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A mess of plastic It is not clear what strategies will be most effective in mitigating harm from the global problem of plastic pollution. Borrelle et al. and Lau et al. discuss possible solutions and their impacts. Both groups found that substantial reductions in plastic-waste generation can be made in the coming decades with immediate, concerted, and vigorous action, but even in the best case scenario, huge quantities of plastic will still accumulate in the environment. Science , this issue p. 1515 , p. 1455

Marine debris is defined as any manmade item, commonly plastics, which ends up in the ocean regardless of the source. Debris found along coastlines can cause harm or even death to nesting and hatchling sea turtles through ingestion, entrapment, or entanglement. Jekyll Island is a prominent nesting beach for loggerhead sea turtles with over 1700 emergences from 2012 to 2017. This study uses debris logged through NOAA's Marine Debris Tracker and loggerhead sea turtle nesting activity on Jekyll Island to generate density maps and evaluate possible interactions. These maps provide valuable information on portions of the coast most at risk for debris and sea turtle interactions. Using these maps help the GSTC Marine Debris Initiative focus citizen science efforts in high overlap areas of the beach. With marine debris being a global issue that impacts all sea turtle and beach nesting species, lessons learned can be applied across a wide range of taxa and management strategies.

Plastic pollution and climate change have commonly been treated as two separate issues and sometimes are even seen as competing. Here we present an alternative view that these two issues are fundamentally linked. Primarily, we explore how plastic contributes to greenhouse gas (GHG) emissions from the beginning to the end of its life cycle. Secondly, we show that more extreme weather and floods associated with climate change, will exacerbate the spread of plastic in the natural environment. Finally, both issues occur throughout the marine environment, and we show that ecosystems and species can be particularly vulnerable to both, such as coral reefs that face disease spread through plastic pollution and climate-driven increased global bleaching events. A Web of Science search showed climate change and plastic pollution studies in the ocean are often siloed, with only 0.4% of the articles examining both stressors simultaneously. We also identified a lack of regional and industry-specific life cycle analysis data for comparisons in relative GHG contributions by materials and products. Overall, we suggest that rather than debate over the relative importance of climate change or marine plastic pollution, a more productive course would be to determine the linking factors between the two and identify solutions to combat both crises.

Marine plastics are considered to be a major threat to the sustainable use of marine and coastal resources of the Caribbean, on which the region relies heavily for tourism and fishing. To date, little work has quantified plastics within the Caribbean marine environment or examined their potential sources. This study aimed to address this by holistically integrating marine (surface water, subsurface water and sediment) and terrestrial sampling and Lagrangian particle tracking to examine the potential origins, flows and quantities of plastics within the Southern Caribbean. Terrestrial litter and the microplastics identified in marine samples may arise from the maritime and tourism industries, both of which are major contributors to the economies of the Caribbean region. The San Blas islands, Panama had the highest abundance of microplastics at a depth of 25 m, and significantly greater quantities in surface water than recorded in the other countries. Modelling indicated the microplastics likely arose from mainland Panama, which has some of the highest levels of mismanaged waste. Antigua had among the lowest quantities of terrestrial and marine plastics, yet the greatest diversity of polymers. Modelling indicated the majority of the microplastics in Antiguan coastal surface were likely to have originated from the wider North Atlantic Ocean. Ocean currents influence the movements of plastics and thus the relative contributions arising from local and distant sources which become distributed within a country's territorial water. These transboundary movements can undermine local or national legislation aimed at reducing plastic pollution. While this study presents a snapshot of plastic pollution, it contributes towards the void of knowledge regarding marine plastic pollution in the Caribbean Sea and highlights the need for international and interdisciplinary collaborative research and solutions to plastic pollution.

As of 2017, 8.3 billion metric tons of plastic had been produced worldwide. Since about 40% is used in things that are thrown away relatively quickly (packaging and single use items), 6.4 billion metric tons had already become discarded materials needing to be managed. Only 9% of these discarded materials were recycled globally. The annual estimate of plastic entering our oceans globally is 5 to 13 million metric tons (MMT) per year. Latin America and the Caribbean (LAC) has an extensive populated coast, 119,000 km of coastline and over 205 million people living within 50 km of that coastline. Waste management infrastructure is still under development in many countries. Economic growth without fully developed infrastructure can lead to increased plastic leakage. This report focuses on municipal solid waste as a source of plastic input into the environment in LAC. The reports estimates that total plastic waste available to enter the ocean in LAC in 2020 was 3.7 MMT . Under business-as-usual projections, the report anticipates that the regional quantity available to enter the oceans in 2030 will be 4.1 MMT and 4.4 MMT in 2050.

Youth can impact environmental attitudes and behaviors among adults. Indeed, research on intergenerational learning has demonstrated the influence of young people on adults in their lives for myriad environmental topics. Intergenerational learning (IGL) refers to the bidirectional transfer of knowledge, attitudes, or behaviors from children to their parents or other adults and vice versa. We suggest an educational framework wherein K-12 marine debris education designed to maximize IGL may be a strategy to accelerate interdisciplinary, community-level solutions to marine debris. Although technical strategies continue to be developed to address the marine debris crisis, even the most strictly technical of these benefit from social support. Here, we present 10 Best Practices grounded in educational, IGL, and youth civic engagement literature to promote marine debris solutions. We describe how integrating IGL and civic engagement into K-12-based marine debris curricula may start a virtuous circle benefiting teachers, students, families, communities, and the ocean.

Plastic waste from the United States contaminates the environment domestically and in countries processing material for recycling., Plastic waste affects environmental quality and ecosystem health. In 2010, an estimated 5 to 13 million metric tons (Mt) of plastic waste entered the ocean from both developing countries with insufficient solid waste infrastructure and high-income countries with very high waste generation. We demonstrate that, in 2016, the United States generated the largest amount of plastic waste of any country in the world (42.0 Mt). Between 0.14 and 0.41 Mt of this waste was illegally dumped in the United States, and 0.15 to 0.99 Mt was inadequately managed in countries that imported materials collected in the United States for recycling. Accounting for these contributions, the amount of plastic waste generated in the United States estimated to enter the coastal environment in 2016 was up to five times larger than that estimated for 2010, rendering the United States’ contribution among the highest in the world.

In recent years, there has been a tremendous increase in work that focuses on the amount and types of waste entering the marine environment from multiple geographies around the world. To date, however, there are few reports about the scale of waste entering the coastal and oceanic waters around Africa. To address this knowledge gap, existing information was collated on waste mismanagement that can become marine debris in Africa at the continental scale. This paper focuses on identifying sources and seeking solutions to waste mismanagement. Stories are shared about opportunities that have arisen and solutions that are taking place in several countries around Africa. Finally, impediments to success are discussed and sectors are described where investments can be made to significantly reduce this growing global problem.

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (poly(3HB-co-3HHx)) thermoplastics are a promising biodegradable alternative to traditional plastics for many consumer applications. Biodegradation measured by gaseous carbon loss of several types of poly(3HB-co-3HHx) plastic was investigated under anaerobic conditions and aerobic seawater environments. Under anaerobic conditions, the biodegradation levels of a manufactured sheet of poly(3HB-co-3HHx) and cellulose powder were not significantly different from one another over 85 days with 77.1 ± 6.1 and 62.9 ± 19.7% of the carbon converted to gas, respectively. However, the sheet of poly(3HB-co-3HHx) had significantly higher methane yield (p ≤ 0.05), 483.8 ± 35.2 mL·g–1 volatile solid (VS), compared to cellulose controls, 290.1 ± 92.7 mL·g–1 VS, which is attributed to a greater total carbon content. Under aerobic seawater conditions (148–195 days at room temperature), poly(3HB-co-3HHx) sheets were statistically similar to cellulose for biodegradation as gaseous...

Synthetic organic polymers—or plastics—did not enter widespread use until the 1950s. By 2015, global production had increased to 322 million metric tons (Mt) year−1, which approaches the total weight of the human population produced in plastic every year. Approximately half is used for packaging and other disposables, 40% of plastic waste is not accounted for in managed landfills or recycling facilities, and 4.8–12.7 Mt year−1 enter the ocean as macroscopic litter and microplastic particles. Here, we argue that such mismanaged plastic waste is similar to other persistent pollutants, such as dichlorodiphenyltrichloroethane (DDT) or polychlorinated biphenyls (PCBs), which once threatened a “silent spring” on land. Such a scenario seems now possible in the ocean, where plastic cannot be easily removed, accumulates in organisms and sediments, and persists much longer than on land. New evidence indicates a complex toxicology of plastic micro- and nanoparticles on marine life, and transfer up the food chain, including to people. We detail solutions to the current crisis of accumulating plastic pollution, suggesting a Global Convention on Plastic Pollution that incentivizes collaboration between governments, producers, scientists, and citizens.

Recycling rates have plateaued and recycling in public spaces has been targeted as a component that can help increase overall recycling rates. Eco-feedback technology and environmental psychology were combined to study recycling in a semi-public space in multiple social environments. A low-cost, low-energy electronic recycling bin design (WeRecycle bin) uses human-computer interaction and social principles to provide behavior-changing eco-feedback. Using mixed-methods research, we tested the WeRecycle bin in three different experiments by varying social settings and time of exposure, documenting impacts for public recycling. Results show that simple low-energy, low-cost eco-feedback technology resulted in statistically significant increases in recycling activity and can be an important tool in the promotion of recycling activity outside the home.

Rivers worldwide are now acting as major transport pathways for plastic pollution and discharge large quantities of waste into the ocean. Previous oceanographic modelling and current drifter data have been used to predict the movement and accumulation of plastic pollution in the marine environment, but our understanding of the transport and fate through riparian systems is still largely unknown. Here we undertook a proof of concept study by applying open source tracking technology (both GPS (Global Positing System) cellular networks and satellite technology), which have been successfully used in many animal movement studies, to track the movements of individual plastic litter items (500 ml PET (polyethylene terephthalate) drinks bottles) through the Ganges River system (known as the Ganga in India and the Padma and Meghna in Bangladesh, hereafter known as the Ganges) and the Bay of Bengal. Deployed tags were successfully tracked through the Ganges river system and into the Bay of Bengal marine system. The “bottle tags” were designed and built (e.g. shape, size, buoyancy) to replicate true movement patterns of a plastic bottle. The maximum distance tracked to date is 2845 km over a period of 94 days. We discuss lessons learnt from the development of these plastic litter tags, and outline how the potential widespread use of this open source technology has the ability to significantly increase understanding of the location of accumulation areas and the timing of large inputs of plastic pollution into the aquatic system. Furthermore, “bottle tags” may act as a powerful tool for stimulating social behaviour change, informing science-based policy, and as valuable educational outreach tools for public awareness.

The rapid growth of the use and disposal of plastic materials has proved to be a challenge for solid waste management systems with impacts on our environment and ocean. While recycling and the circular economy have been touted as potential solutions, upward of half of the plastic waste intended for recycling has been exported to hundreds of countries around the world. China, which has imported a cumulative 45% of plastic waste since 1992, recently implemented a new policy banning the importation of most plastic waste, begging the question of where the plastic waste will go now. We use commodity trade data for mass and value, region, and income level to illustrate that higher-income countries in the Organization for Economic Cooperation have been exporting plastic waste (70% in 2016) to lower-income countries in the East Asia and Pacific for decades. An estimated 111 million metric tons of plastic waste will be displaced with the new Chinese policy by 2030. As 89% of historical exports consist of polymer groups often used in single-use plastic food packaging (polyethylene, polypropylene, and polyethylene terephthalate), bold global ideas and actions for reducing quantities of nonrecyclable materials, redesigning products, and funding domestic plastic waste management are needed.

Marine debris and plastic in our oceans is a global issue of increasing concern. However, the monitoring of litter and debris is challenging at the global scale because of disconnected local organizations and the use of paper and pen for documentation. The Marine Debris Tracker mobile app and citizen science program allow for the collection of global standardized data at a scale, speed, and efficiency that wasn't previously possible. The app also serves as an outreach and education tool, with a Web portal that instantly shows the data that users have logged. User engagement through a top tracker competition and social media keeps people interested in the Marine Debris Tracker community. More than 400,000 items have been tracked, with plastic being the most common category noted; maps provide both global and local distribution of data. The Marine Debris Tracker community and dataset continue to grow daily.

Dumping lots of plastics into our oceans Considerable progress has been made in determining the amount and location of plastic debris in our seas, but how much plastic actually enters them in the first place is more uncertain. Jambeck et al. combine available data on solid waste with a model that uses population density and economic status to estimate the amount of land-based plastic waste entering the ocean. Unless waste management practices are improved, the flux of plastics to the oceans could increase by an order of magnitude within the next decade. Science , this issue p. 768

Plastics have outgrown most man-made materials and have long been under environmental scrutiny. However, robust global information, particularly about their end-of-life fate, is lacking. By identifying and synthesizing dispersed data on production, use, and end-of-life management of polymer resins, synthetic fibers, and additives, we present the first global analysis of all mass-produced plastics ever manufactured. We estimate that 8300 million metric tons (Mt) as of virgin plastics have been produced to date. As of 2015, approximately 6300 Mt of plastic waste had been generated, around 9% of which had been recycled, 12% was incinerated, and 79% was accumulated in landfills or the natural environment. If current production and waste management trends continue, roughly 12,000 Mt of plastic waste will be in landfills or in the natural environment by 2050.

The Sustainable Neighborhoods for Happiness Index (SNHI) is a tool to assess and compare how well individual cities, towns, neighborhoods and communities embrace sustainable practices and how these practices translate to opportunities for residents to pursue happiness. Recent studies have shown that the majority of humanity is concentrated in coastal cities. Thus, it is crucial to consider how to develop/retrofit these areas in the coming years, as these populations continue to grow, sea levels rise and natural resources become more stressed. We applied the SNHI to nineteen coastal cities, all members of the fifty most populous cities in the United States, to assess the current state of sustainability and potential opportunities for residential happiness. SNHI scores were then plotted on The Sustainable Neighborhoods for Happiness Distribution (SNHD) for comparison and assessment. Finally, we perform sensitivity analysis by adjusting subjective measures, simulating reviewer bias, and comparatively rank all cities. Our results show that San Francisco has the greatest SNHI (82.73) while Detroit has the lowest (35.28) and that city rankings remain relatively stable when accounting for bias.

This paper describes the development of the Sustainable Neighborhoods for Happiness Index (SNHI): a tool to assess and compare how well individual cities, towns, neighborhoods and communities embrace sustainable practices and how these practices translate to opportunities for residents to pursue happiness. The SNHI is grounded in findings from primary literature and previous research suggesting associations between aspects of sustainable development and higher levels of self-reported happiness. Nine subsystems of community development were selected for the generation of the SNHI: water management, energy management, urban design, food management, business & economic development, waste management, buildings & infrastructure, transportation and community governance. SNHI scores were generated for sixteen US cities with data compiled from the Green City Index (2011) and the SustainLane US City Rankings (2007). A method was then developed to generate the Sustainable Neighborhoods for Happiness Distribution (SNHD) to plot future SNHI scores for comparison. The SNHI scoring methodology was then applied by collecting data for Athens, Georgia and Ithaca, New York. Our results suggest that San Francisco has the highest SNHI, while Detroit has the lowest and that Athens is just below and Ithaca just above the mean SNHI on the SNHD. The SNHI can serve as a unique tool for decision makers, community stakeholders, engineers, developers, architects, planners and researchers to assess the relative status of any neighborhood or community, with respect to development and happiness.

Microbial fuel cells were designed and operated to treat landfill leachate while simultaneously producing electricity. Two designs were tested in batch cycles using landfill leachate as a substrate without inoculation (908 to 3,200 mg/L chemical oxygen demand (COD)): Circle (934 mL) and large-scale microbial fuel cells (MFC) (18.3 L). A total of seven cycles were completed for the Circle MFC and two cycles for the larger-scale MFC. Maximum power densities of 24 to 31 mW/m(2) (653 to 824 mW/m(3)) were achieved using the Circle MFC, and a maximum voltage of 635 mV was produced using the larger-scale MFC. In the Circle MFC, COD, biological oxygen demand (BOD), total organic carbon (TOC), and ammonia were removed at an average of 16%, 62%, 23%, and 20%, respectively. The larger-scale MFC achieved an average of 74% BOD removal, 27% TOC removal, and 25% ammonia reduction while operating over 52 days. Analysis of the microbial characteristics of the leachate indicates that there might be both supportive and inhibiting bacteria in landfill leachate for operation of an MFC. Issues related to scale-up and heterogeneity of a mixed substrate remain.

In this paper, we assess the associations between self-reported happiness, measured using the Gallup Healthways Well-Being Index (2012), and four US city sustainability indices: the Green City Index (2011), Our Green Cities (2012), Popular Science US City Rankings (2008) and the SustainLane US Green City Rankings (2007). Based on the examination of nonparametric, rank-based correlations, we found positive associations between sustainable development and happiness on all scales and statistically significant correlations for two of the four SD indices. Results support previous research, emphasize the value of explicit consideration of happiness when measuring urban sustainability and highlight the need for future research that assesses the influence of specific subsystems of urban development on self-reported happiness.

Microbial fuel cells were designed and operated to treat landfill leachate while continuously producing power. Two different anodes were tested in batch cycles using landfill leachate as a substrate without inoculation: an activated carbon anode and biochar anode. In addition, a semi-continuous serpentine design was evaluated. No significant difference of the mean was found for the peak voltage, current density or power densities between the batch cell with activated carbon or biochar. Similar COD reduction occurred at both the batch (with biochar) and semi-continuous scale (28% ± 8.8% and 21.7% ± 12.2%, respectively). The batch MFC with activated carbon anode had significantly higher COD removal (74.7% ± 5.5%). BOD was removed by the semi-continuous MFC, but ammonia was not removed in four of the five cycles. The results provide further information on the possibility of using MFCs in landfill leachate treatment systems.

Summary A life cycle assessment (LCA) of various end-of-life management options for construction and demolition (C&D) debris was conducted using the U.S. Environmental Protection Agency's Municipal Solid Waste Decision Support Tool. A comparative LCA evaluated seven different management scenarios using the annual production of C&D debris in New Hampshire as the functional unit. Each scenario encompassed C&D debris transport, processing, separation, and recycling, as well as varying end-of-life management options for the C&D debris (e.g., combustion to generate electricity versus landfilling for the wood debris stream and recycling versus landfilling for the nonwood debris stream) and different bases for the electricity generation offsets (e.g., the northeastern U.S. power grid versus coal-fired power generation). A sensitivity analysis was also conducted by varying the energy content of the C&D wood debris and by examining the impact of basing the energy offsets on electricity generated from various fossil fuels. The results include impacts for greenhouse gas (GHG) emissions, criteria air pollutants, ancillary solid waste production, and organic and inorganic constituents in water emissions. Scenarios with nonwood C&D debris recycling coupled with combustion of C&D wood debris to generate electricity had lower impacts than other scenarios. The nonwood C&D debris recycling scenarios where C&D wood debris was landfilled resulted in less overall impact than the scenarios where all C&D debris was landfilled. The lowest impact scenario included nonwood C&D debris recycling with local combustion of the C&D wood debris to generate electricity, providing a net gain in energy production of more than 7 trillion British thermal units (BTU) per year and a 130,000 tons per year reduction in GHG emissions. The sensitivity analysis revealed that for energy consumption, the model is sensitive to the energy content of the C&D wood debris but insensitive to the basis for the energy offset, and the opposite is true for GHG emissions.

Floating and stranded marine debris is widespread. Increasing sea levels and altered rainfall, solar radiation, wind speed, waves, and oceanic currents associated with climatic change are likely to transfer more debris from coastal cities into marine and coastal habitats. Marine debris causes economic and ecological impacts, but understanding the scope of these requires quantitative information on spatial patterns and trends in the amounts and types of debris at a global scale. There are very few large-scale programs to measure debris, but many peer-reviewed and published scientific studies of marine debris describe local patterns. Unfortunately, methods of defining debris, sampling, and interpreting patterns in space or time vary considerably among studies, yet if data could be synthesized across studies, a global picture of the problem may be avaliable. We analyzed 104 published scientific papers on marine debris in order to determine how to evaluate this. Although many studies were well designed to answer specific questions, definitions of what constitutes marine debris, the methods used to measure, and the scale of the scope of the studies means that no general picture can emerge from this wealth of data. These problems are detailed to guide future studies and guidelines provided to enable the collection of more comparable data to better manage this growing problem.

The proper end-of-life management of chromated copper arsenate (CCA)-treated wood, which contains arsenic, copper, and chromium, is a concern to the solid waste management community. Landfills are often the final repository of this waste stream, and the impacts of CCA preservative metals on leachate quality are not well understood. Monofills are a type of landfill designed and operated to dispose a single waste type, such as ash, tires, mining waste, or wood. The feasibility of managing CCA-treated wood in monofills was examined using a simulated landfill (a leaching lysimeter) that contained a mix of new and weathered CCA-treated wood. The liquid to solid ratio (LS) reached in the experiment was 0.63:1. Arsenic, chromium, and copper leached from the lysimeter at average concentrations of 42 mg/L for arsenic, 9.4 mg/L for chromium, and 2.4 mg/L for copper. Complementary batch leaching studies using deionized water were performed on similar CCA-treated wood samples at LS of 5:1 and 10:1. When results from the lysimeter were compared to the batch test results, copper and chromium leachability appeared to be reduced in the lysimeter disposal environment. Of the three metals, arsenic leached to the greatest extent and was found to have the best correlation between the batch and the lysimeter experiments.

Construction and demolition (C&D) debris comprises a significant portion of the solid waste stream in the United States. Because C&D debris is largely regulated at the state level, the requirements for C&D debris disposal facilities vary from state to state. A review of state regulations was conducted to determine C&D debris disposal facility requirements, including specific requirements for liners, leachate collection, groundwater monitoring, location restrictions, operator training, waste spotters, final cover, financial assurance, and recycling. This review found that little consistency exists in the regulation of C&D debris facilities among states. Twenty-three states require liners, while 27 require groundwater monitoring. Seventeen states reported having regulations pertaining to recycling C&D debris. Several states are currently in the process of reviewing and updating their C&D debris regulations, an indication of the greater recognized importance of this fraction of the solid waste stream.

Insufficient information exists about the speciation of arsenic leaching from in-service chromated copper arsenate (CCA)-treated products and the overall impact to soils and groundwater. To address this issue, two decks were constructed, one from CCA-treated wood and the other from untreated wood. Both decks were placed in the open environment where they were impacted by rainfall. Over a one-year period, rainwater runoff from the decks and rainwater infiltrating through 0.7 m of sand below the decks was collected and analyzed for arsenic species by HPLC-ICP-MS. The average arsenic concentration in the runoff of the untreated deck was 2-3 microg/L, whereas from the CCA-treated deck it was 600 microg/L. Both inorganic As(III) and As(V) were detected in the runoff from both decks, with inorganic As(V) predominating. No detectable levels of organoarsenic species were observed. The total arsenic concentration in the infiltrated water of the treated deck had risen from a background concentration of 3 microg/L to a concentration of 18 microg/L at the end of the study. Data from the deck study were combined with annual CCA-treated wood production statistics to develop a mass balance model to estimate the extent of arsenic leaching from in-service CCA-treated wood structures to Florida soils. Results showed that during the year 2000, of the 28 000 t of arsenic imported into the state and utilized for in-service CCA-treated wood products, approximately 4600 t had already leached. Future projections suggest that an additional 11,000 t of arsenic will leach during in-service use within the next 40 years.

A major product recovered from the processing and recycling of construction and demolition (CD) debris is screened soil, also referred to as fines. A proposed reuse option for CD debris fines is fill material, typically in construction projects as a substitute for natural soil. Waste material that is reused in a manner similar to soil must first be characterized to examine potential risks to human health and the environment. In Florida, samples of CD debris fines from 13 CD debris recycling facilities were characterized for 11 total and leachable heavy metal concentrations. Total metal concentration results (mg/kg) were compared to existing data on background Florida soil concentrations and to Florida's risk-based soil cleanup target levels (SCTLs). All of the detected metals were found to be elevated with respect to background. The 95% upper confidence level of arsenic from 99 samples was 3.2 mg/kg; arsenic presented the greatest limitation to reuse when compared to the SCTLs. Lead was not found to pose a major problem, likely because of the relatively new building infrastructure in Florida, which results in less demolition debris and less material impacted by lead-based paint. The results of batch leaching tests conducted using simulated rainwater (mg/l) were compared directly to risk-based groundwater levels for Florida and were found not to pose a risk using existing risk assessment policies.

International audience; With the goal to move society toward less reliance on fossil fuels and the mitigation of climate change, there is increasing interest and investment in the bioenergy sector. However, current bioenergy growth patterns may, in the long term, only be met through an expansion of global arable land at the expense of natural ecosystems and in competition with the food sector. Increasing thermal energy recovery from solid waste reduces dependence on fossil- and biobased energy production while enhancing landfill diversion. Using inventory data from pilot processes, this work assesses the cradle-to-gate environmental burdens of plasma gasification as a route capable of transforming construction and demolition (C&D) derived biomass (CDDB) and forest residues into electricity. Results indicate that the environmental burdens associated with CDDB and forest residue gasification may be similar to conventional electricity generation. Land occupation is lowest when CDDB is used. Environmental impacts are to a large extent due to coal cogasified, coke used as gasifier bed material, and fuel oil cocombusted in the steam boiler. However, uncertainties associated with preliminary system designs may be large, particularly the heat loss associated with pilot scale data resulting in overall low efficiencies of energy conversion to electricity; a sensitivity analysis assesses these uncertainties in further detail.

Although phased out of many residential uses in the United States, the disposal of CCA-treated wood remains a concern because significant quantities have yet to be taken out of service, and it is commonly disposed in landfills. Catastrophic events have also led to the concentrated disposal of CCA-treated wood, often in unlined landfills. The goal of this research was to simulate the complex chemical and biological activity of a construction and demolition (C&D) debris landfill containing a realistic quantity of CCA-treated wood (10% by mass), produce leachate, and then evaluate the arsenic, copper, and chromium concentrations in the leachate as an indication of what may occur in a landfill setting. Copper concentrations were not significantly elevated in the control or experimental simulated landfill setting (alpha = 0.05). However, the concentrations of arsenic and chromium were significantly higher in the experimental simulated landfill leachate compared to the control simulated landfill leachate (alpha = 0.05, p < 0.001). This indicates that disposal of CCA-treated wood with C&D debris can impact leachate quality which, in turn could affect leachate management practices or aquifers below unlined landfills.

A recent focus of marine debris research is to identify and target pollution sources so that solutions to the problem can be developed through policy and education. This project hopes to expand upon this focus by also examining public attitudes toward marine debris and using this information with cleanup data to systematically implement and test community mitigation techniques. One objective of this research was to examine current community marine debris cleanup and reduction efforts in New Hampshire (as a baseline) by analyzing beach cleanup data. Marine debris monitoring data has been collected by the Blue Ocean Society for Marine Conservation over the past four years. Cleanups have been conducted by the organization at fourteen different New Hampshire sites during this time. A data summary was composed for each which included a compilation of data from 2002 through 2006. Additionally, marine debris composition (e.g., land-based, ocean-based, etc.) was mapped in Geographic Information Systems (GIS) along with significant influencing factors. Besides mapping the marine debris quantity and composition per collection site, the powerful component to GIS is that any potential influencing data available can be tied to all of these locations. The full integration of all available data will allow the evaluation of trends and correlations in marine debris data with myriad potential influences. Additionally, because the amount of ocean-based debris found on the NH Seacoast is greater than land-based debris for the majority of beaches, a new outreach program targeting commercial and recreation fisherman is being implemented. Finally, new technologies for monitoring, specifically, using personal digital assistants (PDAs) with integrated GPS systems to collect marine debris or oiled shoreline data have been evaluated. This technology could be transferred to other applications for monitoring marine pollution.

The US Environmental Protection Agency (US EPA) launched the Resource Conservation Challenge (RCC) in 2002 to help reduce waste and move towards more sustainable resource consumption. The objective of the RCC is to help communities, industries, and the public think in terms of materials management rather than waste disposal. Reducing cost, finding more efficient and effective strategies to manage municipal waste, and thinking in terms of materials management requires a holistic approach that considers life-cycle environmental tradeoffs. The US EPA’s National Risk Management Research Laboratory has led the development of a municipal solid waste decision support tool (MSW-DST). The computer software can be used to calculate life-cycle environmental tradeoffs and full costs of different waste management or materials recovery programs. The environmental methodology is based on the use of life-cycle assessment and the cost methodology is based on the use of full-cost accounting. Life-cycle inventory (LCI) environmental impacts and costs are calculated from the point of collection, handling, transport, treatment, and disposal. For any materials that are recovered for recycling, offsets are calculated to reflect potential emissions savings from use of virgin materials. The use of the MSW-DST provides a standardized format and consistent basis to compare alternatives. This paper provides an illustration of how the MSW-DST can be used by evaluating ten management strategies for a hypothetical medium-sized community to compare the life-cycle environmental and cost tradeoffs. The LCI results from the MSW-DST are then used as inputs into another US EPA tool, the Tool for the reduction and assessment of chemical and other environmental impacts, to convert the LCI results into impact indicators. The goal of this paper is to demonstrate how the MSW-DST can be used to identify and balance multiple criteria (costs and environmental impacts) when evaluating options for materials and waste management. This type of approach is needed in identifying strategies that lead to reduced waste and more sustainable resource consumption. This helps to meet the goals established in the US EPA’s Resource Conservation Challenge.

In their comments, Bessinger et al. of Exponent, Inc. (1) consistently suggest that our approach overestimates leaching rates and by no means suggest that the leaching rates are underestimated. We believe that their underlying assumptions are questionable and that leaching rates may in fact increase if their assumptions are in error. Below are specific examples. Bessinger et al. (1) suggest that leaching rates were overestimated due to the absence of soil within the C&D lysimeters. That leaching rates would decrease with the inclusion of soil is debatable since there is considerable literature that supports an increase in arsenic mobility from soils containing organic and mineral components (2). Given this information it is possible that the inclusion of soil within the lysimeters could also increase leaching rates. Bessinger et al. state that the assumption of a constant leaching rate overestimates arsenic leaching. First, we should point out that anything other than a constant leaching rate would require speculation about the chemistry and infiltration rates occurring over time within the landfill. Furthermore, the C&D scenario showed no decline in leaching rate throughout the study (Figure 2 in ref 4 showed a relatively constant slope) and thus provided no basis upon which to render an assumption other than a constant leaching rate. Bessinger et al. imply that the non-weathered wood fraction in the lysimeters was too high resulting in greater arsenic leaching rates. The assumption that non-weathered wood leaches more than weathered wood is questionable, as weathered wood has been shown to release more arsenic, particularly after long periods of time (5). If weathered wood leaches more arsenic than non-weathered wood, we believe that Bessinger et al.’s primary assumption is in error and one can argue the opposite with respect to leaching rates. Comments made by Bessinger et al. regarding arsenic speciation are misleading. First, the Nico et al. (6, 7) papers cited focused on arsenic and chromium speciation in solid phases using XAS. Arsenic speciation information reported in Khan et al. (4) was for leachates, i.e., aqueous forms. It is inappropriate to validate results obtained from one technique for one matrix using data gained from other matrices. Additionally, Nico et al. (7) found free arsenate ions to be the dominant solution-phase arsenic form and state that “once in solution, arsenic no longer complexes with Cr or Fe”. Nico et al. (7) use our previous results (5) to support their findings. Second, Bessinger et al. incorrectly claims that we introduced uncertainty by using chemical methods incapable of distinguishing between As(V) species and that we reported only total As(V) concentrations. The technique we used, HPLC-ICP–MS, is currently the most widely used analytical method for determining arsenic species in aquatic environments and closer inspection of Figures 2, 3, and 4 in our paper (4) shows the results for all four arsenic species and the total. In their discussion of arsenic mobility below the landfill, Bessinger et al. contradicted their own arguments. In one case, they suggest an inconsistency between the speciation of arsenic from the lysimeters (primarily as As(V)) and those observed in groundwater wells (As(III)) near C&D landfills, which represents a failure to recognize that arsenic speciation can change within the subsurface. In another case, Bessinger et al. argue that arsenic would precipitate as orpiment (As2S3), although recent studies (8) show arsenic–sulfur complexes to play a key role in arsenic mobility and toxicity in sulfate-reducing environments. The observation that sulfate-reducing conditions may increase arsenic mobility thus refutes Bessinger et al.’s assumption that arsenic will be immobilized in the subsurface as a precipitant. In summary, the underlying assumptions made by Bessinger et al. are baseless and their argument that the lysimeter study overestimates arsenic leaching is unjustifiable. Bessinger et al. make inappropriate comparisons between Nico et al. and our article (4). Moreover, Bessinger et al. failed to recognize habitual changes in arsenic speciation and its effects on arsenic mobility in the subsurface, specifically under reducing conditions below landfill (3). Of particular concern is the lack of recognition by Bessinger et al. to the vast quantities of arsenic associated with the use and disposal of treated wood. As acknowledged in their comment and as observed in our data, about 10% of the landfills in Florida are currently experiencing elevated arsenic in their groundwater wells. These impacts are surprising given the time needed for arsenic to leach from the wood, travel through the aquifer, and ultimately be detected at groundwater-monitoring wells; a leaching process that can take tens to hundreds of years and which suggest greater arsenic impacts for the future. The large quantities of arsenic associated with CCA-treated wood and the potential for arsenic-containing leachate to migrate should be accounted for in the management of this material.

Contamination of wood waste with chromated copper arsenate greatly limits recycling opportunities for the wood waste as a whole. Separation of CCA-treated wood from other wood types is one means by which such contamination can be removed. The purpose of the current study was to evaluate two detector technologies for sorting CCA-treated wood from other wood types. The detector technologies evaluated included X-ray fluorescence spectroscopy (XRF) and laser induced breakdown spectroscopy (LIBS). The XRF detector system utilized in this study was capable of rapidly detecting the presence of CCA in painted wood, wet wood, heartwood, sapwood, and at portions of the wood containing knots. Furthermore, the XRF system was capable of distinguishing between CCA-treated wood and wood treated with alternative wood treatment preservatives, but was limited by the fact that it was not designed for on-line operation so tests were conducted in a batch mode on a conveyor. The analysis time used in this study (3 s) can be decreased significantly for an XRF system designed specifically for on-line operation. The LIBS system developed for this study was found to effectively identify CCA-treated wood for pieces ranging in thickness from 1 to 8 cm. High sorting efficiencies were noted when 10 laser shots were taken on a piece of wood. Furthermore, the LIBS system was found to be effective for identifying wood that has been coated with stains and paints in addition to identifying wood that has been CCA treated. The major drawback with the LIBS system developed in this study was the limited laser pulse energy. With an increase in laser pulse energy it is anticipated that the working focal length of the LIBS system can be increased to enable the monitoring of wood samples of more variable thicknesses. Limitations associated with analysis of very rotted pieces of wood and wet wood can also be overcome by using a higher pulse energy laser. Overall, both technologies show incredible promise for sorting CCA-treated wood from other wood types. The next recommended step would be to run an improved full-scale operation at one facility to document sorting efficiencies and fine-tune the improvements proposed in the current study. Such a study could potentially open-the-door for more widespread sorting of wood waste.

Saxe et al. failed to recognize that there is a time lag with respect to disposal of treated wood and its impact on the environment. They were misleading in the references to our work and have chosen to evaluate the FDEP data set in a manner that makes it exceedingly difficult to evaluate trends. Saxe et al. also confused the issue with respect to proposed ultimate disposal recommendations within Florida. Currently the State is considering regulations that would require the disposal of arsenic-treated wood within lined landfills (FDEP, 2006) and the authors of this comment believe that such proposed regulations would help to minimize future impacts associated with the disposal of arsenic-treated wood.

This Activity uses multi-colored breakfast cereal and liquid to model the concepts of leachate and leaching from municipal solid waste disposed of in a landfill. Students create a modern landfill m...