Factors Affecting the Intention to Distribute in Sort Plastic Waste of Vietnamese People: A Case Study in Ho Chi Minh City

Abstract

Purpose: This paper (1) identifies the factors that affect people's changing habits towards waste sorting, (2) evaluates the benefits of waste sorting to the environment and (3) designs communication strategies to change people's behavior and habits in sorting plastic waste in Ho Chi Mnh City, Vietnam. Research design, data and methodology: Using the data from 309 people that are living in Ho Chi Minh City and Structural Equation Modeling (SEM), to evaluate variables and test the hypotheses. Results: Research results show that attitudes, subjective standards, behavioral control, and facilities affect people's intention to classify plastic waste. We find that environmental concerns greatly influence people's attitudes. In contrast, environmental concerns have a relatively weaker effect on people's degree of behavioral control. Conclusion: Environmental protection is a matter of concern in the world. In Vietnam, this issue has been institutionalized into law to create a basis for improving the effectiveness of environmental protection activities. This article has some limitations. Firstly, sample is limited to HCMC residents; the study results are not representative of the entire population of Vietnam. This paper is based on cross-sectional data, which is not the best way to establish a causal relationship between the intention to sort plastic waste and its drivers.

1. Introduction

Awareness of the dangers of waste negatively affecting the environment has become a top concern of people in Vietnam, especially in big cities with high awareness. In a previous study by (Nguyen et al., 2020) conducted a questionnaire survey with 300 Vietnamese people "Mention three main types of environmental pollution in Vietnam, with the question in your opinion, which type of waste has the greatest level of danger and negative impact on the environment and your health?". Respondents ranked plastic waste as the most hazardous that affects both the natural environment and human health, followed by waste from industrial plants and, finally, from manufacturing and agricultural production. Concerns about environmental pollution and potential risks to human health have persisted throughout the past time. However, there have been many changes in environmental quality through changes in people's awareness as well as changes in regulations on waste management and control in Vietnam.

Hazard awareness of different types of waste plays a vital role in promoting people's waste segregation behaviour (Guerrero et al., 2013). With the rapid development of today's society, more and more waste is generated, which means that a large amount of waste is generated every year, and its increase creates unexpected harm. Therefore, separating and recycling waste is essential to reduce the source of hazardous waste, especially plastic waste. Most of the household waste can be sorted right at the household. However, people's mentality is that the garbage classification is done by the waste management unit (Lozano & Vallés, 2007). Therefore, changing people's awareness and behavior of waste separation at home will help reduce the amount of solid waste that goes to landfills to improve environmental quality and can obtain great economic benefits from recyclable and reusable wastes. Many previous studies have made in-depth and comprehensive assessments of the ecological efficiency of waste separation at home (Knickmeyer, 2020). The results show that separating waste at home will reduce the risk of pollution and minimize the residual waste from human activities and production (Klemeš et al., 2020). However, these studies focus on changing household waste sorting habits that contribute to environmental protection in developing countries is still limited. Therefore, in this study, we will focus on addressing this gap.

People living in developing countries like Vietnam are worried about environmental quality issues related to waste management and control, especially the unsorted behavior of people (Omran et al., 2008). In Ho Chi Minh City, about 14 million people and up to 80 tons of plastic waste is discharged into the environment daily. However, awareness of the benefits of household waste separation has not been paid enough attention, which has limited the implementation of waste classification by people in some areas (Knickmeyer, 2020). International experience shows that a high level of awareness about the benefits of household waste sorting will immediately positively affect the quality of people's living environment (K. Kim et al., 2013). Previous studies on the factors influencing behavior change for segregating waste at source have not been conclusive. Therefore, this study aims to consider the factors that change the behavior in the classification of plastic waste before they are collected and treated in Ho Chi Minh City, Vietnam. First, this study identifies the factors affecting people's changing habits in waste sorting in Ho Chi Minh City and evaluates and analyzes the benefits of waste sorting to the environment. Then, these results will allow environmental managers to design communication strategies to change people's behavior and habits in sorting plastic waste at home to minimize the negative impact on the environment.

2. Literature Review

Plastic waste is a substance that is very difficult to decompose in many environments, most of which are single-use plastic products; the most common are: plastic bags, plastic bottles, plastic boxes, straws, and food packaging (An et al., 2020). Plastic waste includes polyethylene (PE) plastic packaging that becomes waste after use. In household waste, other types of plastic also contain waste plastics. Plastic waste is a mixture of plastic; most is PE plastic. Plastic waste contains harmful chemicals that pollute the environment and seriously affect economic growth, global climate change, and social life (Jalil et al., 2013).

2.1. Environmental Knowledge

Environmental knowledge can be defined as general knowledge of facts, concepts, and relationships related to the natural environment and its major ecosystems. Therefore, environmental knowledge refers to what people know about the environment, the key relationships that lead to environmental aspects or impacts, and the collective responsibility necessary for sustainable environmental sustainability (Fryxell & Lo, 2003). People are a vital force for environmental protection. Therefore, raising awareness and action of this target group is necessary. People's awareness of environmental issues can be enhanced via education (Chow et al., 2017). People with environmental knowledge and skills will be more motivated to participate in environmental protection activities (Tali Tal, 2004), thereby generating new ideas to solve environmental problems.

2.2. Theory of Planned Behavior

Theory of Planned Behavior (TPB) (Ajzen, 2011) is often used to support and provide information about the effectiveness of public perceptions and attitudes. TPB delivers a theoretical framework for assessing proenvironmental behaviors and identifies factors influencing intentions to segregate plastic waste systematically. The TPB theory is developed from the earlier Theory of Reasoned Action (TRA). While TRA assumes that people behave rationally, TPB hypothesizes that the determinant of behavior is an individual's intention to perform or not to perform the behavior. The intention is, in turn, influenced by two factors, attitudes, and subjective norms. Luo et al. (2020) argues that the performance of many behaviors will be limited by the lack of appropriate opportunities, skills, and resources. This is why TPB extended TRA to include a third variable, behavioral control, a measure of an individual's perception of their ability to perform a behavior. TPB has been used in many studies to understand a range of environmentally responsible behaviors, including plastic recycling (Kelly, 2002). It can be seen that the more favorable the attitudes and subjective norms and the greater the cognitive control, the stronger the intention to perform the behavior.

This study uses TPB as the background theory and, at the same time, adds some variables suitable to the research context to investigate the intention of people to sort plastic waste. Approaches include environmental concern (EC), attitude (AT), subjective norm (SN), and behavioral control (PB) that can influence people's intention to perform specific behavior toward sorting plastic waste in daily life.

2.3. Determinants of Waste Segregation Behavior

Sorting plastic waste is a significant job in waste management. A major challenge in the plastics recycling industry is sorting plastics by type and color, which can help reduce the risk of segregation of high-grade recycled plastics into non-recyclable low-grade plastics. Manual sorting of plastic waste involves identifying the plastic's shape, color, appearance, and brand to distinguish it (Sreekumar et al., 2009). Manual classification is laborious; this behavior is realized through factors acting on it based on the theory of extended planned behavior (Lejuez et al., 2001).

They perceive environmental influences as a social or cultural construct (Huđek et al., 2021). The factors influencing people's waste segregation can vary from region to region. These differences are caused by differences in social communication, cultural attainment, and infrastructure across regions (Lejuez et al., 2001). Some studies have concluded that residents of urban areas perceive a higher risk of environmental pollution and are more interested in household waste separation activities than residents of rural areas (Stern et al., 1996). Therefore, there are significant environmental perception differences among people living with different socioeconomic characteristics. Consumers often do not have adequate knowledge about the harmful effects of plastic waste on the environment, so communication about the detrimental effects of plastic waste from organizations is also an important psychological factor affecting the environment's intention to segregate waste at its source (Stern et al., 1996). Experimental studies by (Lobb et al., 2010) showed a positive relationship between the communication of organizations and authorities and the perception of waste classification before discharging into the environment citizen. The study of (ABC) concluded that there is a significant influence of some demographic variables such as age, education level, income level, and the presence of children on the perception of pollution environment. Domestic waste is one of the significant sources of environmental pollution in urban areas. Therefore, the classification of hazardous waste in households represents the best control for environmental pollution.

2.4. Relationship between Environmental Concerns and TPB Structures

According to Gill et al. (1986), environmental concern refers to the general perception of environmental protection. Diamantopoulos et al. (2003) argue that environmental concerns have proven to be an essential basis in research on environmental management. Individuals with a serious concern for the environment are more likely to take action for the environment. In this study, it is assumed that environmental concerns influence TPB structures. Therefore, the following hypotheses are proposed:

- H1a: Environmental concerns positively influence attitudes towards plastic waste classification.

- H1b: Environmental concerns positively influence subjective norms in the classification of plastic waste.

- H1c: Environmental concerns positively influence behavioral control in sorting plastic waste.

2.5. Relationship between TPB Structures and Intent to Sort Plastic Waste

The intention is a factor used to evaluate the ability to perform a behavior in the future and is a motivating factor, motivating an individual to be willing to perform a behavior. The intention is directly influenced by "attitude.", “subjective norm” and “behavioral control" (Ajzen, 2011). Attitude is an individual's assessment of the results obtained from performing a behavior. In this study, the attitude towards plastic waste classification is a psychological assessment derived from each individual's perception. If individuals have a positive attitude towards waste segregation, they will form an intention to sort plastic waste. Subjective norm is an individual's perception of societal pressures to perform or not to perform a behavior (Ajzen, 2011). Accordingly, the subjective norm is a social attribute in which the things that individuals consider whether to do or not depend on the opinions and views of others. Perceived behavioral control is defined as an individual's perception of the difficulty or ease of performing a behavior. Sraughan and Robert (1999) argue that people who care about the environment only show behavior towards the environment if they perceive that individual actions can contribute to solving common environmental problems. Based on the above, the following hypotheses are proposed:

- H2a: Attitude positively influences the intention to sort plastic waste.

- H2b: Subjective norm positively influences the intention to classify plastic waste.

- H2c: Behavioral control positively influences the intention to sort plastic waste.

2.6. The Relationship between Facilities and the Intention to Sort Plastic Waste

Providing adequate facilities is important in determining effective waste management in urban areas (Leao et al., 2001). Improving the infrastructure of the waste management system will reinforce people's positive intentions toward waste segregation, which, if lacking, will be a barrier (Leao et al., 2001). In the process of sorting, providing better facilities will facilitate and encourage individuals to voluntarily participate in waste classification. On that basis, the following hypothesis is proposed:

- H3: Facilities positively influence the intention to sort plastic waste.

2.7. Relationship between Time Pressure and Intention to Sort Plastic Waste

Previous studies on waste sorting behavior have shown that conditioning factors such as time pressure are important in predicting an individual's intentions and behavior (Matiiuk, 2021). Considering the context of waste classification in a learning environment, time is quite limited, while waste sorting at schools requires many steps, so it takes a lot of time. However, it helps to protect the environment. Based on this, the following hypothesis is proposed:

- H4: Time pressure negatively affects the intention to sort plastic waste.

Based on the research hypotheses, the theoretical research model is proposed in Figure 1 below:

Figure 1: Proposed Research Model

Of which:

- Environmental Concern (EC) - Attitude (AT)

- Subjective norms (SN) - Perceived behavioral control (PB)

- Facilities (FC) - Time Pressure (TP)

- Separation Intention (SI)

The related literature would be summarized in the table 1 below.

Table 1: The Brief Summary of some Related Studies

3. Research Methods

3.1. Data Collection

The data collected in this study were surveyed on 309 samples by online survey and structured questionnaire using a convenient sampling method. For sample size, Negash et al. (2021) proposes ten samples for one observed variable. The theoretical model includes 28 observed variables, so the minimum number of samples for the study needs 280. The number of survey samples collected and included in the analysis is 309, satisfactory. The survey subjects of the study are people living in Ho Chi Minh City. The high level of concern about environmental safety among Ho Chi Minh City people has provided an opportunity to study the perception of plastic waste sorting about its unsafety risks and long-term effects on the environment.

3.2. Methods of Data Analysis

Data were analyzed using the statistical software SPSS 20.0 and AMOS 20.0. Cronbach's coefficient α is used to analyze the reliability between the observed variables in each measurement scale for the research concepts (according to the standard α ≥ 0.7). Exploratory Factor Analysis (EFA) was used to test the convergent and discriminant validity of the concepts. As suggested by Anderson and Gerbing (1988), a two-step model is used: a measurement model (performing Confirmatory Factor Analysis (CFA) to check overall reliability and conformity. The combination of observed variables with theoretical structure) and Structural Equation Modeling (SEM, to evaluate the fit of the model and test the hypothesis). Standards applied in CFA and SEM: estimated by the method of the maximum likelihood function (Maximum Likelihood), the overall fit is measured by indexes with the following criteria: GFI > 0.9; CFI > 0.9; TLI > 0.9 and RMSEA < 0.08.

4. Finding

4.1. Results of Testing the Reliability of the Scale

The results of testing the scale's reliability by Cronbach's Alpha coefficient are presented in Table 1. The scale and coding columns present the scales in the theoretical model. The initial variable column presents all the observed variables that have been coded for each respective scale. The column of retained variables shows the results of observed variables that meet the requirements of analytical techniques, the variables in the original variable column do not appear here, implying that they have been excluded because they do not meet the test standards.

Table 2: Summary of the results of testing the reliability of the scale

Source: Authors’ calculation.

4.1.1. Exploratory Factor Analysis (EFA)

The analysis is carried out in two steps: step one, analyze each independent factor to identify the contents better to be considered in the step of testing the scale's reliability. Step two uses the oblique rotation method to check the convergent and discriminant values of all variables in the model. The EFA results of all variables, using the oblique rotation method, show that the concepts in the research model have convergent and discriminant validity. The concept of attitude (AT) is the type of observed variable AT2 because it does not reach the convergent value. All remaining observed variables in the model have factor weights > 0.5. Thus, the EFA results show that the research concepts are satisfactory.

4.1.2. Confirmatory Factor Analysis (CFA)

The results of the CFA analysis show that the critical model is suitable, the general goodness of fit indicators such as: Chi-Square/df = 1,511 (< 0.3); GFI = 0.904 (> 0.9); CFI = 0.971 (>0.9); TLI = 0.966 (>0.9); RMSEA = 0.041 (<0.08) meets the requirement.

Figure 2: Critical CFA model

Table 3 presents a summary of the results of the reliability analysis of the scales and the extracted variance of each scale using Cronbach's Alpha coefficient, exploratory factor analysis, and confirmatory factor analysis. The results show the similarity between the methods, the reliability of all scales is more significant than 0.7; The extracted variances of the scales are all 50% larger than the standard.

Table 3: Value and reliability of structures

Source: Authors’ calculation.

The discriminant value test results are presented in Table 4. The square root of AVE is larger than the correlation value in rows and columns; therefore, according to Fornell-Larcker's criteria (Fornell & Larcker, 1981), the research concepts in the theoretical model satisfy the requirement of discriminant validity.

Table 4: Discriminant validity test (Fornell-Larcker criterion)

Source: Authors’ calculation.

From the above results, the confirmatory factor analysis model meets the requirements of general relevance. The scales have aggregate reliability and appropriately extracted variance. The concepts in the research model meet the requirements meet the criteria of convergent and discriminant validity. On this basis, the linear structural model is used to test the research hypotheses.

4.1.3. Analysis of Results of Structural Equation Modeling (SEM)

The SEM model is suitable for testing theoretical models in which the research concepts are latent. The model includes many endogenous relationships (Hair et al., 2017). The results of the SEM analysis are shown in Figure 3.

Figure 3: Research hypothesis testing by SEM

The indicators measuring the model's overall fit all meet the technical requirements: GFI = 0.889, although slightly smaller than the standard 0.9, but still within the acceptable limits; CFI = 0.960; TLI = 0.955; RMSEA = 0.047 are all satisfactory.

3.1.4. Testing the Research Hypothesis

The combined results in Table 5 show that environmental concerns positively impact attitude, subjective standards, and behavioral control. Thus, hypotheses H1a, H1b, and H1c are accepted. Attitudes, subjective standards, and behavioral control affect the intention to classify plastic waste. Thus, hypotheses H2a, H2b, and H2c are accepted. Facilities positively impact the intention to sort plastic waste; Hypothesis H3 is accepted. Time pressure positively impacts the intention to sort plastic waste; Hypothesis H4 is not accepted. The theoretical relationships in the research model are statistically significant at the 5% level.

Table 5: Regression Weights of Theoretical Relationships

Source: Authors’ calculation.

Note: In parentheses, the normalized regression weights are shown; *** P < 0,01.

4.2. Discuss the Results

Research results show that attitudes, subjective standards, behavioral control, and facilities affect people's intention to classify plastic waste. Time pressure tends to affect the research hypothesis. Environmental concerns greatly influence people's attitudes (normalized regression weight = 0.817). People's environmental concerns also strongly influence subjective norms (normalized regression weight = 0.430). The extent to which people control their behavior depends largely on their environmental concerns. Environmental concerns have a relatively weaker effect on people's degree of behavioral control (normalized regression weight = 0.251). According to the theory of planned behavior, if people think they can perform a particular behavior, they are more willing to do it. This is known as behavioral control, which was found to be significantly associated with behavioral intention.

The mediating effects also indicate that environmental concerns indirectly affect the intention to sort plastic waste through the TPB model, i.e. attitude, subjective norm, and behavioral control mediated conveys the effect of people's environmental concerns on the intention to sort plastic waste. This result is consistent with the study of I. Ajzen and Fishbein (1977). Chu and Chiu (2003) demonstrated that people who recycle household waste believe that their actions benefit the environment; therefore, they tend to pay more attention to environmental issues.

Environmental actions can only be taken with the proper infrastructure (nearby recycling facilities, convenient waste collection services, etc.). Lack of infrastructure is one trouble. The provision of facilities to promote waste segregation will only be effective when facilities are tailored to individual requirements (Lorenz et al., 2017). Time pressure was also found to be a significant predictor of plastic waste segregation intentions; However, the results of this study are not consistent with previous studies.

5. Conclusion

Perceptions of the negative environmental impact of plastic waste are shaped by a complex process involving academic, economic, and social factors. This study aims to analyze the factors affecting the intention to classify people's plastic waste in the Ho Chi Minh city. The study results show that raising people's environmental awareness is very important. Once people care about environmental issues, they will have a positive attitude and behavior towards sorting plastic waste. From a macro perspective, relevant agencies need to realize the things that have been legalized in real life and strengthen the training of responsible personnel in environmental pollution management, strictly manage plastic waste treatment processes, monitor, detect and warn early of harmful risks to the environment and should support waste collection and treatment facilities fully. From a micro perspective, schools need to add extra-curricular activities to provide people with knowledge about sorting plastic waste, the harmful effects of plastic utensils, and organizing programs and contests to learn about the environment, encourage the establishment of clubs, organize environmental projects to attract people who have concerns about the environment but have insufficient knowledge.

This article has some limitations. Firstly, because our sample is limited to HCMC residents, the study results are not representative of the entire population of Vietnam. Second, this paper is based on cross-sectional data, which is not the best way to establish a causal relationship between the intention to sort plastic waste and its drivers. Future studies that need to be based on a nationally representative sample from panel data can address these limitations.