Orderly retire China's coal-fired power capacity via capacity payments to support renewable energy expansion

The energy-only-market implemented in China cannot strongly support large-scale renewable energy expansion because the renewable energy expansion may disorderly phase out non-renewable power capacity. However, non-renewable power capacity, particularly the coal-fired power capacity in China, can provide vital power system adequacy needed by renewable energy expansion. We introduce capacity payments to orderly retire current coal-fired power capacity by transforming some of it into reserve capacity in order to support renewable energy expansion. Using generation and transmission expansion results from the SWITCH-China model, this paper proposes an orderly retirement path based on the assumption of implementing capacity payments. Our results show that roughly 100–200 gigawatts (GW) of coal-fired power capacity can continue to serve through 2050, and most of it is used as reserve capacity. Capacity payments of 400–700 billion yuan are needed to achieve this retirement path, and a higher adequacy requirement needs higher payments.

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Renewable energy integration brings contradictory effects to the power system

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Decarbonization of China's power system is a multi-objective decision-making process

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Coal-fired capacity can support renewable energy expansion through capacity payments

Population ageing and deaths attributable to ambient PM2·5 pollution: a global analysis of economic cost

BACKGROUND

The health impacts of ambient air pollution impose large costs on society. Although all people are exposed to air pollution, the older population (ie, those aged ≥60 years) tends to be disproportionally affected. As a result, there is growing concern about the health impacts of air pollution as many countries undergo rapid population ageing. We investigated the spatial and temporal variation in the economic cost of deaths attributable to ambient air pollution and its interaction with population ageing from 2000 to 2016 at global and regional levels.

METHODS

In this global analysis, we developed an age-adjusted measure of the value of a statistical life-year (VSLY) to estimate the economic cost of deaths attributable to ambient PM_2·5 pollution using Global Burden of Diseases, Injuries, and Risk Factors Study 2017 data and country-level socioeconomic information. First, we estimated the global age-specific and cause-specific mortality and years of life lost (YLLs) attributable to PM_2·5 pollution using the global exposure mortality model and global estimates of exposure at 0·1° × 0·1° (about 11 km × 11 km at the equator) resolution. Second, for each year between 2000 and 2016, we translated the YLLs within each age group into a health-related cost using a country-specific, age-adjusted measure of VSLY. Third, we decomposed the major driving factors that contributed to the temporal change in health costs related to PM_2·5. Finally, we did a sensitivity test to analyse the variability of the estimated health costs to four alternative valuation measures. We identified the uncertainty intervals (UIs) from 1000 draws of the parameters and concentration-response functions by age, cause, country, and year. All economic values are reported in 2011 purchasing power parity-adjusted US dollars. All simulations were done with R, version 3.6.0.

FINDINGS

Globally, in 2016, PM_2·5 was estimated to have caused 8·42 million (95% UI 6·50-10·52) attributable deaths, which was associated with 163·68 million (116·03-219·44) YLLs. In 2016, the global economic cost of deaths attributable to ambient PM_2·5 pollution for the older population was US$2·40 trillion (1·89-2·93) accounting for 59% (59-60) of the cost for the total population ($4·09 trillion [3·19-5·05]). The economic cost per capita for the older population was $2739 (2160-3345) in 2016, which was 10 times that of the younger population (ie, those aged <60 years). By assessing the factors that contributed to economic costs, we found that increases in these factors changed the total economic cost by 77% for gross domestic product (GDP) per capita, 21% for population ageing, 16% for population growth, -41% for age-specific mortality, and -0·4% for PM_2·5 exposure.

INTERPRETATION

The economic cost of ambient PM_2·5 borne by the older population almost doubled between 2000 and 2016, driven primarily by GDP growth, population ageing, and population growth. Compared with younger people, air pollution leads to disproportionately higher health costs among older people, even after accounting for their relatively shorter life expectancy and increased disability. As the world's population is ageing, the disproportionate health cost attributable to ambient PM_2·5 pollution potentially widens the health inequities for older people. Countries with severe air pollution and rapid ageing rates need to take immediate actions to improve air quality. In addition, strategies aimed at enhancing health-care services, especially targeting the older population, could be beneficial for reducing the health costs of ambient air pollution.

FUNDING

National Natural Science Foundation of China, China Postdoctoral Science Foundation, and Qiushi Foundation.

Exploring the trade-offs between electric heating policy and carbon mitigation in China

China has enacted a series of policies since 2015 to substitute electricity for in-home combustion for rural residential heating. The Electric Heating Policy (EHP) has contributed to significant improvements in air quality, benefiting hundreds of millions of people. This shift, however, has resulted in a sharp increase in electric loads and associated carbon emissions. Here, we show that China’s EHP will greatly increase carbon emissions. We develop a theoretical model to quantify the carbon emissions from power generation and rural residential heating sectors. We found that in 2015, an additional 101.69–162.89 megatons of CO₂ could potentially be emitted if EHP was implemented in 45–55% of rural residents in Northern China. In 2020, the incremental carbon emission is expected to reach 130.03–197.87 megatons. Fortunately, the growth of carbon emission will slow down due to China’s urbanization progress. In 2030, the carbon emission increase induced by EHP will drop to 119.19–177.47 megatons. Finally, we conclude two kinds of practical pathways toward low-carbon electric heating, and provide techno-economic analyses.

China has enacted Electric Heating Policy to substitute electricity for in-home combustion for rural residential heating. Here the authors show that this shift would greatly increase national carbon emissions by 101.69–162.89 megatons in 2015 while impeding China’s carbon mitigation process in the future.

Near-real-time monitoring of global CO2 emissions reveals the effects of the COVID-19 pandemic

The COVID-19 pandemic is impacting human activities, and in turn energy use and carbon dioxide (CO2) emissions. Here we present daily estimates of country-level CO2 emissions for different sectors based on near-real-time activity data. The key result is an abrupt 8.8% decrease in global CO2 emissions (-1551 Mt CO2) in the first half of 2020 compared to the same period in 2019. The magnitude of this decrease is larger than during previous economic downturns or World War II. The timing of emissions decreases corresponds to lockdown measures in each country. By July 1st, the pandemic's effects on global emissions diminished as lockdown restrictions relaxed and some economic activities restarted, especially in China and several European countries, but substantial differences persist between countries, with continuing emission declines in the U.S. where coronavirus cases are still increasing substantially.

On-Demand Automotive Fleet Electrification Can Catalyze Global Transportation Decarbonization and Smart Urban Mobility

Mobility on-demand vehicle (MODV) services have grown explosively in recent years, threatening targets for local air pollution and global carbon emissions. Despite evidence that on-demand automotive fleets are ripe for electrification, adoption of battery electric vehicles (BEVs) in fleet applications has been hindered by lack of charging infrastructure and long charging times. Recent research on electrification programs in Chinese megacities suggests that top-down policy targets can spur investment in charging infrastructure, while intelligent charging coordination can greatly reduce requirements for battery range and infrastructure, as well as revenue losses due to time spent charging. Such capability may require labor policy reform to allow fleet operators to manage their drivers' charging behavior, along with collection and integration of several key data sets including (1) vehicle trajectories and energy consumption, (2) charging infrastructure installation costs, and (3) real-time charging station availability. In turn, digitization enabled by fleet electrification holds the potential to enable a host of smart urban mobility strategies, including integration of public transit with innovative transportation systems and emission-based pricing policies.

Mapping Opportunities for Transportation Electrification to Address Social Marginalization and Air Pollution Challenges in Greater Mexico City

Amid climate change and public health concerns, world economies are seeking to reduce the greenhouse gas emissions and local air pollution from transportation. Population growth in cities worldwide will further increase demand for clean and affordable transportation. We propose a city-specific environmental justice mapping index, inspired by a similar index used in California, that highlights promising areas for clean transportation interventions in Greater Mexico City to reduce greenhouse gas emissions and local pollution. This novel approach leverages highly spatially resolved population, pollution, and transportation data. The proposed index score is designed as an open source, updateable point of orientation for decisionmakers as they consider investment in transportation electrification from the standpoint of overlapping atmospheric pollution and social vulnerability.

Characterization of the woody biomass feedstock potential resulting from California's drought

Regional tree die-off events generate large quantities of standing dead wood, raising concern over catastrophic wildfire and other hazards. Governmental responses to tree die-off have often focused on incentivizing biomass energy production that utilizes standing dead trees removed for safety concerns. However, the full distribution of potential woody bioenergy feedstock after tree die-off has not been evaluated due to the complexities of surveying and precisely measuring large forested areas. In this paper, we present a novel method for estimating standing dead biomass at a fine spatial resolution that combines aerial survey data with forest structure maps. Using this method, we quantify biomass generated by the unprecedented tree die-off that occurred in California following a 4-year drought and widespread pest outbreaks. The results are used to estimate feasibly recoverable feedstock for energy production. We find that approximately 95.1 million bone-dry tons (BDT) of dead biomass resulted from 2012–2017 mortality, with a lower bound of 26.2 million BDT. In other words, of the aboveground live tree biomass in 2012, ~1.3–4.8% died by 2017. Of the standing dead biomass, 29% meets minimum constraints for potential cost-effective bioenergy feedstock. This proportion drops to as low as 15% in the most affected areas due to terrain slope, wilderness status, and other factors, highlighting the need to complement disposal via biomass energy with other strategies to mitigate the risks of the tree mortality crisis, which is likely to only become more severe over time due to climate change.

Europe's renewable energy directive poised to harm global forests

This comment raises concerns regarding the way in which a new European directive, aimed at reaching higher renewable energy targets, treats wood harvested directly for bioenergy use as a carbon-free fuel. The result could consume quantities of wood equal to all Europe’s wood harvests, greatly increase carbon in the air for decades, and set a dangerous global example.

Trace Metal Content of Coal Exacerbates Air-Pollution-Related Health Risks: The Case of Lignite Coal in Kosovo

More than 6600 coal-fired power plants serve an estimated five billion people globally and contribute 46% of annual CO₂ emissions. Gases and particulate matter from coal combustion are harmful to humans and often contain toxic trace metals. The decades-old Kosovo power stations, Europe's largest point source of air pollution, generate 98% of Kosovo's electricity and are due for replacement. Kosovo will rely on investment from external donors to replace these plants. Here, we examine non-CO₂ emissions and health impacts by using inductively coupled plasma mass spectrometry (ICP-MS) to analyze trace metal content in lignite coal from Obilic, Kosovo. We find significant trace metal content normalized per kWh of final electricity delivered (As (22.3 ± 1.7), Cr (44.1 ± 3.5), Hg (0.08 ± 0.010), and Ni (19.7 ± 1.7) mg/kWh_e). These metals pose health hazards that persist even with improved grid efficiency. We explore the air-pollution-related risk associated with several alternative energy development pathways. Our analysis estimates that Kosovo could avoid 2300 premature deaths by 2030 with investments in energy efficiency and solar PV backed up by natural gas. Energy policy decisions should account for all associated health risks, as should multilateral development banks before guaranteeing loans on new electricity projects.

Sustainable Low-Carbon Expansion for the Power Sector of an Emerging Economy: The Case of Kenya

Fast growing and emerging economies face the dual challenge of sustainably expanding and improving their energy supply and reliability while at the same time reducing poverty. Critical to such transformation is to provide affordable and sustainable access to electricity. We use the capacity expansion model SWITCH to explore low carbon development pathways for the Kenyan power sector under a set of plausible scenarios for fast growing economies that include uncertainty in load projections, capital costs, operational performance, and technology and environmental policies. In addition to an aggressive and needed expansion of overall supply, the Kenyan power system presents a unique transition from one basal renewable resource-hydropower-to another based on geothermal and wind power for ∼90% of total capacity. We find geothermal resource adoption is more sensitive to operational degradation than high capital costs, which suggests an emphasis on ongoing maintenance subsidies rather than upfront capital cost subsidies. We also find that a cost-effective and viable suite of solutions includes availability of storage, diesel engines, and transmission expansion to provide flexibility to enable up to 50% of wind power penetration. In an already low-carbon system, typical externality pricing for CO₂ has little to no effect on technology choice. Consequently, a "zero carbon emissions" by 2030 scenario is possible with only moderate levelized cost increases of between $3 and $7/MWh with a number of social and reliability benefits. Our results suggest that fast growing and emerging economies could benefit by incentivizing anticipated strategic transmission expansion. Existing and new diesel and natural gas capacity can play an important role to provide flexibility and meet peak demand in specific hours without a significant increase in carbon emissions, although more research is required for other pollutant's impacts.

SWITCH-China: A Systems Approach to Decarbonizing China's Power System

We present an integrated model, SWITCH-China, of the Chinese power sector with which to analyze the economic and technological implications of a medium to long-term decarbonization scenario while accounting for very-short-term renewable variability. On the basis of the model and assumptions used, we find that the announced 2030 carbon peak can be achieved with a carbon price of ∼$40/tCO2. Current trends in renewable energy price reductions alone are insufficient to replace coal; however, an 80% carbon emission reduction by 2050 is achievable in the Intergovernmental Panel on Climate Change Target Scenario with an optimal electricity mix in 2050 including nuclear (14%), wind (23%), solar (27%), hydro (6%), gas (1%), coal (3%), and carbon capture and sequestration coal energy (26%). The co-benefits of carbon-price strategy would offset 22% to 42% of the increased electricity costs if the true cost of coal and the social cost of carbon are incorporated. In such a scenario, aggressive attention to research and both technological and financial innovation mechanisms are crucial to enabling the transition at a reasonable cost, along with strong carbon policies.

Spatial distribution of U.S. household carbon footprints reveals suburbanization undermines greenhouse gas benefits of urban population density

Which municipalities and locations within the United States contribute the most to household greenhouse gas emissions, and what is the effect of population density and suburbanization on emissions? Using national household surveys, we developed econometric models of demand for energy, transportation, food, goods, and services that were used to derive average household carbon footprints (HCF) for U.S. zip codes, cities, counties, and metropolitan areas. We find consistently lower HCF in urban core cities (∼ 40 tCO2e) and higher carbon footprints in outlying suburbs (∼ 50 tCO2e), with a range from ∼ 25 to >80 tCO2e in the 50 largest metropolitan areas. Population density exhibits a weak but positive correlation with HCF until a density threshold is met, after which range, mean, and standard deviation of HCF decline. While population density contributes to relatively low HCF in the central cities of large metropolitan areas, the more extensive suburbanization in these regions contributes to an overall net increase in HCF compared to smaller metropolitan areas. Suburbs alone account for ∼ 50% of total U.S. HCF. Differences in the size, composition, and location of household carbon footprints suggest the need for tailoring of greenhouse gas mitigation efforts to different populations.

SunShot solar power reduces costs and uncertainty in future low-carbon electricity systems

The United States Department of Energy's SunShot Initiative has set cost-reduction targets of $1/watt for central-station solar technologies. We use SWITCH, a high-resolution electricity system planning model, to study the implications of achieving these targets for technology deployment and electricity costs in western North America, focusing on scenarios limiting carbon emissions to 80% below 1990 levels by 2050. We find that achieving the SunShot target for solar photovoltaics would allow this technology to provide more than a third of electric power in the region, displacing natural gas in the medium term and reducing the need for nuclear and carbon capture and sequestration (CCS) technologies, which face technological and cost uncertainties, by 2050. We demonstrate that a diverse portfolio of technological options can help integrate high levels of solar generation successfully and cost-effectively. The deployment of GW-scale storage plays a central role in facilitating solar deployment and the availability of flexible loads could increase the solar penetration level further. In the scenarios investigated, achieving the SunShot target can substantially mitigate the cost of implementing a carbon cap, decreasing power costs by up to 14% and saving up to $20 billion ($2010) annually by 2050 relative to scenarios with Reference solar costs.

Energy efficiency as a unifying principle for human, environmental, and global health

A strong analogy exists between over/under consumption of energy at the level of the human body and of the industrial metabolism of humanity. Both forms of energy consumption have profound implications for human, environmental, and global health. Globally, excessive fossil-fuel consumption, and individually, excessive food energy consumption are both responsible for a series of interrelated detrimental effects, including global warming, extreme weather conditions, damage to ecosystems, loss of biodiversity, widespread pollution, obesity, cancer, chronic respiratory disease, and other lethal chronic diseases. In contrast, data show that the efficient use of energy-in the form of food as well as fossil fuels and other resources-is vital for promoting human, environmental, and planetary health and sustainable economic development. While it is not new to highlight how efficient use of energy and food can address some of the key problems our world is facing, little research and no unifying framework exists to harmonize these concepts of sustainable system management across diverse scientific fields into a single theoretical body. Insights beyond reductionist views of efficiency are needed to encourage integrated changes in the use of the world's natural resources, with the aim of achieving a wiser use of energy, better farming systems, and healthier dietary habits. This perspective highlights a range of scientific-based opportunities for cost-effective pro-growth and pro-health policies while using less energy and natural resources.

Quantifying carbon footprint reduction opportunities for U.S. households and communities

Carbon management is of increasing interest to individuals, households, and communities. In order to effectively assess and manage their climate impacts, individuals need information on the financial and greenhouse gas benefits of effective mitigation opportunities. We use consumption-based life cycle accounting techniques to quantify the carbon footprints of typical U.S. households in 28 cities for 6 household sizes and 12 income brackets. The model includes emissions embodied in transportation, energy, water, waste, food, goods, and services. We further quantify greenhouse gas and financial savings from 13 potential mitigation actions across all household types. The model suggests that the size and composition of carbon footprints vary dramatically between geographic regions and within regions based on basic demographic characteristics. Despite these differences, large cash-positive carbon footprint reductions are evident across all household types and locations; however, realizing this potential may require tailoring policies and programs to different population segments with very different carbon footprint profiles. The results of this model have been incorporated into an open access online carbon footprint management tool designed to enable behavior change at the household level through personalized feedback.

The climate impacts of bioenergy systems depend on market and regulatory policy contexts

Biomass can help reduce greenhouse gas (GHG) emissions by displacing petroleum in the transportation sector, by displacing fossil-based electricity, and by sequestering atmospheric carbon. Which use mitigates the most emissions depends on market and regulatory contexts outside the scope of attributional life cycle assessments. We show that bioelectricity's advantage over liquid biofuels depends on the GHG intensity of the electricity displaced. Bioelectricity that displaces coal-fired electricity could reduce GHG emissions, but bioelectricity that displaces wind electricity could increase GHG emissions. The electricity displaced depends upon existing infrastructure and policies affecting the electric grid. These findings demonstrate how model assumptions about whether the vehicle fleet and bioenergy use are fixed or free parameters constrain the policy questions an analysis can inform. Our bioenergy life cycle assessment can inform questions about a bioenergy mandate's optimal allocation between liquid fuels and electricity generation, but questions about the optimal level of bioenergy use require analyses with different assumptions about fixed and free parameters.

Materials availability expands the opportunity for large-scale photovoltaics deployment

Solar photovoltaics have great promise for a low-carbon future but remain expensive relative to other technologies. Greatly increased penetration of photovoltaics into global energy markets requires an expansion in attention from designs of high-performance to those that can deliver significantly lower cost per kilowatt-hour. To evaluate a new set of technical and economic performance targets, we examine material extraction costs and supply constraints for 23 promising semiconducting materials. Twelve composite materials systems were found to have the capacity to meet or exceed the annual worldwide electricity consumption of 17,000 TWh, of which nine have the potential for a significant cost reduction over crystalline silicon. We identify a large material extraction cost (cents/watt) gap between leading thin film materials and a number of unconventional solar cell candidates including FeS2, CuO, and Zn3P2. We find that devices performing below 10% power conversion efficiencies deliverthe same lifetime energy output as those above 20% when a 3/4 material reduction is achieved. Here, we develop a roadmap emphasizing low-cost alternatives that could become a dominant new approach for photovoltaics research and deployment.

Poverty, energy, and resource use in developing countries: focus on Africa

Energy poverty affects poor communities and poor nations far more severely, and more directly, than in developed nations. Poor rural communities are particularly vulnerable, and the poor globally spend by far the largest percentage of income on energy. To make matters worse, record-high oil prices combined with sharp decline in foreign exchange earnings are key processes influencing the energy sector in Africa. These increases cause tremendous local hardships, but can be used to steer development decisions toward renewable energy technologies. At the same time, breaking up of public monopolies and liberalizing generation and distribution provides an opportunity for a new approach to rural electrification. Given the right incentives and institutional framework, a new set of players (e.g., private entrepreneurs, cooperatives, nongovernmental organizations, and communities) are likely to emerge and dominate reformed rural electricity markets in the future. Through technological and institutional "leap-frogging," Africa stands to gain significantly by augmenting current initiatives with experience and lessons recently gained in South Asia and Latin America. In these regions, a number of remarkable recent strides to seed and grow rural electricity markets while stimulating and encouraging private investments. Examples of innovative regulatory tools to address poverty include licensing, standards and guidelines, metering, tariffs, transmission charges, and performance-based contracting for energy services.

Assessment of a low-cost, point-of-use, ultraviolet water disinfection technology

We describe a point-of-use (POU) ultraviolet (UV) disinfection technology, the UV Tube, which can be made with locally available resources around the world for under $50 US. Laboratory and field studies were conducted to characterize the UV Tube's performance when treating a flowrate of 5 L/min. Based on biological assays with MS2 coliphage, the UV Tube delivered an average fluence of 900+/-80 J/m(2) (95% CI) in water with an absorption coefficient of 0.01 cm(-1). The residence time distribution in the UV Tube was characterized as plug flow with dispersion (Peclet Number = 19.7) and a mean hydraulic residence time of 36 s. Undesirable compounds were leached or produced from UV Tubes constructed with unlined ABS, PVC, or a galvanized steel liner. Lining the PVC pipe with stainless steel, however, prevented production of regulated halogenated organics. A small field study in two rural communities in Baja California Sur demonstrated that the UV Tube reduced E. coli concentrations to less than 1/100 ml in 65 out of 70 samples. Based on these results, we conclude that the UV Tube is a promising technology for treating household drinking water at the point of use.

Ethanol can contribute to energy and environmental goals

To study the potential effects of increased biofuel use, we evaluated six representative analyses of fuel ethanol. Studies that reported negative net energy incorrectly ignored coproducts and used some obsolete data. All studies indicated that current corn ethanol technologies are much less petroleum-intensive than gasoline but have greenhouse gas emissions similar to those of gasoline. However, many important environmental effects of biofuel production are poorly understood. New metrics that measure specific resource inputs are developed, but further research into environmental metrics is needed. Nonetheless, it is already clear that large-scale use of ethanol for fuel will almost certainly require cellulosic technology.

Mortality and greenhouse gas impacts of biomass and petroleum energy futures in Africa

We analyzed the mortality impacts and greenhouse gas (GHG) emissions produced by household energy use in Africa. Under a business-as-usual (BAU) scenario, household indoor air pollution will cause an estimated 9.8 million premature deaths by the year 2030. Gradual and rapid transitions to charcoal would delay 1.0 million and 2.8 million deaths, respectively; similar transitions to petroleum fuels would delay 1.3 million and 3.7 million deaths. Cumulative BAU GHG emissions will be 6.7 billion tons of carbon by 2050, which is 5.6% of Africa's total emissions. Large shifts to the use of fossil fuels would reduce GHG emissions by 1 to 10%. Charcoal-intensive future scenarios using current practices increase emissions by 140 to 190%; the increase can be reduced to 5 to 36% using currently available technologies for sustainable production or potentially reduced even more with investment in technological innovation.

A Century of Oil, a Future of Options

Energy at the Crossroads Global Perspectives and Uncertainties. By Vaclav Smil . MIT Press, Cambridge, MA, 2003. 443 pp. $34.95, £22.95. ISBN 0-262-19492-9.

Considering what is possible and what is desirable in our energy future, Smil argues that human dependence on fossil fuels must be reduced not because of impending resource shortages but because of the environmental, economic, and political problems caused by our current consumption.

Greenhouse gas implications of household energy technology in Kenya

Linkages between household energy technology, indoor air pollution, and greenhouse gas (GHG) emissions have become increasingly important in understanding the local and global environmental and health effects of domestic energy use. We report on GHG emissions from common Kenyan wood and charcoal cookstoves. Our estimations are based on 29 d of measurements under the conditions of actual use in 19 rural Kenyan households. Carbon monoxide (CO), particulate matter (PM10), combustion phase, and fuel mass were measured continuously or in short intervals in day-long monitoring sessions. Emissions of pollutants other than CO and PM10 were estimated using emissions ratios from published literature. We estimated that the daily carbon emissions from charcoal stoves (5202 +/- 2257 g of C: mean +/- SD) were lower than both traditional open fire (5990 +/- 1843 g of C) and improved ceramic woodstoves (5905 +/- 1553 g of C), but the differences were not statistically significant. However, when each pollutant was weighted using a 20-yr global warming potential, charcoal stoves emitted larger amounts of GHGs than either type of woodstove (9850 +/- 4600 g of C for charcoal as compared to 8310 +/- 2400 and 9649 +/- 2207 for open fire and ceramic woodstoves, respectively; differences not statistically significant). Non-CO2 emissions from charcoal stoves were 5549 +/- 2700 g of C in 20-yr CO2 equivalent units, while emissions were 2860 +/- 680 and 4711 +/- 919 for three-stone fires and improved ceramic stoves, respectively, with statistically significant results between charcoal and wood stoves. Therefore in a sustainable fuel-cycle (i.e., excluding CO2), charcoal stoves have larger emissions than woodstoves. When the emissions from charcoal production, measured in a previous study, were included in the assessment, the disparity between the GHG emissions from charcoal and firewood increased significantly, with non-CO2 GHG emissions factors (g of C/kg of fuel burned) for charcoal production and consumption 6-13 times higher than emissions from woodstoves. Policy implications and options for environment and public health are discussed.

The health impacts of exposure to indoor air pollution from solid fuels in developing countries: knowledge, gaps, and data needs

Globally, almost 3 billion people rely on biomass (wood, charcoal, crop residues, and dung) and coal as their primary source of domestic energy. Exposure to indoor air pollution (IAP) from the combustion of solid fuels is an important cause of morbidity and mortality in developing countries. In this paper, we review the current knowledge on the relationship between IAP exposure and disease and on interventions for reducing exposure and disease. We take an environmental health perspective and consider the details of both exposure and health effects that are needed for successful intervention strategies. We also identify knowledge gaps and detailed research questions that are essential in successful design and dissemination of preventive measures and policies. In addition to specific research recommendations, we conclude that given the interaction of housing, household energy, and day-to-day household activities in determining exposure to indoor smoke, research and development of effective interventions can benefit tremendously from integration of methods and analysis tools from a range of disciplines in the physical, social, and health sciences.

Household Energy, Indoor Air Pollution, and Health in Developing Countries: Knowledge Base for Effective Interventions

▪ Abstract  Globally, almost three billion people rely on biomass (wood, charcoal, crop residues, and dung) and coal as their primary source of domestic energy. Exposure to indoor air pollution from the combustion of solid fuels is an important cause of disease and mortality in developing countries. Despite recent advances in estimating the health impacts of indoor smoke, there are limited studies targeted toward the design and implementation of effective intervention programs. We review the current knowledge of the relationship between indoor air pollution and disease, and of the assessment of interventions for reducing exposure and disease. This review takes an environmental health perspective and considers the details of both exposure and health effects that are needed for successful intervention strategies. In particular, we summarize the emerging understanding of the central role of household energy technology and day-to-day household activities in determining exposure to indoor smoke. We also identify knowledge gaps and detailed research questions that are essential in successful design and dissemination of preventive measures and policies. In addition to specific research recommendations based on the weight of recent studies, we conclude that research and development of effective interventions can benefit tremendously from integration of methods and analysis tools from a range of disciplines—from quantitative environmental science and engineering, to toxicology and epidemiology, to the social sciences.

Worker exposure and health risks from volatile organic compounds utilized in the paint manufacturing industry of Kenya

This study provides a means for the evaluation of cleaner manufacturing and the provision of cost-effective worker health improvements in developing nations. Individual worker exposure to volatile organic compounds was measured in the paint manufacturing plants of Nairobi, Kenya. A variety of different paint production jobs were monitored, including laboratory researchers, mixers, tinters, fillers, cleaners, raw materials deliverers, and resins producers. Exposure levels were calculated based on a time-weighted average over an entire 8-10 hour workday. The paint solvents used can cause both acute and chronic health problems for the workers exposed. For example, over half of the organics monitored, i.e. benzene, styrene, and xylene, exhibit carcinogenic properties. The lifetime cancer risk from exposure to these paint solvents was estimated utilizing published cancer potencies, and the risks range from 1.90 x 10(-4) for raw materials deliverers to 2.60 x 10-2 for cleaners. The highest exposure tasks included cleaning the mixing vats and mixing the paint product, ranging from risks of 8.5 x 10(-4) to 2.6 x 10(-2), providing evidence that solvent exposure occurs due to point sources. Because of this, simple and inexpensive technologies should significantly reduce the excess exposure of workers in these manufacturing facilities. The cost of minor-innovations in the plants themselves, such as fans, drum and mixing vat covers, and respirators, could amount to as much as five times less than the estimated cost of treating workers who develop cancer due to paint solvent exposure.

Quantifying the effects of exposure to indoor air pollution from biomass combustion on acute respiratory infections in developing countries

Acute respiratory infections (ARI) are the leading cause of burden of disease worldwide and have been causally linked with exposure to pollutants from domestic biomass fuels in developing countries. We used longitudinal health data coupled with detailed monitoring and estimation of personal exposure from more than 2 years of field measurements in rural Kenya to estimate the exposure-response relationship for particulates < 10 microm diameter (PM(10)) generated from biomass combustion. Acute respiratory infections and acute lower respiratory infections are concave, increasing functions of average daily exposure to PM(10), with the rate of increase declining for exposures above approximately 1,000-2,000 microg/m(3). This first estimation of the exposure-response relationship for the high-exposure levels characteristic of developing countries has immediate and important consequences for international public health policies, energy and combustion research, and technology transfer efforts that affect more than 2 billion people worldwide.

Quantifying the effects of exposure to indoor air pollution from biomass combustion on acute respiratory infections in developing countries

Acute respiratory infections (ARI) are the leading cause of burden of disease worldwide and have been causally linked with exposure to pollutants from domestic biomass fuels in developing countries. We used longitudinal health data coupled with detailed monitoring and estimation of personal exposure from more than 2 years of field measurements in rural Kenya to estimate the exposure-response relationship for particulates < 10 microm diameter (PM(10)) generated from biomass combustion. Acute respiratory infections and acute lower respiratory infections are concave, increasing functions of average daily exposure to PM(10), with the rate of increase declining for exposures above approximately 1,000-2,000 microg/m(3). This first estimation of the exposure-response relationship for the high-exposure levels characteristic of developing countries has immediate and important consequences for international public health policies, energy and combustion research, and technology transfer efforts that affect more than 2 billion people worldwide.

The contributions of emissions and spatial microenvironments to exposure to indoor air pollution from biomass combustion in Kenya

Acute and chronic respiratory diseases, which are causally linked to exposure to indoor air pollution in developing countries, are the leading cause of global morbidity and mortality. Efforts to develop effective intervention strategies and detailed quantification of the exposure-response relationship for indoor particulate matter require accurate estimates of exposure. We used continuous monitoring of indoor air pollution and individual time-activity budget data to construct detailed profiles of exposure for 345 individuals in 55 households in rural Kenya. Data for analysis were from two hundred ten 14-hour days of continuous real-time monitoring of concentrations of particulate matter [less than/equal to] 10 microm in aerodynamic diameter and the location and activities of household members. These data were supplemented by data on the spatial dispersion of pollution and from interviews. Young and adult women had not only the highest absolute exposure to particulate matter (2, 795 and 4,898 microg/m(3) average daily exposure concentrations, respectively) but also the largest exposure relative to that of males in the same age group (2.5 and 4.8 times, respectively). Exposure during brief high-intensity emission episodes accounts for 31-61% of the total exposure of household members who take part in cooking and 0-11% for those who do not. Simple models that neglect the spatial distribution of pollution within the home, intense emission episodes, and activity patterns underestimate exposure by 3-71% for different demographic subgroups, resulting in inaccurate and biased estimations. Health and intervention impact studies should therefore consider in detail the critical role of exposure patterns, including the short periods of intense emission, to avoid spurious assessments of risks and benefits.

Underinvestment: the energy technology and R&D policy challenge

This Viewpoint examines data on international trends in energy research and development (R&D) funding, patterns of U.S. energy technology patents and R&D funding, and U.S. R&D intensities across selected sectors. The data present a disturbing picture: (i) Energy technology funding levels have declined significantly during the past two decades throughout the industrial world; (ii) U.S. R&D spending and patents, both overall and in the energy sector, have been highly correlated during the past two decades; and (iii) the R&D intensity of the U.S. energy sector is extremely low. It is argued that recent cutbacks in energy R&D are likely to reduce the capacity of the energy sector to innovate. The trends are particularly troubling given the need for increased international capacity to respond to emerging risks such as global climate change.

High lead exposures resulting from pottery production in a village in Michoacán State, Mexico

This paper reports findings from a screening study conducted to examine potential lead (Pb) exposures in residents of a Mexican village where Pb oxide continues to be used in ceramic pottery production. Extremely high Pb concentrations were measured in personal and indoor air samples, household surface dust samples, and household soil samples. Personal air Pb concentrations for workers performing pottery firing and glazing were up to 454 microg/m3. Results from indoor air samples indicate that airborne Pb concentrations were lower during nonglazing period compared to the glazing period. Soil Pb concentrations measured in 17 homes ranged from 0.39 to 19.8 mg/g. Dust Pb loading on surfaces of household items, hands, and clothes of a worker ranged from 172 to 33,060 microg/ft2. Pb content as high as 2.4 microg/g was found in a bean stew cooked in a pot made in the village. Based on these Pb concentrations measured in multiple media and data adapted for exposure contact rates, we have made rough estimates of Pb exposures via inhalation, soil/dust ingestion, and food ingestion. Estimated total daily Pb intake, on average, is 4.0 mg for adults and 3.4 mg for children living in the village. In the total daily intake, a greatest fraction may be contributed by food ingestion and another significant fraction may come from soil/dust ingestion for the children. Although the sample size is small, these measurements indicate a very significant public health problem for the village residents and a large number of other similar communities in Mexico. (It was estimated that there are approximately 1.5 million glaze potters.) The Pb exposure is implicated in a number of pervasive health problems in the region, and is the cause for national and international attention. Several recommended solutions to this problem range from personal protection and behavioral changes to introduction of alternative glazes.