湿法脱硫烟气中多形态颗粒物的测量方法及组分特征

为全面测量固定源湿法脱硫烟气中多形态颗粒物的排放浓度及其离子组成特征，提出了一种基于一级冷凝、二级过滤和一级冲击吸收的多形态烟气颗粒物的同步测量方法，外场实测了3种湿法脱硫和除尘工艺的排放水平。现场测试表明：简易湿法除尘脱硫（NaOH法）一体化装置烟气中可过滤颗粒物（FPM）浓度为（36±11）mg/m³，可逃逸颗粒物（EPM）浓度为（33±7）mg/m³；氧化镁法+布袋除尘工艺烟气中FPM浓度为（14±5）mg/m³，EPM浓度为（13±6）mg/m³；石灰石-石膏脱硫+电袋除尘工艺烟气中FPM浓度低，小于3 mg/m³，EPM浓度为（6±1）mg/m³；烟气中EPM是传统滤膜法检测FPM浓度的0.7~5.7倍，EPM的主要存在形态为冷凝液中的可溶解颗粒物（DPM），颗粒物的组分与脱硫方法密切相关，各形态颗粒物的主要组分是SO₄^2-、SO₃^2-、NO₃^-、NO₂^-、NH₄⁺、Cl^-、Na⁺、Mg²⁺和Ca²⁺等离子。     

粤北某离子吸附型稀土矿山土壤和地表水重金属分布及风险评价

对粤北某离子吸附型稀土矿24个土壤样品中的As、Cd、Cr、Cu、Mn、Ni、Pb、Zn和Hg,以及15个地表水样品中的As、Cd、Cu、Hg、Mn、Pb和Zn进行了检测,并以多元统计分析与土壤潜在生态风险指数法、地表水健康风险评价模型相结合的方式,研究了重金属的分布特征及风险水平。结果表明:在土壤中,Mn、Zn、Cd和Pb的平均含量均超过了背景值;Mn、Cr、Ni、Cu、Cd和Zn在采区有较明显集聚,As、Pb和Hg的高含量分布相对均匀;Cr、Ni、Cu和Pb含量主要受区域背景影响,Zn、As、Cd和Hg含量与矿区人类活动关系密切,Mn含量受自然和人为因素共同控制;重金属造成的土壤潜在生态风险整体处于轻微水平,Ⅱ采区和Ⅶ采区生态风险较高;Cd和Hg是造成土壤生态危害的主要重金属元素。在地表水中,Mn的平均浓度超过了《地表水环境质量标准》(GB 3838-2002)规定的限值,其余重金属的含量均满足该标准中的Ⅲ类水质要求;重金属浓度在靠近采区及位于河流中下游的位置偏高;Mn、Cd、Pb、Zn和Cu浓度受稀土开采影响较大,As、Hg浓度主要受自然因素影响;重金属产生的健康总风险(9.39×10^-7~1.01×10^-6 a^-1)低于国际辐射防护委员会推荐的参考标准(5×10^-5 a^-1),但儿童通过饮水途径受到的健康风险(1.01×10^-6 a^-1)略超过部分机构的推荐限值;Cd和As是地表水中产生健康风险的主要重金属元素。综上,研究区重金属污染风险管理的主要对象是Cd和Mn。     

上海市城镇污水处理厂氨气排放定量研究

通过对上海市3家城镇污水处理厂主要污水处理工艺臭气收集处理装置进出口有组织排放和二沉池等敞开液面无组织排放氨采样,研究污水处理厂氨气排放特征,建立污水处理厂分季节本地化氨排放系数,并计算2019年上海市城镇污水厂氨排放量。结果表明:3家污水处理厂氨排放系数平均为4.8 mg/m³,其中污水处理环节氨排放系数为3.3 mg/m³,污泥处理环节氨排放系数为1.5 mg/m³。2019年上海市城镇污水处理厂氨排放量为10.3 t。     

污染天气条件下人工降雨对成渝西南区域环境空气质量的影响评估

基于成渝地区大气污染防控形势的严峻性,选取该区域西南部的乐山市作为研究对象,对2016—2020年人工降雨对该城市环境空气质量的影响进行研究。评估发现:冬季改善效果最好,平均每毫米降雨量可降低环境空气质量指数(AQI)约10,对应的SO₂、NO₂、CO、O₃、PM₁₀、PM_2.5浓度分别降低1.8 μg/m³、3.8 μg/m³、0.1 mg/m³、8.1 μg/m³、6.9 μg/m³、8.9 μg/m³;其次是春季,每毫米降雨量可降低AQI约8,对应的6项污染物浓度分别降低1.0 μg/m³、3.3 μg/m³、0.1 mg/m³、8.1 μg/m³、6.1 μg/m³、8.4 μg/m³;再次是夏季,每毫米降雨量可降低AQI约3,对应的6项污染物浓度分别降低0.6 μg/m³、1.6 μg/m³、0.03 mg/m³、6.9 μg/m³、1.2 μg/m³、2.0 μg/m³;秋季每毫米降雨量可降低AQI约1,对应的6项污染物浓度分别降低0.4 μg/m³、0.6 μg/m³、0.01 mg/m³、3.5 μg/m³、0.1 μg/m³、0.1 μg/m³。计算不同季节降雨总量与污染物削减量之间的Pearson相关系数,结果表明,春季人工降雨总量与O₃浓度削减总量呈显著正相关,夏、秋两季人工降雨总量与PM_2.5浓度削减总量呈显著正相关。     

2012—2017年海州湾潮间带大型底栖动物群落结构及变化

为了解海州湾潮间带大型底栖动物群落结构，分析人类养殖活动对其影响，于2012-2017年对该区域大型底栖动物进行调查。结果表明：6年间共发现120种大型底栖动物，依据种类组成进行聚类分析可分为4组；调查中总平均丰度为3 495.9 ind./m²，范围为506.7~17 864.0 ind./m²；总平均生物量为197.26 g/m²，范围为1.58~489.17 g/m²。光滑河蓝蛤（Potamocorbula laevis）为第一优势种，其繁殖盛期在每年9-10月。调查期间生物多样性整体呈下降趋势，人类的养殖活动主导着海州湾潮间带大型底栖动物群落结构的变化。     

离子色谱-柱后衍生可见光检测环境空气中六价铬和废气中铬酸雾

以硫酸铵-氨水溶液为淋洗液，二苯碳酰二肼为柱后显色剂，采用离子色谱-柱后衍生可见光检测环境空气中六价铬和废气中铬酸雾的含量。通过对分析条件的优化，建立了简便、灵敏、选择性好、准确性高和重现性好的分析气体中六价铬的方法。该方法在Cr⁶⁺浓度1.00~600 μg/L之间线性良好，当采集50 L有组织废气和20 L无组织废气时，铬酸雾分析的检出限分别为2.2×10^-5和1.1×10^-5 mg/m³，采集64 m³环境空气时，Cr⁶⁺分析的检出限为7.8×10^-9 mg/m³，以浸提后的样品水溶液连续进样得到其相对标准偏差为1.42%（n=8）。利用该法进行环境空气中六价铬和废气中铬酸雾的测定，回收率在80%~105%之间。监测结果显示：环境空气中六价铬含量处于极低状态；五金厂厂界废气中铬酸雾含量极低，约为5 μg/m³；五金厂废气排气筒监测的气体中则含有较高浓度的铬酸雾，其含量已经超过GB 21900—2008中规定的排放限值。     

西沙永兴岛黑碳浓度特征初探

2012年5月6—9日利用黑碳仪获得了西沙永兴岛小时黑碳浓度数据。结果显示,西沙永兴岛黑碳小时浓度值变化范围为0.1~2.9 μg/m³,平均浓度为0.6 μg/m³,80.5%的小时浓度数据集中在0.2~0.7 μg/m³;黑碳浓度与风速、降水密切相关,风速大于2.5 m/s有利于黑碳扩散,降水对黑碳冲刷作用明显;黑碳浓度与背景区域的瓦里关黑碳浓度相近,高于背景区域的南极中山站,明显低于国内的多个城市及郊区的黑碳浓度。     

运城市区秋冬季大气PM2.5中重金属污染特征及健康风险评估

为了解山西省运城市大气细颗粒物（PM_2.5）中重金属的污染特征和来源及其健康风险,于2020年10月15日—2021年2月14日对运城市大气PM_2.5样品进行连续采集,使用微波消解-电感耦合等离子质谱法（ICP-MS）分析了样品中的铬（Cr）、锰（Mn）、镍（Ni）、铜（Cu）、锌（Zn）、砷（As）、镉（Cd）和铅（Pb）等8种重金属元素的质量浓度。结果表明,采样期间,ρ（PM_2.5）平均值为78.96μg/m³,采暖季ρ（PM_2.5）为（79.84±43.79）μg/m³,高于非采暖季（76.54±23.97）μg/m³,采暖季和非采暖季ρ（PM_2.5）均值均超过《环境空气质量标准》（GB 3095—2012）中的二级标准。富集因子法分析表明,Ni、Cu、Zn、As、Cd和Pb的富集因子均高于10,其中Cd元素的富集因子平均值达到1.089,表明受人为污染影响严重。主成分分析结果表明,运城市区秋冬季大气中重金属主要有3个来源,分别为混合燃烧源、机动车尾气源、工业排放源。健康风险评价结果显示,经手口摄入暴露强度最大,呼吸吸入暴露强度最小,皮肤接触暴露强度居中;儿童在3种暴露途径的总暴露剂量高于成人,儿童重金属暴露风险高于成人。各途径的非致癌风险强度叠加值＜1,表明非致癌风险较小;但As、Pb的非致癌风险相对较高。4种重金属的呼吸吸入途径致癌风险程度排序为：As＞Cr＞Cd＞Ni,单种重金属的致癌风险（TR）值以及重金属的总致癌风险（R）值均＜10^-6,表明本研究中重金属不具有致癌风险。     

基于在线监测的南京市PM2.5中金属元素污染特征及健康风险评估

为了探究南京市细颗粒物（PM_2.5）中金属元素的污染特征及健康风险,利用在线多金属分析仪采集并分析了2022年南京市PM_2.5中10种金属元素的质量浓度,利用正定矩阵因子分解（PMF）模型进行金属元素的来源解析,并采用健康风险评价方法对其中5种重金属元素进行健康危害评估。结果表明,10种金属元素总的年均质量浓度为941.3 ng/m³,占PM_2.5年均质量浓度的3.4%;其中,铁（Fe）、钾（K）、锌（Zn）3种金属年均质量浓度占比为91.2%。来源解析结果表明,污染物主要来源于土壤尘、燃煤、秸秆焚烧及烟花爆竹燃放、机动车尾气排放及机械磨损。健康风险评价结果表明,锰（Mn）、钒（V）、镍（Ni）、砷（As）4种重金属元素的危害商（HQ）均＜1,均不存在非致癌风险;Ni、铅（Pb）的致癌风险（ECR）均＜10^-6,风险可控;As的致癌风险介于10^-6 ~ 10^-4之间,存在一定致癌风险。     

多元线性回归方法对北京地区PM2.5预报的改进应用

利用多元线性回归方法（REG）将多模式空气质量预报系统中3个模式（CMAQ、CAMx和NAQPMS）对北京市2016年PM_2.5的预报结果和观测数据进行集合，并对集合结果进行评估。结果表明：①不同模式的预报结果不尽相同，均能够反映2016年北京地区PM_2.5随时间的变化趋势，CMAQ、CAMx和NAQPMS相关系数为0.6~0.9，标准化平均偏差为-0.6~0.6。3个模式对重污染峰值预报都存在偏差，NAQPMS预报偏差低于其他模式；②基于多元线性回归集成预报模型能显著提高日均PM_2.5预报的准确率，能较好地改进不同季节模式整体高估或者低估的系统性偏差现象，春季国控平均偏差由-23 μg/m³改善至-2.3 μg/m³，冬季平均偏差降低近20 μg/m³；③利用多元线性回归方法对2016年红色预警期间小时PM_2.5订正结果显示，相关系数提高了0.13，均方根误差降低了20~30 μg/m³，并且对峰值浓度有较好的调整，预报峰值更为接近实况峰值，特别是对北部地区的改进效果较为明显，反映了实际观测数据对空气质量数值模式预报修正的研究意义和可行性。     

Evaluation of metal contamination in sediments from north of Morocco: geochemical and statistical approaches

Concentrations of Fe, Mn, Cr, Cu, Ni, Pb, Zn, Cd and Hg were evaluated in surface sediments of two rivers from north of Morocco, known as Souani and Mghogha rivers. Significantly higher concentrations in mg kg^???1 dry weight (dw) of Mn (747.6 vs. 392.9), Cr (86.4 vs. 56.3), Zn (299.5 vs. 138.5) were found in sediment samples from Mghogha when compared with Souani river. Average concentrations of Cd and Hg in several sediment samples from both rivers were above the effect range median that predicts toxic effects to aquatic organisms. The calculation of enrichment factors showed that Mn, Cr, Cu and Ni were depleted, whereas Pb and Hg were enriched. The results of geoaccumulation index revealed that sediments of both rivers were unpolluted with most of the metals and moderately contaminated with Fe and Hg. Some of elevated concentrations of Hg, principally in Mghogha River, were due to anthropogenic sources including the direct discharges of industrial zone.     

抚顺市PM10中元素分布特征及来源分析

为了确定抚顺市PM10中元素的浓度特征及其来源,于2006—2007年的采暖季、风沙季和非采暖季在抚顺市的6个采样点采集PM10样品,并用等离子体原子发射光谱法(ICP-AES)测定样品中Ti、Al、Mn、Mg、Ca、Na、K、Cu、Zn、As、Pb、Cr、Ni、Co、Cd、Fe、V等17种元素的含量。结果表明,Al、Mg、Ca、Na、K、Mn、Fe等地壳元素在17种元素中占有较大比重,全年平均达到97.0%。富集因子分析结果表明,Cu、Zn、Pb、Cr、Co、Cd等元素在各季和各采样点明显受到人为活动影响,是典型的污染元素。主因子分析结果显示,土壤风沙尘、建筑尘、燃煤尘、道路扬尘、机动车尾气排放、金属冶炼、锰、铜、钛工业源是抚顺市PM10中元素的主要来源。     

Chemical Composition and Sources of PM10 and PM2.5 Aerosols in Guangzhou, China

Aerosol samples of PM10 and PM2.5 are collected in summertime at four monitoring sites in Guangzhou, China. The concentrations of organic and elemental carbons (OC/EC), inorganic ions, and elements in PM10 and PM2.5 are also quantified. Our study aims to: (1) characterize the particulate concentrations and associated chemical species in urban atmosphere (2) identify the potential sources and estimate their apportionment. The results show that average concentration of PM2.5 (97.54 μg m⁻³) in Guangzhou significantly exceeds the National Ambient Air Quality Standard (NAAQS) 24-h average of 65 μg m⁻³. OC, EC, Sulfate, ammonium, K, V, Ni, Cu, Zn, Pb, As, Cd and Se are mainly in PM2.5 fraction of particles, while chloride, nitrate, Na, Mg, Al, Fe, Ca, Ti and Mn are mainly in PM2.5-10 fraction. The major components such as sulfate, OC and EC account for about 70–90% of the particulate mass. Enrichment factors (EF) for elements are calculated to indicate that elements of anthropogenic origins (Zn, Pb, As, Se, V, Ni, Cu and Cd) are highly enriched with respect to crustal composition (Al, Fe, Ca, Ti and Mn). Ambient and source data are used in the multi-variable linearly regression analysis for source identification and apportionment, indicating that major sources and their apportionments of ambient particulate aerosols in Guangzhou are vehicle exhaust by 38.4% and coal combustion by 26.0%, respetively.     

Assessment of heavy metal contamination in Candarli Gulf sediment, Eastern Aegean Sea

Concentrations of selected heavy metals (Fe, Mn, Ni, Cu, Zn, Pb, Hg, Cr, Al, and As) in surface sediments from 18 stations in the Candarli Gulf were studied in order to understand current metal contamination due to urbanization and economic development in Candarli region, Turkey. The sediment samples were collected by box corer in Candarli Gulf in 2009 to assess heavy metal pollution. Heavy metal concentrations in surface sediment varied from 1.62% to 3.60% for Fe, 0.38?C2.53% for Al, 173?C1,423 for Mn, 8?C100 for Ni, 3?C46 for Cu, 55?C119 for Zn, 16?C138 for Pb, 0.2?C6.3 for Hg, 16?C71 for Cr, and 11?C37 mg kg^???1 for As. This study showed that the concentrations of Mn, Ni, Zn, Pb, Hg, and Cr in the surface sediment layers were elevated when compared with the subsurface layers. Both metal enrichment and contamination factors show that Hg, Zn, and Pb contamination exists in the entire study area and contamination of other metals is also present in some locations depending on the sources.     

Heavy metal contamination and metallothionein mRNA in blood and feathers of Black-tailed gulls (Larus crassirostris) from South Korea

The objectives of this study were to determine levels of heavy metal in the feathers and blood of Black-tailed gulls (Larus crassirostris), to evaluate metallothionein (MT) mRNA level in Black-tailed gulls on three independent islets, and to examine the correlation between heavy metal concentrations and MT mRNA expression. Eleven heavy metals (Al, Cd, Mn, Pb, Cr, Fe, Cu, Zn, Se, Hg, and As) were investigated in blood and feathers of 65 chicks from breeding colonies (Seomando, Hongdo, and Dokdo islet) of South Korea in 2010. Heavy metals were assayed by PerkinElmer NexION 300 inductively coupled plasma mass spectrometry. The mean concentrations of non-essential heavy metals were found to blood containing Cd (0.002?~?0.02 ppm), Pb (0.06?~?0.18) ppm, Hg (0.03?~?0.05) ppm, and As (0.26?~?0.48 ppm), and feather containing Cd (0.05?~?0.30 ppm), Pb (2.47?~?10.80 ppm), Hg (1.18?~?1.57 ppm), and As (0.15?~?0.44 ppm). Chicks on Seomando islet showed the highest levels of metals (Cd, Pb, Mn, Cr, Cu, and Se in blood; Al, As, Mn, Cr, Fe, Cu, and Se in feathers) among the colonies. Concentrations of Pb and Hg in feathers were the highest on Hongdo, and the levels of Cd and Zn in feathers were the highest on Dokdo islet. MT mRNA in the blood of Black-tailed gulls was relatively higher in gulls from Seomando than in gulls from Hongdo and Dokdo islet. MT mRNA level is thus positively correlated to heavy metal concentrations in Black-tailed gulls.     

Assessment of heavy metal levels in sediment samples of Kapulukaya Dam Lake (Kirikkale) and lower catchment area

In this study, the concentrations of 13 elements (Al, Fe, Mn, Cr, Ni, Zn, Co, As, Pb, Cu, Mo, Hg, and Cd) were determined in the sediments of three different sites in the Kapulukaya Dam Lake between May 2007 and November 2008. They ranged from 1.47 to 4.64 for Al, 0.92 to 3.48 for Fe (in percent), 326.60 to 1053.00 for Mn, 98.00 to 1,116.00 for Cr, 24.70 to 127.10 for Ni, 14.80 to 124.20 for Zn, 11.0 to 43.20 for Co, 5.00 to 29.30 for Cu, 9.10 to 69.70 for As, 8.60 to 34.00 for Pb, 2.50 to 5.20 for Mo, 1.00 to 1.60 for Hg, and 0.50 to1.80 for Cd in microgram per gram dry weight sediment. The contamination degree of the sediment was assessed on the basis of enrichment factor and corresponding sediment quality guideline. The calculated enrichment factors (EF, measured metal vs. background concentrations) indicated that the effect of man-made activities on the occurrence of concentrations could be accounted for the majority of heavy metals namely Mn, As, Ni, Cu, Zn, Cr, Co, Mo, and Cd, whereas such affect was not detected for Hg and Pb. The maximum values of the EF were represented by As, minimum values by Hg at all sites. Mean EF values were 36.60 and 0.70 for As and Hg, respectively. This study has clearly assessed a certain level of heavy metal pollution in the region, based particularly on the findings from sediment.     

西宁市非采暖季和采暖季PM2.5中14种金属元素特征

于2012年11月采暖季和2013年9月非采暖季,在青藏高原典型城市西宁市4个采样点采集细颗粒物(PM_(2.5))样品,共获得40个有效样品。用微波消解-ICP-MS法、原子荧光法分析了样品中14种重点防控金属。结果表明:14种重点防控金属中Ag、Tl平均质量浓度为0.10~0.50 ng/m~3,Co、Sb、Hg平均质量浓度为0.50~4.00 ng/m~3,V、Cd、Cr、Ni、Cu、As平均质量浓度为4.00~50.0 ng/m~3,Mn、Pb、Zn平均质量浓度为50.0~2 000 ng/m~3。采样期间,采暖季相比非采暖季,PM_(2.5)质量浓度有下降趋势,不同采样区金属元素浓度有增有减。富集因子分析结果表明,重点防控金属元素在非采暖季主要来源于土壤风沙扬尘、机动车尾气和工业排放,采暖季主要来源于土壤风沙扬尘、燃煤、燃油、机动车尾气和工业排放。非采暖季Zn、Ag、Cd、Hg、Tl和Pb富集因子较高,采暖季Zn、As、Ag、Cd、Sb、Hg、Tl、Pb富集因子较高,更容易受到人为源的影响。     

Spatial distribution and metal contamination in the coastal sediments of Al-Khafji area,Arabian Gulf,Saudi Arabia

To document the spatial distribution and metal contamination in the coastal sediments of the Al-Khafji area in the northern part of the Saudi Arabian Gulf, 27 samples were collected for Al, V, Cr, Mn, Cu, Zn, Cd, Pb, Hg, Sr, As, Fe, Co, and Ni analysis using inductively coupled plasma-mass spectrometer (ICP-MS). The results revealed the following descending order of the metal concentrations: Sr > Fe > Al > As > Mn > Ni > V > Zn > Cr > Cu > Pb > Co > Hg > Cd. Average levels of enrichment factor of Sr, As, Hg, Cd, Ni, V, Cu, Co, and Pb were higher than 2 (218.10, 128.50, 80.94, 41.50, 12.31, 5.66, 2.95, 2.90, and 2.85, respectively) and that means the anthropogenic sources of these metals, while Al, Zn, Cr and Mn have enrichment factor less than 2, which implies natural sources. Average values of Sr, Hg, Cd, Cr, Ni, and As in the coastal sediments of Al-Khafji area were mostly higher than the values recorded from the background shale and earth crust and from those results along coasts of the Caspian Sea and the Mediterranean Sea. The highest levels of Cu in the northern part of the studied coastline might be due to Al-Khafji desalination plant, while levels of Al, Ni, Cr, Fe, Mn, Pb, and Zn in the central part may be a result of landfilling and industrial sewage. The highest levels of As, Cd, Co, Cu, Hg, and V in the southern part seem to be due to oil pollutants from Khafji Joint Operations (KJO). The higher values of Sr in the studied sediments in general and particularly in locality 7 could relate to the hypersalinity and aragonitic composition of the scleractinian corals abundant in that area.     

Ecological risk assessment of heavy metals in surface sediments of northern littoral zone of Lake Çıldır,Ardahan, Turkey

In this paper, the heavy metal levels (Cu, Pb, Zn, Ni, Mn, Fe, As, Cd, Cr, Hg), organic carbon, and chlorophyll degradation products were studied to prove their ecological effects in Lake Ç?ld?r, where fossil fuels are used as an energy source in the studied area for most of the year, and domestic waste from settlements is discharged directly into the lake. Sediment samples were collected from six sites on the northern shore of Ç?ld?r Lake, Turkey in November 2012. Enrichment (EF) and contamination factor (CF) values were determined, and Pollution Load (PLI) and Potential Ecological Risk (PER) indices were calculated. Average concentrations of heavy metals in the sediments were, in descending order, Fe?>?Mn?>?Zn?>?Ni?>?Cr?>?Cu?>?Pb?>?As?>?Cd?>?Hg, respectively. According to mean values, the source of these elements may be considered natural due to lack of enrichment in Cu, Pb, Zn, Ni, and Cr in the sediment samples. Regarding enrichment of As, Cd, Mn, and Hg, the highest EF belongs to Hg. PLI and PER values indicate there are moderate ecological risk in the lake.     

Characterization of As and trace metals embedded in PM10 particles in Puebla City, México

Forty-eight air-filter samples (PM₁₀) were analysed to identify the concentration level of partially leached metals (PLMs; As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and V) from Puebla City, México. Samples were collected during 2008 from four monitoring sites: (1) Tecnológico (TEC), (2) Ninfas (NIN), (3) Hermanos Serdán (HS) and (4) Agua Santa (AS). The results indicate that in TEC, As (avg. 424 ng m^?3), V (avg. 19.2 ng m^?3), Fe (avg. 1,202 ng m^?3), Cu (avg. 86.6 ng m^?3), Cr (41.9 ng m^?3) and Ni (18.6 ng m^?3) are on the higher side than other populated regions around the world. The enrichment of PLMs is due to the industrial complexes generating huge dust particles involving various operations. The results are supported by the correlation of metals (Mn, Cd and Co) with Fe indicating its anthropogenic origin and likewise, As with Cd, Co, Fe, Mn, Pb and V. The separate cluster of As, Fe and Mn clearly signifies that it is due to continuous eruption of fumaroles from the active volcano Popocatépetl in the region.