Informing Methane Emissions Inventories Using Facility Aerial Measurements at Midstream Natural Gas Facilities.

Increased interest in greenhouse gas (GHG) emissions, including recent legislative action and voluntary programs, has increased attention on quantifying and ultimately reducing methane emissions from the natural gas supply chain. While inventories used for public or corporate GHG policies have traditionally utilized bottom-up (BU) methods to estimate emissions, the validity of such inventories has been questioned. Therefore, there is attention on utilizing full-facility measurements using airborne, satellite, or drone (top-down (TD)) techniques to inform, improve, or validate inventories. This study utilized full-facility estimates from two independent TD methods at 15 midstream natural gas facilities in the U.S.A., which were compared with a contemporaneous daily inventory assembled by the facility operator, employing comprehensive inventory methods. Estimates from the two TD methods statistically agreed in 2 of 28 paired measurements. Operator inventories, which included extensions to capture sources beyond regular inventory requirements and integration of local measurements, estimated significantly lower emissions than the TD estimates for 40 of 43 paired comparisons. Significant disagreement was observed at most facilities, both between the two TD methods and between the TD estimates and operator inventory. These findings have two implications. First, improving inventory estimates will require additional on-site or ground-based diagnostic screening and measurement of all sources. Second, the TD full-facility measurement methods need to undergo further testing, characterization, and potential improvement specifically tailored for complex midstream facilities.

Analysis and measurement of SOx, CO2, PM and NOx emissions in port auxiliary vessels.

The objective of this paper is to provide an estimation of air emissions (CO2, NOx, SOx and PM) released by port assistant vessels at port level. The methodology is based on the "full bottom-up" approach and starts by assessing the fuel consumed by each tug ship during its individual port exercises (movements during docking and undocking of merchant vessels). The scenario selected for the analysis and measurements is one of the most significant Port of the Mediterranean Sea, where seven auxiliary vessels were monitored for 407 calls. The analysis also gathers real-time data from the Automatic ship Identification System (AIS), tug ship particulars from IHS sea-web database ( www.maritime.ihs.com ) and emission factors established by the International Maritime Organization (IMO). The research findings show that the key indicators are inventory emissions per dock, types of towed vessels and docking and undocking manoeuvres. This paper also presents an action protocol for the assessment of the inventory of emissions produced by the main engines of tug ships operating inside ports, which can be extrapolated to other ports operating with tug ships of the same technical characteristics. Evaluating, therefore, the amounts emitted of nitrogen oxides, sulphur oxides, carbon dioxide and particulate matter.

Simplified speciation and atmospheric volatile organic compound emission rates from non-aerosol personal care products.

Volatile organic compounds (VOCs) emitted from personal care products (PCPs) can affect indoor air quality and outdoor air quality when ventilated. In this paper, we determine a set of simplified VOC species profiles and emission rates for a range of non-aerosol PCPs. These have been constructed from individual vapor analysis from 36 products available in the UK, using equilibrium headspace analysis with selected-ion flow-tube mass spectrometry (SIFT-MS). A simplified speciation profile is created based on the observations, comprising four alcohols, two cyclic volatile siloxanes, and monoterpenes (grouped as limonene). Estimates are made for individual unit-of-activity VOC emissions for dose-usage of shampoos, shower gel, conditioner, liquid foundation, and moisturizer. We use these values as inputs to the INdoor air Detailed Chemical Model (INDCM) and compare results against real-world case-study experimental data. Activity-based emissions are then scaled based on plausible usage patterns to estimate the potential scale of annual per-person emissions for each product type (eg, 2 g limonene person-1  yr-1 from shower gels). Annual emissions from non-aerosol PCPs for the UK are then calculated (decamethylcyclopentasiloxane 0.25 ktonne yr-1 and limonene 0.15 ktonne yr-1 ) and these compared with the UK National Atmospheric Emissions Inventory estimates for non-aerosol cosmetics and toiletries.

Industrial point source CO2 emission strength estimation with aircraft measurements and dispersion modelling.

CO2 remains the greenhouse gas that contributes most to anthropogenic global warming, and the evaluation of its emissions is of major interest to both research and regulatory purposes. Emission inventories generally provide quite reliable estimates of CO2 emissions. However, because of intrinsic uncertainties associated with these estimates, it is of great importance to validate emission inventories against independent estimates. This paper describes an integrated approach combining aircraft measurements and a puff dispersion modelling framework by considering a CO2 industrial point source, located in Biganos, France. CO2 density measurements were obtained by applying the mass balance method, while CO2 emission estimates were derived by implementing the CALMET/CALPUFF model chain. For the latter, three meteorological initializations were used: (i) WRF-modelled outputs initialized by ECMWF reanalyses; (ii) WRF-modelled outputs initialized by CFSR reanalyses and (iii) local in situ observations. Governmental inventorial data were used as reference for all applications. The strengths and weaknesses of the different approaches and how they affect emission estimation uncertainty were investigated. The mass balance based on aircraft measurements was quite succesful in capturing the point source emission strength (at worst with a 16% bias), while the accuracy of the dispersion modelling, markedly when using ECMWF initialization through the WRF model, was only slightly lower (estimation with an 18% bias). The analysis will help in highlighting some methodological best practices that can be used as guidelines for future experiments.

Response of trace elements in urban deposition to emissions in a northwestern river valley type city: 2010-2021.

Anthropogenic activities release significant quantities of trace elements into the atmosphere, which can infiltrate ecosystems through both wet and dry deposition, resulting in ecological harm. Although the current study focuses on the emission inventory and deposition of trace elements, their complex interactions remain insufficiently explored. In this study, we employ emission inventories and deposition data for eight TEs (Cr, Mn, Ni, Cu, Zn, As, Cd, Pb) in Lanzhou City to unveil the relationship between these two aspects. Emissions in Lanzhou can be roughly divided into two periods centered around 2017. Preceding 2017, industrial production constituted the primary source of TEs emissions except for As; coal combustion was the primary contributor to Cr, Mn, and As emissions; waste incineration played a significant role in As, Zn, and Cd emissions; biomass combustion influenced Cr and Cd emissions; and transportation sources were the predominant contributors to Pb and Cu emissions. With the establishment of waste-to-energy plants and the implementation of ultra-low emission retrofits, emissions from these sources decreased substantially after 2017. Consequently, emissions from industrial production emerged as the main source of TEs. The deposition concentrations of Cr, Mn, Ni, Cu, and Pb followed a similar trend to the emissions. However, Cd and As exhibited lower emissions and a less pronounced response relationship. Moreover, Zn concentrations fluctuated within a narrow range and showed a weaker response to emissions. The consistent changes in emissions and TEs deposition concentrations signify a shift in deposition pollution in Lanzhou city from Coal-fired pollution to that driven by transportation and industrial activities. Within this transition, the industrial production process offers significant potential for emission reduction. This insight provides a crucial foundation for managing TEs pollution and implementing strategies to prevent ecological risks.

Recent decline in carbon monoxide levels observed at an urban site in Ahmedabad, India.

Carbon monoxide (CO) is a prominent air pollutant in cities, with far-reaching implications for both local air quality and global atmospheric chemistry. The long-term change in atmospheric CO levels at a specific location is influenced by a complex interplay of local emissions, atmospheric transport, and photochemical processes, making it a subject of considerable interest. This study presents an 8-year analysis (2014-2021) of in situ CO observations using a cutting-edge laser-based analyzer at an urban site in Ahmedabad, western India. The long-term observations reveal a subtle trend in CO levels, masked by contrasting year-to-year variations, particular after 2018, across distinct diurnal time windows. Mid-afternoon (12:00-16:00 h) CO levels, reflecting background and regional conditions, remained relatively stable over the study period. In contrast, evening (18:00-21:00 h) CO levels, influenced by local emissions, exhibited substantial inter-annual variability without discernible trends from 2014 to 2018. However, post-2018, evening CO levels showed a consistent decline, predating COVID-19 lockdown measures. This decline coincided with the nationwide adoption of Bharat stage IV emission standards and other measures aimed at reducing vehicular emissions. The COVID-19 lockdown in 2020 further resulted in a noteworthy 29% reduction in evening CO levels compared to the pre-lockdown (2014-2019) period, highlighting the potential for substantial CO reduction through stringent vehicular emission controls. The observed long-term changes in CO levels do not align with the decreasing emission estimated by various inventories from 2014 to 2018, suggesting a need for improved emission statistics in Indian urban regions. This study underscores the importance of ongoing continuous CO measurements in urban areas to inform policy efforts aimed at controlling atmospheric pollutants.

Anthropogenic emission inventory and spatial analysis of greenhouse gases and primary pollutants for the Galapagos Islands.

Climate change and air pollution are critical challenges that humanity is currently facing. Understanding the sources of emissions released into the atmosphere is of great importance to evaluate the local footprint, the impacts of human activities, and the opportunities to develop and implement solutions to mitigate emissions and adapt to climate change particularly in vulnerable places like the Galapagos Islands. In this study, we present an anthropogenic emissions inventory for Santa Cruz, San Cristobal, and Isabela Islands in which emissions were spatially mapped for greenhouse gasses (GHGs) and primary pollutants (PP). Emissions were estimated for the energy stationary sources, energy mobile sources, waste, and other sectors, and emissions for 2019 were spatially distributed along with an uncertainty assessment. Results demonstrated that energy mobile sources which are aerial, terrestrial, and maritime transportation generated the most significant emissions in the Galapagos Islands in terms of PP and GHGs. In fact, maritime transportation was the highest one in 2019, at 41% of total CO2 emissions for Galapagos, with the most predominant PP being NOx and CO. The aerial transportation made up 36% of emissions, and the electricity generation contributed 15%. Emissions from waste and other sectors comprise a smaller percentage relative to the rest of the emission sectors. These results highlight the strong dependency of the islands on fossil fuels for transportation and electricity generation. Alternatives to mitigate and reduce emissions from the islands are discussed. This spatially mapped emissions inventory for the Galapagos Islands represents a powerful tool to make informed decisions to contribute to the long-term sustainability of the archipelago.

On-road vehicle emission inventory and its spatial and temporal distribution in the city of Guayaquil, Ecuador.

Emissions from mobile sources have become a major concern for health, environmental sustainability and climate change and high-resolution inventories are needed to support the design and assessment of abatement measures in urban areas. This study addresses the development of a traffic emissions inventory for Guayaquil, the second largest city in Ecuador, using the International Vehicle Emissions Model (IVE). Emissions are allocated with a spatial resolution of 1 km × 1 km and a temporal resolution of 1 h using a top-down methodology. This application combines traffic statistics already available in the city with the data from a field campaign to characterize vehicle fleet composition and activity patterns. The estimated annual emissions for the city were 237.1 kt of CO, 46.4 kt of NOx, 28.5 kt of VOC, 7.7 kt of PM10, 0.70 kt of SO2 and 4549.7 kt of CO2. 92.3 % of CO and 85.4 % of VOC were emitted by light gasoline vehicles, including private passenger vehicles and taxis, which represents 68.6 % and 8.8 %, respectively of the total fleet and contributes 52 % and 22 % of the total vehicle kilometer traveled (VKT), respectively. 48.9 % of NOx and 82 % of PM10 were emitted by the bus fleet although buses only represent 7.5 % of the total fleet and contribute 10.6 % of total VKT in the city. 41.1 % and 36.5 % of CO2 were emitted by buses and private vehicles, respectively. Even though, the average age of the fleet is below 10 years, the fleet in Guayaquil presents outdated emission standards and high emission factors. We found the higher emission rates in dense populated areas are associated to secondary roads. There is not much variability of emissions between months, but the typical daily pattern of emissions shows a peak in the morning and another in the afternoon.

Why are methane emissions from China's oil & natural gas systems still unclear? A review of current bottom-up inventories.

There is growing awareness and concern on methane (CH4) emissions from China's oil and natural gas (ONG) systems owing to the carbon neutral target. This paper aims to present a comprehensive review on the bottom-up inventories of the CH4 emissions from the perspective of the ONG systems in China. The trend and magnitude of total emissions in the last four decades were revealed and limitations of current estimations were explored. Previous studies showed that the average CH4 emissions from China's ONG systems have almost tripled from 1980 (760 Gg) to 2015 (2180 Gg) with a trend of steady increase. However, the estimated values varied by an order-of-magnitude with the largest discrepancy of 2700 Gg. This discrepancy was unlikely caused mainly by the incompleteness of estimation, since dominant emission sources were all covered by representative studies. Moreover, the differences of activity-level data were within ±10%, which ruled out the possibility that it was the main contributor to the large discrepancies. The emissions estimate has huge variation in large part because of differences in assumed emission factors (EFs) that vary by an order of magnitude. The difficulty was to determine which of the EFs were accurate due to measurement-based data availability. Thus, the large discrepancies stem from the scarcity of publicly available data, which enlarged the impact from various methods adopted by previous studies. For better understanding of CH4 emissions from the ONG systems in China, the measurements of facility-level emissions and statistics on the ONG infrastructure are required urgently. Due to the high cost and experience-oriented measurement work, international cooperation and communications are critical prerequisites for future CH4 emission estimates and effective mitigation strategies.

Emission Inventories and Particulate Matter Air Quality Modeling over the Pearl River Delta Region.

The Pearl River Delta (PRD) region is located on the southeast coast of mainland China and it is an important economic hub. The high levels of particulate matter (PM) in the atmosphere, however, and poor visibility have become a complex environmental problem for the region. Air quality modeling systems are useful to understand the temporal and spatial distribution of air pollution, making use of atmospheric emission data as inputs. Over the years, several atmospheric emission inventories have been developed for the Asia region. The main purpose of this work is to evaluate the performance of the air quality modeling system for simulating PM concentrations over the PRD using three atmospheric emission inventories (i.e., EDGAR, REAS and MIX) during a winter and a summer period. In general, there is a tendency to underestimate PM levels, but results based on the EDGAR emission inventory show slightly better accuracy. However, improvements in the spatial and temporal disaggregation of emissions are still needed to properly represent PRD air quality. This study's comparison of the three emission inventories' data, as well as their PM simulating outcomes, generates recommendations for future improvements to atmospheric emission inventories and our understanding of air pollution problems in the PRD region.

[Gridded Emission Inventories of Major Criteria Air Pollutants and Source Contributions in Lan-Bai Metropolitan Area, Northwest China].

Lan-Bai Metropolitan Area in Gansu province is an important heavy-industry base with the highest level of total air pollutant emissions in Northwest China. It is significant to study the high-resolution pollutant emission inventory to forecast regional air quality and to simulate pollutant emission reduction, as well as provide early warnings and forecasts, and to control air pollution. Taking Lanzhou and Baiyin as the main research areas, this study established the gridded emission inventories of seven major criteria air pollutants in the Lan-Bai Metropolitan Area based on emission data and statistical yearbooks of 2015-2016. The spatial pollution characteristics and emission source contributions were also studied. The results showed that the total annual emissions of seven major criteria air pollutants in the Lan-Bai Metropolitan Area were as followings:NOx 2.22×105 t, NH3 4.53×104t, VOCs 7.74×104t, CO 5.62×105 t, PM10 4.95×105 t, PM2.5 1.91×105 t, and SO2 1.37×105 t. Among them, annual CO emissions were the highest, while the annual emissions of NH3 were the lowest. The comparison of this gridded emission inventories with the Peking and Tsinghua University's MEIC inventories, found that the consistency of the three inventories for traffic source was relatively high, but for the total emissions and industrial source emissions of CO, a 30%-40% difference was found when compared with emissions in the Peking and Tsinghua University's inventories. The main differences were from the collected emission factors and the different resolution and years for collected data. The industrial non-combustion process sources, accounting for the largest proportion, were mainly concentrated in urban areas for the other six major criteria air pollutants except for NH3. The main contributing sources of NH3 were from the use of nitrogen fertilizers and livestock emissions, so its spatial pollution distribution was mainly affected by farmland distribution and other factors. It can be concluded that countermeasures, such as controlling industrial non-combustion process sources, integrating high-quality and high-efficiency power supply, using clean energy, strict dust emission control on construction sites and industrial production facilities, as well as urban greening could effectively reduce the emissions of six major criteria air pollutants including NOx, VOCs, CO, PM10, PM2.5, and SO2 in the Lan-Bai Metropolitan Area. The reduction of NH3 emission mainly depends on reducing the use of nitrogen fertilizer and controlling livestock emissions in the rural regions of Lan-Bai Metropolitan Area. This paper also used Monte Carlo uncertainty analysis to evaluate uncertainty in the gridded emission inventories, in which the maximum uncertainty was -31%-30% for NH3, the uncertainty of CO at -18%-16% was minimal. Therefore, the overall credibility was high for the established gridded emission inventories in this study.

Evaluation of comprehensive monthly-gridded methane emissions from natural and anthropogenic sources in China.

The observed atmospheric methane (CH4) concentration in China has grown rapidly in recent years, showing marked spatial-temporal variation. However, existing inventories, most of which are yearly, provincial, and incomplete, have failed to reflect the spatial variation and seasonal trends of CH4 emissions. This study aims to develop a high-resolution (0.05° × 0.05°) monthly inventory of CH4 emissions across China in 2015 from eight major natural and anthropogenic sources. The inventory evaluation of CH4 emissions was based on the gridded activity data and high spatial-temporal resolution emission factors, which were estimated by their relationship with environmental factors in most source sectors. The results showed that the annual CH4 emissions across China were 61.65 Tg, of which 85% was associated with anthropogenic emissions. Energy activities, livestock, and paddy fields were the largest contributors, accounting for 31% (19.06 Tg), 24% (15.01 Tg) and 19% (11.45 Tg) of the total emissions respectively, followed by vegetation (7%, 4.52 Tg), wetlands (7%, 4.20 Tg), wastewater (6%, 3.43 Tg), municipal solid waste, (4%, 2.59 Tg) and biomass burning (2%, 1.40 Tg). However, these proportions varied by month; paddy fields, vegetation, and wetlands emitted the most CH4 in July and August with approximately 29%, 14%, and 8% of total emissions, respectively, and least in January and December with 0%, 2%, and 2%, respectively, leading to a CH4 emissions peak in summer and a valley in winter. Moreover, the major contributing provinces of CH4 emissions in China were Inner Mongolia, Shanxi, Sichuan, Guizhou, and Hunan, accounting for 33% of China's total emissions. The dominant emission sources were energy activities in Mongolia, Shanxi, and Guizhou; livestock in Sichuan; and paddy fields in Hunan. This improved inventory of CH4 emissions can help understanding the spatial-temporal variation of CH4 concentration in the atmosphere and formulating regional-seasonal-specific emission reduction policies.

China's CH4 emissions from coal mining: A review of current bottom-up inventories.

As the world's largest CH4 emitter, China's CH4 emissions contribute to climate change more than the amount emitted by many developed countries combined. The rapid growth of China's coal demand has important implications for CH4 emissions from coal mining or coal mine methane (CMM) emissions. This paper aims to present an overview of bottom-up estimation of China's CMM emissions, including the trend in the last four decades and the limitations of current understanding on CH4 emissions. Although characterized by significant differences in inventory compilation, statistically, the total CMM emissions rose from 4.64 to 16.41 Tg with a peak of 21.48 Tg from 1980 to 2016. Large discrepancies of inventory results existed in previous studies, which were affected by the coverage of emission sources, emission factors and activity-level data. The disagreements can be largely attributable to the emission factors of underground mining, which contain substantial variances in both spatial and temporal dimensions. To develop more reliable CMM inventories and make targeted mitigation measures, more attention should be paid to the transparency of the estimated results, coal statistics, on-site CMM emission factors, and the emissions from abandoned coal mines. As the leading CH4 emission source in China, the estimations of CMM emissions urgently need to overcome existing and emerging challenges for compiling a consistent and accurate inventory.

Data-driven estimates of global nitrous oxide emissions from croplands.

Croplands are the single largest anthropogenic source of nitrous oxide (N2O) globally, yet their estimates remain difficult to verify when using Tier 1 and 3 methods of the Intergovernmental Panel on Climate Change (IPCC). Here, we re-evaluate global cropland-N2O emissions in 1961-2014, using N-rate-dependent emission factors (EFs) upscaled from 1206 field observations in 180 global distributed sites and high-resolution N inputs disaggregated from sub-national surveys covering 15593 administrative units. Our results confirm IPCC Tier 1 default EFs for upland crops in 1990-2014, but give a ∼15% lower EF in 1961-1989 and a ∼67% larger EF for paddy rice over the full period. Associated emissions (0.82 ± 0.34 Tg N yr-1) are probably one-quarter lower than IPCC Tier 1 global inventories but close to Tier 3 estimates. The use of survey-based gridded N-input data contributes 58% of this emission reduction, the rest being explained by the use of observation-based non-linear EFs. We conclude that upscaling N2O emissions from site-level observations to global croplands provides a new benchmark for constraining IPCC Tier 1 and 3 methods. The detailed spatial distribution of emission data is expected to inform advancement towards more realistic and effective mitigation pathways.

[Emission Characteristics and List of Inorganic Elements in Fine Particles of Typical Industrial Kilns in Zhengzhou City].

Samples of particulate matter from flue gas emissions of typical brick, cement, and firebrick industrial kilns in Zhengzhou City were collected by dilution channel systems. Cr, Mn, Fe, Co, Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Ni, Cu, Zn, Ga, As, Se, Sr, Cd, Sb, Sn, Ba, and Pb were analyzed. The emission factors (EFs) and emissions of inorganic elements of PM2.5 from kilns flue gases of three industries in Zhengzhou City during 2016 were calculated. A grid list of 1 km×1 km was also established. The results show that the highest concentration of total inorganic elements was in the firebrick industry, corresponding to(609.97±490.97) µg·m-3. The concentration of inorganic elements in the three industries accounted for 34%-54%, 27%-42%, and 23%-53% of PM2.5. The inorganic elements emitted from industrial kilns in brick and cement industries were mainly crust elements, and the highest concentration elements were Cl and Al. The inorganic elements emitted by industrial furnaces in the firebrick industry were mainly heavy metals, and the highest concentration element was Pb. The coefficient of divergence (CD) of inorganic elements in brick and cement industry was 0.389, that is slightly different. The CD between cement and refractory industry was 0.732, which represents a significant difference between inorganic element emissions. In 2016, the emissions of Pb, S, Zn, Cl, K, As, Fe, Si, Cr, Al, Na, and Ca in PM2.5 from major industrial furnaces in Zhengzhou City were 919.0, 793.1, 124.7, 378.6, 82.6, 12.2, 60.4, 145.4, 7.4, 86.6, 15.8, and 111.4 kg·a-1, respectively. Heavy metal emission in the Xinmi area was the highest, representing a high health risk.

Characterizing emission rates of regulated pollutants from model year 2012+ heavy-duty diesel vehicles equipped with DPF and SCR systems.

The regulated emissions of five 2012 and newer, low-mileage, heavy-duty Class 8 diesel trucks equipped with diesel particulate filters (DPFs) and selective catalytic reduction (SCR) systems were evaluated over test cycles representing urban, highway, and stop-and-go driving on a chassis dynamometer. NOx emissions over the Urban Dynamometer Driving Schedule (UDDS) ranged from 0.495 to 1.363g/mi (0.136 to 0.387g/bhp-hr) for four of the normal emitting trucks. For those trucks, NOx emissions were lowest over the cruise (0.068 to 0.471g/mi) and high-speed cruise (0.067 to 0.249g/mi) cycles, and highest for the creep cycle (2.131 to 9.468g/mi). A fifth truck showed an anomaly in that it had never regenerated throughout its relatively short operating lifetime due to its unusual, unladed service history. This truck exhibited NOx emissions of 3.519g/mi initially over the UDDS, with UDDS NOx emissions decreasing to 0.39g/mi after a series of parked regenerations. PM, THC, and CO emissions were found to be very low for most of the testing conditions, due to the presence of the DPF/SCR aftertreatment system, and were comparable to background levels in some cases.

Intercomparison of methods to estimate black carbon emissions from cookstoves.

Black carbon is the second largest contributor to climate change and also poses risks to human health. Despite the need for black carbon (BC) emissions estimates from residential biomass burning for cooking, quantitative data are still scarce. This scarcity is mainly due to the scattered location of the stoves, as well as relatively costly and complex analytical methods available. Two low cost and easy-to-use optical methods, a cell-phone based system and smoke stain reflectometry, where compared to elemental carbon (EC) concentrations by the Sunset OCEC Analyzer (TOT). The three techniques were challenged with different aerosol types (urban and biomass cookstoves), and different filter substrates (quartz and glass fibre). A good agreement was observed between the two low cost techniques and the reference system for the aerosol types and concentrations assessed, although the relationship was statistically different for each type of aerosol. The quantification of correction factors with respect to the reference method for the specific conditions under study is essential with either of the low-cost techniques. BC measurements from the cell-phone system and the reflectometer were moderately affected by the filter substrate. The easy use of the cell-phone based system may allow engaging cookstove users in the data collection process, increasing the amount and frequency of data collection which may, otherwise, not be feasible in resourced constrained locations. This would help to raise public awareness about environmental and health issues related to cookstoves.

A novel approach to screen and compare emission inventories.

A methodology is proposed to support the evaluation and comparison of different types of emission inventories. The strengths and weaknesses of the methodology are presented and discussed based on an example. The approach results in a "diamond" diagram useful to flag out anomalous behaviors in the emission inventories and to get insight in possible explanations. In particular, the "diamond" diagram is shown to provide meaningful information in terms of: discrepancies between the total emissions reported by macro-sector and pollutant, contribution of each macro-sector to the total amount of emissions released by pollutant, and the identification and quantification of the different factors causing the discrepancies between total emissions. A practical example in Barcelona is used for testing and to provide relevant information for the analyzed emission datasets. The tests show the capability of the proposed methodology to flag inconsistencies in the existing inventories. The proposed methodology system may be useful for regional and urban inventory developers as an initial evaluation of the consistency of their inventories.

[Emission Inventory of Anthropogenic VOCs and Its Contribution to Ozone Formation in Shanxi Province].

Based on the activity levels, emission factors and composition characteristics of VOCs, which was obtained in statistic data and references, the emission amount of anthropogenic VOCs in Shanxi province in 2013 was calculated, and the ozone formation potential of VOCs was studied in this study. The results showed that the emission amount of anthropogenic VOCs in Shanxi province in 2013 was 723700 t, with the major sector of the industrial emission and vehicle emission, accounting for 36.47% and 24.28% of total emission amount, respectively. Coke and chemicals production, the major emission source of VOCs in industrial emission, emitting 190600 t and 38800 t VOCs in 2013, accounting for 72.22% and 14.72% of industrial emission, respectively. The emission amount of ozone precursor VOCs was 435900 t, and the total amount of ozone formation potential in Shanxi province in 2013 was 1769900 t. The sources of the greatest contribution to total ozone were vehicle emission, combustion sources and industrial emission. The results indicated that industrial emission was the major source of VOCs emission, which showed the simplification and heavy industrial structure. The increasing numbers of vehicles led to the huge emission of VOCs in recent years. In conclusion, the main measure of controlling the ozone pollution caused by VOCs emissions was controlling the VOCs emission from industrial emission and vehicle emission.

A preliminary compilation and evaluation of a comprehensive emission inventory for polychlorinated biphenyls in China.

Emission inventories for polychlorinated biphenyls (PCBs) are crucial input data for atmospheric transport modeling and for the study of source-receptor relationships and the environmental behavior of these chemicals. Three types of primary PCB sources are considered in this study: intentionally produced PCBs (IP-PCBs), unintentionally produced PCBs (UP-PCBs), and PCB emissions from two e-waste sites (EW-PCBs). This study presents the historical emissions of all IP-, UP- and EW-PCBs into the air in China and the gridded Chinese emission inventories at a resolution of 1/6° latitude×1/4° longitude from 1950 to 2010. The UP-TPCB emissions from 1950 to 2010 were re-estimated to be 8.56t from eight emission sources comprising 96.3% of the Chinese UP-TPCB emissions. The EW-TPCB emissions from 1990 to 2010 were estimated to be 103.5 t, of which 7.1t and 12.3t were EW-PCB28 and EW-7PCB congeners (i.e., indicator-PCB28, 52, 101, 118, 138, 153, 180), respectively. The IP-PCB28 and IP-7PCB congener emissions from 1965 to 2010 were estimated to be 57.4 t and 130.1t, respectively. A significant correlation was found between congener PCB28 and 7PCBs (R(2)=0.988 and P=0.000), which suggests that PCB28 is a good marker congener for describing the emission trends of all 7PCB emission sources. The gridded emission data were compared with published measured atmospheric concentrations for 2004 and 2008, and a significant correlation was found between the modeled emissions and monitoring data. To our knowledge, this study presents the first comprehensive gridded emission inventories that include all IP-, UP-, and EW-PCBs on a national scale.