长沙市空气自动站周边区域大气污染物排放源清单

以长沙市空气自动站周边3 km为研究对象,基于统计年鉴和实地调查,获得了该地区2015年储存运输源、废弃物处理源、工艺过程源、化石燃料固定燃烧源、农业源、生物质燃烧源、扬尘源、移动源8个源类的活动水平数据。以大气污染物排放源清单编制技术指南为依据,建立了2015年长沙市空气自动站周边3 km区域NH_3、NO_x、PM_(10)、PM_(2.5)、SO_2、VOCs等6项污染物的源排放清单。结果表明,2015年长沙空气自动站周边3 km内,8类大气污染源排放的NH_3、NO_x、PM_(2.5)、PM_(10)、SO_2、VOCs总量分别为53.65t、4 899.35t、1 846.09t、6 257.75t、989.49t、4 383.31t。NH_3、NO_x、PM_(2.5)、PM_(10)、SO_2、VOCs排放量最大的源分别是农业源、移动源、扬尘源、扬尘源、化石燃料固定燃烧源和移动源,贡献率分别为98.45%、84.24%、60.82%、85.90%、97.33%、49.88%。优化道路交通、减少燃煤、减少建筑工地扬尘排放可促进长沙市空气自动站周边空气质量改善。     

京津冀地区重点耗煤行业大气污染物排放清单研究

本研究通过京津冀地区各行业的年度煤炭消费量确定火电行业、钢铁行业和焦化行业为重点耗煤行业,以在线监测数据、污染源调查(现场调研、环评、验收)数据、排放因子数据为基础,自下而上建立了2013年京津冀地区重点耗煤行业大气污染物排放清单,分析研究了SO_2、NO_x和PM_(10)的排放量与污染贡献分布情况,掌握了京津冀地区重点耗煤行业大气污染物排放现状,为大气污染物减排提供数据基础。研究表明,2013年京津冀火电、钢铁焦化行业共排放SO_2 72.35万t、NO_x 131.99万t、PM_(10) 30.36万t。     

Temporal‐spatial variations of air pollutants in Lanzhou,Gansu Province,China, during the spring–summer periods, 2014–2016

In this article, we analyzed the mass concentrations of particulate matter 2.5 micrometers (µm) or less in size (PM_2.5), particulate matter 10 µm or less in size (PM₁₀), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), and ozone (O₃) in Lanzhou, the capital of Gansu province, China. We analyzed monitoring data collected from five air quality monitoring stations during the spring–summer period from 2014 to 2016. Our comparison of contaminant concentrations and average diurnal, daily, monthly, and annual concentrations revealed that the average concentrations of PM_2.5 and PM₁₀ amounted to 128.57 and 46.4 micrograms per cubic meters (µg/m³), respectively, exceeding the Chinese National Ambient Air Quality Standard (NAAQS). We used the Pearson correlation coefficient to establish connections between particulate matter and gaseous pollutants. The results show significant differences in the concentration levels of airborne pollutants. The Pearson correlation coefficient between PM_2.5 and PM₁₀ had the highest coefficient of r = 0.842. A correlation between the two particulate matter sizes (PM_2.5 and PM₁₀) and SO₂ was PM_2.5 and SO₂ r = 0.313; PM₁₀ and SO₂ r = 0.279; and CO and the two particulate matter sizes, PM_2.5 and CO r = 0.304; and PM₁₀ and CO r = 0.203. The average monthly ratio for the study months of PM_2.5 to PM₁₀ was 0.361. In addition, we used the hybrid single particle Lagrangian integrated trajectory model for tracking sources and pathways of the air pollutants in Lanzhou.     

《大气污染防治行动计划》实施环境效果模拟

本研究利用2010年污染源普查数据和MEIC排放清单建立全国大气污染物高时空分辨率排放清单,在此基础上利用2012年环境统计数据对其进行修订建立2012年全国大气污染物高时空分辨率排放清单;结合《大气污染防治行动计划》(以下简称《计划》)研究工作,测算了《计划》实施后在污染源综合治理、落后产能淘汰、能源结构调整方面对SO2、NOx、颗粒物、VOCs的减排量,同时对污染物新增量进行了预测,建立了《计划》实施后全国大气污染物高时空分辨率排放清单;利用CMAQ空气质量模型模拟分析了《计划》实施的空气质量改善效果。结果表明:《计划》实施后,将可以减少641万吨SO2、859万吨NOx、547万吨颗粒物(不含扬尘污染控制)、627万吨VOCs,全国、京津冀、长三角及珠三角区域PM2.5年均浓度将分别比2012年下降22.08%、33.99%、23.98%、24.04%。如果《计划》要求全部落实,可以实现空气质量改善目标。     

基于产业链分析的长三角地区CO2与大气污染物排放研究

长三角地区作为我国大气污染较为严重区域之一,如何在保持经济增长的同时减少CO₂与大气污染物的排放已成为一个重要挑战。本研究基于2007年与2012年长三角区域间投入产出表,定量分析了长三角地区省市间贸易引致的二氧化碳和大气污染物排放转移特征和变化趋势。同时,运用产业关联系数法,从前向关联与后向关联双重视角分析了长三角地区减缓CO₂和大气污染物排放的关键行业。研究结果表明,长三角的SO₂、PM_2.5排放总量表现为消费端大于生产端,CO₂、NO_x排放总量表现为生产端大于消费端。安徽省总体呈现为长三角地区贸易的SO₂、NO_x与PM_2.5排放净调出地,而上海与浙江表现为多数污染物排放净调入地。CO₂与大气污染物协同前向减排的关键行业为江苏省、浙江省和安徽省的电力、热力的生产和供应业,安徽省的煤炭开采和洗选业等,可以通过生产端技术革新和能源结构优化来促进减排;CO₂与大气污染物后向协同减排的关键行业为江苏省、浙江省和安徽省的建筑业等,对于这些行业,调整消费结构是有效的减排措施。为更好地制定长三角地区减排与污染防治政策,应当综合考虑行业减排、协同减排等,以确保经济持续增长的同时达到减排目标。     

Aerosol chemistry and the effect of aerosol water content on visibility impairment and radiative forcing in Guangzhou during the 2006 Pearl River Delta campaign

Optical and chemical aerosol measurements were obtained from 2 to 31 July 2006 at an urban site in the metropolitan area of Guangzhou (China) as part of the Program of Regional Integrated Experiment of Air Quality over Pearl River Delta (PRIDE-PRD2006) to investigate aerosol chemistry and the effect of aerosol water content on visibility impairment and radiative forcing. During the PRIDE-PRD2006 campaign, the average contributions of ammonium sulfate, organic mass by carbon (OMC), elemental carbon (EC), and sea salt (SS) to total PM_2.5 mass were measured to be 36.5%, 5.7%, 27.1%, 7.8%, and 3.7%, respectively. Compared with the clean marine period, (NH₄)₂SO₄, NH₄NO₃, and OMC were all greatly enhanced (by up to 430%) during local haze periods via the accumulation of a secondary aerosol component. The OMC dominance increased when high levels of biomass burning influenced the measurement site while (NH₄)₂SO₄ and OMC did when both biomass burning and industrial emissions influenced it. The effect of aerosol water content on the total light-extinction coefficient was estimated to be 34.2%, of which 25.8% was due to aerosol water in (NH₄)₂SO₄, 5.1% that in NH₄NO₃, and 3.3% that in SS. The average mass-scattering efficiency (MSE) of PM₁₀ particles was determined to be 2.2 ± 0.6 and 4.6 ± 1.7 m² g⁻¹ under dry (RH < 40%) and ambient conditions, respectively. The average single-scattering albedo (SSA) was 0.80 ± 0.08 and 0.90 ± 0.04 under dry and ambient conditions, respectively. Not only are the extinction and scattering coefficients greatly enhanced by aerosol water content, but MSE and SSA are also highly sensitive. It can be concluded that sulfate and carbonaceous aerosol, as well as aerosol water content, play important roles in the processes that determine visibility impairment and radiative forcing in the ambient atmosphere of the Guangzhou urban area.     

京津冀地区环境资产负债表编制研究

环境容量资产的核算是自然资源资产负债表编制中的主要组成部分。本文基于环境容量提出京津冀地区环境资产负债表编制方法,阐明该地区环境资产负债表的编制内容、核算范围以及编制路径,对2013年该地区及13个城市的环境容量资产进行核算,并编制了实物量资产负债表。在此基础上,提出了京津冀地区降低环境资产负债的政策建议,指出我国环境资产负债核算工作逐步规范化、制度化的方向。结果表明,京津冀地区大气及水环境容量均处于严重负债状态,其中,主要大气污染物SO2、NOx和PM2.5环境容量资产负债率分别为-235%、-263%和-316%,主要水污染物COD和NH3-N环境容量资产负债率分别为-414%和-850%。本文研究成果可为京津冀地区资源环境与经济发展决策提供科学基础,同时也可为其他地区开展环境资产核算研究提供参考。     

我国长江流域中三角区域大气污染物排放特征研究

中三角区域已经是我国第四个国家级城市群,也将成为我国经济增长的"第四极"。在经济发展的同时,更需要以节能减排、资源环境等为重点,以实现经济建设与生态文明"双可持续"的协同发展。本文以二氧化硫、氮氧化物、烟(粉)尘为主要大气污染物,对我国中三角区域大气污染物排放进行了详细的分析,并与京津冀、长三角、珠三角、"三区十群"等进行了多方位比较。结果表明,2013年中三角区域二氧化硫排放量为151.7万t,其中工业二氧化硫排放量为140.1万t;氮氧化物排放量为147.2万t,其中工业氮氧化物排放量为93.6万t;烟(粉)尘排放量为81.8万t,其中工业烟(粉)尘排放量为71.4万t。中三角区域二氧化硫、氮氧化物、烟(粉)尘排放量均位于"四极"的第三。中三角区域二氧化硫、氮氧化物、烟(粉)尘单位GDP排放强度分别为25.03t/亿元、24.29 t/亿元、13.50 t/亿元,分别位于"四极"的第一、第二、第二。同时,本文还从经济发展模式、产业结构调整、煤炭消费方式等方面对我国中三角等经济"四极"提出了相关建议。     

The impact of urban growth on regional air quality surrounding the Langat River Basin, Malaysia

Studies of air quality were carried out in the towns of Kajang, Nilai and Banting in the Langat River Basin, southern region of Kuala Lumpur to determine the status and trend of air quality. The determination of air quality was based on several parameters such as suspended solids with diameters less than 10???m (PM₁₀) and gaseous pollutants of sulphur dioxide (SO₂), nitrogen dioxide (NO₂), ozone (O₃), and carbon monoxide (CO). Primary concentration data of air pollutants were compiled through fieldwork studies and combined with secondary data obtained from the regular monitoring data as collected by Alam Sekitar Malaysia Sdn. Bhd. (ASMA) on behalf of Malaysian Department of Environment (DOE) at their stations in Kajang and Nilai. Results showed that the average concentrations of PM₁₀, SO₂, NO₂, O_3, and CO at all sampling stations were still below the permissible values recommended by the Malaysian DOE. The level of gaseous pollutants of NO₂, O_3, and CO was recorded at statistically higher levels (p?<?0.05) than values recorded at the control station at Pangsun Recreational Area. These pollutants were suspected to have originated mainly from exhaust systems of motor vehicles. Data for the years 1996 to 2006 as obtained from ASMA showed long-term air quality trends of increasing O₃ and NO₂ concentrations in Kajang whilst concentrations of PM₁₀ recorded at both Kajang and Nilai stations were mostly expected coming from transboundary sources especially biomass burning and the development activities around the study areas.     

城市电动汽车规模化发展的大气环境影响研究

发展电动汽车被认为是有效缓解城市交通污染的重要措施,但大规模的电动汽车发展不仅有增加电力部门排放的风险,而且可能影响电网运营的稳定性。本研究以南京市为例,综合应用充电行为模式调研、蒙特卡洛模拟、COPERT模型、排放因子法等方法,系统研究了私家车、出租车和公交车三种类型电动汽车的充电特征及其对区域交通和电力部门排放的影响。结果表明,当三种车型的电动化率分别达到50%、100%和100%时,城市的NOx、PM_(2.5)、CO、VOCs和CO_2排放量将分别比基准情景减少378t、305t、20 223t、3649t和480万t。但是,SO_2排放增加了1152t,并且导致南京市电网的夏季峰值负荷增加10%。为更好地改善中国城市环境空气质量,应综合考虑电动汽车有序充电、协同促进清洁电力等发展策略,最大限度地实现电动汽车的环境效益。     

Trace Gas Emissions from Biomass Burning from Northeast Region in India—Estimates from Satellite Remote Sensing Data and GIS

Biomass burning associated with shifting cultivation areas from the northeastern region of India is an important source of trace gas emissions in the Southeast Asian region. In the present study, satellite data pertaining to IRS-P4 OCM data and DMSP-OLS has been used to quantify the intensity, areal extent and amount of biomass burnt in the northeastern region states at district level. Trace gas emissions have been quantified both by using IPCC based emission ratios and ground based emission ratios obtained from field based studies. Areal estimates with respect to shifting cultivation areas from IRS-P4 OCM satellite data of 4th April 2000 suggested nearly 112.99 km² of the northeastern region of India affected due to shifting cultivation. In the study, DMSP OLS nighttime data has been used to capture the real time fires during the dry season. The results suggested high amount of fires during the March season when compared to April and May. Using the emission ratios obtained from the ground-based studies and IPCC emission ratios, the emissions for the individual non-CO₂ trace gases have been computed in a GIS framework using the biomass data, combustion factors and emission ratios. Results suggested emissions of 2.063 Mt CH₄, 17.94 Mt CO, 1.419 Mt N₂O, and 51.28 Mt NO _x and 2.643 Mt release of CH₄, 3.7204 Mt CO, 0.145 Mt N₂O, and 8.477 Mt NO _x , respectively, from biomass burning due to shifting cultivation for the year 2000, from the northeastern region in India. The study highlights the importance of Satellite Remote sensing data and GIS in quantifying the trace gas emissions from biomass burning.     

A Review on the Present Scenario of Air Quality Associated with Indian Mining Operations

Compositional changes to air quality from coal mining are not only the most visible impact from these activities on the environment, they can also immediately affect the health of mine professionals and adjoining populations. The presence of gases and suspended solids emitted by mining activities affects the human respiratory system and decreases production in mines. This article summarizes a case study of several Northern Coalfields Limited (NCL) coal mines with an emphasis on particulate matter (PM) to report the status of air quality connected to coal production and overburden removal. The concentrations of sulfur dioxide (SO₂), nitrogen oxides (NO_x), and suspended particulate matter (SPM) reported in the literature are also summarized in table form to allow comparisons to the permissible standards set by the Indian Central Pollution Control Board (CPCB) and other standards used around the world. An up‐to‐date status of air quality at coal mines is compared for mines located in different parts of India. Subsequently, all coal mines were divided into different classes in regard to the severity of their emissions. These classes are, in increasing order of severity, green, yellow, red, and black. SPM measurements were tabulated in regard to concentration and composition. Our article concludes with the recommendation that an environmental impact assessment (EIA) to be conducted to better characterize changes in the environment from mining emissions to develop integrated mitigation measures and to identify additional parameters to define air quality at mines.     

Impact of COVID-19 lockdown on the elemental profile of PM10 present in the ambient aerosol of an educational institute in Kolkata,India

Reduction in air pollution level was prime observation during COVID-19 lockdown globally. Here, the study was conducted to assess the impact of lockdown on the elemental profile of PM₁₀ in ambient aerosol to quantify the elemental variation. To quantify the variation, phase-wise sampling of air pollutants was carried out using the gravimetric method for PM₁₀, while NO₂ and SO₂ were estimated through the chemiluminescence and fluorescent spectrometric method respectively. The elemental constituents of PM₁₀ were carried out using an Inductively Coupled Plasma Optical Emission Spectrometer and their source apportionment was carried out using the Positive Matrix Factorization model. The results showed that PM₁₀, NO₂ and SO₂ reduced by 86.97%, 83.38%, and 88.60% respectively during the lockdown sampling phase. The highest mean elemental concentration reduction was found in Mn (97.47%) during the lockdown. The inter-correlation among the pollutants exhibited a significant association indicating that they originate from the same source. The metals like Mn and Cu were found at a higher concentration during the lockdown phase corresponding to vehicular emissions. The comparative analysis of the elemental profile of PM₁₀ concluded that the lockdown effectuated in reduction of the majority of elements present in an aerosol enveloping metropolitan like Kolkata.     

基于LMDI的长江中下游城市群污染排放强度分析

长江中下游城市群地区工业重化特征明显,工业水污染排放贡献超过10%,大气污染物占比更超过70%。本文采用迪氏对数指标分解法(LMDI)识别长江中下游城市群污染排放的主要影响因子,对长江中下游城市群重点行业COD、氨氮、SO_2、NO_x排放强度进行分析。将排放强度拆分为末端削减、技术工业和产品结构三个指标,分析2012—2020年和2020—2030年两个时间段内,对污染排放强度降低贡献度最高的影响因素。结果表明,末端削减和技术工艺对污染排放强度降低影响大,贡献值之和约为90%,两者分别代表末端处理技术对污染排放的削减程度,以及高附加值行业单位产值污染物产生水平;COD、SO_2和氨氮的排放强度由末端削减和技术工艺共同作用,NO_x的排放强度较高且未来末端削减水平进步小,未来需要重视该污染物的减排和治理。     

Effect of ceramic industrial particulate emission control on key components of ambient PM10

The relationship between specific particulate emission control and ambient levels of some PM₁₀ components (Zn, As, Pb, Cs, Tl) was evaluated. To this end, the industrial area of Castellón (Eastern Spain) was selected, where around 40% of the EU glazed ceramic tiles and a high proportion of EU ceramic frits are produced. The PM₁₀ emissions from the ceramic processes were calculated over the period 2000–2006, taking into account the degree of implementation of corrective measures throughout the study period. Abatement systems were implemented in the majority of the fusion kilns for frit manufacture in the area as a result of the application of the Directive 1996/61/EC, leading to a marked decrease in PM₁₀ emissions. By contrast, emissions from tile manufacture remained relatively constant because of the few changes in the implementation of corrective measures. On the other hand, ambient PM₁₀ levels and composition measurements were carried out from 2002 to 2006. A high correlation between PM₁₀ emissions from frit manufacture and ambient levels of Zn, As, Pb and Cs (R² from 0.61 to 0.98) was observed. On the basis of these results, the potential impact of the implementation of corrective measures to reduce emissions from tile manufacture was quantified, resulting in a possible decrease of 3–5 μg/m³ and 2 μg/m³ in ambient mineral PM₁₀ (on an annual basis) in urban and suburban areas, respectively. This relatively simple methodology allows us to estimate the direct effect of a reduction in primary particulate emissions on ambient levels of key particulate components, and to make a preliminary quantification of the possibilities of air quality improvement by means of further emission reduction. Therefore, it is a useful tool for developing future air quality plans in the study area and in other industrialised areas.     

我国大气环境管理历程与展望

随着大气环境问题从煤烟型向以PM_2.5和O₃为特征的区域复合型污染演变，我国大气污染控制模式从以污染物排放浓度控制为核心、以污染物排放总量控制为核心逐渐走向以大气环境质量改善为核心。特别是近几年，全国各地在空气质量管理、科学精准治污等领域开展一系列积极的探索与实践，取得了显著成效。本文系统回顾了近50年来我国不同阶段大气环境管理工作的特点，重点梳理了2013年《大气污染防治行动计划》实施以来，空气质量管理经验与成绩，结合减污降碳总体部署对我国2035年“美丽中国建设目标基本实现”时的空气质量进行了展望，从PM_2.5与O₃协同控制的角度出发，提出了“十四五”期间我国大气环境管理的总体思路。     

Life cycle assessment of a pulverized coal power plant with post-combustion capture, transport and storage of CO2

In this study the methodology of life cycle assessment has been used to assess the environmental impacts of three pulverized coal fired electricity supply chains with and without carbon capture and storage (CCS) on a cradle to grave basis. The chain with CCS comprises post-combustion CO₂ capture with monoethanolamine, compression, transport by pipeline and storage in a geological reservoir. The two reference chains represent sub-critical and state-of-the-art ultra supercritical pulverized coal fired electricity generation. For the three chains we have constructed a detailed greenhouse gas (GHG) balance, and disclosed environmental trade-offs and co-benefits due to CO₂ capture, transport and storage. Results show that, due to CCS, the GHG emissions per kWh are reduced substantially to 243 g/kWh. This is a reduction of 78 and 71% compared to the sub-critical and state-of-the-art power plant, respectively. The removal of CO₂ is partially offset by increased GHG emissions in up- and downstream processes, to a small extent (0.7 g/kWh) caused by the CCS infrastructure. An environmental co-benefit is expected following from the deeper reduction of hydrogen fluoride and hydrogen chloride emissions. Most notable environmental trade-offs are the increase in human toxicity, ozone layer depletion and fresh water ecotoxicity potential for which the CCS chain is outperformed by both other chains. The state-of-the-art power plant without CCS also shows a better score for the eutrophication, acidification and photochemical oxidation potential despite the deeper reduction of SO_x and NO_x in the CCS power plant. These reductions are offset by increased emissions in the life cycle due to the energy penalty and a factor five increase in NH₃ emissions.     

柳州市2009-2014年空气污染变化

近年来,城市空气污染日益严重,已成为公众广泛关注的环境问题之一。柳州是中国西部的工业重镇、广西有名的工业城市,位列国家划定的113个大气污染防治重点城市之中,是广西第一个开展PM2.5监测的城市。本研究于2009—2014年连续6年对柳州市大气主要污染物SO2、NO2、PM10和PM2.5的浓度进行在线观测,获得了污染物的长期时间和空间分布特征。结果显示,SO2浓度呈逐年下降趋势,并于2011年达标之后显著下降,2014年相比2009年下降了50.0%;NO2浓度一直在低于标准以下波动(24.6~35.1μg/m3);PM10浓度呈逐年增长趋势,并从2011年开始超标,2014年相对于2009年增长了69.3%。各污染物浓度都具有显著的季节变化:冬季秋季春季夏季。SO2、NO2、PM10和PM2.5的浓度冬季相比夏季分别提高82.9%、56.3%、66.9%和133.6%。冬季SO2和秋冬季PM10超标,PM2.5除7月外全线超标。PM2.5/PM10的比值冬季也高于夏季,表明冬季更易富集细颗粒。各污染物浓度也表现出不同的空间分布。九中各污染物的浓度都最高,可能与其离柳州钢铁公司距离较近有关。SO2除九中外,其他站点均达标。NO2全部达标。PM10市监测站和九中超标。PM2.5所有站点超标严重。本研究结果表明,柳州市煤烟型污染得到有效控制,但颗粒物污染,尤其是细颗粒物污染日益严重。     

Assessing the current practice and policy with recommendations for emission control strategy for coal‐fired thermal power plants under Indian regulatory framework emphasizing the roles of R&D

On December 7, 2015, the Ministry of Environment, Forest and Climate Change (MoEFCC), Government of India (GoI), promulgated stack emission standards for sulfur dioxide (SO₂), oxides of nitrogen (NO_x), and mercury (Hg) from coal‐fired thermal power plants (TPPs). These standards were promulgated in addition to tightening the emission standard for particulate matter. Thus far, the GoI and a non‐governmental organization (NGO) have recommended the use of limestone‐based flue‐gas desulfurization (FGD) technology for removing only SO₂ emissions, which would then require the application of additional technologies to remove the other regulated pollutants. A single technology, such as the Multi‐pollutants Control Technology (MPCT), which was recently developed elsewhere in the world and can remove all of the pollutants from the TPP, could be more economical than introducing separate technologies for the removal of each pollutant. Furthermore, unlike the limestone‐based FGD technology, which generates carbon dioxide (CO₂) during the desulfurization process, the MPCT does not increase power plant CO₂ emissions. Water consumption is also lower in MPCT than with the limestone‐based FGD technology. Thus, MPCT offers a lower carbon footprint as well as a lower water footprint than the limestone‐based FGD technology in accordance with the United Nations Environmental Programme's Sustainable Development Goals. In light of these observations, this article aims to assess current practices and policies and offers policy recommendations for Indian TPPs with the goal of providing a cogent technological solution that also strengthens the Decision Support System for the holistic protection of the Indian environment.     

Economic and Environmental Analysis of Retrofitting a Large Office Building with Energy-Efficient Lighting Systems

An evaluation of the economic and environmental costs and benefits that would result if the Zorinsky Federal Building, located in Omaha, Nebraska, USA, converted its current lighting system to a more energy-efficient system (i.e., joined the EPA's Green Lights Program) was conducted. Lighting accounts for 20–25 percent of all electricity sold in the United States. Costs considered in the study included the cost of retrofitting the building's existing lighting system and the cost of disposal of the current lamps and ballast fixtures. Benefits included a reduction of electric utility costs and a reduction of emissions of SO₂, NO _x , CO₂, and CO from electric utility power plants. Environmental and health issues for air pollutant emissions were also addressed. The results showed that significant reductions in utility bills as well as reductions in air emissions would result from a major building converting to a more energy efficient lighting system. The results showed that conversion of this large building would reduce SO₂ emissions by 14.6 tons/yr and NO _x emissions by 6.3 tons/yr. In addition, the conversion would reduce annual energy costs by approximately $114,000.