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Record W4406892922 · doi:10.1016/j.clwas.2025.100217

Invisible Green Guardians: A long-term study on informal waste pickers' contributions to recycling and the mitigation of greenhouse gas emissions

2025· article· en· W4406892922 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.

Bibliographic record

VenueCleaner Waste Systems · 2025
Typearticle
Languageen
FieldEnvironmental Science
TopicMunicipal Solid Waste Management
Canadian institutionsUniversity of Victoria
FundersFundação Amparo e Desenvolvimento da PesquisaConselho Nacional de Desenvolvimento Científico e Tecnológico
KeywordsGreenhouse gasTerm (time)Waste managementEnvironmental scienceNatural resource economicsEngineeringEconomicsGeology

Abstract

fetched live from OpenAlex

Recycling plays a crucial role in the circular economy by reintroducing materials into the supply chain. However, certain aspects of the recycling chain, such as the role of informal waste pickers remain underappreciated, despite their significant impact on energy savings and CO 2 recovery. This study investigates the contribution of informal waste pickers to the recovery of recyclable solid waste in Salvador, one of the largest cities in South America, over a 13-year period. Using data from pre-recycling centers that exclusively handle materials collected by waste pickers, we tracked the temporal impact of their activities in diverting solid waste from landfills. From 2010–2022, waste pickers recovered approximately 5700 tonnes of recyclable solid waste, preventing an estimated 27,100 tonnes of CO 2 emissions through material substitution and landfill diversion. The most recovered materials were PET, aluminum, and paper/cardboard, with a notable shift toward increased aluminum recovery. Aluminum and PET contributed most to avoided emissions, with aluminum surpassing PET in recent years. This study underscores the critical yet often undervalued role of informal waste pickers in municipal solid waste management (MSWM) and their contribution to greenhouse gas emission reductions. Given the global prevalence of waste pickers, particularly in low- and middle-income countries, further research on this topic could significantly enhance awareness of the benefits derived from their labor. Recognizing and integrating informal waste pickers into formal waste management systems could strengthen sustainability initiatives in cities and enhance climate change mitigation strategies under dynamic needs of urban populations. • Informal waste pickers had a pivotal role in recyclables recovery and GHG emission reduction in a large urban center. • Temporal analysis reveals a dynamic shift in material recovery and annual CO 2 mitigation. • Recognizing and integrating informal waste pickers is therefore essential for sustainable urban waste management.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

Full frame distilled prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Simulation or modeling · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.299
Threshold uncertainty score0.646

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.001
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.001
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.011
GPT teacher head0.273
Teacher spread0.262 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it