Costs and Benefits of Household Fuel Policies and Alternative Strategies in the Jing-Jin-Ji Region

Air pollution is still one of the most severe problems in northern China, especially in the Jing-Jin-Ji region around Beijing. In recent years, China has implemented many stringent policies to address the air quality issue, including promoting energy transition toward cleaner fuels in residential sectors. But until 2020, even in the Jing-Jin-Ji region, nearly half of the rural households still use solid fuels for heating. For residents who are not covered by the clean heating campaign, we analyze five potential mitigation strategies and evaluate their environmental effects as well as the associated health benefits and costs. We estimate that substitution with electricity or gas would reduce air pollution and premature mortality more strongly, while the relatively low investment costs of implementing clean coal or biomass pellet lead to a larger benefit-cost ratio, indicating higher cost efficiency. Hence, clean coal or biomass pellet could be transitional substitution options for the less developed or remote areas which cannot afford a total transition toward electricity or natural gas in the short term.

Analysis of the air pollution reduction and climate change mitigation effects of the Three-Year Action Plan for Blue Skies on the "2+26" Cities in China

City clusters play an important role in air pollutant and greenhouse gas (GHG) emissions reduction in China, primarily due to their high fossil energy consumption levels. The "2 + 26" Cities, i.e., Beijing, Tianjin and 26 other perfectures in northern China, has experienced serious air pollution in recent years. We employ the Greenhouse Gas and Air Pollution Interactions and Synergies model adapted to the "2 + 26" Cities (GAINS-JJJ) to evaluate the impacts of structural adjustments in four major sectors, industry, energy, transport and land use, under the Three-Year Action Plan for Blue Skies (Three-Year Action Plan) on the emissions of both the major air pollutants and CO₂ in the "2 + 26" Cities. The results indicate that the Three-Year Action Plan applied in the "2 + 26" Cities reduces the total emissions of primary fine particulate matter with an aerodynamic diameter of ≤ 2.5 μm (PM_2.5), SO₂, NO_x, NH₃ and CO₂ by 17%, 25%, 21%, 3% and 1%, respectively, from 2017 to 2020. The emission reduction potentials vary widely across the 28 prefectures, which may be attributed to the differences in energy structure, industrial composition, and policy enforcement rate. Among the four sectors, adjustment of industrial structure attains the highest co-benefits of CO₂ reduction and air pollution control due to its high CO₂ reduction potential, while structural adjustments in energy and transport attain much lower co-benefits, despite their relatively high air pollutant emissions reductions, primarily resulting from an increase in the coal-electric load and associated carbon emissions caused by electric reform policies..

Reducing global air pollution: the scope for further policy interventions

Over the last decades, energy and pollution control policies combined with structural changes in the economy decoupled emission trends from economic growth, increasingly also in the developing world. It is found that effective implementation of the presently decided national pollution control regulations should allow further economic growth without major deterioration of ambient air quality, but will not be enough to reduce pollution levels in many world regions. A combination of ambitious policies focusing on pollution controls, energy and climate, agricultural production systems and addressing human consumption habits could drastically improve air quality throughout the world. By 2040, mean population exposure to PM2.5 from anthropogenic sources could be reduced by about 75% relative to 2015 and brought well below the WHO guideline in large areas of the world. While the implementation of the proposed technical measures is likely to be technically feasible in the future, the transformative changes of current practices will require strong political will, supported by a full appreciation of the multiple benefits. Improved air quality would avoid a large share of the current 3-9 million cases of premature deaths annually. At the same time, the measures that deliver clean air would also significantly reduce emissions of greenhouse gases and contribute to multiple UN sustainable development goals. This article is part of a discussion meeting issue 'Air quality, past present and future'.

Mitigation pathways towards national ambient air quality standards in India

Exposure to ambient particulate matter is a leading risk factor for environmental public health in India. While Indian authorities implemented several measures to reduce emissions from the power, industry and transportation sectors over the last years, such strategies appear to be insufficient to reduce the ambient fine particulate matter (PM_2.5) concentration below the Indian National Ambient Air Quality Standard (NAAQS) of 40 μg/m³ across the country. This study explores pathways towards achieving the NAAQS in India in the context of the dynamics of social and economic development. In addition, to inform action at the subnational levels in India, we estimate the exposure to ambient air pollution in the current legislations and alternative policy scenarios based on simulations with the GAINS integrated assessment model. The analysis reveals that in many of the Indian States emission sources that are outside of their immediate jurisdictions make the dominating contributions to (population-weighted) ambient pollution levels of PM_2.5. Consequently, most of the States cannot achieve significant improvements in their air quality and population exposure on their own without emission reductions in the surrounding regions, and any cost-effective strategy requires regionally coordinated approaches. Advanced technical emission control measures could provide NAAQS-compliant air quality for 60% of the Indian population. However, if combined with national sustainable development strategies, an additional 25% population will be provided with clean air, which appears to be a significant co-benefit on air quality (totaling 85%).

Air Quality Improvement Co-benefits of Low-Carbon Pathways toward Well Below the 2 °C Climate Target in China

This research links the Integrated MARKAL-EFOM system model of China (China TIMES) and the Greenhouse Gas and Air Pollution Interactions and Synergies model (GAINS) to assess the co-benefits of air quality improvement under the Nationally Determined Contribution (NDC) and the well below 2 °C (WBD2) target. Results show that the industry sector and power sector are the key sources necessary to reduce air pollutant emissions, mainly due to the phasing out of fossil fuels. The electrification in the building sector will be another main source by which to decrease PM_2.5 emissions. The adoption of various low-carbon constraints and further air pollutant control strategies will significantly alleviate the current air pollution problems in China by reducing the concentration and scope of the air pollutants and reducing the corresponding number of premature deaths. A stricter air pollutant control strategy will lead to increases in air pollutant control costs; however, the low-carbon targets will help reduce these costs in the long run. Compared to the current national policy, within the same air pollutant control strategy, the reduction of air pollutant control cost can cover the incremental CO₂ mitigation cost under the NDC target, while this cannot be realized under the WBD2 target.

Mitigation pathways of air pollution from residential emissions in the Beijing-Tianjin-Hebei region in China

Air pollution is one of the most harmful consequences of China's rapid economic development and urbanization. Particularly in the Beijing-Tianjin-Hebei (BTH) regions, particulate matter concentrations have consistently exceeded the national air quality standards. Over the last years, China implemented ambitious measures to reduce emissions from the power, industry and transportation sectors, with notable success during the 11th and 12th Five Year Plan (FYP) periods. However, such strategies appear to be insufficient to reduce the ambient PM_2.5 concentration below the National Air Quality Standard of 35 μg m^-3 across the BTH region within the next 15 years. We find that a comprehensive mitigation strategy for the residential sector in the BTH region would deliver substantial air quality benefits. Beyond the already planned expansion of district heating and natural gas distribution in urban centers and the foreseen curtailment of coal use for households, such a strategy would redirect some natural gas from power generation units towards the residential sector. Rural households would replace biomass for cooking by liquid petroleum gas (LPG) and electricity, and substitute coal for heating by briquettes. Jointly, these measures could reduce the primary PM_2.5 and SO₂ emissions by 28% and 11%, respectively, and the population-weighted PM_2.5 concentrations by 13%, i.e., from 68 μg m^-3 to 59 μg m^-3. We estimate that such a strategy would reduce premature deaths attributable to ambient and indoor air pollution by almost one third.

Applying Integrated Exposure-Response Functions to PM2.5 Pollution in India

Fine particulate matter (PM2.5, diameter ≤2.5 μm) is implicated as the most health-damaging air pollutant. Large cohort studies of chronic exposure to PM2.5 and mortality risk are largely confined to areas with low to moderate ambient PM2.5 concentrations and posit log-linear exposure-response functions. However, levels of PM2.5 in developing countries such as India are typically much higher, causing unknown health effects. Integrated exposure-response functions for high PM2.5 exposures encompassing risk estimates from ambient air, secondhand smoke, and active smoking exposures have been posited. We apply these functions to estimate the future cause-specific mortality risks associated with population-weighted ambient PM2.5 exposures in India in 2030 using Greenhouse Gas-Air Pollution Interactions and Synergies (GAINS) model projections. The loss in statistical life expectancy (SLE) is calculated based on risk estimates and baseline mortality rates. Losses in SLE are aggregated and weighted using national age-adjusted, cause-specific mortality rates. 2030 PM2.5 pollution in India reaches an annual mean of 74 μg/m³, nearly eight times the corresponding World Health Organization air quality guideline. The national average loss in SLE is 32.5 months (95% Confidence Interval (CI): 29.7⁻35.2, regional range: 8.5⁻42.0), compared to an average of 53.7 months (95% CI: 46.3⁻61.1) using methods currently applied in GAINS. Results indicate wide regional variation in health impacts, and these methods may still underestimate the total health burden caused by PM2.5 exposures due to model assumptions on minimum age thresholds of pollution effects and a limited subset of health endpoints analyzed. Application of the revised exposure-response functions suggests that the most polluted areas in India will reap major health benefits only with substantial improvements in air quality.

Assessing recovery from acidification of European surface waters in the year 2010: evaluation of projections made with the MAGIC model in 1995

In 1999 we used the MAGIC (Model of Acidification of Groundwater In Catchments) model to project acidification of acid-sensitive European surface waters in the year 2010, given implementation of the Gothenburg Protocol to the Convention on Long-Range Transboundary Air Pollution (LRTAP). A total of 202 sites in 10 regions in Europe were studied. These forecasts can now be compared with measurements for the year 2010, to give a "ground truth" evaluation of the model. The prerequisite for this test is that the actual sulfur and nitrogen deposition decreased from 1995 to 2010 by the same amount as that used to drive the model forecasts; this was largely the case for sulfur, but less so for nitrogen, and the simulated surface water [NO3(-)] reflected this difference. For most of the sites, predicted surface water recovery from acidification for the year 2010 is very close to the actual recovery observed from measured data, as recovery is predominantly driven by reductions in sulfur deposition. Overall these results show that MAGIC successfully predicts future water chemistry given known changes in acid deposition.

Dealing with fixed emissions ceilings in an uncertain future: Offsetting under environmental integrity

National emission ceilings are a policy instrument to reduce adverse environmental impacts of transboundary air pollution. Such ceilings for SO2, NOx, NH3 and VOC are established, for example, in the Gothenburg Protocol of the Convention on Long-range Transboundary Air Pollution (UNECE, 1999) and the National Emission Ceilings (NEC) Directive of the European Union (EC, 2001a, b). They prescribe for each pollutant a fixed upper limit on emissions for a specific year. Flexibility in achieving them could lower implementation costs if reality develops differently from what was foreseen during negotiations. In this paper, we explore the conditions under which emission reductions for one pollutant (e.g., SO2) could be offset by additional cuts of another pollutant (e.g., NOx) within the same country, without compromising the environmental improvements that are envisaged from the original set of emission ceilings. We employ the impact module of the GAINS (Greenhouse gas - Air pollution Interactions and Synergies) model to examine possible exchange rates across pollutants for the 2012 negotiations on the revision of the Gothenburg Protocol in Europe. Our analysis shows that exchange rates that satisfy the environmental integrity condition can be established, but that their values vary substantially across countries. Extending the environmental integrity condition to downwind countries will require significantly higher exchange rates. We discuss aspects that decision makers would need to consider before adopting an offsetting schema for future international environmental agreements.

Effects on well-being of investing in cleaner air in India

Over the past decade, India has experienced rapid economic growth along with increases in levels of air pollution. Our goal is to examine how alternative policies for air pollution abatement affect well-being there. In particular, we estimate the effects of policies to reduce the levels of ambient fine particulates (PM2.5), which are especially harmful to human health, on well-being, quantified using the United Nations' human development index (HDI). Two of the three dimensions of this index are based on gross domestic product (GDP) per capita and life expectancy. Our approach allows reductions in PM2.5 to affect both of them. In particular, economic growth is affected negatively through the costs of the additional pollution control measures and positively through the increased productivity of the population. We consider three scenarios of PM2.5 abatement, corresponding to no further control, current Indian legislation, and current European legislation. The overall effect in both control scenarios is that growth in GDP is virtually unaffected relative to the case of no further controls, life expectancy is higher, and well-being, as measured by the HDI, is improved. In India, air pollution abatement investments clearly improve well-being.

Estimating long-term population exposure to ozone in urban areas of Europe

Tropospheric ozone concentrations regarded as harmful for human health are frequently encountered in Central Europe in summertime. Although ozone formation generally results from precursors transported over long distances, in urban areas local effects, such as reactions due to nearby emission sources, play a major role in determining ozone concentrations. Europe-wide mapping and modeling of population exposure to high ozone concentrations is subject to many uncertainties, because small-scale phenomena in urban areas can significantly change ozone levels from those of the surroundings. Currently the integrated assessment modeling of European ozone control strategies is done utilizing the results of large-scale models intended for estimating the rural background ozone levels. This paper presents an initial study on how much local nitrogen oxide (NOx) concentrations can explain variations between large-scale ozone model results and urban ozone measurements, on one hand, and between urban and nearby rural measurements, on the other. The impact of urban NOx concentrations on ozone levels was derived from chemical equations describing the ozone balance. The study investigated the applicability of the method for improving the accuracy of modeled population exposure, which is needed for efficient control strategy development. The method was tested with NOx and ozone measurements from both urban and rural areas in Switzerland and with the ozone predictions of the large-scale photochemical model currently used in designing Europe-wide control strategies for ground-level ozone. The results suggest that urban NOx levels are a significant explanatory factor in differences between urban and nearby rural ozone concentrations and that the phenomenon could be satisfactorily represented with this kind of method. Further research efforts should comprise testing of the method in more locations and analyzing the performance of more widely applicable ways of deriving the initial parameters.

Purification of pro- and eukaryotic superoxide dismutases by charge-controlled hydrophobic chromatography

The process of purifying superoxide dismutases was simplified using charge-controlled hydrophobic chromatography on 10-carboxydecyl Sepharose. In only one chromatographic step following ammonium sulphate precipitation, Fe-containing superoxide dismutase from Pseudomonas putida and Cu,Zn-containing superoxide dismutase from bovine erythrocytes were purified with an overall yield of about 70% to electrophoretic homogeneity. The specific activities of the crystalline enzyme preparations were expressed in McCord and Fridovich units and were 3000 and 3200 U/mg, respectively.

Histochemically demonstrable activity of phosphate-activated glutaminase in the postnatally developing rat hippocampus

Phosphate-activated glutaminase (PAG) mediating the conversion of glutamine to glutamate and ammonia, appears to be the major glutamate metabolizing enzyme in brain. The functional relevance of PAG in postnatally maturing glutamatergic/aspartatergic structures of the rat hippocampus was studied by means of quantitative enzyme histochemistry as an alternative to immunocytochemical techniques. The calibration of the histochemical PAG reaction as well as several control experiments for specificity were carried out to ensure reliability of findings. PAG activity increased markedly during the first weeks of life with a drastic rise between postnatal days 12 and 15. On the other hand, activity of NADH diaphorase involved in the histochemical PAG assay as an auxiliary enzyme, showed a different distribution pattern as well as a different developmental sequence with high levels early in ontogenesis. The topographical and temporal parallelisms of PAG activity to several other parameters which are putatively associated with postnatally maturing glutamatergic/aspartatergic transmission processes, mutually indicate their significance in such a functional context.

[Characterization and differentiation of fluorescent pseudemonads by substrate utilization studies]

A rapid procedure is described for detecting and differentiating pseudomonads by their ability to degrade substrates with diverse physico-chemical properties, including volatile and non-volatile water-insoluble compounds, strong organic acids and bases, surfactants, disinfectants, and other toxic substances. The bacteria are embedded in an agar medium containing mineral salts and exposed to about 5 mg amounts of six to eight different substrates placed on the surface of an agar plate. After incubation at 25 degrees C for 24 hrs, growth zones around utilizable substrates may be used to differentiate various Pseudomonas strains and species.

Kinetics and reaction mechanism of yeast alcohol dehydrogenase with long-chain primary alcohols

Kinetic studies of yeast alcohol dehydrogenase with NAD+ and ethanol, hexanol or decanol as substrates invariably result in non-linear Lineweaver-Burk plots if the alcohol is the variable substrate. The kinetic coefficients determined from secondary plots are consistent with an 'equilibrium random-order' mechanism for extremely low alcohol concentrations and for all alcohols, the transformation of the ternary complexes being the rate-limiting step of the reaction. This mechanism also applies to long-chain substrates at high concentrations, whereas the rate of the ethanol-NAD+ reaction at high ethanol concentrations is determined by the dissociation of the enzyme-NADH complex. The dissociation constants for the enzyme-NAD+ complex and for the enzyme-alcohol complexes obtained from the kinetic quotients satisfactorily correspond to the dissociation constants obtained by use of other techniques. It is suggested that the non-linear curves may be attributed to a structural change in the enzyme itself, caused by the alcohol.

Separation of dehydrogenases on polyaminomethylstyrene

The binding of dehydrogenases, especially alcohol dehydrogenase, and other proteins to several ion exchangers and hydrophobic polymers was investigated. Quantitative parameters for the stability of the polymer-protein complexes (obtained form double reciprocal plots) indicate a high but different affinity of many proteins for polyaminomethylstyrene. The chromatography of a mixture of five dehydrogenases and human serum albumin on polyaminomethylstyrene is described.