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1.
Nature ; 548(7669): 523, 2017 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-28858306
2.
Prev Chronic Dis ; 15: E101, 2018 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-30095404

RESUMEN

INTRODUCTION: Increases in physical activity can lead to decreases in the prevalence of chronic diseases. Parks provide an ideal setting for physical activity. We investigated the effect of a fitness equipment installation on the intensity of park users' physical activity at a community park. METHODS: We used the System for Observing Play and Recreation in a Community to record physical activity in Eastgate Park in Garden Grove, California, in August 2015 (preintervention [n = 1,650 person-periods]) and in February 2016 (postintervention [n = 1,776 person-periods]). We quantified physical activity in target areas of the park during 15-minute observation periods in 2 ways: 1) we categorized each user's activity level during the period (sedentary, walking, vigorous), and 2) we converted activity levels to numeric metabolic equivalent task (MET) scores and calculated the period-average score across users. We used mixed-effects regression models to assess 1) the proportional odds of higher activity level at postintervention and 2) the association between intervention status (pre vs post) and mean period-average MET scores. RESULTS: In the immediate zone around the fitness equipment, the odds ratio for a higher activity level was 1.58 (95% confidence interval [CI], 1.14-2.18; P = .006) and the mean period-average MET score was 0.33 (95% CI, -0.07 to 0.74; P = .11) units higher at postintervention. Across the park as a whole, the odds ratio for a higher activity level was 1.41 (95% CI, 1.21-1.63; P < .001), and the mean period-average MET score was 0.34 (95% CI, 0.12-0.56; P = .003) units higher at postintervention. CONCLUSION: Installing fitness zones appears to be an effective intervention for increasing physical activity of park users. Further studies need to be conducted to understand the sustained impact of fitness zones over time.


Asunto(s)
Entorno Construido , Ejercicio Físico , Parques Recreativos , Adolescente , Adulto , Anciano , California , Niño , Femenino , Promoción de la Salud/métodos , Humanos , Masculino , Persona de Mediana Edad , Aptitud Física , Análisis de Regresión , Adulto Joven
3.
Environ Res ; 153: 55-62, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27898310

RESUMEN

Most households and workplaces all over the world possess furnishings and electronics, all of which contain potentially toxic flame retardant chemicals to prevent fire hazards. Indoor dust is a recognized repository of these types of chemicals including polybrominated diphenyl ethers (PBDEs) and non-polybrominated diphenyl ethers (non-PBDEs). However, no previous U.S. studies have differentiated concentrations from elevated surface dust (ESD) and floor dust (FD) within and across microenvironments. We address this information gap by measuring twenty-two flame-retardant chemicals in dust on elevated surfaces (ESD; n=10) and floors (FD; n=10) from rooms on a California campus that contain various concentrations of electronic products. We hypothesized a difference in chemical concentrations in ESD and FD. Secondarily, we examined whether or not this difference persisted: (a) across the studied microenvironments and (b) in rooms with various concentrations of electronics. A Wilcoxon signed-rank test demonstrated that the ESD was statistically significantly higher than FD for BDE-47 (p=0.01), BDE-99 (p=0.01), BDE-100 (p=0.01), BDE-153 (p=0.02), BDE-154 (p=0.02), and 3 non-PBDEs including EH-TBB (p=0.02), BEH-TEBP (p=0.05), and TDCIPP (p=0.03). These results suggest different levels and kinds of exposures to flame-retardant chemicals for individuals spending time in the sampled locations depending on the position of accumulated dust. Therefore, further research is needed to estimate human exposure to flame retardant chemicals based on how much time and where in the room individuals spend their time. Such sub-location estimates will likely differ from assessments that assume continuous unidimensional exposure, with implications for improved understanding of potential health impacts of flame retardant chemicals.


Asunto(s)
Contaminación del Aire Interior/análisis , Polvo/análisis , Exposición a Riesgos Ambientales/análisis , Retardadores de Llama/análisis , California , Electrónica , Monitoreo del Ambiente/métodos , Éteres Difenilos Halogenados/análisis , Vivienda , Humanos , Laboratorios , Universidades
5.
Environ Sci Technol ; 49(12): 7095-108, 2015 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-26007633

RESUMEN

A number of efforts have been launched to solve the global electronic waste (e-waste) problem. The efficiency of e-waste recycling is subject to variable national legislation, technical capacity, consumer participation, and even detoxification. E-waste management activities result in procedural irregularities and risk disparities across national boundaries. We review these variables to reveal opportunities for research and policy to reduce the risks from accumulating e-waste and ineffective recycling. Full regulation and consumer participation should be controlled and reinforced to improve local e-waste system. Aiming at standardizing best practice, we alter and identify modular recycling process and infrastructure in eco-industrial parks that will be expectantly effective in countries and regions to handle the similar e-waste stream. Toxicity can be deleted through material substitution and detoxification during the life cycle of electronics. Based on the idea of "Control-Alt-Delete", four patterns of the way forward for global e-waste recycling are proposed to meet a variety of local situations.


Asunto(s)
Residuos Electrónicos , Administración de Residuos/métodos , Ecotoxicología , Electrónica , Reciclaje , Control Social Formal , Administración de Residuos/legislación & jurisprudencia
6.
J Air Waste Manag Assoc ; 65(6): 743-50, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25976487

RESUMEN

UNLABELLED: The plasma display panel (PDP) is rapidly becoming obsolete, contributing in large amounts to the electronic waste stream. In order to assess the potential for environmental pollution due to hazardous metals leached from PDP glass, standardized leaching procedures, chemical speciation assessments, and bioavailability tests were conducted. According to the Toxicity Characteristic Leaching Procedure (TCLP), arsenic in back glass was present at 4.46 ± 0.22 mg/L, close to its regulation limit of 5 mg/L. Zn is not available in the TCLP, but its TCLP leaching concentration in back glass is 102.96 ± 5.34 mg/L. This is because more than 90% of Zn is in the soluble and exchangeable and carbonate fraction. We did not detect significant levels of Ag, Ba, or Cu in the TCLP leachate, and the main fraction of Ag and Ba is residual, more than 95%, while the fraction distribution of Cu changes SEP by SEP. Ethylenediamine tetraacetic acid (EDTA)- and diethylenetriamine pentaacetic acid (DTPA)-extractable Ag, As, Ba, Cu, Zn, and Ni indicate a lower biohazards potential. These results show that, according to the EPA regulations, PDP glass may not be classified as hazardous waste because none of the metals exceeded their thresholds in PDP leachate. However, the concentrations of As and Zn should be lowered in the manufacturing process and finished product to avoid potential pollution problems. IMPLICATIONS: The plasma display panel is rapidly becoming obsolete because of the liquid crystal display. In this study, the leachability of heavy metals contained in the waste plasma display panel glass was first examined by standardized leaching tests, typical chemical speciation assessments, and bioavailability tests, providing fundamental data for waste PDP glass recovery, recycling, and reuse.


Asunto(s)
Residuos Electrónicos/análisis , Contaminantes Ambientales/análisis , Residuos Peligrosos/clasificación , Metales Pesados/análisis , Disponibilidad Biológica , China , Monitoreo del Ambiente , Política Ambiental , Contaminantes Ambientales/metabolismo , Contaminantes Ambientales/toxicidad , Vidrio/análisis , Regulación Gubernamental , Residuos Peligrosos/análisis , Humanos , Metales Pesados/metabolismo , Metales Pesados/toxicidad , Estados Unidos
7.
J Environ Sci Health B ; 49(4): 255-62, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24502212

RESUMEN

This research aimed to develop slow-release formulations (SRFs) of 2,4-dichlorophenoxyacetic acid (2,4-D) using zeolite and bentonite minerals modified with cetyltrimethylammonium (CTMA) surfactant. Adsorption-desorption, greenhouse bioassay and column experiments were carried out to assess the potential of the SRFs to control weeds while reducing the herbicide leaching losses to deep layers of soil. The results showed that only 6.5 mmol 2,4-D kg(-1) was retained by Na-bent, and the herbicide was not adsorbed by Na-zeol at all. The surface modification with CTMA surfactant, however, improved the 2,4-D adsorption capacity of the zeolite and bentonite up to 207.5 and 415.8 mmol kg(-1), respectively. The synthesized organo-minerals slowly released the retained 2,4-D discharging 22 to 64% of the adsorbed 2,4-D to the solution phase within 7 days. The SRFs significantly (P = 0.05) reduced the herbicide mobility within the soil columns keeping a great portion of the herbicide active ingredient in the upper 5 cm soil layer. The SRFs were significantly (P = 0.05) as effective as the free technical herbicide in weed control without harming the ryegrass as the main plant. Therefore, the synthesized SRFs could be considered as useful tools for weed control in sustainable agriculture.


Asunto(s)
Ácido 2,4-Diclorofenoxiacético/química , Bentonita/química , Química Farmacéutica/métodos , Preparaciones de Acción Retardada/química , Herbicidas/química , Zeolitas/química , Ácido 2,4-Diclorofenoxiacético/farmacología , Adsorción , Preparaciones de Acción Retardada/farmacología , Malezas/efectos de los fármacos , Control de Malezas
8.
Artículo en Inglés | MEDLINE | ID: mdl-38837720

RESUMEN

Commercialization of rechargeable lithium-ion (Li-ion) batteries has revolutionized the design of portable electronic devices and is facilitating the current transition to electric vehicles. The technological specifications of Li-ion batteries continue to evolve through the introduction of various high-risk liquid electrolyte chemicals, yet critical evaluation of the physical, environmental, and human health hazards of these substances is lacking. Using the GreenScreen for Safer Chemicals approach, we conducted a chemical hazard assessment (CHA) of 103 electrolyte chemicals categorized into seven chemical groups: salts, carbonates, esters, ethers, sulfoxides-sulfites-sulfones, overcharge protection additives, and flame-retardant additives. To minimize data gaps, we focused on six toxicity and hazard data sources, including three empirical and three nonempirical predictive data sources. Furthermore, we investigated the structural similarities among selected electrolyte chemicals using the ChemMine tool and the simplified molecular input line entry system inputs from PubChem to evaluate whether chemicals with similar structures exhibit similar toxicity. The results demonstrate that salts, overcharge protection additives, and flame-retardant additives contain the most toxic components in the electrolyte solutions. Furthermore, carbonates, esters, and ethers account for most flammability hazards in Li-ion batteries. This study supports the complementary use of quantitative structure-activity relationship models to minimize data gaps and inconsistencies in CHA. Integr Environ Assess Manag 2024;00:1-14. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

9.
J Hazard Mater ; 473: 134545, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38761760

RESUMEN

Printed circuit boards (PCBs) make up a substantial amount of electronic waste (e-waste) generated annually. Waste PCBs contain high quantities of copper and gold in comparison to natural ores. As such, "urban mining" of waste PCBs to recover these metals is of commercial interest. In this work, we used life cycle assessment to compare the environmental impact of four copper and gold recovery processes. We evaluated pyrometallurgy, chemical leaching, and bioleaching, as well as a hybrid leaching process that uses bioleaching to recover copper and chemical leaching to recover gold. Furthermore, we considered differences in environmental impact based on differences in electricity sources. If electricity comes from fossil fuels, the pyrometallurgical process results in the lowest environmental impact in all impact categories studied. If electricity comes from carbon-free sources, the pyrometallurgical process results in the lowest environmental impact in all categories studied except global warming, where the hybrid leaching process results in the lowest impact. In all cases, metal recovery from waste PCBs leads to lower environmental impact than primary metal production. Our goal is to guide e-waste recyclers towards more environmentally sustainable metal recovery processes and to provide knowledge gaps in the field to guide future research.

10.
iScience ; 27(6): 109898, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38812545

RESUMEN

Decarbonization plans depend on the rapid, large-scale deployment of batteries to sufficiently decarbonize the electricity system and on-road transport. This can take many forms, shaped by technology, materials, and supply chain selection, which will have local and global environmental and social impacts. Current knowledge gaps limit the ability of decision-makers to make choices in facilitating battery deployment that minimizes or avoids unintended environmental and social consequences. These gaps include a lack of harmonized, accessible, and up-to-date data on manufacturing and supply chains and shortcomings within sustainability and social impact assessment methods, resulting in uncertainty that limits incorporation of research into policy making. These gaps can lead to unintended detrimental effects of large-scale battery deployment. To support decarbonization goals while minimizing negative environmental and social impacts, we elucidate current barriers to tracking how decision-making for large-scale battery deployment translates to environmental and social impacts and recommend steps to overcome them.

11.
Environ Sci Technol ; 47(10): 5495-503, 2013 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-23638841

RESUMEN

Rechargeable lithium-ion (Li-ion) and lithium-polymer (Li-poly) batteries have recently become dominant in consumer electronic products because of advantages associated with energy density and product longevity. However, the small size of these batteries, the high rate of disposal of consumer products in which they are used, and the lack of uniform regulatory policy on their disposal means that lithium batteries may contribute substantially to environmental pollution and adverse human health impacts due to potentially toxic materials. In this research, we used standardized leaching tests, life-cycle impact assessment (LCIA), and hazard assessment models to evaluate hazardous waste classification, resource depletion potential, and toxicity potentials of lithium batteries used in cellphones. Our results demonstrate that according to U.S. federal regulations, defunct Li-ion batteries are classified hazardous due to their lead (Pb) content (average 6.29 mg/L; σ = 11.1; limit 5). However, according to California regulations, all lithium batteries tested are classified hazardous due to excessive levels of cobalt (average 163,544 mg/kg; σ = 62,897; limit 8000), copper (average 98,694 mg/kg; σ = 28,734; limit 2500), and nickel (average 9525 mg/kg; σ = 11,438; limit 2000). In some of the Li-ion batteries, the leached concentrations of chromium, lead, and thallium exceeded the California regulation limits. The environmental impact associated with resource depletion and human toxicity is mainly associated with cobalt, copper, nickel, thallium, and silver, whereas the ecotoxicity potential is primarily associated with cobalt, copper, nickel, thallium, and silver. However, the relative contribution of aluminum and lithium to human toxicity and ecotoxicity could not be estimated due to insufficient toxicity data in the models. These findings support the need for stronger government policy at the local, national, and international levels to encourage recovery, recycling, and reuse of lithium battery materials.


Asunto(s)
Suministros de Energía Eléctrica , Litio , Eliminación de Residuos , Humanos , Litio/toxicidad
12.
Environ Sci Technol ; 47(2): 1040-7, 2013 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-23237340

RESUMEN

Artificial lighting systems are transitioning from incandescent to compact fluorescent lamp (CFL) and light-emitting diode (LED) bulbs in response to the U.S. Energy Independence and Security Act and the EU Ecodesign Directive, which leads to energy savings and reduced greenhouse gas emissions. Although CFLs and LEDs are more energy-efficient than incandescent bulbs, they require more metal-containing components. There is uncertainty about the potential environmental impacts of these components and whether special provisions must be made for their disposal at the end of useful life. Therefore, the objective of this study is to analyze the resource depletion and toxicity potentials from the metals in incandescent, CFL, and LED bulbs to complement the development of sustainable energy policy. We assessed the potentials by examining whether the lighting products are to be categorized as hazardous waste under existing U.S. federal and California state regulations and by applying life cycle impact-based and hazard-based assessment methods (note that "life cycle impact-based method" does not mean a general life cycle assessment (LCA) but rather the elements in LCA used to quantify toxicity potentials). We discovered that both CFL and LED bulbs are categorized as hazardous, due to excessive levels of lead (Pb) leachability (132 and 44 mg/L, respectively; regulatory limit: 5) and the high contents of copper (111,000 and 31,600 mg/kg, respectively; limit: 2500), lead (3860 mg/kg for the CFL bulb; limit: 1000), and zinc (34,500 mg/kg for the CFL bulb; limit: 5000), while the incandescent bulb is not hazardous (note that the results for CFL bulbs excluded mercury vapor not captured during sample preparation). The CFLs and LEDs have higher resource depletion and toxicity potentials than the incandescent bulb due primarily to their high aluminum, copper, gold, lead, silver, and zinc. Comparing the bulbs on an equivalent quantity basis with respect to the expected lifetimes of the bulbs, the CFLs and LEDs have 3-26 and 2-3 times higher potential impacts than the incandescent bulb, respectively. We conclude that in addition to enhancing energy efficiency, conservation and sustainability policies should focus on the development of technologies that reduce the content of hazardous and rare metals in lighting products without compromising their performance and useful lifespan.


Asunto(s)
Sustancias Peligrosas/toxicidad , Iluminación/efectos adversos , Iluminación/instrumentación , Metales/toxicidad , Cobre/análisis , Cobre/toxicidad , Ambiente , Diseño de Equipo , Fluorescencia , Sustancias Peligrosas/análisis , Incandescencia , Plomo/análisis , Plomo/toxicidad , Iluminación/economía , Metales/análisis
13.
Environ Sci Technol ; 47(21): 12409-16, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24073987

RESUMEN

Waste printed circuit boards (WPCBs) are resource-rich but hazardous, demanding innovative strategies for post-consumer collection, recycling, and mining for economically precious constituents. A novel technology for disassembling electronic components from WPCBs is proposed, using hot air to melt solders and to separate the components and base boards. An automatic heated-air disassembling equipment was designed to operate at a heating source temperature at a maximum of 260 °C and an inlet pressure of 0.5 MPa. A total of 13 individual WPCBs were subjected to disassembling tests at different preheat temperatures in increments of 20 °C between 80 and 160 °C, heating source temperatures ranging from 220 to 300 °C in increments of 20 °C, and incubation periods of 1, 2, 4, 6, or 8 min. For each experimental treatment, the disassembly efficiency was calculated as the ratio of electronic components released from the board to the total number of its original components. The optimal preheat temperature, heating source temperature, and incubation period to disassemble intact components were 120 °C, 260 °C, and 2 min, respectively. The disassembly rate of small surface mount components (side length ≤ 3 mm) was 40-50% lower than that of other surface mount components and pin through hole components. On the basis of these results, a reproducible and sustainable industrial ecological protocol using steam produced by industrial exhaust heat coupled to electronic-waste recycling is proposed, providing an efficient, promising, and green method for both electronic component recovery and industrial exhaust heat reutilization.


Asunto(s)
Residuos Electrónicos/análisis , Calor , Residuos Industriales/análisis , Automatización , Rastreo Diferencial de Calorimetría , Electrólisis , Electrónica , Termogravimetría
14.
One Health Outlook ; 5(1): 8, 2023 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-37280666

RESUMEN

BACKGROUND: One Health is defined as an integrated, unifying approach that aims to sustainably balance and optimize the health of people, animals and ecosystems; this approach attracts stakeholders from multiple sectors, academic disciplines, and professional practices. The diversity of expertise and interest groups is frequently and simultaneously framed as (1) a strength of the One Health approach in the process of understanding and solving complex problems associated with health challenges such as pathogen spillovers and pandemics and (2) a challenge regarding consensus on essential functions of One Health and the sets of knowledge, skills, and perspectives unique to a workforce adopting this approach. Progress in developing competency-based training in One Health has revealed coverage of various topics across fundamental, technical, functional, and integrative domains. Ensuring that employers value the unique characteristics of personnel trained in One Health will likely require demonstration of its usefulness, accreditation, and continuing professional development. These needs led to the conceptual framework of a One Health Workforce Academy (OHWA) for use as a platform to deliver competency-based training and assessment for an accreditable credential in One Health and opportunities for continuing professional development. METHODS: To gather information about the desirability of an OHWA, we conducted a survey of One Health stakeholders. The IRB-approved research protocol used an online tool to collect individual responses to the survey questions. Potential respondents were recruited from partners of One Health University Networks in Africa and Southeast Asia and international respondents outside of these networks. Survey questions collected demographic information, measured existing or projected demand and the relative importance of One Health competencies, and determined the potential benefits and barriers of earning a credential. Respondents were not compensated for participation. RESULTS: Respondents (N = 231) from 24 countries reported differences in their perspectives on the relative importance of competency domains of the One Health approach. More than 90% of the respondents would seek to acquire a competency-based certificate in One Health, and 60% of respondents expected that earning such a credential would be rewarded by employers. Among potential barriers, time and funding were the most cited. CONCLUSION: This study showed strong support from potential stakeholders for a OHWA that hosts competency-based training with opportunities for certification and continuing professional development.

15.
One Health ; 14: 100386, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35445151

RESUMEN

Scientific evidence for the urgency of curbing the emergence and spread of antimicrobial resistance is incontrovertible. Yet, the translation of knowledge into effective design and implementation of action plans is hampered by gaps in perception, attitudes and practices in the human health, agriculture, and environmental sectors. To fill these gaps in regions where the disease burden attributable to antimicrobial resistance is heaviest, a cadre of One Health Stewards equipped with strategies to translate and meld global and local evidence for knowledge dissemination is deemed necessary. This opinion articulates a case for cultivating and deploying One Health Antibiotic Stewards according to specific actions within the environmental context of antibiotic resistance.

16.
Front Public Health ; 10: 954025, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35958832

RESUMEN

In response to a University of California systemwide initiative to expand the knowledge base of climate change, two half-day workshops were held for faculty in the College of Health Sciences at the UC Irvine. In the first workshop, 20 participants who teach in the Schools of Nursing, Medicine, Pharmacy, and Pharmaceutical Science, or the Program in Public Health convened to explore concepts of sustainability, theoretical models of curriculum integration, challenges to adding new competencies into professional training, and strategies for integrating climate change modules and case studies into the curricula. The second half-day workshop was held a year after the first workshop to review how faculty members have modified their syllabus to integrate climate change information with varying degrees of success. A case study is presented regarding an asynchronous fully online course Introduction to Global Health, which is open to enrollment by students from all campuses of the University of California. The outcomes revealed preferential adoption of models of curriculum integration which minimized disruption of the sequence of topics in pre-existing courses. These include, for example, the use of longitudinal climate datasets for quantitative analysis of disease outcomes, and description of episodic events involving extreme weather conditions to explore differences in social determinants of vulnerability to climate change impacts in different populations. Integration of climate change as a distinct topic seems easier in elective courses in comparison with required courses designed to cover pre-established professional knowledge, competencies, and skills. The emergent requirement for interprofessional training in the health sciences provides an opportunity for the development of a cross-cutting competency domain including climate change as a unifying theme in a stand-alone course or set of courses in a sequenced model of curriculum integration.


Asunto(s)
Cambio Climático , Curriculum , Humanos
17.
J Hazard Mater ; 437: 129301, 2022 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-35716560

RESUMEN

Batteries are important for promoting renewable energy, but, like most engineered products, they contain multiple hazardous materials. The purpose of this study is to evaluate industrial-scale batteries using GreenScreen® for Safer Chemicals, an established chemical hazard assessment (CHA) framework, and to develop a systematic, transparent methodology to quantify the CHA results, harmonize them, and aggregate them into single-value hazard scores, which can facilitate quantitative comparison and a robust evaluation of data gaps, inconsistencies, and uncertainty through the implementation of carefully selected scenarios and stochastic multicriteria acceptability analysis (SMAA). Using multiple authoritative toxicity data sources, six battery products are evaluated: three lithium-ion batteries (lithium iron phosphate, lithium nickel cobalt manganese hydroxide, and lithium manganese oxide), and three redox flow batteries (vanadium redox, zinc-bromine, and all-iron). The CHA results indicate that many materials in these batteries, including reagents and intermediates, inherently exhibit high hazard; therefore, safer materials should be identified and considered in future designs. The scenario analysis and SMAA, combined, provide a quantitative evaluation framework to support the decision-making needed to compare alternative technologies. Thus, this study highlights specific strategies to reduce the use of hazardous materials in complex engineered products before they are widely used in this rapidly-expanding industry sector.

18.
Waste Manag ; 141: 154-162, 2022 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-35123249

RESUMEN

Waste printed circuit boards (WPCBs) contain valuable material resources and hazardous substances, thereby posing a challenge for sustainable resource recovery and environmental protection initiatives. Overcoming this challenge will require mapping the toxic footprint of WPCBs to specific materials and substances used in manufacturing electronic components (ECs). Therefore, this work collected 50 EC specimens from WPCBs in five ubiquitous consumer products, such as television, refrigerator, air conditioner, washing machine and computer. The work extracted and analyzed metal contents and used leachability assessments based on tests adopted by the regulatory policies from China and the United States. The work found that copper and iron are the most abundant constituents in ECs, with concentrations ranging 5.90-796.62 g/kg and 0-831.53 g/kg, respectively; whereas abundance of precious metal content is in the order of silver > gold > palladium > platinum, with silver concentration ranging 15-5290 mg/kg. The content of marginally-regulated toxic substance arsenic ranged 0-9700 mg/kg; whereas fully regulated toxic metals such as chromium, lead and mercury did not exceed the thresholds set by China and US standards. The work found new toxic threats from arsenic and selenium leached from 20 of 50 ECs exceeding regulatory standards. These results will aid manufacturers and recyclers in protecting workers' health and environmental quality from arsenic and selenium pollution, and should initiate discussion about regulating these toxic components as part of a comprehensive program to reduce the toxic footprint of electronic products.

19.
Environ Sci Technol ; 50(16): 8401-2, 2016 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-27467531
20.
Environ Sci Technol ; 45(1): 320-7, 2011 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-21138290

RESUMEN

Light-emitting diodes (LEDs) are advertised as environmentally friendly because they are energy efficient and mercury-free. This study aimed to determine if LEDs engender other forms of environmental and human health impacts, and to characterize variation across different LEDs based on color and intensity. The objectives are as follows: (i) to use standardized leachability tests to examine whether LEDs are to be categorized as hazardous waste under existing United States federal and California state regulations; and (ii) to use material life cycle impact and hazard assessment methods to evaluate resource depletion and toxicity potentials of LEDs based on their metallic constituents. According to federal standards, LEDs are not hazardous except for low-intensity red LEDs, which leached Pb at levels exceeding regulatory limits (186 mg/L; regulatory limit: 5). However, according to California regulations, excessive levels of copper (up to 3892 mg/kg; limit: 2500), Pb (up to 8103 mg/kg; limit: 1000), nickel (up to 4797 mg/kg; limit: 2000), or silver (up to 721 mg/kg; limit: 500) render all except low-intensity yellow LEDs hazardous. The environmental burden associated with resource depletion potentials derives primarily from gold and silver, whereas the burden from toxicity potentials is associated primarily with arsenic, copper, nickel, lead, iron, and silver. Establishing benchmark levels of these substances can help manufacturers implement design for environment through informed materials substitution, can motivate recyclers and waste management teams to recognize resource value and occupational hazards, and can inform policymakers who establish waste management policies for LEDs.


Asunto(s)
Residuos Electrónicos/análisis , Sustancias Peligrosas/análisis , Residuos Peligrosos/análisis , Iluminación , Metales/análisis , Conservación de los Recursos Naturales , Residuos Electrónicos/clasificación , Residuos Electrónicos/estadística & datos numéricos , Ambiente , Monitoreo del Ambiente , Sustancias Peligrosas/toxicidad , Residuos Peligrosos/clasificación , Residuos Peligrosos/estadística & datos numéricos , Plomo/análisis , Plomo/toxicidad , Metales/toxicidad , Medición de Riesgo , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
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