生活饮用水放射性水平调查

目的：为了解吉林省饮用水中放射性水平。方法：依据《生活饮用水卫生规范》和《饮用天然矿泉水标准》,采用BH1217型弱α,β测量仪和FD一125室内氡钍测定仪,对饮用水总α、总β和5个行政区域矿泉水中226Ra放射性水平分析测定。结果：自来水,深井水的总α放射性含量分别为13×10-3Bq/L,16.7×10-3Bq/L。总β放射性含量分别为82×10-3Bq/L,71×10-3Bq/L,57×10-3Bq/L。五个行政区域的226Ra平均值为8.6×10-3Bq/L。结论：吉林省生活饮用水中总α、总β和226Ra放射性活度在国家卫生标准限值范围内。     

石河子-昌吉地区地下水水质时空变化及污染源解析

为了探明新疆石河子-昌吉地区地下水水质时空变化并解析污染源,综合运用基于香农熵的贝叶斯水质评价模型、 Spearman秩相关系数、主成分分析和绝对主成分得分-多元线性回归受体模型(APCS-MLR)等方法,对23眼原位井2016～2021年逐年地下水水质数据进行分析.结果表明：(1)研究区多年地下水水质状况总体较好,潜水水质类别以Ⅰ类和Ⅱ类为主,承压水主要为Ⅰ类.(2)从时间看,2016年和2017年分别为潜水和承压水水质变化的关键时间节点,Ⅳ类和Ⅴ类水仅出现在节点之前,之后在Ⅰ～Ⅲ类水范围内波动.(3)从空间看,潜水水质优劣排序为：石河子市≈呼图壁县>玛纳斯县>昌吉市;承压水为：石河子市≈昌吉市>呼图壁县>玛纳斯县.(4)研究区多年地下水水质类别和主要水质指标在时空变化上基本对应,且异质性较强.(5)潜水水质主要受到溶滤作用(67.30%)、溶滤-迁移作用(10.89%)和农业-生活污染(9.44%)的影响,溶滤-富集作用(52.08%)、农业-生活污染(16.06%)和碱性环境的离子交换作用(12.64%)对承压水水质影响较大.尽管研究区多年水质状况整体呈改...     

基于APCS-MLR受体模型和地统计法的矿区周边农用地土壤重金属来源解析

为探明矿区周边土壤重金属来源,为地区土壤污染防治提供有效建议,在重庆市黔江区五里乡北部采集表层土壤(0～20 cm)样品118件,分析了土壤中重金属(Cd、 Hg、 Pb、 As、 Cr、 Cu、 Zn和Ni)含量及土壤pH,利用地统计法和APCS-MLR受体模型对土壤重金属空间分布和来源进行了研究.结果表明,土壤重金属含量明显高于重庆市背景值,存在明显的表层累积.Hg、 Pb、 Cd、 As和Zn均表现为极强变异.土壤Cd、 Hg、 Pb、 As和Zn超过风险筛选值的比例分别为47.11%、 6.61%、 4.96%、 5.79%和7.44%,土壤Cd、 Hg、 Pb和As超过风险管制值的比例分别为0.83%、 4.13%、 0.83%和0.83%,土壤重金属超标问题显著.土壤Cd、 As、 Cr、 Cu和Ni主要受到成土母质的影响,对土壤元素总量的贡献率分别为77.65%、 68.55%、 71.98%、 90.83%和82.19%,土壤Hg、 Pb和Zn主要受到汞矿和铅锌矿开采的影响,贡献率分别为86.59%、 88.06%和91.34%.此外,农业活动也会影响土壤Cd和As的含...     

Effects of estrogen exposure in mussels, Mytilus edulis, at different stages of gametogenesis

Mytilus edulis were exposed to 17β-estradiol (E2) and the synthetic estrogens ethinyl estradiol (EE2) and estradiol benzoate (EB) for 10 days. Two exposures were performed to determine their effect on vitellogenin (VTG) and estrogen receptor 2 (ER2) mRNA expression at different stages of the reproductive cycle. Significant natural variation was not observed in VTG mRNA expression, though ER2 mRNA expression displayed significantly lower values during January, February and July compared with other times of the year. A significant increase in VTG and ER2 mRNA expression was observed in mussels exposed to estrogens at the early stage of gametogenesis. In contrast, mature mussels displayed no statistically significant change in the VTG or ER2 mRNA expression. The data presented suggests that the reproductive physiology of molluscs, in terms of VTG and ER2 mRNA expression, may be susceptible to damage by environmental estrogens at certain points in their gametogenesis process.     

Endocrine disruptors in bottled mineral water: total estrogenic burden and migration from plastic bottles

Background, aim, and scope  Food consumption is an important route of human exposure to endocrine-disrupting chemicals. So far, this has been demonstrated by exposure modeling or analytical identification of single substances in foodstuff (e.g., phthalates) and human body fluids (e.g., urine and blood). Since the research in this field is focused on few chemicals (and thus missing mixture effects), the overall contamination of edibles with xenohormones is largely unknown. The aim of this study was to assess the integrated estrogenic burden of bottled mineral water as model foodstuff and to characterize the potential sources of the estrogenic contamination. Materials, methods, and results  In the present study, we analyzed commercially available mineral water in an in vitro system with the human estrogen receptor alpha and detected estrogenic contamination in 60% of all samples with a maximum activity equivalent to 75.2 ng/l of the natural sex hormone 17β-estradiol. Furthermore, breeding of the molluskan model Potamopyrgus antipodarum in water bottles made of glass and plastic [polyethylene terephthalate (PET)] resulted in an increased reproductive output of snails cultured in PET bottles. This provides first evidence that substances leaching from plastic food packaging materials act as functional estrogens in vivo. Discussion and conclusions  Our results demonstrate a widespread contamination of mineral water with xenoestrogens that partly originates from compounds leaching from the plastic packaging material. These substances possess potent estrogenic activity in vivo in a molluskan sentinel. Overall, the results indicate that a broader range of foodstuff may be contaminated with endocrine disruptors when packed in plastics.     

Biogenic volatile organic compounds as a potential stimulator for organic contaminant degradation by soil microorganisms

The effects of monoterpenes on the degradation of ¹⁴C-2,4-dichlorophenol (DCP) were investigated in soils collected from areas surrounding monoterpene and non-monoterpene-emitting vegetation. Indigenous microorganisms degraded ¹⁴C-2,4-DCP to ¹⁴CO₂, after 1 d contact time. Degradation was enhanced by prior exposure of the soils to 2,4-DCP for 32 d, increasing extents of mineralisation up to 60%. Monoterpene amendments further enhanced 2,4-DCP degradation, but only following pre-exposure to both 2,4-DCP and monoterpene, with total 2,4-DCP mineralisation extents of up to 71%. Degradation was greatest at the higher monoterpene concentrations (≥1 μg kg⁻¹). Total mineralisation extents were similar between concentrations, but higher than the control and the 0.1 μg kg⁻¹ amendment, indicating that increases in monoterpene concentration has a diminishing enhancing effect. We suggest that monoterpenes can stimulate the biodegradation of 2,4-DCP by indigenous soil microorganisms and that monoterpene amendment in soils is an effective strategy for removing organic contaminants.     

Characterization of phosphogypsum wastes associated with phosphoric acid and fertilizers production

The present work is directed to characterize the phosphogypsum (PG) wastes associated with phosphoric acid produced by the wet process in industrial facility for the production of fertilizers and chemicals in Egypt. The PG waste samples were characterized in terms of spectroscopic analysis (X-ray diffraction, X-ray fluorescence, IR spectra) and radiometric analysis (γ- and α-measurements). The γ-ray measurements showed that the average activity concentrations are 140 ± 12.6, 459 ± 36.7, 323 ± 28.4, 8.3 ± 0.76 and 64.3 ± 4.1 Bq/kg for U-238, Ra-226, Pb-210, Th-232 and K-40, respectively. The α-particle measurements of uranium isotopes showed that the average activity concentrations of U-238, U-235 and U-234 were 153 ± 9.8, 7 ± 0.38, 152 ± 10.4 Bq/kg, respectively. The average radiochemical recovery (%) of the destructive α-particle measurements is ∼70% with a resolution (FWHM) of ∼30 keV. Activity ratios of U-238/Ra-226 and U-238/Pb-210 were less than unity (i.e., <1) and equal to 0.31 ± 0.02 and 0.47 ± 0.16, respectively. The isotopic ratios of U-238/U-235 and U-238/U-234 (in PG and PR samples) were close to the normal values of ∼21.7 and ∼1, respectively and are not affected by the wet processing of phosphate rock (PR). The obtained results of PG waste samples were compared with phosphate rock (PR) samples. The radiation hazard indices are namely, radium activity index (Ra-Eq > 370 Bq/kg), total absorbed gamma dose rate (D_γr > 5 nGy/h) and radon emanation fraction (Rn-EF > 20%). Uncertainty of the sample counting was 95% confidence level of σ. The results indicated the necessity to find suitable routes to decrease and/or redistribute the radionuclide of environmental interest (i.e., Ra-226) in PG wastes, consequently to reduce its radiation impacts in the surrounding environment.