2005年中国气态α HCH的人体暴露和健康风险分析

为评估由我国大气中α HCH所导致的人体健康风险,利用CanMETOP 模拟的2005年日均α HCH大气浓度,基于吸入因子和致癌风险进行研究。结果表明年吸入因子呈东部>西部,北部>南部的特征,东中和东北部地区的吸入因子分别主要由人口密度和α HCH大气浓度贡献,东中和东南部地区的个体健康损失小于东北地区,东中和东南部地区年内逐月吸入因子分配较为均匀,而东北地区主要集中的夏季,东北地区个体致癌风险系数明显高于中部和南部。推测由其它污染物所形成的暴露风险具有类似的时空分布。加之夏季东北地区集中降水所形成的湿沉降以及气温升高等因素,使摄食暴露和皮肤接触暴露增大,东北地区人群的复合暴露风险将显著大于其它地区     

臭氧氧化法降解聚氯乙烯离心母液废水中3种有机物

以聚氯乙烯离心母液废水中含量较高的3种有机物(聚乙烯醇、异辛醇和α-甲基苯乙烯)作为目标物,考察臭氧氧化工艺对3种有机物的去除效果,同时考察反应时间、臭氧投加量和初始pH对处理效果的影响。实验结果表明,臭氧氧化处理3种废水的最佳反应时间和臭氧投加量分别为:聚乙烯醇25 min,136 mg/L;异辛醇60min,312 mg/L;α-甲基苯乙烯60 min,32 mg/L。在此条件下,3种有机物的去除率分别为98%、85%和95%。此外,碱性条件有助于臭氧氧化工艺对3种有机物的降解。产物分析结果表明,经臭氧氧化,聚乙烯醇断链后进一步反应生成了草酸单乙酯,异辛醇和α-甲基苯乙烯分别生成了和苯乙酮。     

辉县市城区环境空气质量现状及污染防治对策

对辉县市城区2006—2011年间环境空气质量监测数据进行了评价,并对城区污染物浓度时空变化进行了分析。结果表明,辉县市城区大气污染主要表现为可吸入颗粒物污染严重,主要是能源结构不合理、锅炉废气污染严重、城区道路保洁方式落后等原因造成的,由此提出了合理规划城市布局、减少结构性污染等对策。     

Gene expression profiles in the testis associated with testis-ova in adult Japanese medaka (Oryziaslatipes) exposed to 17α-ethinylestradiol

The occurrence of oocytes in the testis (testis-ova) of several fish species is often associated with exposure of estrogenic chemicals. However, induction mechanisms of the testis-ova remain to be elucidated. To develop marker genes for detecting testis-ova in the testis, adult male medaka were exposed to nominal concentration of 100 ng L⁻¹ of 17α-ethinylestradiol (EE2) for 3-5 weeks, and 800 ng estradiol benzoate (EB) for 3 weeks (experiment I), and a measured concentration of 20 ng L⁻¹ EE2 for 1-6 weeks (experiment II). Histological analysis was performed for the testis, and microarray analyses were performed for the testis, liver and brain. Microarray analysis in the estrogen-exposed medaka liver showed vitellogenin and choriogenin as estrogen responsive genes. Testis-ova were induced in the testis after 4 weeks of exposure to 100 ng L⁻¹ EE2, 3 weeks of exposure to 800 ng EB, and 6 weeks of exposure to 20 ng L⁻¹ EE2. Microarray analysis of estrogen-exposed testes revealed up-regulation of genes related to zona pellucida (ZP) and the oocytes marker gene, 42Sp50. Using quantitative RT-PCR we confirmed that Zpc5 gene can be used as a marker for the detection of testis-ova in male medaka.     

Propiconazole inhibits the sterol 14α-demethylase in Glomus irregulare like in phytopathogenic fungi

The increasing concentrations impact (0.02, 0.2 and 2 mg L⁻¹) of a Sterol Biosynthesis Inhibitor (SBI) fungicide, propiconazole, was evaluated on development and sterol metabolism of two non-target organisms: mycorrhizal or non-mycorrhizal transformed chicory roots and the arbuscular mycorrhizal fungus (AMF) Glomus irregulare using monoxenic cultures. In this work, we provide the first evidence of a direct impact of propiconazole on the AMF by disturbing its sterol metabolism. A significant decrease in end-products sterols contents (24-methylcholesterol and in 24-ethylcholesterol) was observed concomitantly to a 24-methylenedihydrolanosterol accumulation indicating the inhibition of a key enzyme in sterol biosynthesis pathway, the sterol 14α-demethylase like in phytopathogenic fungi. A decrease in end-product sterol contents in propiconazole-treated roots was also observed suggesting a slowing down of the sterol metabolism in plant. Taken together, our findings suggest that the inhibition of the both AM symbiotic partners development by propiconazole results from their sterol metabolism alterations.     

Risk assessment of xenoestrogens in a typical domestic sewage-holding lake in China

Release of domestic sewage leads to accumulation of xenoestrogens in holding waters, especially in closed or semi-enclosed waters such as lakes. In the study, the occurrence, distribution, estrogenic activity and risk of eight xenoestreogens were evaluated in Lake Donghu, China. Nonylphenol (NP), octylphenol (OP), and bisphenol A (BPA) were identified as the main xenoestrogens ranging from tens of ng L⁻¹ (in the surface water) or ng g⁻¹ dw (in the suspended particles and sediment) to tens of μg L⁻¹ or μg g⁻¹ dw. The sum of 17β-estradiol equivalents (∑EEQs) ranged from 0.32 to 45.02 ng L⁻¹ in the surface water, 0.53 to 71.86 ng g⁻¹ dw in the suspended particles, and 0.09 to 24.73 ng g⁻¹ dw in the sediment. Diethylstilbestrol (DES) was determined as the main contributor to ∑EEQs followed by NP. The risk assessment showed a higher risk in the surface water than in the suspended particles and sediment in such domestic sewage-holding lake.     

Prenatal tests for Sanfilippo disease type B in four pregnancies

We report the prenatal diagnosis of two fetuses with Sanfilippo disease type B. In both pregnancies there were excessive amounts of heparan sulphate in amniotic fluid and the activity of N-acetyl-α-D-glucosaminidase was undetectable in cultured amniotic fluid cells. The predictions were confirmed by enzyme assay of cultured skin fibroblasts from the aborted fetus or the affected infant. The disorder was excluded for two other pregnancies at risk and the predictions are considered to be correct because of the normal progress of the healthy children.     

Detection of fetomaternal haemorrhage associated with cordocentesis using serum α-fetoprotein and the kleihauer technique

Fetomaternal haemorrhage (FMH) was studied after 46 cordocenteses. α-Fetoprotein (AFP) concentration and Kleihauer staining of maternal blood, taken both before and after the procedure, revealed increases in AFP values of more than 40 per cent in 30 per cent of the patients examined; fetal haemorrhage of more than 0.25 ml was detected in 46 per cent of the cases by the Kleihauer test. In the second trimester of pregnancy both techniques are comparable, while in the third trimester the Kleihauer technique appears to be more sensitive in detecting FMH after cordocentesis. An anterior position of the placenta is a risk factor for FMH.     

Ultrasound evaluation of pregnancies at risk for homozygous α-thalassaemia-1

Twenty-six pregnant Chinese women who were at risk of giving birth to a fetus affected with homozygous α-thalassaemia-1 were examined serially by ultrasound. Six of these 26 pregnancies were affected. In one third of the affected pregnancies progressive fetal ascites appeared before 24 weeks gestation and these pregnancies were terminated. In the remaining two thirds abnormal estimated fetal weight-placental volume (EFW-PV) ratio and fetal growth retardation as evidenced by a falling biparietal diameter (BPD), femur length (FL) but a normal abdominal circumference (AC) was apparent by 28 weeks gestation. Increased transverse cardiac (TC) diameter was another consistent finding but appeared late. All these features appeared before the onset of fetal ascites. A normal EFW-PV ratio and fetal growth until 28 weeks gestation was a reassuring sign of normality. Abnormal EFW-PV ratio was the earliest sign to appear in affected pregnancies and a normal ratio until 28 weeks gestation had a 100 per cent predictive value.     

Microbial degradation of 17β -estradiol and 17α -ethinylestradiol followed by a validated HPLC-DAD method

This work aimed at studying the biodegradation of two estrogens, 17α -estradiol (E2) and 17β -ethinylestradiol (EE2), and their potential metabolism to estrone (E1) by microbial consortia. The biodegradation studies were followed by High Performance Liquid Chromatography–Diode Array Detector (HPLC–DAD) using a specifically developed and validated method. Biodegradation studies of the estrogens (E2 and EE2) were carried out with activated sludge (consortium A, CA) obtained from a Wastewater Treatment Plant (WWTP) and with a microbial consortium able to degrade recalcitrant compounds, namely fluorobenzene (consortium B, CB). E2 was more extensively degraded than EE2 by CA whereas CB was only able to degrade E2. The addition of acetate as a supplementary carbon source led to a faster biodegradation of E2 and EE2. E1 was detected as a metabolite only during the degradation of E2. The 16S rRNA gene sequence analyses of strains recovered from the degrading cultures revealed the presence of the genera Pseudomonas, Chryseobacterium and Alcaligenes. The genera Pseudomonas and Chryseobacterium were retrieved from cultures supplied with E2 and EE2, while the genus Alcaligenes was found in the presence of E2, suggesting that they might be involved in the degradation of these compounds.