Applying social life cycle assessment in the informal recycling sector: Understanding challenges and limitations

The transition towards Circular Economy (CE) is a promising approach to sustainable development that may cause significant social impacts. Despite the benefits of CE initiatives, key players such as informal recyclers face serious social issues such as poverty, lack of social security, and discrimination. Although evaluating social impacts remains a considerable challenge, Social Life Cycle Assessment (SLCA) is recognized as a suitable methodology with a life cycle perspective. While most SLCA experiences are conducted in the formal sector, it is important to consider the informal sector, which plays a crucial role in developing countries. This article presents an analysis of SLCA studies in informal recycling settings in order to identify the challenges and adjustments required for informal settings. The analysis is based on a literature review and a documentary review of a pilot application of SLCA in the informal recycling system in Cuenca, Ecuador. The results show that SLCA requires adaptation to be applied in informal settings. There are particular challenges in delineating boundaries due to the fuzzy nature and variability of informal activities. Tasks such as establishing specific indicators, developing reference scales and data collection, require careful planning and active stakeholder participation. For instance, indicators regarding Fair Salary or Working hours were adapted based on best practices. Furthermore, tasks such as verifying and disseminating results should be included in interpretation phases to generate long-term impacts and influence behaviors. The study underscores SLCA's multidimensional view but highlights the need for further standardization and adaptation for informal sectors.

Incorporating self-employed maintainers into WEEE formal recycling system: A system dynamic approach

The establishment and operation of a formal recycling system for waste electrical and electronic equipment is an important measure to reduce environmental hazards and improve the recycling of resources, but how to incorporate self-employed maintainers into the system has formed an important research gap. Based on the perspective of extended producer responsibility, we argue that self-employed maintainers are required to assume the corresponding environmental responsibility for the environmental externality caused by informal maintenance activities. Using qualitative structural analysis techniques of system dynamics approach with quantitative simulation analysis techniques, we construct an incentive model for self-employed maintainers' participation in formal recycling system, based on which we propose four incentive strategies. A simulation analysis is further conducted by using the case of waste mobile phones recycling in Qingdao to verify the effectiveness of our incentive model and strategies.

Gaseous elemental mercury emissions from informal E-Waste recycling facilities in Pakistan

Detrimental effects of mercury (Hg) on ecosystems and human health have been well-documented. Whereas emissions of gaseous elemental mercury (GEM) from e-waste recycling have been reported in developed countries, much less is known about the situation in the Global South. Using a total of 132 passive air samplers, seasonally resolved concentrations of GEM in air were measured continuously at 32 informal e-waste recycling facilities and background location in Pakistan for a period of one year between September 2020 and December 2021. Annual average GEM concentrations at the studied locations ranged from 1.8 to 92 ng m-3. Among the studied cities, higher concentrations were measured in Karachi (mean ± s.d: 17 ± 22, range: 4.2-92 ng m-3), Lahore (16 ± 4.2, 8.2-22 ng m-3) and Peshawar (15 ± 17, 4.9-80 ng m-3), while lower levels were measured in Hyderabad (6.9 ± 6.2, 3.1-25 ng m-3), consistent with a higher rate of informal recycling activities in metropolitan areas. Seasonally, higher GEM levels occurred during autumn (15 ± 16: 3.3-92 ng m-3) and summer (13 ± 8.7: 1.8-80 ng m-3) than in winter (12 ± 8.4: 2.5-49 ng m-3) and spring (9.2 ± 7.3: 1.8-80 ng m-3), possibly reflecting enhanced volatilization at higher temperatures and/or varying magnitude of recycling operations in different seasons. Policies and strict regulations related to e-waste management should be developed and implemented urgently in the country.

Informal E-waste recycling practices and environmental pollution in Africa: What is the way forward?

Globally, e-waste is the fastest growing and most valuable waste-stream. While countries worldwide are increasingly acknowledging the e-waste problem and introducing policies and regulations that deal with e-waste, large quantities of e-waste still go undocumented. Much of these global e-wastes are accumulating in open-dumpsites and landfills in African-countries where they are recycled informally resulting in significant environmental and public-health concerns. Although, there is a plethora of studies on e-waste management and disposal, only a few-studies have focused on African-countries who are major recipients of e-waste. Moreover, despite the attempts to mitigate the problem of e-waste in African-countries, e-waste has remained a major-concern and there are currently very limited workable solutions. This study examines informal e-waste recycling, environmental pollution and the extent of environmental and health impacts in major countries of concern including Ghana, Nigeria, Egypt, Kenya and South Africa. The global e-waste Waste Atlas Report, 2020 identified these countries as major recipients of e-waste. To achieve the aims of this research, previous studies from 2005 to 2022 are collected from various databases and analyzed. Accordingly, this study focuses on environmental pollution and public-health impacts resulting from e-waste dumping and informal recycling practices, illegal transboundary shipment of e-waste to the selected countries, and the interventions of governments and international organizations in reducing the impact of e-waste pollution and informal recycling practices in Africa. Based on the outcomes of this study, practical approaches on the way-forward are recommended. The findings of this study contribute to a growing-body of research on informal e-waste recycling practices in Africa to document that individuals working within e-waste sites and residents in nearby communities are exposed to a number of toxic-substances, some at potentially concerning levels.

Exploring the coevolution of residents and recyclers in household solid waste recycling: Evolutionary dynamics on a two-layer heterogeneous social network

China's household solid waste recycling system has long faced the challenge of recycling formalization. This process is affected by the complexity of the interdependence of the recycler and resident decisions. The aim of this study was to gain a better understanding of the coevolution of residents' and recyclers' recycling decisions. To this end, this study applied agent-based modeling and network-based evolutionary game methods to construct evolutionary game models based on a two-layer social network. The two layers of heterogeneous social networks depicted the connections between residents and recyclers, respectively. Residents and recyclers choose either formal or informal recycling strategies within layers according to evolutionary game theory. Waste flows and cash flows underlie the interdependent coevolution between the two layers. Using this model, the effects of resident subsidies, recycler subsidies, and regulatory policies on the coevolution of residents and recyclers were simulated. The results showed that the impact of policies on recycling systems relies on long-term social interaction. The trends in the strategic evolution of residents and recyclers were similar, and emerged from their interdependence and mutual influence. Resident-oriented subsidy incentives can promote formal recycling stably and positively. However, recycler subsidies and regulatory policies have opposite marginal promotion effects, as is reflected by the fact that the evolution of formal recycling is insensitive to high recycler subsidies and sensitive to high-intensity regulatory policies. These findings provide a more comprehensive insight into the development of recycling systems and inform the design of waste management policies.

Assessing China's potential for reducing primary copper demand and associated environmental impacts in the context of energy transition and "Zero waste" policies

To conserve resources and enhance the environmental performance, China has launched the "Zero waste" concept, focused on reutilization of solid waste and recovery of materials, including copper. Although several studies have assessed the copper demand and recycling, there is a lack of understanding on how different waste management options would potentially reduce primary copper demand and associated environmental impacts in China in the context of energy transition. This study addresses this gap in view of a transition to low-carbon energy system and the optimization of copper waste management combining MFA and LCA approaches. Six types of waste streams (C&DW, ELV, WEEE, IEW, MSW, ICW) are investigated in relation to various "Zero waste" strategies including reduction, reuse (repair, remanufacturing or refurbishment), recycling and transition from informal to formal waste management. Under present Chinese policies, reuse and recycling of copper containing products will lead to a somewhat lower dependency on primary copper in 2100 (11187Gg), as well as lower total GHG emissions (64869 Gg CO2-eq.) and cumulative energy demand (1.18x10^12 MJ). Maximizing such "Zero waste" options may lead to a further reduction, resulting in 65% potential reduction of primary copper demand, around 55% potential reduction of total GHG emissions and total cumulative energy demand in 2100. Several policy actions are proposed to provide insights into future waste management in China as well as some of the challenges involved.

E-waste management and its effects on the environment and human health

Challenges in managing electronic waste (E-waste) arise from a lack of technical skills, poor infrastructure, inadequate financial support, and inactive community engagement. This study provides a systematic review of efforts to overcome these challenges in the context of inappropriate recycling protocols of E-waste and their toxic effects on human health and the environment. An inventory of end-of-life electronic products, which can be established through the creation of an environment friendly regulatory regime for recycling, is essential for the proper control of E-waste. An approach has been articulated to help implement effective management of E-waste in both developed and developing countries. Enforcement of systematic management measures for E-waste in developing countries coupled with best practices is expected to minimize adverse impacts while helping maintain a sustainable and resilient environment.

Understanding the role of informal sector for sustainable development of municipal solid waste management system: A case study in Vietnam

Although the informal sector of waste collection has an important role in income diversification for the poor and contribution to waste recycling, this sector is still not recognised in any government official policies and is usually underestimated in the Mekong Delta of Vietnam. This paper employs a systems thinking approach to analyse the crucial roles of the informal sector in solid waste management (SWM) system in Vietnam. From a circular economy viewpoint, the flow diagram was built for the first time, which could integrate the actors and activities of the informal sector into a wider SWM system in Vietnam. The map focuses on analysing the contributions and activities of the informal sector, focusing on its roles and impacts on the recycling system. This paper then employed the systems thinking approach to further analyse the systematic problem of the informal sector. The analysis builds on the field survey including elements and key driving forces of the systems with 36 scrap dealers, 127 scrap buyers, and 760 households and in-depth interviews with experts in the Mekong Delta region, Vietnam. Based on the practices and experience in waste-related activities of informal sector, this sector should be integrated into the general waste management process. With the relevance of informal systems, the authorities could establish an effective waste recycling system, and improve the livelihoods and working conditions of those involved, especially the poor.

Assessment of municipal solid waste selective collection scenarios with geographic information systems in Bolivia

The analysis of municipal solid waste (MSW) selective collection (SC) scenarios is compulsory for planning future policies and actions towards circular economy. The use of geographic information system (GIS) is appropriated for obtaining reliable data about SC yields and management costs. However, in low-middle income countries, advanced assessments are difficult to introduce due to the lack of technical knowledge, financial support and the presence of the informal recycling sector. This research aims to assess the main potentialities of the introduction of SC systems in a Bolivian developing city taking into account the informal SC system in place. The study was conducted with QGIS3.8 software in order to evaluate the main advantages of the implementation of formal and informal recycling chains. Results reported that, comparing the implementation of formal SC of MSW with the scenario that considered the inclusion of the informal recycling, the activity of waste pickers allows reducing the expenses of about 10%, increasing the recycling rate of about 3.5%, and reducing the distances traveled with compactor trucks of about 7%. It means that, the annual path traveled by the collection trucks for gathering about 16,000ty^-1, is reduced by 2734kmy^-1, reducing the waste disposed to landfill of about 543.6ty^-1 and the expenses of about €59,000 per year. The presentation of these results to policy-makers can support decision-making boosting the implementation of recycling activities including waste pickers. The study provided a contribution to the scientific literature assessing the main challenges and opportunities for implementing the circular economy in developing regions.

Assessing young consumers' awareness and participation in sustainable e-waste management practices: a survey study in Northwest China

The massive generation of electronic waste (e-waste) and the informal recycling of e-waste are serious concerns in China. As a hazardous waste stream, e-waste calls for sustainable management practices to avoid adverse effects on environment and health. However, consumers' awareness and active participation are needed to make e-waste management successful. Therefore, this study is an exploratory attempt to investigate young consumer awareness, knowledge, and participation in sustainable e-waste management practices. Meanwhile, the study reviews the current situation of e-waste recycling, its related legislative framework, and practices in China. The survey revealed that the respondents have keen environmental consciousness, while they have low awareness about e-waste-related rules and regulations, recycling programs, and the formal and informal recycling sector. The findings provide valuable insights for practitioners in order to promote environmental awareness and sustainable e-waste management practices among young consumers in China.

A relative risk assessment of the open burning of WEEE

Waste electric and electronic equipment (WEEE) represents a potential secondary source of valuable materials, whose recovery is a growing business activity worldwide. In low-income countries, recycling is carried out under poorly controlled conditions resulting in severe environmental pollution. High concentrations of both metallic and organic pollutants have been confirmed in air, soil, water, and sediments in countries with informal recycling areas. The release of these contaminants into the environment presents a risk to the health of the exposed population that has been widely acknowledged but still needs to be quantified. The aim of this work was to evaluate the relative risk from inhalation associated with the open burning of different kinds of WEEE. The shrinking core model was applied to estimate the concentration of the metals which would be released into the environment during the incineration of different types of WEEE. In addition, the potential generation of dioxins during the same informal practice was estimated, based on the plastic content of the WEEE. The results provided for the first time a comparative analysis of the risk posed from the open burning of WEEE components, proposing a methodology to address the absolute risk assessment to workers from the informal recycling of WEEE.

Assessing the generation, recycling and disposal practices of electronic/electrical-waste (E-Waste) from major cities in Pakistan

Rapid increase in the quantity of electronic/electrical-waste (e-waste) has become an emerging issue throughout the world. To avoid higher expenditures on safe disposal and recycling, large quantities of e-waste are being exported from developed to developing countries like Pakistan. Emerging issue of e-waste in Pakistan demands its effective management strategy for the country. However, it cannot be achieved until assessment of e-waste quantification and disposal is carried out. The main objective of this study was to quantify the e-waste inventory and it's processing from major cities of Pakistan to evaluate its generation (domestic/import) and recycling practices. This study comprises the information of only those e-waste items (desktop computers, laptops/notebooks, computer monitors and liquid-crystal display units) which form the major portion of e-waste imported to Pakistan. Survey based data collected from three major cities/areas have been extrapolated to develop an e-waste generation inventory for the country. The study reveals that approximately 50 kt of e-waste is being imported as scrap in addition to its local generation of about 38 kt per year. During field visits and data collection surveys, it has been observed that the processing of e-waste in the country is being carried out in crude manner without safety gears. Findings of our study strongly recommend dire need for urgent and effective monitoring as well as control of informal e-waste management in Pakistan.

Informal recycling, income generation and risk: Health and social harms among people who use drugs

BACKGROUND

Informal recycling refers to the street-based collection of discarded materials for reuse, resale, or return to a recycling facility for money. While qualitative research has explored experiences and perceptions of informal recycling, little is known about the scope and exposures associated with informal recycling among people who use drugs (PWUD).

METHODS

Using data from two prospective longitudinal cohorts of PWUD, we examined the prevalence of informal recycling and its association with social, structural and health risks, including criminal justice system involvement.

RESULTS

Between June 2010 and May 2015, of 1664 participants, 557 (33.5%) reported engaging in informal recycling during the study period. In multivariable generalised estimating equations (GEE) analyses, informal recycling was positively associated with injection drug use (Adjusted Odds Ratio (AOR) = 1.43, 95% Confidence Interval (CI) 1.21-1.68), public injection (AOR = 1.27, 95% CI 1.09-1.49), methamphetamine use (AOR = 1.35, 95% CI 1.05-1.72), difficulty finding harm reduction equipment (AOR = 1.16, 95% CI 1.02-1.32), and police interactions (AOR = 1.35, 95% CI 1.18-1.55). Sub-analyses revealed PWUD engaged in informal recycling were more likely to be told to move on, ticketed, stopped for jaywalking, and directed to services by police.

CONCLUSIONS

These findings suggest informal recycling as a situated practice for PWUD, with potential indications for higher-risk drug use, experiencing greater surveillance, and difficulty accessing health and addiction treatment services. This research highlights the significance of the broader risk environment and the need for health-promoting policies for socioeconomically marginalised PWUD engaged in informal recycling.

Transitions in income generation among marginalized people who use drugs: A qualitative study on recycling and vulnerability to violence

BACKGROUND

Income is an important determinant of health among people who use drugs (PWUD). However, understanding transitions between differing types of income generation within the formal and informal economy and how they can be shaped by vulnerability to risk and harm remain poorly understood. This study examines how transitions in income-generating activities are shaped by and influence exposure to violence among marginalised PWUD, in Vancouver, Canada's, Downtown Eastside (DTES) neighbourhood.

METHODS

Qualitative interviews were conducted with twenty-six individuals engaged in informal and illegal income-generating activities in the DTES. Interview transcripts were analyzed thematically, focusing on relationships between income generation and violence during the study period between January 2014 to April 2015 and drew upon concepts of social violence when interpreting these themes.

RESULTS

Participants' engagement in informal and illegal income-generating activities represented a means to negotiate survival given multiple barriers to formal employment and inadequate economic supports. Our findings highlight how informal and illegal income-generating activities in the DTES are characterized by structural, symbolic and everyday violence, while transitions from 'high risk' (e.g., sex work, drug dealing) to perceived 'low risk' (e.g., recycling) activities represent attempts to reduce exposure to violence. However, participants emphasized how informal income generation was nonetheless shaped by structural violence (e.g., gendered hierarchies and police harassment), experienced as everyday violence, and introduced exposure to alternate risks.

CONCLUSION

Our findings underscore the critical role of income generation in shaping exposure to violence, highlighting the need for low-threshold employment interventions targeting PWUD as a central component of harm reduction strategies.

Impact of informal electronic waste recycling on metal concentrations in soils and dusts

Electronic and electrical equipment contains over 1000 different substances, including metals. During informal e-waste recycling some of these substances such as metals, are released into the environment causing environmental pollution. This study assessed the impact of different informal e-waste recycling activities (burning, dismantling, and repairing) on metal concentrations in top soils and various dust. A comparative cross-sectional study design was adopted to assess metal concentrations in top soils and in various dust samples from multiple e-waste recycling sites. Metal concentrations at e-waste recycling sites were compared to the concentrations at control sites in three study locations in Nigeria (Lagos, Ibadan, and Aba). In the three study locations, mean metal concentrations at the e-waste recycling sites exceeded the concentrations at the control sites and the Nigerian standard guideline values by 100 s to 1000 s times. Burning sites showed the highest pollution level, followed by dismantling sites, then repair sites. Our findings show serious environmental and public health concerns. The metal concentrations were also higher than levels reported in other studies at the same locations in Nigeria, indicating that the situation is worsening. This study provides scientific evidence for an urgent need to develop effective strategies to strengthen enforcement of existing e-waste regulations in Nigeria.

Heavy metals distribution and risk assessment in soil from an informal E-waste recycling site in Lagos State, Nigeria

Informal E-waste recycling can pose a risk to human health and the environment which this study endeavours to evaluate. The distribution of a number of heavy metals in soil from an informal recycling site in the largest market for used and new electronics and electrical equipment in West Africa was investigated. The potential bioavailability of heavy metals, extent of contamination, potential risk due to the recycling activities and impact of external factors such as rainfall were also assessed. The concentrations of all the heavy metals tested were higher in the area where burning of the waste occurred than at the control site, suggesting an impact of the recycling activities on the soil. The order of total metal concentrations was Cu > Pb > Zn > Mn > Ni > Sb > Cr > Cd for both the dry and wet seasons. The total concentrations of Cd, Cu, Mn, Ni and Zn were all significantly higher (p < 0.001) in the dry season than in the wet season. The concentrations of Cu (329-7106 mg kg^-1), Pb (115-9623 mg kg^-1) and Zn (508-8178 mg kg^-1) were consistently higher than international soil guideline values. Using a sequential extraction method, the potential bioavailability of the heavy metals was indicated as Cd > Sb > Zn > Cu > Ni > Pb > Cr. When the risk was assessed using the Potential Ecological Risk Index (PERI), Cu was found to contribute the most to the potential ecological risk and Cd gave rise to the greatest concern due to its high toxic-response factor within the study site. Similarly, utilising the Risk Assessment Code (RAC) suggested that Cd posed the most risk in this site. This research establishes a high level of contamination in the study site and underscores the importance of applying the appropriate chemical speciation in risk assessment.

Exploring the Awareness Regarding E-waste and its Health Hazards among the Informal Handlers in Musheerabad Area of Hyderabad

Introduction

Occupational Health hazards of handling and management of electronic waste is a nascent subject. Improper and unscientific handling of e-waste can invite significant human and environmental health risks.

Objective

To study the level of awareness about electronic waste and its health hazards amongst informal handlers in Musheerabad, Hyderabad.

Methodology

Ethical approval and informed consents were obtained from Institutional Ethical Committee, University of Hyderabad and from the participants respectively before the commencement of study. This was a descriptive cross-sectional study conducted in randomly selected twenty-six waste handling centers from sixty of them in the locality. From each of the centers four handlers agedbetween 18 and 45 were randomly selected. Total of 104 handlers were interviewed using semi-structured schedule. Interviews were also conducted among 10 owners of such centres on the waste management practices.

Results

About 72% of the handlers did not know the meaning of electronic waste and 71% were not aware of associated health risks, 85% did not use any protective gears, while 16% acknowledged health issues attributed to improper handling of e-waste, 77% felt their handling of e-waste was appropriate. Majority of center owners felt that informal e-waste handling does not pose any health risks, and reported that there was no awareness campaign by any agency as of then.

Conclusion

This study highlights the need for awareness campaigns on proper e-waste management practices to ensure occupational safety among the waste handlers who belong to lower socio-economic strata.

Relationship between e-waste recycling and human health risk in India: a critical review

Informal recycling of waste (including e-waste) is an emerging source of environmental pollution in India. Polychlorinated biphenyls (PCBs), polychlorinated diphenyl ethers (PBDEs), and heavy metals, among other substances, are a major health concern for workers engaged in waste disposal and processing, and for residents living near these facilities, and are also a detriment to the natural environment. The main objective of this review article was to evaluate the status of these impacts. The review found that, huge quantity of e-waste/waste generated, only a small amount is treated formally; the remainder is processed through the informal sector. We also evaluated the exposure pathways, both direct and indirect, and the human body load markers (e.g., serum, blood, breast milk, urine, and hair), and assessed the evidence for the association between these markers and e-waste exposure. Our results indicated that the open dumping and informal e-waste recycling systems should be replaced by the best available technology and environmental practices, with proper monitoring and regular awareness programs for workers and residents. Further and more detailed investigation in this area is also recommended.

Cooperative urban mining in Brazil: Collective practices in selective household waste collection and recycling

Solid waste is a major urban challenge worldwide and reclaiming the resources embedded in waste streams, involving organized recyclers, is a smart response to it. Informal and organized recyclers, mostly in the global south, already act as important urban miners in resource recovery. The paper describes the complex operations of recycling cooperatives and draws attention to their economic, environmental, and social contributions. A detailed discussion based on empirical data from the recycling network COOPCENT-ABC in metropolitan São Paulo, Brazil, contextualizes this form of urban mining. The analysis is situated within Social and Solidarity Economy (SSE) and Ecological Economy (EE) theory. Current challenges related to planning, public policy, and the implementation of cooperative recycling are analysed on the level of individual recyclers, cooperatives, municipalities and internationally. There are still many hurdles for the informal, organized recycling sector to become recognized as a key player in efficient material separation and to up-scale these activities for an effective contribution to the SSE and EE. Policies need to be in place to guarantee fair and safe work relations. There is a win-win situation where communities and the environment will benefit from organized urban mining.

Urban political ecologies of informal recyclers׳ health in Buenos Aires, Argentina

Buenos Aires׳ informal recyclers (cartoneros) confront multiple health hazards in their work. Based in a survey with (n=397) informal recyclers, this study establishes that these workers experience uneven health landscapes as evidenced through their health outcomes, the social determinants of their health, and their living and working environments. I argue that the analytical framework of urban political ecology can provide insights to the ways that the urban environments where cartoneros live and work are socially-constructed phenomena, drawing on concepts of crisis, metabolism, and multi-scalar analyses.

Spatial characteristics of cadmium in topsoils in a typical e-waste recycling area in southeast China and its potential threat to shallow groundwater

Informal electrical and electronic waste (e-waste) recycling often creates secondary sources of cadmium (Cd) pollution. To characterize the total Cd concentration (Cdtotal) in topsoil and evaluate the threat of Cd in topsoils to shallow groundwater, 187 topsoil samples and 12 shallow groundwater samples were collected in a typical e-waste recycling area in southeast China. Soil organic matter content, soil pH and Cdtotal in topsoil, pH and dissolved Cd concentration in shallow groundwater were measured. Cdtotal in the topsoils showed an inverse distribution trend with soil pH in that high Cd concentrations (and low pH values) were found in the surrounding area of the metal recycling industrial park where there were many family-operated e-waste recycling facilities before the industrial park was established and with low concentrations (and high pH values) in other areas, and they had similar spatial correlation structures. Cd accumulation and acidification were synchronous in topsoils, and soil pH was significantly correlated with Cdtotal in topsoils with low to moderate negative correlation coefficient (r=-0.24), indicating that both of them maybe correlated with informal recycling. The shallow groundwater in the surrounding area of the metal recycling industrial park was seriously contaminated by Cd, and topsoil Cd accumulation and acidification in the surrounding area of e-waste recycling sites significantly increase the risk of shallow groundwater contaminated by Cd. Action is urgently required to control Cd accumulation and acidification by improving the recycling operations of e-wastes in order to reduce the risk of Cd leaching from topsoils and shallow groundwater contamination.