Exploring the Complexities of Waste Separation Behaviors in Bogota, Colombia
The effective management of solid waste presents a pressing challenge within the environmental sector, given its adverse impacts on health and the environment (water, soil, air). This global concern is particularly relevant for cities striving to implement efficient waste management strategies. This study explores the factors that impact environmental awareness and solid waste management practices in Bogota, offering valuable insights for designing and implementing effective public policies and environmental management strategies.
By understanding the drivers of environmental behavior among city residents, local authorities can devise more precise interventions and implement environmental education and awareness programs aimed at fostering sustainable waste management practices. The city of Bogota faces unique challenges in waste management, considering that the amount of waste generated per capita has increased fivefold in recent years, coupled with being a densely populated city.
Data from the 2021 Environmental Culture Survey conducted by Bogota’s Mayor’s Office, consisting of 266,994 entries, was analyzed using LASSO regularized logistic regression. LASSO offers advantages such as automatic feature selection, multicollinearity reduction, regularization to prevent overfitting, computational efficiency, and flexibility in a variety of modeling problems.
The study provides significant insights into waste separation behaviors in Bogota, Colombia. The algorithm, with a 70% accuracy coefficient, indicates a direct correlation with the number of years individuals have resided in the city, demonstrating a 3.2% increase in the probability of consistently separating waste. Residents of Usaquén, Chapinero, Barrios Unidos, Bosa, and Teusaquillo exhibit higher probabilities of consistent waste separation, while those in San Cristóbal, Usme, Suba, Antonio Nariño, Rafael Uribe Uribe, and Ciudad Bolívar tend to have lower probabilities.
Confidence in the recycling process significantly impacts behavior, with a 62.7% increase in the probability of consistently separating waste among those assured of the process. The study also highlights the importance of recycling bin availability, as individuals with only one bin in the kitchen show an 81.2% likelihood of almost never separating waste.
The discoveries from this study regarding the factors influencing household waste separation and recycling practices offer valuable insights for enhancing environmental education and promotion strategies. By delving into the intricate dynamics of sociodemographic, geographical, and attitudinal elements, this research sheds light on the complexities of waste separation behaviors. These insights are pivotal for crafting tailored policies that can yield greater effectiveness in promoting sustainable practices and facilitating environmental conservation.
Solid Waste Management: A Global Challenge with Local Implications
Solid waste management presents a significant environmental challenge in contemporary society. The proliferation of waste generation, coupled with inadequate disposal methods, can have detrimental effects on public health and the environment, including water, soil, and air (Gu et al., 2024; Kannankai & Devipriya, 2024; Seif et al., 2024; Sharma et al., 2024). Despite regulations aimed at mitigating their impact, waste generates leachate during decomposition, which contaminates soil and water resources, threatening life. It is important to note that these leachates contain various types of contaminants that can persist in the environment, enter the food chain, and affect both the ecosystem and human health (Iravanian & Ravari, 2020).
In addition to the aforementioned, the lack of waste classification has adverse effects on water and air quality. There are various types of contaminants, such as inorganic ones including heavy metals (mercury, lead, and cadmium), and biological contaminants (Siddiqua et al., 2022). In water, heavy metals once released can accumulate in sediments and aquatic organisms, affecting the food chain. In the air, these metals can be released through industrial processes, fossil fuel combustion, and mining activities. Once in the air, they can disperse and be transported over long distances before being deposited in the soil or bodies of water through atmospheric deposition, such as acid rain. Inhalation of vapors or particles of these metals can cause respiratory problems and damage to the central nervous system, among other adverse effects on human health and the environment (Zhang et al., 2022).
Batista et al. (2021) highlight the urgent need for a deeper analysis of sustainable and integrated solid waste management in municipalities of developing countries. These nations still lack adequate procedures to address society’s needs, particularly regarding urban solid waste management. Factors such as inequality, urbanization, and economic growth, along with socio-economic, cultural, and political aspects, further complicate this management in developing countries. Therefore, studies are needed to contribute to more comprehensive diagnostics so that actions and policies can be tailored to municipal realities.
In this regard, Awino and Apitz (2024) emphasize that successful implementation of solid waste management requires broad stakeholder participation and integrated planning and infrastructure. They stress the crucial importance of public and personal perceptions, attitudes, and behaviors in informed decisions about solid waste management. However, the lack of formal and informal stakeholder integration, incorrect institutional information, and limited recycling programs hinder the development of sustainable solid waste management systems, especially in regions of the Global South.
The research gap this study aims to fill is the absence of effective, contextually tailored procedures in sustainable and integrated solid waste management in developing countries. Specifically, a deeper understanding is needed of how socio-economic, cultural, and political factors influence waste management practices in different urban communities. Thus, the focus is on answering the following research question: What factors predict waste separation in the population of Bogota in 2021?
Methodology: Leveraging Data and Advanced Analytics
To address the previous question, data from the 2021 Environmental Culture Survey conducted by the Mayor’s Office of Bogota, consisting of 266,994 entries, was utilized. It is noteworthy that Bogota faces significant challenges in waste management, with waste generation increasing from 0.2 to 1 kg per person per day (Rodríguez-Díaz et al., 2022). According to Greenpeace Colombia, the city produces over 9,000 tons of waste daily, of which approximately 3,000 tons could be recycled. However, the majority of this waste ends up in the Doña Juana landfill, while only 1,530 tons are recycled (Greenpeace, 2023).
The variable of interest was the question regarding the frequency at which respondents separated waste in their households. The predictors encompass aspects such as sociodemographic and economic factors, environmental knowledge, economic incentives and regulations, cultural context, and infrastructure for recycling.
A logistic regression model was employed using the LASSO regularization algorithm, which is renowned for its ability to construct accurate and efficient statistical models. Unlike traditional regression methods, LASSO utilizes an automatic feature selection technique that reduces the variable set by eliminating those less relevant to prediction. This, combined with its ability to address multicollinearity and prevent overfitting, positions it as a powerful tool for data analysis. Additionally, LASSO is highly flexible and computationally efficient, making it suitable for analyzing large datasets in diverse contexts (Geng et al., 2023; Hastie et al., 2001; Hu et al., 2021; Ravindra et al., 2023).
The hyperparameter λ, which regulates the penalty, was estimated; higher values of λ are associated with a greater number of excluded predictors (James et al., 2013). Orange Data Mining (Siqueira Alencar, 2023) was utilized for the analysis (Siqueira Alencar, 2023).
Sensitivity analysis was performed by testing different values of the regularization parameter C, which governs the strength of penalization. Additionally, 5-fold cross-validation was applied to evaluate the performance of the Lasso logistic regression model reliably and robustly. The data was standardized using the mean and standard deviation, a common and effective normalization technique to mitigate the effect of outliers in Lasso regression.
Factors Influencing Waste Separation Practices in Bogota
Several patterns were observed across different locations in Bogota (Table 3 and Figure 3). Individuals residing in Usaquén, Chapinero, Barrios Unidos, Bosa, and Teusaquillo exhibited an increased likelihood of always separating waste (5.8%, 3.4%, 14%, 39.7%, and 39%, respectively). Conversely, individuals living in San Cristóbal, Usme, Suba, Antonio Nariño, Rafael Uribe Uribe, and Ciudad Bolívar experienced a decrease in the likelihood of always separating their waste by 19.2%, 34.6%, 6.4%, 15.1%, 1.5%, and 11.2%, respectively (Figure 3). It is noteworthy that these areas are predominantly inhabited by individuals from socioeconomic strata 1, 2, and 3.
Regarding the length of residence in Bogota, the results showed a direct relationship. Individuals who had resided in the capital for a longer period were more likely to always separate their waste. As the length of residence in Bogota increases, the probability of always separating waste increases by 3.2%, while the probability of separating waste almost always or sometimes decreases by 7.5% and 10%, respectively (Table 3).
Marital status also influenced waste separation patterns. In the case of individuals in civil unions, the probability of always separating waste decreased by 11.2%, while the probability of doing so sometimes and rarely increased by 12.9% and 14.4%, respectively. On the other hand, married individuals showed a lower probability of almost always or never separating waste by 26.7% and 16.2%, respectively. Widowed or separated individuals exhibited a decrease of 100% in the probability of never separating waste (Table 3 and Figure 4).
The highest level of education also played a role, with individuals holding a graduate degree with a title having a higher probability of always separating waste (53.4%) compared to other educational levels. Meanwhile, if individuals had a graduate degree without a title, incomplete undergraduate, technological, or technical studies, the probability of always separating waste decreased (Table 3 and Figure 5).
Belonging to a racial, cultural, or ethnic group also affected waste separation. Individuals who identify as indigenous or white have a lower probability of always separating their waste (6.2% and 7.6%, respectively). In the mestizo group, there was an increase in the probability of always separating their waste by 8.4%. As for individuals of African descent, the probability of never separating waste increased by 81.7% (Table 3 and Figure 6).
The Importance of Infrastructure and Systemic Factors
Having only one recycling bin in the kitchen increases the probability of almost never separating waste by 81.2%, while having two bins increases the probability of doing so sometimes by 59.6%, but decreases it by 100% for never. On the other hand, people who had three or four bins were more likely to always separate waste by 35.4% and 20.2%, respectively (Table 4 and Figure 7).
Being sure that waste was delivered to a recycler had a significant impact on waste separation behavior. Those who were confident that their waste was being delivered for recycling showed a notable increase of 62.7% in the probability of always separating their waste. On the other hand, those who were unsure about this process showed an increase of 60.5% in the probability of separating the waste, suggesting a strong influence of trust in the recycling system on waste separation behavior (Table 4).
Among the difficulties in separating waste, the model showed that when it is challenging to ensure that all household members practice waste separation, the probability of always doing waste separation decreases by 34.7%, while doing it sometimes increases by 89.1%. Additionally, limited space availability makes it difficult to incorporate multiple waste bins, increasing the likelihood of never separating waste by 4.2% (Table 4).
Motivations and Environmental Awareness
Concern for environmental impact emerges as a significant intrinsic motivation for waste separation, demonstrating a 45.8% increase in the likelihood of always doing so and a 38.9% decrease in the likelihood of never doing it. This connection rooted in environmental responsibility and planet care drives a stronger commitment to the practice. On the other hand, the integration of waste separation into cultural traditions and customary practices shows a substantial 122.7% increase in the likelihood of always doing it, highlighting the importance of its ingraining in culture for lasting adoption (Table 5 and Figure 8).
However, motivations such as support for recycling workers and legal compliance show lesser positive impact, evidenced by an increase in the likelihood of rarely or never separating, suggesting that extrinsic motivations may not be effective in fostering consistent separation. Lastly, the maintenance of structure and organization, while not inherently environmental, contributes to practice adoption by reducing the likelihood of never doing it by 100% (Table 5).
The findings also reveal a close relationship between various pro-environmental behaviors and waste separation practices, emphasizing the intricate interconnection between attitudes and actions toward environmental conservation. Engaging in activities such as donating unused items, avoiding plastic straws, and reducing consumption demonstrate a higher likelihood of consistent waste separation. Conversely, purchasing food with plastic packaging or choosing products from eco-friendly markets are associated with lower probabilities of waste separation (Table 5).
Implications and Recommendations for Sustainable Waste Management
The findings of this study offer valuable insights for enhancing environmental education and promotion strategies in Bogota. Tailored educational campaigns should target specific population segments, such as low-income areas, single individuals, and those with lower educational levels, addressing the socio-economic, cultural, and behavioral nuances that influence waste separation practices.
Improving recycling infrastructure, particularly in peripheral and low-income neighborhoods, is crucial. Exploring innovative solutions for households with limited space, such as collapsible containers or customized collection systems, can enhance access to recycling facilities. Engaging the community, including all household members, in waste separation efforts is essential for fostering widespread adoption.
Strengthening trust in the recycling system and improving transparency around waste management processes can significantly influence behavior. Integrating informal waste collectors into the official waste management system and ensuring efficient recycling operations can build confidence among residents.
Emphasizing the environmental and cultural significance of waste separation is key to fostering intrinsic motivation. Campaigns that highlight the positive impact on the environment and the alignment with traditional practices can encourage more consistent participation.
Recognizing the interconnectedness of sustainable behaviors is crucial. Promoting a holistic approach that encourages a range of pro-environmental actions, such as reducing consumption, composting, and reusing, can lead to more comprehensive and lasting behavioral changes.
By addressing the multifaceted factors influencing waste separation practices, Bogota can develop more effective and tailored policies and programs to enhance environmental awareness and solid waste management in urban communities.
Conclusion
This study on waste management practices in Bogota provides valuable insights into the complex dynamics that shape household waste separation behaviors. The findings underscore the importance of considering socio-demographic, geographic, infrastructure, and attitudinal factors in designing effective waste management strategies.
Tailored educational campaigns, improved recycling infrastructure, and fostering trust in the recycling system emerge as key priorities. Additionally, emphasizing the environmental and cultural significance of waste separation, as well as recognizing the interconnectedness of sustainable behaviors, can lead to more comprehensive and lasting behavioral changes.
The lessons learned from Bogota’s experience can inform the development of sustainable waste management practices in other urban settings facing similar challenges. By adopting a nuanced, context-specific approach and addressing the multifaceted drivers of environmental awareness, cities can make significant strides toward more effective and equitable solid waste management.