纳米SiO2与常规SiO2颗粒对Hela细胞的细胞毒性作用

为了探讨纳米SiO2和常规SiO2颗粒对Hela细胞的细胞毒性作用,采用不同浓度的纳米SiO2和常规SiO2颗粒(0.05、0.1、0.2、0.4、0.8、1.6μg·μL-1)对Hela细胞进行12h染毒,应用MTT法检测细胞毒性效应.研究发现,较低浓度(≤0.2μg·μL-1)的纳米SiO2和常规SiO2对Hela细胞无明显细胞毒性(p>0.05);较高浓度时,纳米SiO2(≥0.4μg·μL-1)和常规SiO2(≥0.8μg·μL-1)对Hela细胞具有明显细胞毒性作用(p<0.01),并且随浓度增大细胞毒性增强;当浓度≥0.4μg·μL-1时,纳米SiO2的细胞毒性明显高于相同浓度的常规SiO2(p<0.05).以上结果表明,纳米SiO2和常规SiO2颗粒均能对Hela细胞产生细胞毒性,且纳米SiO2的细胞毒性强于常规SiO2;低浓度(≤0.2μg·μL-1)的纳米SiO2和常规SiO2具有很好的生物相容性.     

不同粒径大气颗粒物几种重金属成分分析及其致突变性研究

采集冬季太原市一采样点不同粒径大气颗粒物,经分析,总悬浮颗粒物日均浓度为1.04mg/m~3,严重超标。其中粒径小于7.0μm的占49.6％,小于3.3μm的占33.5％。颗粒物无机提取液中5种金属元素的浓度由高到低依次为Pb、Mn、Cr、Ni和Cd。每一种元素均呈随颗粒物粒径减小浓度增高的趋势。以SOS显色法和小鼠体内骨髓细胞染色体畸变试验检测颗粒物的无机提取液和模拟肺泡液溶出液的遗传毒性,表明小粒径颗粒物遗传毒性较强;小于1.1μm的颗粒物,仅用相当于5m~3或10m~3空气量的样品液,即可诱发SOS反应或致染色体损伤。     

Colloidal gold probe-based immunochromatographic assay for the rapid detection of lead ions in water samples

One-step immunochromatographic assay (ICA) has been developed using colloidal gold-labeled monoclonal antibody probe for the rapid detection of lead ions in water samples. The ICA was based on the theory of competitive reactivity, and the results can be easily judged based on the presence or absence of a red colored test line with visual detection. Under optimal conditions, this method shows high detecting sensitivity with a LOD (limit of detection) of 50 ng/ml. Stability test indicates that the immunochromatographic strips are stable for 8 weeks at room temperature. During practical application, nanometer TiO₂ is used to enrich the lead ions in water samples. The ICA is successfully applied in the measurement of lead ion concentrations in local water samples, and the results are highly consistent with that of ICP-MS. Detecting lead ions with ICA can be done within 4 min and is very useful for the rapid onsite testing.     

A protocol for the evaluation of genotoxicity in bile of carp (Cyprinus carpio) exposed to lake water treated with different disinfectants

A sensitive and rapid method to evaluate toxic and genotoxic properties of drinking water supplied from Lake Trasimeno (Umbria, Central Italy) was worked out analysing bile in Cyprinus carpio exposed for 20 d to lake water treated with 3 different disinfectants, sodium hypochlorite (NaClO), chlorine dioxide (ClO₂) and peracetic acid (PAA). Fish were sacrificed at 0, 10 and 20 d in order to investigate the time course of these endpoints. An aliquot of bile samples was fractionated by adsorption on C₁₈ silica cartridges and the genotoxic potential of whole bile and of bile fractions was evaluated by the single-cell microgel-electrophoresis (comet) assay on human colonic adenocarcinoma cells (Caco-2). Bile (both whole and fractionated) from specimens exposed to the three disinfectants always showed a genotoxic activity as compared to the control group. The results of this study provide evidence that all three disinfectants cause an increase in bile genotoxicity of chronically exposed fish.     

Genotoxicity in the freshwater gastropod Lymnaea luteola L: assessment of cell type sensitivities to lead nitrate

The aquatic ecosystems are converting into the highly contaminated site due to environmental pollutants. The present study explores the oxidative stress and toxic potential of lead nitrate in freshwater snail Lymnaea luteola (L. luteola) L. The snails were exposed to an environmentally relevant concentration of lead nitrate for 24 and 96?h. Later exposure to lead nitrate (0, 10, 20 and 40?µg/mL) to the freshwater snail, the level of reactive oxygen species, malondialdehyde and nitric oxide (NO) were increased and glutathione, glutathione-S-transferase were decreased. Lead-nitrate-induced haemocyte cell death and it was observed by using Annexin-V FITC/PI through a flow cytometer. DNA damage in haemocyte cells was measured at above doses of lead-nitrate exposure for 24 and 96?h and it was compared to the untreated snail. Average tail DNA (%) and olive tail moment in single-cell gel test were increased dose and duration fashion and maximum DNA damage was measured at 96?h. These results indicate the potential toxicity and genotoxicity of lead nitrate in acute treatment to L. luteola and single-cell gel test are the assay for rapid detection of genetic effects.     

Fine atmospheric particles emitted by industrial,traffic and urban sources in France: characterization and genotoxicity

Health risks associated with inhalation of fine particulate matter of 2.5 µm in diameter or smaller depend on their atmospheric levels and physicochemical properties. The relationships between chemical compositions and genotoxic activities of particles emitted by mineral industries, traffic and urban sources during summer and winter in the region of Provence-Alpes-Côte d'Azur (France) were investigated.

The fine particles were separated in respect to water-soluble (13 minerals and metals) and organic-extractable (16 polycyclic aromatic hydrocarbons) components that were quantified. The chromosome damaging properties of the hydrophilic and lipophilic extracts were assessed using the centromeric micronucleus assay on a human lung fibroblast cell line.

The composition of the fine particulate matter was variable and depended upon the sources and seasons. Both the hydrophilic and lipophilic extracts induced chromosome damage: (1) in hydrophilic extracts, Ca and Zn affected chromosome losses induction; (2) acenapthylene affected chromosome damage (breakages and losses) induction and naphthalene affected chromosome damage and losses induction in lipophilic extracts without metabolic activation; and (3) benzo[a]pyrene affected chromosome losses induction in lipophilic extracts with metabolic activation. Fine particulate matter arising from coal-fired power station, road traffic, and other urban sources were the most efficient to induce chromosome breakage.     

Genotoxicity monitoring of freshwater environments using caged crayfish (Astacus leptodactylus)

Genotoxicity of freshwater pollution was assessed by measuring DNA damage in haemocytes of caged freshwater crayfish Astacus leptodactylus by the means of Comet assay and micronucleus test, integrated with the measurements of physiological (total protein concentration) and immunological (total haemocyte count) haemolymph parameters as biomarkers of undergone stress. Crayfish were collected at the reference site (River Mre?nica) and exposed in cages for 1 week at three polluted sites along the Sava River (Zagreb, Sisak, Krapje). The long term pollution status of these locations was confirmed by chemical analyses of sediments. Statistically significant increase in DNA damage measured by the Comet assay was observed at all three polluted sites comparing to the crayfish from reference site. In addition, native crayfish from the mildly polluted site (Krapje) cage-exposed on another polluted site (Zagreb) showed lower DNA damage than crayfish from the reference site exposed at the same location indicating adaptation and acclimatisation of crayfish to lower levels of pollution. Micronuclei induction showed similar gradient of DNA damage as Comet assay, but did not reach the statistical significance. Observed increase in total haemocyte count and total protein content in crayfish from polluted environments in the Sava River also confirmed stress caused by exposure to pollution. The results of this study have proved the applicability of caging exposure of freshwater crayfish A. leptodactylus in environmental genotoxicity monitoring using Comet assay and micronucleus test.     

Aerosols near by a coal fired thermal power plant: Chemical composition and toxic evaluation

Industrial processes discharge fine particulates containing organic as well as inorganic compounds into the atmosphere which are known to induce damage to cell and DNA, both in vitro and in vivo. Source and area specific studies with respect to the chemical composition, size and shape of the particles, and toxicity evaluations are very much limited. This study aims to investigate the trace elements associated with the aerosol particles distributed near to a coal burning thermal power plant and to evaluate their toxicity through Comet assay. PM₁₀ (particles determined by mass passing an inlet with a 50% cut-off efficiency having a 10-μm aerodynamic diameter) samples were collected using respirable dust samplers. Twelve elements (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, Se, Hg, and As) were analyzed using ICP-AES. Comet assay was done with the extracts of aerosols in phosphate buffered saline (PBS). Results show that Fe and Zn were found to be the predominant elements along with traces of other analyzed elements. Spherical shaped ultrafine particles of <1 μm aerodynamic diameter were detected through scanning electron microscope. PM₁₀ particles near to the coal burning power plant produced comets indicating their potential to induce DNA damage. DNA damage property is found to be depending upon the chemical characteristics of the components associated with the particles besides the physical properties such as size and shape.     

Comparing differential tolerance of native and non-indigenous marine species to metal pollution using novel assay techniques

Recent research suggests anthropogenic disturbance may disproportionately advantage non-indigenous species (NIS), aiding their establishment within impacted environments. This study used novel laboratory- and field-based toxicity testing to determine whether non-indigenous and native bryozoans (common within marine epibenthic communities worldwide) displayed differential tolerance to the common marine pollutant copper (Cu). In laboratory assays on adult colonies, NIS showed remarkable tolerance to Cu, with strong post-exposure recovery and growth. In contrast, native species displayed negative growth and reduced feeding efficiency across most exposure levels. Field transplant experiments supported laboratory findings, with NIS growing faster under Cu conditions. In field-based larval assays, NIS showed strong recruitment and growth in the presence of Cu relative to the native species. We suggest that strong selective pressures exerted by the toxic antifouling paints used on transport vectors (vessels), combined with metal contamination in estuarine environments, may result in metal tolerant NIS advantaged by anthropogenically modified selection regimes.     

Assessing the genotoxicity of urban air pollutants using two in situ plant bioassays

Genotoxicity of urban air has been analysed almost exclusively in airborne particulates. We monitored the genotoxic effects of airborne pollutants in the urban air of Perugia (Central Italy). Two plant bioindicators with different genetic endpoints were used: micronuclei in meiotic pollen mother cells using Tradescantia-micronucleus bioassay (Trad-MCN) and DNA damage in nuclei of Nicotiana tabacum leaves using comet assay (Nicotiana-comet). Buds of Tradescantia clone # 4430 and young N. tabacum cv. Xanthi plants were exposed for 24 h at three sites with different pollution levels. One control site (indoor control) was also used. The two bioassays showed different sensitivities toward urban pollutants: Trad-MCN assay was the most sensitive, but DNA damage in N. tabacum showed a better correlation with the pollutant concentrations. In situ biomonitoring of airborne genotoxins using higher plants combined with chemical analysis is thus recommended for characterizing genotoxicity of urban air.