Brief introduction: From the perspective of environmental hygiene, according to certain evaluation standards and methods, the environmental quality of a certain area is investigated, analyzed, evaluated and predicted objectively and qualitatively. Environmental quality evaluation is essentially a process of evaluating environmental quality, including the determination of environmental evaluation factors, environmental monitoring, evaluation standards, evaluation methods and environmental identification. Therefore, the correctness of environmental quality assessment is reflected in the scientificity and objectivity of the above five links. There are two commonly used methods: mathematical statistics and environmental index.
Environmental impact assessment is an important part of the project evaluation system, including studying the environmental conditions required by the project construction scheme, identifying and analyzing the environmental factors affecting the project construction, the protection countermeasures and measures to be taken, and the relevant economic analysis of environmental losses and environmental benefits. This lecture focuses on the evaluation method of environmental value.
First, the main method of environmental value assessment Environmental value is the monetary quantitative value of environmental quality. Generally, direct market method, alternative market method and willingness survey and evaluation method are used to quantify environmental value.
(I) Direct Market Method The direct market method is a method of directly using money price (market price or shadow price) to observe and measure the environmental quality changes that may be affected by the project construction. Mainly includes:
1. The impact of the investment and construction activities of the market value or productivity method on the environmental quality may lead to the change of the output level of the corresponding commodity market, so the change of commodity sales caused by the change of the output level can be used to measure the change of environmental value. For example, the emission of a certain kind of waste will affect the production of other manufacturers in its surrounding areas, so the environmental value can be calculated by the gross national product reduced by other manufacturers due to production reduction. If the goods affected by the change of environmental quality are sold under the condition of giving full play to the role of market mechanism, the environmental value can be directly measured by the market price of the goods. If the goods affected by environmental quality changes are sold under the condition of imperfect market mechanism (for example, there is monopoly or price subsidy, or enterprises are responsible for their own profits and losses, so they can raise prices indiscriminately regardless of market supply and demand and product sales, etc.). ), the shadow price should be used to calculate the environmental impact value.
2. The change of environmental quality by human capital method or income loss method has many effects on human health. This influence is not only manifested in the direct loss caused by the increase of the morbidity and mortality of workers (which can be measured by the market value method), but also in the increase of medical expenses caused by the deterioration of environmental quality and the loss of income caused by people's premature illness or death. Human capital method or income loss method is a special method to evaluate the environmental value reflected by personal health. From an economic point of view, human capital refers to the capital embodied in workers, mainly including their cultural and technical level and health status. Human investment is an investment in the health status and cultural and technical level of workers. The cost (expense) of human investment includes the expenditure of individuals and society on education and medical care, and the income (benefit) of human investment includes the increase of personal income and social benefits brought by personal education and medical care. In order to simplify the calculation, the human capital method only calculates the increase of medical expenses caused by changes in environmental quality and the personal income loss caused by premature illness or death of workers. The former is equivalent to the product of the number of patients increased due to environmental quality changes and the average treatment cost of each patient (weighted by different diseases), while the latter is equivalent to the product of the impact of environmental quality changes on the expected life expectancy and working years of workers and the present value of the expected income of workers (excluding non-human capital income).
3. Protection cost method When an activity may lead to environmental pollution, people can take corresponding measures to prevent or control environmental pollution. The method to evaluate the environmental value with the cost of taking these measures is the protection cost method. The burden of protection costs can be borne in different ways, such as taking? Who pollutes, who controls? The way by which polluters buy and install environmental protection equipment to eliminate pollution, or take? Who pollutes, who pays? In this way, a special pollutant treatment enterprise can be established to treat pollutants in a centralized way, or the victims can buy corresponding equipment by themselves (such as installing sound insulation equipment in the homes of noise victims), and the polluters will give corresponding compensation. The required cost can be used as the basis for calculating the environmental impact value of the project.
4. Recovery cost method or replacement cost method If the environmental pollution that leads to the deterioration of environmental quality cannot be effectively controlled, then other methods have to be adopted to restore the damaged environment in order to maintain the original environmental quality. The cost of restoring the destroyed environmental quality to the state before destruction is the restoration cost. The repair cost is generally calculated according to the replacement cost, so as to accurately reflect the repair cost at the real price level.
5. Shadow project method Shadow project method is a special form of recovery cost method. When the construction of a project will destroy the environmental quality, and it is technically impossible to recover or the cost of recovery is too high, people can design another supplementary project as a substitute for the original environmental quality at the same time, so as to keep the impact of environmental quality on economic development and people's living standards unchanged. There are usually multiple schemes for the same project (including supplementary projects), and these alternative project schemes that cannot be implemented at the same time are shadow projects. When it is difficult to directly evaluate the losses caused by environmental pollution, people often use the cost of this shadow project to estimate the monetary value of environmental quality changes, which can protect economic development and people's lives from environmental pollution.
(II) Alternative Market Method In real life, some goods and services can be observed and measured, and they can also be measured by money prices, but their prices only partially and indirectly reflect people's evaluation of environmental value changes. The method to measure the change of environmental value by the price of such goods and services is the alternative market method, also known as the indirect market method. Substitute into the market magic map, find those goods and services that can indirectly reflect people's evaluation of environmental quality, and measure the environmental value with the prices of these goods and services. Because the information involved in this method often reflects the comprehensive consequences of many factors, and environmental factors are only one of them, and it is often difficult to exclude the interference of other factors on the data, which makes the results obtained by this method less credible. Alternative market method mainly includes:
1. Consequence Prevention Law The deterioration of environmental quality will cause damage to economic development. In order to prevent this from happening, two methods can be adopted: one is to prescribe the right medicine and ensure economic development by improving environmental quality. However, when the deterioration of environmental quality is irreversible (at least not by a certain party or even a certain country), another method is often adopted, that is, increasing other inputs or expenditures to reduce or offset the consequences of environmental quality deterioration. In this case, it can be considered that changes in other inputs or expenditures reflect changes in environmental values. The method to measure the monetary value of environmental quality change by the amount of these inputs or expenditures is the consequence prevention method.
2. Asset value method Asset value method is sometimes called comfort price method. The value of assets closely related to local environmental conditions, such as houses and land, is obviously affected by local environmental quality. Other things being equal, the difference of environmental quality will affect consumers' willingness to pay, and then affect the market price of these assets. Therefore, we can use the price difference of similar real estate and other assets caused by different surrounding environmental quality (other conditions being the same) to measure the monetary value of environmental quality changes.
3. Wage difference method Under the same other conditions, the difference of environmental conditions in the workplace of workers (such as the size of their voices, whether they are exposed to pollutants, etc.). ) will affect their career choices. In order to attract workers to engage in occupations with poor working environment and make up for the losses caused by environmental pollution, manufacturers have to compensate workers in terms of wages, working hours and vacations. This method of measuring the monetary value of environmental quality by the difference of wage level (the difference of working hours and vacations can be converted into wages) is the wage difference method.
4. Travel cost method This method holds that the travel cost of tourists to comfortable environmental resources such as famous mountains and rivers, strange peaks and rocks, rare birds and animals (including the ticket price paid by tourists, the cost required to go to these places and the opportunity cost of the time spent on the journey) indirectly reflects the tourists' dissatisfaction with the environmental quality of their work and residence to some extent, thus reflecting the tourists' willingness to pay for environmental quality. Therefore, after excluding the influence of other factors (such as income), we can indirectly measure the monetary value of environmental quality changes with tourism expenses (including the monetary value of environmental quality of tourist spots and the monetary value of environmental quality of tourists' work and living places).
(III) Willingness Survey Evaluation Method If the observable and measurable results caused by environmental quality changes cannot be found (whether such results can be directly or indirectly priced), or the appraiser wants to know the appraiser's willingness to pay or be compensated for environmental quality changes, in this case, the appraiser can evaluate his willingness to pay or be compensated through direct investigation. This is a willingness survey and evaluation method, which mainly includes:
1. Asking directly about the respondents' willingness to pay or their willingness to get compensation includes:
(1) bidding game method. By simulating the auction process of items, the willingness of respondents to pay or be compensated is investigated. Investigators first explain to the respondents the impact of environmental quality changes and the specific ways to solve environmental problems, and then ask the respondents whether they are willing to pay a certain amount of money to improve the environment (or whether they are willing to accept a certain degree of environmental quality deterioration under the premise of accepting certain compensation). If the respondents answer yes, they will increase (or decrease) the amount until the respondents give a negative answer. Then, the investigator changes the amount to find out the exact amount that the respondent is willing to pay.
(2) Trade-off game method. Through the respondents' choice of two schemes, we can investigate the respondents' willingness to pay or get compensation. Investigators should first explain to the respondents the impact of environmental quality changes and the specific methods to solve environmental problems, and then put forward two groups of programs. Among them, the first group only includes a certain environmental quality, and the second group needs the respondents to pay a certain amount of money (or compensate the respondents for a certain amount of money) in addition to the specified environmental quality. Respondents were asked to choose between different combinations of environmental quality and money expenditure. If the Respondent chooses the first group, it will reduce the amount that the Respondent needs to pay (or increase the amount of compensation to the Respondent), and if the Respondent chooses the second group, it will increase the amount that the Respondent needs to pay (or reduce the amount of compensation to the Respondent) until the Respondent feels that no matter which group scheme is selected, it is the same. At this point, the investigator will sum up the amounts that all the respondents in the second group of schemes are willing to pay or accept, and then the monetary value of the above environmental quality differences can be obtained.
2. Ask the interviewee's demand for certain goods or services, and infer the interviewee's willingness to pay or be compensated.
Mainly includes:
(1) no-cost selection method. Respondents are required to choose from several schemes, but no matter which scheme, they are not required to pay, only to choose a certain combination of environmental quality and a certain amount of other goods or services (including money). In this way, respondents' willingness to be compensated for differences in environmental quality can be expressed through their choice of other goods or services.
(2) Priority evaluation method. First, tell the respondents the prices of different environmental quality (such as tap water with different water quality), and then give the respondents a budget, asking them to use the money (which must be used up) to buy a group of goods with environmental quality. In this way, respondents' willingness to pay for environmental quality changes can be expressed through the combination of goods they buy.
(3) Delphi method. Obtain environmental quality evaluation information through expert investigation. Willingness survey and evaluation method directly evaluates the respondents' willingness to pay or get compensation. Theoretically, the result should be closest to the monetary value of environmental quality. However, it must be admitted that in the process of determining the willingness to pay or be compensated, the information held by the investigator and the respondent is asymmetric, and the respondent knows his wishes better than the investigator. In addition, the willingness survey and evaluation method evaluates the respondents' willingness to declare, rather than the actual actions taken by the respondents according to their own wishes, so the survey results may be biased. When respondents think their answers can influence decision-making; So that their actual private cost is lower than the expected value under normal circumstances, and the survey results may be strategically biased; When investigators introduce various alternatives incompletely or misleadingly, the survey results may produce data bias; The assumed collection or payment method in the questionnaire is improper, and the survey results may be biased; Respondents enjoy the environment and ecological resources free of charge for a long time? Free ride? Psychological science leads the respondents to regard this enjoyment as a natural right and oppose paying for it, thus making the survey results hypothetical. It can be seen that if careful preparation is not made, the conclusion drawn by this method is likely to have a major deviation. Therefore, when estimating the monetary value of environmental quality, the direct market method should be adopted as far as possible; If the conditions for adopting the direct market method are not met, the alternative market method shall be adopted. Only when the above two methods can not be applied, will we have to adopt investigation and evaluation methods.
Second, the assessment of environmental impact loss
(1) Environmental pollution control cost and environmental protection cost refer to the sum of resources invested to control and eliminate the environment after the fact that environmental pollution is caused by the project construction. The cost of environmental protection includes the sum of all kinds of losses that may be caused, such as the cost of environmental governance, the cost of preventing environmental damage, the compensation for victims, the cost of developing environmental protection industry, and the' loss' of idle resources. The cost of environmental pollution control is only an integral part of the cost of environmental protection, that is, it only refers to the cost of environmental control in the cost of environmental protection.
(2) Estimation of environmental impact loss caused by flood disaster.
1. Estimation of flood environmental impact loss The estimation of flood environmental impact loss focuses on industrial and mining enterprises, railways, highways and other facilities affected by the project and property losses such as houses, crops and young forest land, usually direct economic losses. In addition, there are indirect economic losses caused by dam break, long-term flood caused by dam break or high-speed water flow attack, such as the increase of population morbidity and mortality, economic losses caused by floods in disaster-stricken areas outside flooded areas, backlog of products, shortage of raw materials and insufficient water supply. Generally, the value of crops, trees, engineering facilities, residents' property, industrial and mining enterprises' property, institutions' assets and other properties in flood-stricken areas is estimated by evaluating the scope and degree of floods, and the property loss rate is considered for calculation.
2. Estimation of environmental impact loss of flood disaster. Waterlogging disasters are usually caused by engineering construction (such as hydropower, flood control, highways, railways and other large-scale projects) changing the natural topography, causing changes in groundwater level and drainage conditions, thus affecting the changes in the ecological environment and leading to economic losses. From the environmental point of view, the economic losses caused by waterlogging will not only lead to crop reduction or even crop failure, but also lead to drinking water pollution, an increase in the incidence of infectious diseases and an increase in epidemic prevention and disinfection personnel and chemicals. Property losses include economic losses of crops and soil salinization. It can be determined by investigating the loss rate or yield reduction rate of local similar crops.
(3) Estimate the losses caused by soil erosion to human health and environment.
1. Estimation of environmental impact loss of soil erosion Due to the construction and operation of the project, the process (rate) of soil erosion is strengthened or the amount of soil erosion is increased, which is the direct impact of the project on the environment. However, the increase of soil erosion amount or intensity has caused many environmental changes. When calculating the economic loss of environmental impact, it should include two aspects: the impact of engineering on soil erosion and the impact of soil erosion on secondary environment. The impact of the project on soil erosion includes two aspects: land loss or landscape change caused by man-made destruction of land, or land loss or landscape change caused by land destruction caused by project implementation.
2. Estimation of economic loss caused by population health The premise of economic loss estimation caused by population health is that the project does have factors that induce diseases and even lead to population death, that is, through the special prediction and analysis of population morbidity and mortality by environmental medicine, it is pointed out that the project (or related projects in the whole region) will affect the increase of population morbidity and mortality. However, if the specialty of environmental medicine can't provide specific data, the economic loss of population health impact can't be estimated. However, this does not hinder the study of economic loss estimation methods, because the prediction of population morbidity and mortality does not belong to the category of environmental economics, and its task is how to estimate this part of economic loss through some method according to the specific data put forward by environmental medicine. In order to estimate the economic loss of population health, we must first determine the value of human life. Once the environmental impact of the project is determined, the increase of human morbidity and mortality can be determined. By estimating the value of human life, we can infer the environmental and economic losses caused by the health impact of the population.
(4) Estimate the environmental losses caused by water and air pollution.
1. Estimation of environmental loss caused by water pollution Water pollution refers to the loss caused by the discharge of waste water and sewage due to the implementation of engineering projects, which makes the quality of clean natural water exceed the standard and leads to the weakening or loss of water function. Generally, the economic losses caused by water shortage should be considered, including the losses of industrial water, domestic water and irrigation water caused by the cut-off of water supply sources, the losses of agricultural irrigation and fishery production caused by low-temperature water used in engineering projects, and the economic losses of fish production reduction caused by thermal pollution and water pollution.
2. Estimation of economic loss of air pollution. Once SO2, nitrogen oxides, TsP, CO, CnHm and some radioactive substances in the air enter the human body, exceeding the dose will lead to human death. SO2 in the atmosphere is the main cause of acid rain, which leads to the increase of soil acidity, directly affects the output of trees, crops and fisheries, corrodes equipment, affects the service life of equipment and causes economic losses.
(5) Calculation of other environmental impact losses
1. Loss estimation of induced earthquake. Induced earthquake refers to the earthquake caused by engineering construction, or the earthquake intensity increases because of the existence of engineering. Taking the water conservancy and hydropower project as an example, after the reservoir is impounded, the geostress changes and the groundwater state changes, which leads to the revival of the original fault. The causes of earthquakes induced by water conservancy projects can be roughly divided into three categories: first, earthquakes occur in areas where large strain energy and gravity energy are gathered at the edge of huge gravity gradient zone or mantle uplift and structural development; Second, the landslide and landslide earthquake caused by reservoir impoundment; The third type is the collapse earthquake caused by cave collapse caused by water storage in karst areas. To determine the influence range and property loss of induced earthquake, the influence areas of each intensity level can be delineated according to the intensity distribution map of induced earthquake, and the key investigation and analysis can be carried out. If conditions permit, the seismic capacity of all buildings (structures) should be investigated to determine the damage degree and property loss rate. Economic losses include property economic losses and profit and tax losses caused by earthquake or ground collapse, which should be estimated separately. If there are earthquake monitoring facilities, the expenses shall be calculated together.
2. Estimation of soil pollution loss Soil pollution can be caused in two ways: directly (such as waste gas emission, dust suppression, waste water emission, waste residue, etc. ) and indirect (such as upstream salt water, blocked drainage and waterlogging caused by the project. ). Most of the former methods belong to pollution projects; The latter projects are mostly destructive projects. The economic losses caused by soil environmental changes are often linked to the yield and quality of crops (or trees). Simply changing the soil environment (in fact, the soil quality) itself cannot analyze its economic losses. In other words, soil pollution will reduce the value of soil, and the value of soil is reflected through its function. The most obvious example of soil pollution reducing its value is acid-base pollution, which can make crops, trees and grasslands extinct. As for heavy metal pollution, because the enrichment of heavy metals in soil is a slow process, it usually affects the quality of roots, stems and leaves and grains of plants. When the content of heavy metals in grain or pasture exceeds the prescribed edible standard, it should also be regarded as crop failure, and the corresponding losses should be estimated.
3. Estimation of radioactive pollution loss: Does radioactive material pollution refer to nuclear engineering or radioactive material? Three wastes? According to the degree of harm to human body and its correlation, the loss of human life value is estimated. The emission of radioactive substances not only pollutes the atmosphere, but also pollutes the water body, so the economic loss caused by radioactive pollution will not only cause the loss of human life value, but also cause the economic loss of terrestrial organisms and aquatic organisms. Its economic loss estimation includes the sum of economic losses caused by air pollution and water pollution.
4. Estimation of wildlife loss From the perspective of environmental economy, wildlife can be divided into two categories: ordinary and rare. They all have the same life value (or ecological value) and scientific research and species value, but the estimation methods are different. The former focuses on analyzing their meat value (price) or ecological value; The latter is mainly to estimate its life value or scientific research value. Since rare animals and plants are endangered species, they should be endowed with higher life value, scientific research value and species value. The life value of wild animals can be estimated by different methods according to their species classification, and it is reflected in scientific research and species value, ornamental value, meat value and ecological value. But the life value of wild animals can only be one of the calculated values. For example, the life value of an animal has already calculated its scientific research value and species value, so it cannot be added with its ornamental value or ecological value. Wild plants, like wild animals, have a process of growth and extinction. Their natural survival time is many times longer than that of wild animals, and they have the same scientific research value, species value, ecological value, ornamental value and social value as wild animals.
5. Estimation of environmental losses of cultural relics and historic sites, including cultural relics, ancient cultural relics and ancient buildings, all have the value of scientific research, sightseeing and export. In principle, all cultural relics should be protected, which is an important state-owned resource. From the perspective of environmental economy, any cultural relics and historic sites are valuable. Damage to them will cause corresponding economic losses. In the evaluation, we should measure its scientific research value, tourism value and ornamental value.
6. The project's estimation of the loss of the deposit has two effects on the deposit. One is that the project affects the mineral deposits being mined around, and the other is that the area affected by the project has been identified, and there are mineral deposits buried underground, but they have not been mined. The influence of the two situations is different. For the mineral deposits being mined, there are not only unexploited ore, but also a set of equipment, tunnels, houses and employees. Once the project is started, it is very likely that the whole mining facility will be scrapped and the remaining unexploited mineral resources will suffer losses. The mine stopped production and the workers were unemployed; Or the project interferes with or destroys mining operations, and is forced to change mining methods and divert transportation, so that some mining facilities are scrapped, mining equipment is replaced, and some properties suffer losses. For the mineral resources to be developed, once the project is launched, it is very likely that the whole mineral resources will be buried, even if it is technically feasible and economically unreasonable, which will cause losses to mineral resources; Another possibility is that the project affected the mining technology, which could have saved money, but had to adopt high-cost technology, which affected profits and taxes. Therefore, the project should comprehensively consider the ore reserves, deposit types, mining years, mining value, and the way and degree of the project's impact on the deposit.
7. Estimation of noise environmental loss Noise can change people's brain waves, causing dizziness, insomnia, lethargy, fatigue, memory loss, inattention and other diseases, which can develop into insanity in severe cases. The economic losses caused can be estimated by medical expenses, coverage area of epidemic areas, population density, labor productivity loss and population growth rate.
Third, the environmental impact benefit evaluation
(A) the project environmental impact benefit evaluation refers to the inherent characteristics of the project itself without taking environmental protection measures.
The benefits brought. These benefits are not considered in the investment of the main project, nor do they belong to the functional scope of the main project, but objectively have a beneficial impact on the environment. 1. Environmental benefits of tail water supply for hydropower projects The construction of water conservancy and hydropower projects has changed the river regime under the dam, reduced the peak flow and increased the flow in dry season. Especially for some small and medium-sized hydropower projects, the downstream river water is greatly affected before and after the project construction. In natural downstream rivers, water supply is insufficient in dry season, which often leads to water competition between industry and agriculture; In the rainy season, a lot of water is lost and can't be used. After the completion of the hydropower project, due to the regulation of the reservoir, the contradiction of water shortage in the downstream water supply department was objectively alleviated and the income of the water supply department was increased. This increase should be attributed to the construction of upstream hydropower projects. Including irrigation water supply benefits and industrial water supply benefits, but also divided into the benefits of increasing water supply and improving water quality.
2. Fishery economic benefits Reservoir projects and other projects conducive to aquaculture can obtain fishery economic benefits. Reservoir projects are built for other purposes, excluding those aimed at developing fisheries. This economic benefit is endowed by the main project. Reservoir water storage has expanded the water area and increased the water depth, providing an adequate living environment for aquatic organisms, and the fishery output has doubled the water area; On the other hand, the biomass of reservoirs is higher than that of natural rivers, that is, the fishing productivity will be higher than that of natural rivers. In this way, the fishing output of the reservoir will increase obviously, thus producing corresponding benefits.
3. Tourism economic benefits Many construction projects that do not aim at tourism can produce obvious tourism economic benefits. Generally, tourism cost method and daily value method are used for calculation.
4. Environmental benefits of alternative projects The improvement of a project construction or a production process, while there are one or more alternative projects (or projects). For example, the low chromium plating solution in electroplating process and the electrophoretic paint process of mechanical parts have become light pollution or pollution-free technical transformation projects, all of which are relatively advanced (in terms of environmental impact) production processes. Before their technical transformation, there was an old production process of high concentration chromium-containing waste liquid and paint solution. Although the products they produce have not changed, the degree of environmental pollution is different due to different process routes. We call the technical route scheme before technical transformation an alternative scheme or an alternative project. The difference between the total economic loss of environmental impact of alternative projects and the total economic loss of environmental impact of construction projects can be used as the basis for calculating the environmental benefits of proposed projects.
5. Economic Benefits of Fertilization in Submerged Soils Although floods caused by engineering projects will bring inundation losses to crops, at the same time, flooded farmland can increase its soil fertility, increase crop yield and gain benefits. When calculating its benefits, we can select some representative areas and compare the crop yield one year after the flood with that one year before the flood. Under the same irrigation and other agricultural technical measures, the difference between the crop yield one year after the flood and the crop yield one year before the flood is the benefit of increasing production brought by soil fertility.
(II) Benefit Evaluation of Environmental Protection Measures Environmental protection measures are engineering measures taken to reduce the economic losses of the project to the environment. Generally speaking, the impact of polluting construction projects on the environment is mainly loss. And this kind of economic loss can only be made up by the sales benefit or social benefit of the product. Moreover, the above-mentioned environmental economic loss refers to the pollution (or destruction) caused by engineering pollutants (or destruction factors) to the environment, and it also occurred without taking any preventive (or protective) measures. In fact, according to the relevant laws and regulations, it is impossible for projects that have a great impact on the environment to be discharged at will without taking any measures. Therefore, the actual environmental impact economic loss is far less than the above calculation results. The environmental impact benefit after taking measures should be the difference between the losses before and after taking measures.
The environmental impact forms of the project can be divided into pollution type and destruction type. The environmental protection measures adopted by the project include various measures such as governance, prevention and protection. In the specific evaluation, the environmental benefits should be evaluated according to the characteristics of various environmental protection measures such as drainage, water and soil conservation, water quality protection, atmospheric protection, induced earthquake prevention, wildlife environmental protection, cultural relics protection, mineral resources protection, noise prevention and crowd health protection.
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