4种天然温石棉致大鼠肺损伤及对HO-1和HSP-70的影响

探讨了我国四大矿区天然温石棉致大鼠肺部损伤作用及肺组织中HO-1和HSP-70的表达差异。从我国四大天然矿区采集4种天然温石棉,用扫描电镜、红外光谱和X射线荧光光谱分析其粉尘形貌、表面活性基团和化学组分。将90只初断乳SPF级Wistar大鼠,随机分为5组(甘肃阿克塞、青海茫崖、四川新康、陕西陕南温石棉组和生理氯化钠溶液阴性对照组),用2. 0 mg/m L温石棉粉尘悬液0. 5 m L(1次/月)对大鼠非暴露式气管内滴注染毒。于1、6、12个月分批处死大鼠6只,测定支气管肺泡灌洗液(BALF)中的乳酸脱氢酶(LDH)、碱性磷酸酶(AKP)和总蛋白(TP)含量,采用qRT-PCR检测肺组织中血红素氧化合酶1(HO-1)和热休克蛋白70(HSP-70) mRNA表达水平,采用western blot检测肺组织中HO-1和HSP-70蛋白表达水平。结果显示,阿克塞、茫崖和新康温石棉组LDH及各温石棉组AKP和TP在各时间点均比阴性对照组高(P 0. 05),且随染毒时间延长呈上升趋势(P 0. 05)。染毒1月时,各染毒组HO-1、HSP-70 mRNA和HO-1、HSP-70蛋白表达量比阴性对照组高(P 0. 05);染毒6月时,各染毒组比阴性对照组高,阿克塞和陕南温石棉组低于茫崖和新康温石棉组(P 0. 05);染毒12月时,阿克塞和陕南温石棉组高于茫崖和新康温石棉组(P 0. 05),茫崖和新康温石棉组低于阴性对照组。     

基于多次非暴露式气管滴注的染毒法研究温石棉致大鼠肺损伤的作用

温石棉是一种安全性存在争议的石棉,合理可行并且能够真实反映其暴露致病过程的染毒方法对深入研究其致病机理有着重要意义。本文采用多次非暴露式气管滴注的染毒方法对雄性Wistar大鼠分别进行不同浓度温石棉悬液的染毒,在染毒1、3和6个月后记录体重和肺脏器系数,观察肺组织大体及苏木素-伊红(HE)染色的病理形态,对支气管肺泡灌洗液(BALF)中白细胞总数进行分类计数,并测定总蛋白(TP)、乳酸脱氢酶(LDH)、酸性磷酸酶(ACP)和碱性磷酸酶(AKP)的含量。结果表明,多次滴注的方式大鼠死亡率较低,并且每次滴注后能够苏醒的大鼠没有死亡发生;随着四川新康温石棉染毒时间的延长和染毒剂量增加,大鼠体重增长缓慢,肺脏器系数升高,肺大体出现水肿、肉芽肿、萎缩实质化,HE染色观察则表现为炎性细胞增多、肺泡结构遭到破坏以及出现纤维化;随着染毒时间的延长,支气管肺泡灌洗液(BALF)中的白细胞总数、中性粒细胞和淋巴细胞百分比呈上升趋势,巨噬细胞百分比呈下降趋势,TP、LDH、ACP和AKP均表现为上升的趋势,并呈现一定的剂量-效应关系。综上所述,多次非暴露式气管滴注方法可用于模拟温石棉慢性暴露的致病过程,四川新康温石棉可以通过破坏巨噬细胞、肺泡上皮细胞及肺泡上皮-毛细血管屏障造成大鼠的肺损伤。     

温石棉和陶瓷纤维致大鼠炎症及氧化应激的毒性效应

探讨了温石棉和陶瓷纤维致Wistar大鼠肺部炎症反应和氧化应激的毒性效应。将54只初断乳Wistar大鼠随机分为3组,即温石棉染毒组、陶瓷纤维染毒组和阴性对照组。采用非暴露式气管内滴注进行染毒(2. 0 mg/m L,1次/月),并于1、6、12个月分批处死6只,观察肺组织病理学改变以及支气管肺泡灌洗液(BALF)和肺组织相关指标。结果显示,染毒组均出现不同程度的病理改变,其BALF中白细胞总数在染毒各时间点均高于阴性对照组(p 0.05);染毒组白细胞总数、中性粒细胞和淋巴细胞的百分比随染毒时间延长而升高(p 0. 05),巨噬细胞百分比则下降(p 0. 05);染毒组肺组织中IL-6、TNF-α、NF-κB含量在染毒各时间点均高于阴性对照组并随染毒时间延长而升高(p 0. 05),且温石棉组高于陶瓷纤维组(p 0. 05);染毒组肺组织中ROS、MDA浓度在染毒各时间点均高于阴性对照组并随染毒时间延长而升高(p 0. 05),且温石棉组高于陶瓷纤维组(p 0. 05);染毒组SOD活力均随染毒时间延长而下降(p 0. 05),染毒一个月时与阴性对照组比较无差异(p 0. 05),染毒6个月和12个月时温石棉组低于陶瓷纤维组且均低于阴性对照组(p 0. 05)。综上,温石棉和陶瓷纤维均能对大鼠肺组织造成毒性作用,可引起炎症反应和氧化应激;温石棉致大鼠肺毒性的能力较陶瓷纤维强。     

PM2.5降尘对A549细胞线粒体氧化损伤的影响

将不同浓度PM_(2.5)降尘作用于A549细胞后,利用MTT法检测其存活率,W-G染色观察细胞形态,荧光探针法检测细胞ROS和MMP相对水平,以探讨PM_(2.5)降尘对A549细胞线粒体氧化损伤的影响及作用机制。结果显示,经12. 5μg/m L的PM_(2.5)降尘作用A549细胞3 h后,细胞存活率为(81. 77±6. 15)%,并随作用浓度及时间增加呈递减趋势。PM_(2.5)染毒后可观察到细胞形态不规则,胞膜溶解破坏,细胞微核出现。PM_(2.5)降尘作用于细胞24 h后,胞内ROS相对含量随暴露浓度增加呈递增趋势,细胞MMP相对水平随染毒浓度增加而降低,且胞内ROS和MMP两者间存在显著相关关系(R2=0. 878)。提示PM_(2.5)降尘处理A549细胞后可通过刺激ROS的产生,诱导细胞MMP下降,造成细胞线粒体氧化损伤。     

PM_(2.5)降尘诱导A549细胞G2/M期阻滞的机制研究

PM_(2.5)降尘作用于A549细胞后,MTT法检测细胞存活率,扫描电镜观察细胞形态,流式细胞术检测细胞周期改变,RT-PCR检测周期阻滞相关基因p53、p21、CDK1、c-myc和lncRNA H19的表达水平,Western-blot检测周期蛋白cyclin B1表达。通过转染H19 siRNA干扰H19的表达,RT-PCR检测其对p53、c-myc及CDK1表达的影响,以探讨PM2.5降尘诱导A549细胞周期阻滞的作用机制。结果显示,PM2.5降尘暴露可降低A549细胞存活率,随作用浓度及时间增加呈递减趋势,并可观察到细胞形态破坏,细胞膜表面吸附聚集大量粉尘颗粒。PM2.5作用于细胞24 h后,A549细胞增殖阻滞在G2/M期,周期阻滞相关基因p53、p21及H19表达增加,CDK1及cyclin B1表达降低。此外,转染H19 siRNA后成功干扰H19的表达,并调控CDK1表达进一步降低。综合以上结果,PM2.5降尘处理A549细胞后可通过激活p53及p21活性,抑制CDK1和cyclin B1表达水平,诱导G2/M期阻滞从而抑制细胞增殖。短期暴露于PM2.5后,lncRNA H19在染毒细胞中可能发挥特异性癌基因的作用,通过与p53及c-myc结合参与调控细胞周期,干扰H19低表达使细胞G2/M期阻滞更加明显。     

兰州市城关区采暖期大气PM2.5成份分析及对子代小鼠的影响研究

为了解兰州市采暖期大气PM_2.5污染情况及其主要重金属和多环芳烃（PAHs）含量,并同时研究其对小鼠胎儿出生质量的影响,对兰州市城关区2015年11月至2016年3月大气PM_2.5进行重金属元素和PAHs的成份分析,同时将处理好的PM_2.5通过气管滴注对30只成功受孕10d的昆明小鼠（随机分成4个剂量组,每组6只）进行染毒（PM_2.5剂量：0、50、100、200μg·ml^-1·d^-1）,直到子鼠出生,分析窝产仔量和子鼠体重、心体比、肺体比等指标进而对子鼠出生质量进行评估。结果表明,兰州市城关区2015年采暖期大气PM_2.5总日均浓度符合国家标准,但有48d超过国家标准,最高浓度达到151μg·m^-3,主要的重金属和PAHs分别为铅和萤蒽。动物实验结果表明,PM_2.5染毒剂量越高,子鼠体重越轻,下降的幅度越大。与零剂量组比较,PM_2.5剂量组子鼠的心体系数和肺体系数显著降低,但窝产仔量和性别无明显差异。这表明采暖期大气PM_2.5可能会对妊娠期雌鼠产生作用,影响子代小鼠的出生质量和发育情况,这或许与其重金属和PAHs成分有关。     

贵州安龙县耕地表层土壤营养元素地球化学特征

在安龙县耕地质量地球化学调查评价的基础上，通过对不同成土母岩、不同土壤类型和不同耕地地类表层土壤中有机质、N、P、K、Mn、B、Cu、Mo、Zn等营养元素进行分析研究。研究结果表明:(1)营养元素平均含量由高到低依次为:有机质＞K＞N＞Mn＞P＞Zn＞B＞Cu＞Mo，其中P、Mn、Mo、Cu、Zn平均含量高于贵州和全国背景值；有机质、N、B平均含量高于全国背景值、低于贵州背景值；K平均含量低于贵州和全国背景值。有机质、N、P、K、B 、Cu变异系数小于060，含量变化幅度相对较小； Mn、Mo、Zn变异系数在091110间，含量变化幅度相对较大。(2)不同成土母岩土壤表层营养元素中，有机质与N、B，N与B，Mn与Zn在 001 水平上显著正相关。P与K在 001 水平上显著负相关；Cu与有机质、N、B在 005 水平上显著负相关。(3)不同土壤类型营养元素主要呈微-弱富集或微-弱贫化，仅石灰土中Mn为中等富集、红壤中Cu为中等贫化。耕地表层土壤营养元素富集与贫化受成土母岩、土壤类型和耕地地类影响，成土母岩为主要影响因素。     

滇池内源磷释放潜力的区域差异:来自沉积物磷形态的证据

采集了7组滇池近代沉积物柱芯,测定了其中总P(TP)、Fe、Al、Ca的含量,并首次获得了埋深大于25 cm的沉积物的不同形态磷的数据,分析了TP与不同形态磷的时空分布特征及TP与总Fe、Al、Ca含量的关系,探讨了滇池内源磷释放潜力的区域差异和制约因素。结果表明,自北向南,TP含量出现随深度先升高后降低的变化特征,各形态P之间的关系为:碎屑磷(DP)>有机磷(OP)≈铁结合态磷(Fe-P)>闭蓄态磷(Oc P)>钙结合态磷(Ca-P)>铝结合态磷(Al-P)>可交换态磷(SRP)。纵向上Fe-P随深度逐渐升高,Oc P逐渐降低,其它形态P的变化规律不明显;区域上TP、DP、OP、Fe-P、Ca-P和Al-P南部高于北部。在滇池南部DP通量较高的区域,TP与Fe、Al呈正相关关系,与Ca呈负相关关系,其它区域无相关性。分析表明,滇池南部内源磷的释放潜力大于中部和北部,而南部内源磷受DP输入的影响,风浪扰动对北部内源磷的释放有更强的抑制作用。     

土地利用方式对喀斯特峰林谷地土壤养分的影响—— 以广西环江县大才村为例

通过密集采样研究了土地利用方式对喀斯特峰林谷地土壤养分的影响。结果表明: 林地和水田土壤有机碳(分别为24. 84± 10. 18 g /kg 和24. 54± 7. 83 g /kg )极显著高于旱地( 13. 25± 4. 48 g /kg , p < 0. 01) ,水田土壤全氮含量( 2. 64± 0.76 g /kg )显著高于林地( 2. 45± 1. 17 g /kg , p < 0. 05) ,且二者极显著地高于旱地( 1. 68± 0. 53 g /kg , p < 0. 01)。林地全磷含量( 0. 62± 0. 33 g /kg )显著高于旱地( 0. 57± 0. 18 g /kg , p < 0. 05) ,二者又极显著地高于水田( 0. 50± 0. 17 g /kg , p <0. 01)。全氮与有机碳呈极显著的线性相关。土壤碳氮比受到有机质组成和肥料施用的共同影响,说明土地利用方式通过植被、人为管理等途径影响土壤养分,为该类型区土壤养分的人为调控提供了基础。      

NO在两种圆柏属植物叶片抗冻过程中的信号功能研究

通过测定自然降温过程中抗氧化系统、膜脂过氧化、NO释放量、NO合成酶(NOS)和硝酸还原酶(NR)活性的季节变化,研究植物内源NO在圆柏属植物祁连圆柏(Sabina przewalskii)和圆柏(Sabina chinensis)叶抗冻过程中的信号功能.结果表明:随温度降低,过氧化氢酶(CAT)、过氧化物酶(POD)、抗坏血酸氧化酶(APX)活性和谷胱甘肽(GSH)、脯氨酸(Pro)、类胡罗卜素(Car)含量增加并在冬季达最大值,NO释放率、NOS和NR活性以及丙二醛(MDA)含量也显著增加并在9月和2月出现两峰值;两树种叶中的抗氧化酶活性和抗氧化剂含量都与平均温度和MDA含量负相关,而且NO的产生总是发生在抗氧化酶活性和抗氧化剂含量增加之前,表明抗氧化系统在清除氧自由基抑制膜脂过氧化提高抗冻性方面具有重要作用,NO作为信号分子可能激活了抗氧化系统诱导植物抗冻性.在抗冻过程中,祁连圆柏叶的NO释放率、NOS和NR活性、抗氧化酶活性以及抗氧化剂含量都高于圆柏,表明祁连圆柏具有较强的适应性策略.     

中国北方典型中小盆地城市大气颗粒物污染特征及趋势对比

分析了2014~2018年北方5个典型中小盆地城市(兰州、银川、临汾、太原、南阳)PM10与PM2.5的浓度变化特征和大致来源类型。除2018年银川PM2.5浓度外,各市PM10和PM2.5年均浓度均超标;兰州、银川和南阳PM10与PM2.5呈逐年下降趋势,南阳下降最明显;临汾PM10与PM2.5呈逐年上升趋势;太原PM10与PM2.5稳定维持在一个高浓度状态。5个城市颗粒物浓度的季节变化特征一致:冬春高、夏秋低。对PM2.5/PM10值而言,冬季和夏季该比值较高,分别受取暖和降水的影响;春季和秋季该比值较低,分别受沙尘和秸秆焚烧及高强度建筑施工的影响。5市PM2.5和PM10浓度具有良好的线性关系,细颗粒占比大小顺序为临汾>南阳>太原>银川>兰州。     

广州市大气颗粒物PM2.5显微形貌特征和来源解析

PM_2.5是近年来影响我国城市大气环境的首要污染物,其成因机制复杂。本文采用扫描电镜和ICP-MS研究了广州市大气颗粒物PM_2.5的显微形貌及其化学组成特征,并应用富集因子法进行源解析。结果表明,PM_2.5的颗粒形态以无定形态为主;主要物质表现为含Fe、Mg、Al、K、Na的硅酸盐组合,具有道路扬尘、建筑施工排放等一次粒子特征;单个无定形颗粒物能谱表现出硫酸盐+硝酸盐的组合特征,为汽车尾气所排放的前体污染气体NO_x和SO₂进入大气环境中,在特定的物理化学条件下通过成核作用发生相态改变所形成的二次粒子。PM_2.5中高度富集Cd、Se、Zn、Cu、Pb、As等重金属,异常富集的Br主要为当地普遍使用的阻燃剂十溴联苯醚和拆解电子垃圾所致,稀土元素的浓度在0.022~0.582 ng/m³之间,具有重稀土元素富集的特征。这些特征反映出广州市PM_2.5颗粒物的组成既有一次粒子,也有二次粒子,物质来源具有多重性。     

Assessment of spatial variations of particulate matter (PM<Subscript>10</Subscript> and PM<Subscript>2.5</Subscript>) in Bahrain identified by air quality index (AQI)

The rapid urbanization, industrialization, modernization, and the frequent Middle Eastern dust storms have negatively impacted the ambient air quality in Bahrain. The objective of this study is to identify the most critical atmospheric air pollutants with emphasis on their potential risk to health based on calculated AQI (air quality index) values using EPA approach. The air quality datasets of particulate matters (PM₁₀ and PM_2.5), ozone (O₃), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and carbon monoxide (CO) were measured in January 2012 and August 2012 using five mobile air quality monitoring stations located at different governorates. The results of this study demonstrated that PM₁₀ and PM_2.5 are the most critical air pollutants in Bahrain with PM_2.5 prevailing during January 2012 and PM₁₀ prevailing during August 2012. The corresponding AQI categories were utilized to evaluate spatial variability of particulate matters in five governorates. The impact of meteorological factors such as ambient air temperature, wind speed, relative humidity, and total precipitation on ambient air quality were discussed. The analysis demonstrated that the highest PM₁₀ concentrations were observed in the Northern Governorate while the highest PM_2.5 concentrations were observed in the Capital, Central, and Northern Governorates during August 2012. It was observed that the levels of PM_2.5 pollution were higher within proximity of the industrial zone. The results suggested that the average PM_2.5/PM₁₀ ratio in August 2012 was lower than in January 2012 due to the Aeolian processes. This study concludes that higher wind speed, total precipitation, relative humidity rates, and lower ambient air temperature in January 2012 assisted with the dissipation of particulate matter thus lowering the pollution levels of both PM₁₀ and PM_2.5 in comparison to August 2012.     

Inorganic chemistry,granulometry and mineralogical characteristics of the dust fall over phosphate mine adjacent area,central Jordan

Eight selected heavy metals and phosphorus (Fe, Zn, Pb, Cu, Cr, Cd, Ni and P) were analyzed in the dust fall samples collected from the surrounding areas adjacent to Al-Hisa phosphate mine central Jordan during summer 2008. The chemical analysis was done using the ICP-AES, after being digested with (HNO₃/HCl/HF) acid mixture, beside the identification of their mineral constituents using the XRD. Moreover, the particulate matter (PM) size was investigated and divided into four fractions (PM_2.5, PM_2.5–10, PMC_10–100 and PM_>100). The PM₁₀–PM₁₀₀ were found to be the most abundant in the local atmosphere followed by PM_2.5–PM₁₀, while the respirable fraction (PM_2.5) and giant fraction (PM_>100) showed lower levels. The studied samples contain less PM_2.5 and PM₁₀ particulates (9.39 and 28.67), respectively, than samples located far from the mine area (blank samples) (17.32 and 51.7) for PM_2.5 and PM₁₀, respectively. The meteorological effects, mainly the prevailing wind direction beside the distance to emission sources affect the distribution of dust particle sizes. Heavy metal contents in studied samples are similar to some extent to those found in Isa Town (Bahraian), which related to similar arid and low precipitation climatic conditions. The effect of phosphate mining activities was obvious as indicated from the presence of apatite as the main mineral phase and the higher P contents. Moreover, the studied samples contain higher Zn, Ni, Cu and to lesser extent Cr than blank samples. They exhibited a significant positive correlation with P, as they are usually associated with the phosphate rocks.     

Spatio-temporal variations of respirable particles at residential areas located in the vicinity of opencast coal projects,India: a case study

The objective of the study is to investigate spatio-temporal variations of PM₁₀, PM_2.5, and PM₁ concentrations at seven residential sites, located in the vicinity of opencast coal projects, Basundhara Garjanbahal Area (BGA), India. Meteorological parameters such as wind speed, wind direction, relative humidity, and temperature were collected simultaneously with PM concentrations. Mean concentrations of PM₁₀ in the range 215 ± 169–526 ± 412 μg m^?3, PM_2.5 in the range of 91 ± 79–297 ± 107 μg m^?3, PM₁ in the range of 68 ± 60–247 ± 84 μg m^?3 were obtained. Coarse fractions (PM_2.5–10) varied from 27 to 58% whereas fine fractions (PM_1–2.5 and PM₁) varied in the range of 51–73%. PM_2.5 concentration was 41–74% of PM₁₀ concentration, PM₁ concentration was 31–62% of PM₁₀ concentration, and PM₁ concentration was 73–83% of PM_2.5 concentration. Role of meteorology on PM concentrations was assessed using correlation analysis. Linear relationships were established among PM concentrations using least square regression analysis. With the aid of principal component analysis, two components were drawn out of eight variables, which represent more than 75% of variance. The results indicated that major sources of air pollutants (PM₁₀, PM_2.5, PM₁, CO, CO₂) at the residential sites are road dust raised by vehicular movement, spillage of coal generated during transportation, spontaneous combustion of coal, and biomass burning in village area.     

Ecological model analysis of respiratory health risk factors by ambient air pollution in Lucknow,the capital City of Uttar Pradesh,India

Ambient air pollution, particularly in the urban environment of developing countries, has turned out to be a major health risk factor. We explore the compounded impact of age sensitivity, exposure, poverty, co-morbidity, etc., along with composite air pollution in determining morbidity and health burden of people in Lucknow, India. This cross-sectional study is confined to analyse respiratory health status across different socio-economic and geographic locations using n = 140 in-depth questionnaire method. We used mean daily ambient air pollution data of PM₁₀, PM_2.5, SO_2, and NO₂ for the 2008–2018 period. We used the ecological model framework to assess the risk at different hierarchical levels and compounded severity on a spatial scale. We also used Logistic regression model with log odds and odds ratio to analyze the association of risks outcomes with composite air pollution scores calculated using the principal component analysis method. There is a strong association of location-specific respiratory disease prevalence with an overall 32 percent prevalence. The prevalence of ecological model 1 (individual domain) is 4.3 percent, while ecological model 2 (community domain) has the highest prevalence at 32.4 percent. The logistic regression model shows that respiratory disease load is positively associated with age sensitivity (P < .001) and composite pollution level (P < .001). For another model with suffocation as the outcome variable, composite pollution level (P < .001) and exposure (P < .001) are positively associated. Optimum interventions are required at Ecological models 1, 2, and 3 levels for better respiratory health outcomes.

     

Mercury,Trace Elements and Organic Constituents in Atmospheric Fine Particulate Matter,Shenandoah National Park,Virginia, USA: A Combined Approach to Sampling and Analysis

Compliance with U.S. air quality regulatory standards for atmospheric fine particulate matter (PM_2.5) is based on meeting average 24 hour (35 μ m^?3) and yearly (15 μg m^?3) mass‐per‐unit‐volume limits, regardless of PM_2.5 composition. Whereas this presents a workable regulatory framework, information on particle composition is needed to assess the fate and transport of PM_2.5 and determine potential environmental/human health impacts. To address these important non‐regulatory issues an integrated approach is generally used that includes (1) field sampling of atmospheric particulate matter on filter media, using a size‐limiting cyclone, or with no particle‐size limitation; and (2) chemical extraction of exposed filters and analysis of separate particulate‐bound fractions for total mercury, trace elements and organic constituents, utilising different USGS laboratories optimised for quantitative analysis of these substances. This combination of sampling and analysis allowed for a more detailed interpretation of PM_2.5 sources and potential effects, compared to measurements of PM_2.5 abundance alone. Results obtained using this combined approach are presented for a 2006 air sampling campaign in Shenandoah National Park (Virginia, USA) to assess sources of atmospheric contaminants and their potential impact on air quality in the Park. PM_2.5 was collected at two sampling sites (Big Meadows and Pinnacles) separated by 13.6 km. At both sites, element concentrations in PM₂₅ were low, consistent with remote or rural locations. However, element/Zr crustal abundance enrichment factors greater than 10, indicating anthropogenic input, were found for Hg, Se, S, Sb, Cd, Pb, Mo, Zn and Cu, listed in decreasing order of enrichment. Principal component analysis showed that four element associations accounted for 84% of the PM_2.5 trace element variation; these associations are interpreted to represent: (1) crustal sources (Al, REE); (2) coal combustion (Se, Sb), (3) metal production and/or mobile sources (Mo, Cd, Pb, Cu, Zn) and (4) a transient marine source (Sr, Mg). Concentrations of Hg in PM_2.5 at background levels in the single pg m^?3 were shown by collection and analysis of PM_2.5 on filters and by an automated speciation analyser set up at the Big Meadows air quality site. The speciation unit revealed periodic elevation of reactive gaseous mercury (RGM) that co‐occurred with peaks in SO₂, indicating an anthropogenic source. GC/MS total ion current chromatograms for the two sites were quite similar indicating that organic signatures were regional in extent and/or that the same compounds were present locally at each site. Calculated carbon preference index values for n‐alkanes indicated that plant waxes rather than anthropogenic sources, were the dominant alkane source. Polycyclic aromatic hydrocarbons (PAHs) were detected, with a predominance of non‐alkylated, and higher molecular weight PAHs in this fraction, suggestive of a combustion source (fossil fuel or forest fires).