Radon in indoor concentrations and indoor concentrations of metal dust particles in museums and other public buildings

The aim of this study was to evaluate the public and occupational exposure to radon and metal-bearing particles in museums and public buildings located in the city of Rio de Janeiro, Brazil. For this study, four buildings were selected: two historic buildings, which currently house an art gallery and an art museum; and two modern buildings, a chapel and a club. Integrated radon concentration measurements were performed using passive radon detectors with solid state nuclear track detector-type Lexan used as nuclear track detector. Air samplers with a cyclone were used to collect the airborne particle samples that were analyzed by the particle-induced X-ray emission technique. The average unattached-radon concentrations in indoor air in the buildings were above 40 Bq/m³, with the exception of Building D as measured in 2009. The average radon concentrations in indoor air in the four buildings in 2009 were below the recommended reference level by World Health Organization (100 Bq/m³); however, in 2011, the average concentrations of radon in Buildings A and C were above this level, though lower than 300 Bq/m³. The average concentrations of unattached radon were lower than 148 Bq/m³ (4pCi/L), the USEPA level recommended to take action to reduce the concentrations of radon in indoor air. The unattached-radon average concentrations were also lower than the value recommended by the European Union for new houses. As the unattached-radon concentrations were below the international level recommended to take action to reduce the radon concentration in air, it was concluded that during the period of sampling, there was low risk to human health due to the inhalation of unattached radon in these four buildings.     

Cytotoxicity and cell membrane depolarization induced by aluminum oxide nanoparticles in human lung epithelial cells A549

The cytotoxicity of 13 and 22 nm aluminum oxide (Al₂O₃) nanoparticles was investigated in cultured human bronchoalveolar carcinoma-derived cells (A549) and compared with 20 nm CeO₂ and 40 nm TiO₂ nanoparticles as positive and negative control, respectively. Exposure to both Al₂O₃ nanoparticles for 24 h at 10 and 25 µg mL^?1 doses significantly decreased cell viability compared with control. However, the cytotoxicity of 13 and 22 nm Al₂O₃ nanoparticles had no difference at 5–25 µg mL^?1 dose range. The cytotoxicity of both Al₂O₃ nanoparticles were higher than negative control TiO₂ nanoparticles but lower than positive control CeO₂ nanoparticles (TiO₂ < Al₂O₃ < CeO₂). A real-time single cell imaging system was employed to study the cell membrane potential change caused by Al₂O₃ and CeO₂ nanoparticles using a membrane potential sensitive fluorescent probe DiBAC₄(3). Exposure to the 13 nm Al₂O₃ nanoparticles resulted in more significant depolarization than the 30 nm Al₂O₃ particles. On the other hand, the 20 nm CeO₂ particles, the most toxic, caused less significant depolarization than both the 13 and 22 nm Al₂O₃. Factors such as exposure duration, surface chemistry, and other mechanisms may contribute differently between cytotoxicity and membrane depolarization.     

室内空气和灰尘中全(多)氟烷基化合物的研究进展

全(多)氟烷基化合物(per(poly)fluoroalkyl substances,PFASs)在环境各个介质及人体样品中广泛被检出,近年,在室内空气和灰尘中也普遍发现PFASs.研究表明,室内空气中PFASs的含量普遍高于室外空气,室内空气和灰尘中的PFASs可能是室外空气的污染来源及人体暴露源,因此室内环境中PFASs成为环境领域的又一个研究热点.但目前为止,我国还没有开展室内空气中PFASs的相关研究,室内灰尘中PFASs的研究也相对较少.本文就室内空气和灰尘中PFASs的采样与分析方法、污染现状、来源分析及人体暴露等4个方面进行了综合阐述,以期为我国室内环境中PFASs的研究提供参考.     

Concentration,sources, influencing factors and hazards of heavy metals in indoor and outdoor dust: A review

Environmental Chemistry Letters - Heavy metals are a common class of toxic contaminants in soil, water and air, yet their occurrence in indoor environments is less known. Heavy metals enter...     

兰州市室内空气重金属污染水平与健康风险评价

为探究兰州市室内空气中重金属的污染程度及健康风险水平,于2018年9—12月在兰州市居民住宅采集室内空气样品,共设置了85个采样点.计算了室内空气中重金属Pb、Cd、As的浓度,并利用USEPA健康风险评价模型对居民经呼吸途径的健康风险进行了评价.结果表明,兰州市室内空气Pb、Cd和As的平均浓度分别为(0.0532±...     

室内灰尘中多环芳烃及其衍生物的赋存与人体暴露研究进展

多环芳烃(polycyclic aromatic hydrocarbons,PAHs)作为典型的持久性有机污染物(persistent organic pollutants,POPs)中的重要类别,具有半挥发性、生物蓄积性、长期残留性和明显的毒性(包括致癌、致畸、致突变)等特点,因此是环境中的一类重要污染物.PAHs衍...     

The distribution of phthalate esters in indoor dust of Palermo (Italy)

In this work, phthalic acid esters (PAEs): dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate, benzyl butyl phthalate, bis(2-ethylhexyl) phthalate, and di-n-octyl phthalate in indoor dust (used as passive sampler) were investigated. The settled dust samples were collected from thirteen indoor environments from Palermo city. A fast and simple method using Soxhlet and GC–MS analysis has been optimized to identify and quantify the phthalates. Total phthalates concentrations in indoor dusts ranged from 269 to 4,831 mg/kg d.w. (d.w. = dry weight). The data show a linear correlation between total PAEs concentration and a single compound content, with the exclusion of the two most volatile components (DMP and DEP) that are present in appreciable amounts only in two samples. These results suggest that most of the PAEs identified in the samples of settled dust originate from the same type of material. This evidence indicates that, in a specific indoor environment, generally is not present only one compound but a mixture having over time comparable percentages of PAEs. Consequently, for routine analyses of a specific indoor environment, only a smaller number of compounds could be determined to value the contamination of that environment. We also note differences in phthalate concentrations between buildings from different construction periods; the total concentration of PAEs was higher in ancient homes compared to those constructed later. This is due to a trend to reduce or remove certain hazardous compounds from building materials and consumer goods. A linear correlation between total PAEs concentration and age of the building was observed (R = 0.71).     

城市和电子垃圾拆解区室内灰尘中溴代阻燃剂(BFRs)的浓度和生物有效性

本文以广州市区和电子垃圾拆解区室内灰尘为研究对象,分析不同粒径(50—2000μm)灰尘中溴代阻燃剂(brominated flame retardants, BFRs)的浓度、组成和生物有效性.广州市区灰尘中BFRs以十溴二苯乙烷(decabromodiphenyl ethane, DBDPE)(4930—7280 ng·g~(-1))为主,电子垃圾拆解区以十溴联苯醚(polybrominated diphenyl ether 209, BDE209)(5570—602600 ng·g~(-1))为主.对比研究结果发现,城市灰尘中BFRs的分布无粒径差异,而电子垃圾拆解区最细粒径灰尘中BFRs含量最高.广州市区灰尘中BFRs生物有效性随化合物的lg K_(ow)增加而降低.电子垃圾拆解区灰尘生物有效性显著低于市区灰尘,表明在电子垃圾拆解区灰尘中电子垃圾碎片的存在很大程度上降低了BFRs的生物有效性.人体暴露评估结果显示,广州市区人体暴露风险低于电子垃圾拆解区暴露风险.     

Seasonal concentrations of lead in outdoor and indoor dust and blood of children in Riyadh,Saudi Arabia

Because detrimental effects of exposure to lead (Pb) on human health have been observed, we previously investigated concentrations of Pb in water supplies and blood of adult residents of Riyadh, Saudi Arabia. The objectives of the present study were to: (1) examine seasonal rates of deposition of Pb in dust in several areas of Riyadh city, (2) measure concentrations of Pb in both outdoor and indoor dust, (3) compare concentrations of Pb in dust in Riyadh with those reported for other cities, and (4) quantify Pb in blood of children living in Riyadh. Mean, monthly deposition of PB in outdoor dust was 4.7 × 10¹ ± 3.6 tons km^?2, with a mean Pb concentration of 2.4 × 10² ± 4.4 × 10¹ μg/g. Mean, monthly deposition of Pb in indoor dust was 2.7 ± 0.70 tons km^?2, with a mean concentration of 2.9 × 10¹ ± 1.5 × 10¹ μg Pb/g. There was a significant (P < 0.01) correlation between concentrations of Pb in outdoor and indoor dust. There was no correlation between concentrations of Pb in indoor dust and that in blood of children of Riyadh, whereas there was a weakly significant (P < 0.05) correlation between concentrations of Pb in outdoor dust and that in blood of children. The mean (±SD) concentration of Pb in blood of children in Riyadh was 5.2 ± 1.7, with a range of 1.7–1.6 × 10¹ μg/dl. Concentrations of Pb in blood of 17.8 % of children in Riyadh were greater than 10 μg/dl, which is the CDC’s level of concern.     

住宅室内降尘中邻苯二甲酸酯的污染特征及传输途径

本文分别于夏季和冬季在北京市40户家庭的客厅和卧室采集降尘样品,研究降尘中邻苯二甲酸酯(PAEs)的污染特征.结果表明,室内降尘中主要的PAEs(及其浓度)为DIBP (39.6 ng·mg~(-1),几何平均浓度,下同)、DBP (38.7 ng·mg~(-1))和DEHP (418.5 ng·mg~(-1)).降尘中PAEs的浓度与温度、相对湿度和换气次数均呈显著正相关(P0.005).这是由于室温升高和换气次数增高加快PAEs的源排放速率,促进室内空气中PAEs积累并通过气相媒介传输使得降尘PAEs浓度增高;湿度升高促进空气中PAEs向降尘的传质,增大降尘中PAEs浓度.3种因素共同影响使得夏季降尘中3种PAEs的浓度均显著高于冬季(P0.0001).研究还发现,源材料中PAEs至降尘的传输途径包括以气相为媒介的间接传输和源至降尘的直接转移,因此降尘PAEs浓度与采集平面材料相关;降尘PAEs浓度还受降尘在室内的停留时间影响.因此,相关研究需指明降尘的类型、采集位置和平面材料,便于利用测量数据进行准确的暴露评估.     

Combined toxic effect of airborne heavy metals on human lung cell line A549

Many studies have demonstrated that heavy metals existing as a mixture in the atmospheric environment cause adverse effects on human health and are important key factors of cytotoxicity; however, little investigation has been conducted on a toxicological study of a metal mixture from atmospheric fine particulate matter. The objective of this study was to predict the combined effects of heavy metals in aerosol by using in vitro human cells and obtain a suitable mixture toxicity model. Arsenic, nickel, and lead were selected for mixtures exposed to A549 human lung cancer cells. Cell proliferation (WST-1), glutathione (GSH), and interleukin (IL)-8 inhibition were observed and applied to the prediction models of mixture toxicity, concentration addition (CA) and independent action (IA). The total mixture concentrations were set by an IC₁₀-fixed ratio of individual toxicity to be more realistic for mortality and enzyme inhibition tests. The results showed that the IA model was statistically closer to the observed results than the CA model in mortality, indicating dissimilar modes of action. For the GSH inhibition, the results predicted by the IA and CA models were highly overestimated relative to mortality. Meanwhile, the IL-8 results were stable with no significant change in immune reaction related to inflammation. In conclusion, the IA model is a rapid prediction model in heavy metals mixtures; mortality, as a total outcome of cell response, is a good tool for demonstrating the combined toxicity rather than other biochemical responses.     

贵阳市区地表灰尘重金属污染分析与评价

以贵阳市区为研究地点,采集了贵阳城区工业区、交通区、商业区、居民区、文教区、公园广场、对照区7个类别共80个采样点的地表灰尘,分析了地表灰尘重金属在不同区域的分布特征,并分析其可能来源。最后,应用潜在生态危害指数法对6个功能区（工业区、交通区、商业区、居民区、文教区、公共区）样品中重金属的潜在生态危害进行评价。结果表明：贵阳市地表灰尘重金属的平均质量分数均高于贵州省土壤环境背景值,Cd、As、Cu污染质量分数都超过4倍以上背景值水平,其余重金属污染水平大多处于1~3倍背景值水平。就单个重金属潜在生态危害系数平均值来看,地表灰尘的潜在生态危害最大的是Hg,其次是Cd,生态危害最低的是Cr。6个功能区生态危害水平均属于强生态危害水平,其中工业区和公共区生态危害水平最高。     

高校室内降尘粒度、磁学特征与重金属污染垂向分布特征

以南通某高校为采样点,采集3个校区教学楼不同楼层室内降尘,测试并分析样品的粒度、磁学特征、重金属污染的垂向分布规律,讨论重金属污染影响因素.研究发现,样品的粒度特征在垂向上呈明显波动变化,在人流量大的教学层,粒度特征受教学活动影响;在人流量小的办公层,粒度大小与楼层高度有关,即随楼层增加,粒度逐渐减小,如校区3教学楼1-3、7、9层粒度分别为35.4、29.0、28.8、27.3、23.2μm.室内降尘磁性矿物主要以亚铁磁性矿物和不完整反铁磁性矿物为主,χARM值垂向变化趋势与χlf基本一致,指示单畴颗粒对样品磁化率贡献较大.各校区教学楼不同楼层Cu、Zn、Pb、As元素富集因子(EF)值由10降至接近1,指示随楼层增加重金属元素污染程度从严重污染到无污染;校区3教学楼1—5楼重金属污染程度均相对较高(内梅罗指数平均为20.08),6层及以上样品重金属污染程度较低(内梅罗指数平均为9.01),说明随着楼层的增加,重金属污染总体呈降低趋势.小于20μm粒径颗粒对重金属元素As具有较好吸附作用,大于20μm颗粒对重金属元素吸附作用较弱.饱和等温剩磁(SIRM)与重金属元素As具较好的正相关关系(R2=0.4351),用SIRM可快速指示室内降尘重金属元素As的污染状况.     

Evidence for DNA-diquat interaction and cytotoxicity in in vitro rat cells

Over 98% of sprayed insecticides and 95% of herbicides reach non-target species in air, soil, and water. Numerous studies have reported that pesticide residues can cause acute and chronic toxicity. Pesticide residues can be carcinogenic, mutagenic, and immunotoxic. There are actually too few studies that bridge the disciplines of chemobioanalysis and environmental toxicology. Here, we assessed the cytotoxicity of a bipyridilium herbicide diquat in rat adrenal pheochromocytoma cells (PC12). Our results show that diquat caused the decrease in cell viability with a lethal concentration 50 (LC₅₀) of 1.4 × 10⁻⁵ mol/L. This cytotoxicity may result from diquat-induced apoptosis, characterized by nuclear fragmentation and chromatin condensation by Hoechst 33324 staining. To explore the possible mechanisms, the interaction between herbicide diquat and calf thymus DNA (ctDNA) was further investigated using fluorescence quenching. The detection of static quenching showed that diquat was linked with ctDNA by electrostatic interaction with a binding constant of 9.288 × 10⁴ L/mol. This is the first study on the interaction of DNA with herbicide diquat by fluorometric method as well as on the evaluation of cytotoxicity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Hoechst staining. Given the widespread use of synthetic pesticides, the data would be valuable for the risk assessment of pesticide residues.     

Fluoride induces DNA damage and cytotoxicity in human hepatocellular carcinoma cells

Humans are primarily exposed to fluoride (Fl), a widespread environmental pollutant, via contaminated drinking water and foodstuffs. The aim of this study was to examine whether sodium fluoride (NaF) exerted cytotoxic effects in human hepatocarcinoma (HepG2) cells. HepG2 cells were incubated with different concentrations of NaF and reactive oxygen species (ROS) levels, cell cycle, apoptosis, and DNA damage determined. Concentration-dependent studies showed that exposure to HepG2 cells with different concentrations of NaF for 24 hr significantly decreased cell viability and intracellular antioxidant capacity. Furthermore, NaF exposure increased lipid peroxidation levels and accumulation of intracellular ROS; and lowered antioxidant glutathione concentrations. In addition to oxidative impairments, NaF treatment enhanced HepG2 cell death via apoptotic pathway as evidenced by DNA fragmentation and cell cycle arrest. Sodium fluoride treatment unregulated p53 level, and Bax and Bcl2 expression. Diminished cell viability and changes in cell cycle accompanied a rise in p53 expression.     

城市不同功能区内叶面尘与地表灰尘的粒径和重金属特征

在城市粉尘污染研究中,叶面尘与地表灰尘被认为是新的切人点.以南京市不同功能区为例,分别收集了各功能区典型绿化树种的叶面尘与同区域的地表灰尘,采用激光粒径分析仪测定了叶面尘与地表灰尘的粒径分布规律,应用ICP-AES对样品重金属含量进行了测定,并以此为基础,对重金属的生态风险进行了评价,最后分析了叶面尘与地表灰尘所含重金属元素之间的相关性.结果表明,叶面尘与地表灰尘中颗粒物粒径集中分布于100 μm以内,两者粒径累积曲线均呈现正态单峰分布,其中商业区和工业区颗粒物粒径较小.不同功能区重金属含量差异显著,污染水平递减顺序为:商业区、工业区、交通枢纽区、街道复层绿化区、科教生活区.潜在生态危害评价表明,叶面尘的生态危害大于地表灰尘,除科教生活区外,叶面尘在其余四个功能区均产生中等生态危害.重金属Pearson相关分析发现,叶面尘与地表灰尘存在相似来源,即主要来自交通排放、工业污染等人为源.粒径与重金属两方面的研究指示出南京市粉尘污染最严重的是商业区与工业区,这为进一步控制城市粉尘污染提供了有力依据.     

基于监测数据对邻苯二甲酸酯在室内PM2.5-空气和灰尘-空气间分配状态的研究

邻苯二甲酸酯(PAEs)是室内环境中广泛存在的内分泌干扰物之一.过去认为气相媒介传输机制主导包括PAEs在内的SVOCs在室内环境中分配的观点近年来已受到质疑.为探究PAEs在真实室内环境中的分配状态,本文利用监测数据计算PAEs在PM2.5-空气和灰尘-空气之间的分配系数(分别为Kp和Kd),并与平衡状态下的分配系数...     

Comparison of basal cytotoxicity of seven carbamates in CHO-K1 cells

The cytotoxic effects of seven carbamate pesticides, aldicarb, aldicarb sulfone, aldicarb sulfoxide, benfuracarb, pirimicarb, propoxur and thiobencarb, were compared in Chinese hamster ovary (CHO-K1) cell line of Circetulus griseus. The endpoints evaluated were lysosomal function by neutral red assay and mitochondrial integrity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT assay). The carbamates tested were evaluated in both serum-free medium and in serum-containing medium. Results demonstrate that CHO-K1 lysosomes appeared more susceptible to propoxur, aldicarb and its metabolites than mitochondria. Aldicarb was the most toxic carbamate pesticide tested on CHO-K1 cells and aldicarb sulfoxide the least. The presence of foetal calf serum (FCS) diminished significantly the cytotoxicity of tested carbamates.     

Identification of important precursors and theoretical toxicity evaluation of byproducts driving cytotoxicity and genotoxicity in chlorination

• NOM formed more C-DBPs while amino acids formed more N-DBPs during chlorination • Aspartic acid and asparagine showed the highest toxicity index during chlorination • Dichloroacetonitrile might be a driving DBP for cytotoxicity and genotoxicity • Dichloroacetonitrile dominated the toxicity under different chlorination conditions Chlorination, the most widely used disinfection process for water treatment, is unfortunately always accompanied with the formation of hazardous disinfection byproducts (DBPs). Various organic matter species, like natural organic matter (NOM) and amino acids, can serve as precursors of DBPs during chlorination but it is not clear what types of organic matter have higher potential risks. Although regulation of DBPs such as trihalomethanes has received much attention, further investigation of the DBPs driving toxicity is required. This study aimed to identify the important precursors of chlorination by measuring DBP formation from NOM and amino acids, and to determine the main DBPs driving toxicity using a theoretical toxicity evaluation of contributions to the cytotoxicity index (CTI) and genotoxicity index (GTI). The results showed that NOM mainly formed carbonaceous DBPs (C-DBPs), such as trichloromethane, while amino acids mainly formed nitrogenous DBPs (N-DBPs), such as dichloroacetonitrile (DCAN). Among the DBPs, DCAN had the largest contribution to the toxicity index and might be the main driver of toxicity. Among the precursors, aspartic acid and asparagine gave the highest DCAN concentration (200 g/L) and the highest CTI and GTI. Therefore, aspartic acid and asparagine are important precursors for toxicity and their concentrations should be reduced as much as possible before chlorination to minimize the formation of DBPs. During chlorination of NOM, tryptophan, and asparagine solutions with different chlorine doses and reaction times, changes in the CTI and GTI were consistent with changes in the DCAN concentration.