抚顺大气悬浮颗粒物、PAHs和NPAHs污染调查

目的　了解抚顺大气悬浮颗粒污染物,特别是可吸入性颗粒物(PM10 )、细颗粒物(PM2 5)和超细颗粒物(PM1 0 )、多环芳烃(PAHs)和硝基多环芳烃(NPAHs)的浓度、分布及季节变化情况。方法　选择抚顺市内距同一污染源下风侧不同距离的3所小学为监测点,于2 0 0 2年7月～2 0 0 3年4月每季监测2周,每次4 8h连续采样,重量法测定大气悬浮颗粒物浓度、粒径分布和季节变化情况;用高压液相色谱/荧光检测仪、化学发光检测仪检测PAHs、NPAHs的种类与含量。结果　3监测点的大气悬浮颗粒物污染情况相近;TSP在冬、春两季超过国家环境空气质量二级标准1. 2 8～1 .5 4倍;PM10 全年各季节、每次采样测量均超标1. 0 7～2 . 2 2倍;PM2 . 5超美国EPA细颗粒物空气质量标准3. 84～7 76倍,甚至每次采样测量值几乎都超美国标准的每日最高允许值。冬季大气悬浮颗粒物污染加重。在大气悬浮颗粒物中检出9种PAHs、12种NPAHs ,冬季浓度高于夏季,以苯并(b)荧蒽(BbF)、艹屈(Chr)和荧蒽(Flu)等4苯环的PAHs浓度较高;NPAHs在12月采暖期以2 -硝基荧蒽(2NF)为高,7月非采暖期以2 -硝基芘(2NP)为高,是其它NPAHs的几十到几千倍。PAHs、NPAHs在<2 . 1μm粒径颗粒物中的重量百分比为6 7. 2 3% ,79 .73%。结论　抚顺大气悬浮颗粒物、多环芳烃和硝基多环     

沈阳市大气悬浮颗粒物及PAHs、NPAHs分析

目的 调查了解沈阳市大气中悬浮颗粒物及其多环芳烃(PAHs)、硝基多环芳烃(NPAHs)的浓度、分布及季节变化情况。分析其健康效应。方法 选择沈阳市内机动车交通量有差别的3所小学校，于夏季非采暖期和冬季采暖期各监测1周，每天连续24h样。分别测定样品中PAHs、NPAHs种类与含量。结果 测定的10种PAHs主要以4个苯环的多环芳烃为主，即：Chr(Qu)、13aA(苯并a蒽)、Pyr(芘)、Flu(荧蒽)；测定11种NPAHs主要以2NP(夏季)、2-NF(冬季)为主，其中粒径在2．1μm以下的分别占71％，67％。夏季非采暖期以粒径0．7μm和5μm的粒子为主，冬季采暖期在机动车流量较低地区PAHs、NPAHs浓度大幅度升高，并以粒径2.1～7.0μm的颗粒物为主。结论 沈阳市大气中悬浮颗粒物及PAHs、NPAHs主要来源于冬季燃煤等污染，应进一步加以治理。     

Toxicity and modulations of biomarkers in Xenopus laevis embryos exposed to polycyclic aromatic hydrocarbons and their N-heterocyclic derivatives

Effects of a newly identified group of organic environmental pollutants of concern (N-heterocyclic derivatives of polycyclic aromatic hydrocarbons, NPAHs) were investigated using the 96 h FETAX (Frog Embryo Teratogenesis Assay - Xenopus). Beside standard FETAX parameters (mortality, malformations), changes in several biochemical markers were studied as early signs of intoxication. Biomarkers included determination of glutathione (GSH) levels and lipid peroxidation as well as activities of important detoxification and antioxidant enzymes (glutathione-S-transferase, glutathione peroxidase, glutathione reductase). 1,10-Phenathroline was the most toxic of all tested compounds (96 h LC(50) = 4 microM). All tested NPAHs induced malformations in the frog embryos. The data suggest that the exposure to NPAHs can induce oxidative stress in amphibians; most biochemical markers were modulated at concentrations lower than those resulting in significant mortality. Results document mortality and teratogenicity of all studied NPAHs to amphibian embryos while no significant mortality, teratogenicity or modulations in biochemical markers could be observed with unsubstituted polycyclic aromatic hydrocarbons (PAHs) at concentrations up to their water solubility. This information along with the significantly greater solubility and thus bioavailability compared to their nonsubstituted parent compounds suggests that NPAHs could contribute significantly to the overall aquatic toxicity of mixtures of PAHs and their derivatives.     

Toxicity of four nitrogen-heterocyclic polyaromatic hydrocarbons (NPAHs) to soil organisms

The aims of this study were: (i) to investigate the toxicity of N-heterocyclic polyaromatic hydrocarbons (NPAHs) quinoline, acridine, phenazine, and 1,10-phenanthroline to the soil invertebrates Eisenia fetida, Enchytraeus crypticus, Folsomia candida, and Caenorhabditis elegans, (ii) to compare the toxicity of four NPAHs and the species sensitivity, and (iii) to discuss possible risks of these compounds in soils. Different toxicities were found for the tested NPAHs which might be partially explained by their structure and properties. Effect concentrations expressed as soil pore-water concentrations were related to log K_ow, which indicated narcosis as the most probable mode of toxic action. The species sensitivity decreased in the rank: springtails >enchytraeids=earthworms> nematodes. Predicted no-effect concentration (PNEC) values were calculated for all tested species giving values from 0.5 to 6.8 mg/kg. It is unlikely that there is a risk for soil organisms in natural soils where lower NPAHs concentrations are expected.     

Nitropolycyclic aromatic hydrocarbons are inducers of mitotic homologous recombination in the wing-spot test of Drosophila melanogaster

In this study, the widespread environmental pollutants 1-nitronaphthalene (1NN), 1,5-dinitronaphthalene (1,5DNN), 2-nitrofluorene (2NF) and 9-nitroanthracene (9NA), were investigated for genotoxicity in the wing somatic mutation and recombination test (SMART) of Drosophila--using the high bioactivation (HB) cross. Our in vivo experiments demonstrated that all compounds assessed induced genetic toxicity, causing increased incidence of homologous somatic recombination. 2NF, 9NA and 1NN mutant clone induction is almost exclusively related to somatic recombination, although 1,5DNN-clone induction depends on both mutagenic and recombinagenic events. 1NN has the highest recombinagenic activity (approximately 100%), followed by 2NF (approximately 77%), 9NA (approximately 75%) and 1,5DNN (33%). 1NN is the compound with the strongest genotoxicity, with 9NA being approximately 40 times less potent than the former and 2NF and 1,5DNN approximately 333 times less potent than 1NN. The evidence indicating that the major effect observed in this study is an increased frequency of mitotic recombination emphasizes another hazard that could be associated to NPAHs--the increment in homologous recombination (HR).