Assessing the toxicity and teratogenicity of pond water in north-central minnesota to amphibians

BACKGROUND: Incidence of amphibian deformities have increased in recent years, especially in the northern region of the United States. While many factors have been proposed as being responsible for generating deformities (e.g., contaminants, ultraviolet radiation [UV], parasites), no single cause has been definitively established. METHODS: To determine whether waterborne chemicals are responsible for amphibian deformities in ponds in north-central Minnesota, we deployed semipermeable membrane devices (SPMDs) in an impacted and a reference site to accumulate lipophilic contaminants. We then exposed native tadpoles (northern leopard frogs; Rana pipiens) to the SPMD extracts combined with two agricultural pesticides (atrazine, carbaryl) at two levels of UV radiation. RESULTS AND DISCUSSION: UV radiation alone caused a slight increase in hatching success and tadpole growth rate. Deformity rate among hatchlings was high following exposure to SPMD extracts from the reference site in the absence of UV, suggesting that chemicals present at this site are broken down by UV to less harmful forms, or become less bioavailable. Conversely, impacted site SPMD extracts caused hatchling deformities only in the presence of UV, suggesting that UV potentiates the teratogenicity of the compounds present there. Impacted site SPMD extracts significantly increased the number of bony triangles among metamorphs, a common deformity observed at this site. The incidence of skin webbings increased significantly with SPMD extracts from both sites as well as with our pesticide control containing atrazine and carbaryl alone. CONCLUSIONS: Higher deformity rates among tadpoles reared in the presence of UV radiation and SPMD extracts from sites where deformities are common indicates a chemical compound (or compounds) in the water at this site may be causing the deformities. RECOMMENDATIONS AND OUTLOOK: It is important to examine the effects of chemical stressors in the presence of other natural stressors (e.g., UV radiation) to gain a better understanding of how multiple stressors work to impact amphibians and amphibian populations.     

The role of the egg jelly coat in protecting<Emphasis Type="Italic">Hyla regilla</Emphasis> and<Emphasis Type="Italic">Bufo canorus</Emphasis> embryos from ultraviolet B radiation during development

BACKGROUND: Previous studies have suggested that Ultraviolet B (UVB) radiation may play a role in amphibian population declines. Some of these studies also indicate that egg hatching success is unaltered in some species of anurans as a result of UVB exposure. It has been proposed that the egg mass jelly provides photoprotection to the developing embryos. METHODS: Direct spectrophotometric scans of egg jelly, scans of egg jelly methanol extracts, and experimental manipulation in a solar simulator during development were all used to assess the role of egg mass jelly as a photoprotective agent. RESULTS/DISCUSSION: For Hyla regilla, scans of egg jelly and methanolic extracts (for mycosporine-like amino acid content) both displayed no absorption in the UV range. Experimental manipulation (removal of egg mass jelly) with both Hyla regilla and Bufo canorus egg masses in a solar simulator demonstrated that egg mass jelly played no apparent role in photoprotection of either of these species. CONCLUSIONS: Based on the results in this study it seems unlikely that the egg jelly coat is playing a crucial role in protecting developing embryos from the impact of UVB radiation.     

南京北郊地区黑碳气溶胶对光解系数的影响

采用2018年6月以及2017年10月南京黑碳气溶胶（BC）垂直观测数据和Mie散射理论计算BC光学厚度（AOD_BC）,并将结果输入TUV辐射传输模型,探讨BC对光解系数J[O¹D]和J[NO₂]日变化及垂直变化的影响.结果表明,在地面,J[O¹D]和J[NO₂]日变化均呈单峰型分布,峰值在正午12：00,但BC对J[O¹D]和J[NO₂]的衰减作用正午时最小,在6：00和18：00左右较大,最大分别可达-13.7%和-19.0%.AOD_BC与光解系数呈非线性负相关,BC对光解系数的衰减能力随着AOD_BC增大而下降.当天顶角为0°时,光解系数对AOD_BC的变化最敏感.在边界层0~1km内,光解系数与高度呈线性正相关,这与紫外辐射密切相关,J[O¹D]和J[NO₂]在垂直高度上与紫外辐射的相关系数R均高达0.99.BC对光解系数的衰减程度随高度下降而增大,但幅度较小,距平的最大值仅0.1%.     

First in situ UV profile across the UTLS accompanied by ozone measurement over the Tibetan Plateau

Ultraviolet radiation (UV) and ozone can greatly affect human health and the Earth's ecological environment. By deploying a UV radiometer aboard a stratospheric balloon released at Qaidam (QDM) during the Asian summer monsoon (ASM) period in 2019, we provided in situ measurement of the UV profiles from the surface to the upper troposphere and lower stratosphere over the Tibetan Plateau (TP), China, for the first time. Based on two in situ UV profiles accompanied by four ozonesonde measurements, this study exhibited detailed variations of downwelling UV and vertical ozone distributions over the TP during the ASM period. The UV differences between the surface and stratospheric balloon flight altitudes were 16.7, 15.8, 12.6 and 18.0 Wm^?2 during the four ozonesonde launches. Due to the diurnal variations in photochemical production and the stratosphere-troposphere exchange, the integrated ozone columns below 30 km ranged from 184.4 to 221.6 DU from four ozonesonde measurements. A positive correlation between UV attenuation and ozone column was exhibited under low cloud cover and clear sky conditions. The results of this study are expected to improve our understanding of UV and ozone properties, as well as their potential effects on terrestrial ecosystems and living environments over this significant plateau.     

元古宙—寒武纪疑源类的辐射演化、绝灭作用与海洋地球化学演变——兼论扬子区元古宙—奥陶纪疑源类的演化

通过对目前全世界元古宙———寒武纪地层中的浮游植物 (疑源类 )的统计 ,发现在新元古代晚期和早、中寒武世相对较短的时间间隔内发生了一系列的微体植物 (疑源类 )辐射和绝灭事件。而这些辐射和绝灭事件又与早期后生生物的辐射、绝灭都有密切的镜像关系。通过对古海洋的δ13 C、87Sr/ 86Sr研究 ,发现元古宙—寒武纪浮游植物 (疑源类 )的辐射演化、绝灭作用与古海洋环境变化有着密切的关系 ,即生物辐射时期 ,δ13 C、　87Sr/ 86Sr呈现高异常 ;生物绝灭时期 ,δ13 C、87Sr/ 86Sr呈现低异常 ;冰期δ13 C呈现明显的负异常。     

interactions amongst policies designed to resolve individual air issues

Six air issues are currently on science and policy agendas in Canadaand elsewhere. These are climate change, stratospheric ozone depletion(increased UV-B radiation), acidic deposition, SMOG (increasedground-level ozone), suspended particulate matter, and hazardous airpollutants. Atmospheric scientists and decision makers have largelyaddressed these issues individually resulting in single-issue policies. However, it is now recognized that these issues are inter-related, andthey may interact to cause negative as well as some beneficial effects,not only on the state of the atmosphere but also on societal andecological systems. This paper illustrates through several examples theatmospheric dysfunction caused by the linkages among the six airissues. It also points to potentially conflicting policies arising from thesingle-issue approach, and it emphasizes the need for better integrationof air issues. The linkages are summarized qualitatively in Table I.     

Uranium, Thorium, and Potassium in Soils Along the Shore of Lake Issyk-Kyol in the Kyrghyz Republic

The Kyrghyz Republic, located in the southeastern region ofthe former Soviet Union, maintains a population of more thanone-half-million persons and is heavily dependent on LakeIssyk-Kyol, both to draw tourists to the area and for itsutilization by some as a food and recreation source. Historical surveys, conducted primarily for geologicalexploration, have indicated that localized areas ofshoreline on Lake Issyk-Kyol have relative radiation levelsin excess of ambient background by as much as a factor often. Uranium mining operations in the mountains borderingthe lake to the south may have resulted in the contaminationof a number of areas on the lake's southern shore. Concentrations of naturally occurring uranium, thorium, andpotassium are present in these soils in elevated quantities. This paper presents the results of an investigation of soilconcentrations along the shoreline of Lake Issyk-Kyolrelative to previously discovered areas of high exposurerate.     

微波消解法测定水样中总氮

提出了用微波法对水和废水样品进行消解，测定总氮含量的实验方法．经过对实际样品的测定，证明与原有测定方法具有可比性，并具有操作简单、快速省时、测定准确的特点。     

广州市GSM移动电话基站发射电磁波对环境污染影响分析

依据国标《环境电磁波卫生标准》(GB91 75 -88) ,从理论上讨论了 GSM移动通信基站电磁辐射对环境的影响 ;并利用若干基站的实际测试数据 ,说明在一般情况下 ,对于基站周围的民居或其它楼宇里居住或工作的人群 ,移动通信基站的电磁辐射强度远低于国家标准 ,也远低于美国的标准     

大同市某医院放疗装置环境辐射调查

大同市环境监察支队对大同市某医院医用电子直线加速器及近距离遥控后装机工作场所及其周围环境辐射水平进行了调查。表明，加速器及近距离遥控后装机室内X、γ辐射剂量率，在关机或开机状态下监测结果变化不明显，基本在本底范围内。加速器及近距离遥控后装机室外X、γ辐射剂量率范围接近1987年“全国放射性水平调查”的天然贯穿辐射剂量平均值；屋顶X、γ辐射剂量率监测结果也居正常本底水平。