures to Reduce Primary Microplastics
□ [Source] According to the ECHA information of the European Union, who are preparing regulations on primary microplastics, there are eight sources of primary microplastics, including cosmetics (personal hygiene and personal care products, including beauty care products), detergents and cleaning agents, agricultural and horticultural products, paints and inks, medical devices and pharmaceuticals, synthetic infill materials, oil and gas, and construction materials and products.
□ [Policy trends] Policy responses for the management of primary microplastics can be divided into ‘international joint responses’ and ‘individual responses on a national and regional basis.’
○ Individual responses on a national basis can be further classified into autonomous regulations centered around Australia and legislative regulations in ten countries, including the United States, Canada, Argentina, France, the United Kingdom, Sweden, Italy, New Zealand, South Korea, and Taiwan.
○ The European Union has been deliberately restricting the use of primary microplastics in products under the REACH regulation, and have adopted a regulation proposal on primary microplastics since 2019, with the main content outlining product information labeling and reporting.
- After the final proposals submitted to the Socio-Economic Analysis Committee (SEAC) and Risk Assessment Committee (RAC) were integrated last February, follow-up work, such as the first draft of the revision of Annex XVII, has been underway since October 2021.
□ [Technology trends] The development of substances and technologies to replace primary microplastics involves using natural materials as alternatives, or not using microplastics at all. The trends show that natural materials are replacing microbeads in the cosmetics and detergent industries.
○ It is difficult to develop alternative technologies to microcapsules and coatings used for emission control. There are examples of cases where microcapsule technologies were developed in crops in Europe, and cases of binders and coating agents based on natural materials being developed to be applied in seeds and the commercialization of related products. The development of alternative technologies in other industries is currently lacking, and the commercialization of bio-based plastics is expected to take longer as a result.
□ [Nationwide survey] A survey was conducted to determine public knowledge regarding the perception, understanding, and main policy alternatives of microplastics, and confirmed that the general public has a severely low level of understanding of microplastics. Policies regarding the management of primary microplastics are deemed to require highly active responses, such as legislation and regulations, and transitions to using alternative materials. Agriculture, cosmetics and personal hygiene products, construction materials and supplies, and paints are the sources with high policy preference, and synthetic infill materials have low policy priority.
□ [Policy proposal] South Korea has restricted the use of primary microplastics in five detergent products, rinse-off cosmetics, and quasi-drugs. However, as there are no special management policies regarding other sources and sub-standard products, the following policy measures must be considered.
○ Among the cosmetics and quasi-drugs that are currently being regulated, personal hygiene and care products and detergents are not yet regulated. However, step-by-step regulations of many products with high usage and environmental emissions must be planned and prepared in detail.
○ Agriculture and horticulture, medical devices and pharmaceuticals, and synthetic infill materials are not yet well recognized as microplastic sources in Korea, indicating that the social consensus regarding the need for regulation is lacking. Securing the legitimacy of the policy design should be prioritized through the development and promotion of policy information, and domestic management measures should be prepared for the implementation of regulations by the European Union ECHA.
Ⅵ. Secondary Microplastic Management Plans: Measures to Reduce Outflow to Sewage Systems and Manage Bottle Caps
□ Measures to reduce microplastics from tire abrasion and fine fiber outflow to sewage systems
○ In addition to being aware of how microplastics are generated, we also need to understand the outflow routes of microplastics into the environment and manage them accordingly.
- In the first year, the amount of tire abrasion microplastics generated was estimated, and the amount of fine fiber generated was estimated in the second year.
- The outflow route in the sewage system was identified in the third year.
- In particular, flow analysis was mainly conducted on untreated outflowing water, excluding the effluent of the sewage treatment facilities.
○ We collected data on the sewer distribution rate, proportion of separate sewage systems, leaked overflow loading rate, number of days of heavy rainfall, misconnection rate in separate sewage systems, treatment efficiency in treatment facilities, sludge prevalence in sewage, and treatment status.
- Related research reports and case results were referred to based on sewer statistics.
- In the case of the loading rate of pollutants (leaked overflow loading rate) leaked as overflow during heavy rainfall in combined sewer systems, data on the concentration of microplastics in overflow is unavailable. According to the estimation of the BOD outflow loading rate based on the research result proving that there is a relationship between microplastics and BOD behavior, 22.7% are estimated to be leaked due to overflow during heavy rainfall (Analysis request made to Professor Jae Il Oh of Chung-Ang University).
- Overflow also occurs in separate sewer systems due to misconnection, and we assumed the effect to be 37% of that of combined sewer systems by referring to relevant literature.
- We assumed the misconnection rate in separate sewer systems to be 13% based on the cities of Jeju and Ulsan, where the proportion of separate sewage systems are 100%.
- The treatment efficiency in sewage treatment facilities was assumed based on domestic and international papers published on microplastics (98.5% in sewage treatment facilities, 90% in wastewater treatment facilities (biological treatment), and 85% in intercept treatments during heavy rainfall (only primary treatment conducted)).
○ The outflow of fine fibers was determined based on the 2019 data for Korea, and 10.4% of the generated fine fibers are assumed to flow out to the water system.
- 242 tons of fine fibers leak to the water system annually.
- The efficiency of sewage treatment facilities is 98.5%, but the outflow volume increases due to untreated outflow.
- The wastewater leaking from rainwater pipes due to misconnections in separate sewage systems is the greatest contributor to outflow to water systems, followed by effluents in sewer treatment facilities, overflow, and untreated outflowing water.
- The amount of fine fibers stacked onto sewage sludge leaked into the soil through composting is estimated to be 154.6 tons per year.
○ As fine fibers are generated in wastewater, we can deduce that the proportions of separate sewage systems and untreated areas are the main factors influencing outflow routes. The independent analysis of Seoul City and Gyeongsangbuk-do, where there are high proportions of combined sewer systems and untreated areas, respectively, showed that 7.5% of the generated fine fibers are leaked into the water system in Seoul, with the highest contribution being observed for overflow in combined sewer systems. In Gyeongsangbuk-do, 14.6% of the generated fine fibers are leaked into the water system, with outflowing water in untreated areas making the highest contribution.
- This should be understood as a change in outflow due to the high proportion of combined sewer systems and untreated areas, rather than as actual states of Seoul City and Gyeongsangbuk-do (it is necessary to supplement input characterization data for each region).
○ A flow chart showing the outflow of tire abrasion microplastics in 2019 in Korea was created, and 73% of the generated microplastics (excluding the 10% that move to the atmosphere) are estimated to be leaked into water systems. This result does not consider facilities that reduce nonpoint source pollution on roads and the effect of road cleaning.
- Outflow from the rainwater pipes of separate sewer systems is the greatest contributor to outflow into water systems.
- Tire abrasion microplastics exist in rainwater, and, as the proportions of separate sewer systems and sewage treatment areas are the main influencing factors, we separately analyzed the flow in Seoul City and Chungcheongnam-do, where there are high proportions of combined sewer systems and sewer treatment facilities, respectively.
- 34.4% of the generated microplastics are leaked into water systems in Seoul, and 86.2% of the generated microplastics are leaked into water systems in Chungcheongnam-do.
○ We confirmed that the outflow of abrasion microplastics to water systems was most affected by unprocessed rainwater or misconnections in separate sewer systems. Overflow management was deemed necessary in combined sewer systems.
○ This study mainly adopted national statistical data and literature values to prepare the flowchart of outflow as an example, indicating that more accurate data for each city and province must be supplemented. We also need to estimate cases in industries, in addition to households.
○ The flowchart of outflow produced in this study does not consider the reduction caused by certain sources, such as laundry bags and road cleaning.
- Approximately 50% of the outflow can be reduced when using washing drainage filters (Coraball has a removal efficiency of 26%, while LUV-R has an average removal efficiency of 87%).
- For tire abrasion microplastics, ongoing related projects, such as measures to reduce nonpoint source pollution on roads and measures regarding resuspended dust, may evoke partial reduction effects. However, it is necessary to calculate the exact level of outflow reduction based on data such as the removal efficiency and installation ratio.
○ The Ministries of Environment, Land, Infrastructure and Transport, Oceans and Fisheries, and Agriculture, Food, and Rural Affairs should jointly and accurately calculate the amount of microplastics outflow in each region, including areas where the effect of microplastics outflow is concerning (aquaculture of shellfish or seaweed, salt fields, water supply sources, and so on). The effect on agricultural water and soil must also be considered.
- In particular, management plans regarding nonpoint source pollution caused by rainwater are urgently required (tire abrasion microplastics).
□ Methods to collect and recycle bottle caps among macroplastics
○ During the first year of research in 2019, we ranked management priorities based on the prevalence of marine waste, material and morphological risks, recycling status, and management standards. The results of the investigation of the top six waste products on land based on the annual monitoring of marine waste conducted by the Ministry of Oceans and Fisheries and the Korea Marine Environment Management Corporation showed that drink bottles and bottle caps were the most produced types of marine waste.
- There have been no cases of management policies reviewed for bottle caps in South Korea, but strategies to prevent bottle caps from being thrown away are being implemented in Europe.
- Bottle caps attached to bottles will become compulsory in Europe as of July 2024, and there is a high interest in the management of caps, even after enforcing the security deposit.
- Bottle caps were found to inflict a large amount of damage to birds in particular.
○ The higher the economic value of materials, the lower the probability of the materials being disposed of as marine waste, indicating that improving the resource circulation of marine waste can ultimately prevent waste disposal.
- We investigated the disposal status of bottle caps, waste management status, and policy measures to enhance resource circulation.
○ The status of marine disposal of bottle caps in Korea differs greatly for each monitoring point.
- A particularly large number of bottle caps were discovered in Dumo Mongdol Beach in Geoje City and Guryongpo in Pohang City, and their numbers were significantly larger than the number of PET drink bottles.
- The effects of protective caps on gas cans need to be investigated along with bottle caps.
- Owing to the large regional deviations, monitoring data on marine waste for each region need to be utilized.
○ Bottle cap separation and disposal methods differ between countries.
- Bottle caps are separated from PET bottles in Japan before being disposed of, while bottle caps are recommended to be disposed of by being attached to their bottles in Europe and the United States, or no separate guidelines are provided.
- In South Korea, bottle caps are recommended to be disposed of by being attached to their PET bottles following the clear plastic bottles
separation and disposal policy. Meanwhile, after the movement of waste management companies in 2018, in which they refused to collect plastic waste in the Seoul Capital Area, the public interest in waste increased, leading to the proliferation of the ‘Precious Plastic Movement’, a regional social movement to circulate plastics and programs in which bottle caps were separately collected.
○ We propose a decision tree to determine a bottle cap separation anddisposal policy by considering the impact of mixing bottle caps on the recycling process, recycling status of bottle caps that are separated during the process, and citizen participation in the separation and disposal of bottle caps.
- According to on-site investigations and written surveys completed by companies, the effect of bottle caps on the purity of PET bottles and the recycling process is low. The bottle cap (LDPE) and label (PP) materials separated during the process are mixed to be recycled as pallets.
- The participation survey conducted on citizens regarding the separation and disposal of bottle caps showed that 93.3% will participate if collection boxes are available within their apartment complex, 59.7% will participate if collection points are nearby, and 26.0% will participate if the bottle caps must be sent as courier post using their own money.
- Owing to the high receptivity of bottle caps in the PET bottle recycling industry, the current national guidelines for the disposal of bottle caps by being attached to their bottles are generally appropriate. However, separate collection systems can be constructed for different regions to establish a better recycling system for bottle cap materials. In the use of unmanned collecting stations, bottle caps need to be collected at the same time as the PET bottles.
○ We conducted a case study on ‘Plastic Mills,’ a voluntary program that separately collects bottle caps (submitted a request to the Team Leader Dong-Yi Lee of the Korean Federation for Environmental Movement).
- Various activities are being conducted at the level of the Precious Plastic Movement, an international plastic regional circulation movement. The collection was initially conducted by courier delivery, but recently moved to be conducted at collection points.
- Although the bottle caps can be used to produce a variety of daily necessities with relatively safe materials (drive to produce practical products), the need to prepare workshop spaces and acquire human resources is a limitation.
- We can also expect educational effects to be evoked by increasing public awareness of the use of disposable plastics through separate bottle cap collection programs; as such, support from local governments must be considered from an educational and resource circulation perspective.
- Public participation and collection probability must be increased through reward provisions, especially in coastal areas where marine disposal is likely to occur.
- More cases, such as the regional resource linkage methods in Daejeon and the ‘Jaejudojoa’ program in Jeju Island, where marine waste and ‘Precious Plastics’ were combined, need to be expanded.
○ Plans to improve resource circulation of bottle caps regarding microplastic reduction
- Expansion of materials resource circulation and enhancement of economic value prevent outflow of microplastics.
- Quality improvement of bottle cap material recycling (same purpose prioritized, recycled in the order of highest value) - Monitoring of microplastics during the recycling process is required (gravity separation after crushing).
- Expansion of separate bottle cap collection programs and rewards
○ Review needed on attaching bottle caps to bottles to prevent disposal
- The public survey showed that 65.5% of the respondents lost bottle caps, 63.5% said they would buy bottles with attached caps, and 9.7% said they would not buy them (the rest of the responses were neutral).
- PET bottle recycling facilities do not need to worry about mixing bottle caps. Even the rings of the attachable bottle caps can be removed during separation, meaning that they can play a significant role in separate collection systems.
Ⅶ. Microplastics Research and Policy Database & Development of Information Platforms
□ The development of the microplastics information platform, KMPic (KEI Microplastic & Plastic Information Channel), was completed. This includes the three research databases regarding the analysis of previous research related to environmental pollution and its influence, and a policy database that analyzed the regulation status for different countries. The utilization of policies is expected to be high; as such, it will be necessary to plan follow-up projects to consistently update and manage the data.