Atrazine uptake,photosynthetic inhibition,and short-term recovery for the submersed vascular plant,Potamogeton perfoliatus L.

The processes of atrazine (2-chloro-4-[ethylamino]-6-[isopropylamino-]-s-tri-azine) uptake and release in the submersed vascular plant,Potamogeton perfoliatus L., were rapid, approaching equilibrium with the surrounding environment within one hr. The ratio of internal atrazine concentration to external concentration was approximately 10 at the point of maximum photosynthetic inhibition and rapidly increased at lower external atrazine concentrations. The I₅₀ (the concentration inhibiting photosynthesis by 50%) for atrazine in solution was 80 g/L with the maximum observed photosynthetic reduction (87%) at a solution concentration of 650 g/L. Initial photosynthetic recovery ofP. perfoliatus following exposure to atrazine was rapid with oxygen evolution from treated plants (5, 25, and 100 g/L) being statistically indistinguishable from control plants after two hr of atrazine-free wash. However, there was an indication of residual photosynthetic depression in dosed plants, even after a 77 hr recovery period. In Chesapeake Bay, potential long-term exposure of submersed plants to concentrations of atrazine greater than 10 g/L is doubtful so that reduction ofP. perfoliatus photosynthesis under such conditions would be minimal and reversible.     

Uptake and phytotoxicity of soil-sorbed atrazine for the submerged aquatic plant,Potamogeton perfoliatus L.

The photosynthetic inhibitory effect of atrazine-sorbed soil placed on the leaf surfaces ofPotamogeton perfoliatus was investigated under laboratory conditions. Leaves simultaneously exposed to atrazine both in solution and sorbed to soil exhibited a similar uptake of atrazine and associated photosynthetic reduction as did leaves exposed to the same concentration of atrazine in solution only. A small quantity of atrazine (0.19 /gdw leaf) was found in leaves treated with atrazine-sorbed soil at 120 /kg whereas a significantly larger amount (3.57 g/gdw leaf) was present in leaves treated with dissolved atrazine at a concentration of 100 g/L. It is concluded that atrazine sorbed to soil on leaf surfaces is less available for uptake by aquatic plants than atrazine in solution. Of greater physiological concern is the physical presence of the soil on the leaves and the resultant reduction of light.     

Hygienic examinations of the water quality in the coastal zone of Lake Balaton

From hygienic water examinations of Lake Balaton during the period 1981–1990, in the coastal water area only the hygienic safety of bathing improved due to different measures taken for the sake of improving water quality. The water of the beaches is characterized by surface water qualities classified from a bacteriological point of view as 'clean' (class I) and ‘moderately contaminated’ (class II), suitable for bathing. From the point of chemical contamination, the required ‘clean’ water quality — still awaited as a result of the water‐quality protective measures taken in the above period — could not be detected. The accumulated nutrients in the lake, and other contaminants burdening the coastal area, present a considerable risk also in the future, from the point of view of water quality. Further water‐ and environment protective measures are urged to decrease and/or stop these unfavourable conditions.     

Multigeneration acclimation of Daphnia magna Straus to different bioavailable copper concentrations

A large acclimation experiment was performed with Daphnia magna in which two different copper bioavailability (as Cu2+) groups (N and M) were used. In the N group the cupric ion activity increased with increasing dissolved copper-acclimation concentration, while in the M group the ion activity decreased with increasing dissolved copper concentration. The activity of copper carbonates and hydroxides was up to an order of magnitude lower than the cupric ion activity. After five generations of acclimation, the acute copper sensitivity (mean +/- SD) of the N group ranged from 193 /- 24 to 296 +/- 50 microg Cu L(-1) and for the M group from 198 +/- 27 to 315 +/- 38 microg Cu L(-1) for daphnids acclimated to 1 and 100 microg Cu L(-1), respectively. The internal copper concentration of the acclimated daphnids also resulted in similar results between the two groups. Acclimation of the two daphnid groups for five consecutive generations to the three dissolved copper concentrations resulted in a shift in the optimal concentration range toward 1 microg Cu L(-1), using energy reserves as an endpoint. Our results suggest that copper acclimation and accumulation are related to the dissolved copper concentration of the culture medium, but not to the copper activity.     

Electronic signature thrives in different environments

Implementing electronic signature has been a positive experience for both our organizations. The benefits we sought were there, and unforeseen benefits surfaced. Five activities that facilitated the success of electronic signature at our two facilities were (1) flowcharting the electronic signature process prior to purchase and installation; (2) becoming familiar with legal requirements for electronic signature, and assuring that products under consideration meet these requirements; (3) gaining the support of medical staff leadership; (4) using a written agreement of password confidentiality and document responsibility with physicians; and (5) thoroughly training medical records staff, then establishing a positive one-on-one training procedure for physicians with a high degree of staff attention.     

Presence of endotoxins in different agricultural environments

Gram-negative bacterial endotoxins are contaminants of dusts from agricultural products. They represent a potential health hazard for farmers working in many different processes. However, the occurrence of endotoxins has not been well characterized in the various farming operations. Therefore, two farming activities with potential for generating airborne endotoxins were studied: 1) chopping of baled corn stalks or straw for bedding in New York State, and 2) oat bin unloading in Alabama. Actual airborne endotoxin levels in dusts obtained during bedding chopper operations far exceeded [90 endotoxin units (EU)/m3] the level at which acute pulmonary function decrements occur in cotton dust-exposed individuals. Endotoxin contamination of laboratory-generated dust from an oat sample likewise exceeded these levels. This study documents the presence of potentially hazardous exposures to endotoxins in two common farm processes, which expands the knowledge of airborne endotoxin exposures on the farm.     

Risk assessment of exposure to volatile organic compounds in different indoor environments

The lifetime cancer risks of exposure of cooks and food service workers, office workers, housewives, and schoolchildren in Hong Kong to volatile organic compounds (VOCs) in their respective indoor premises during normal indoor activities were assessed. The estimated cancer risk for housewives was the highest, and the second-highest lifetime cancer risk to VOC exposure was for the groups of food service and office workers. Within a certain group of the population, the lifetime cancer risk of the home living room was one to two orders of magnitude higher than that in other indoor environments. The estimated lifetime risks of food service workers were about two times that of office workers. Furthermore, the cancer risks of working in kitchen environments were approximately two times higher than the risks arising from studying in air-conditioned classrooms. The bus riders had higher average lifetime cancer risks than those travelling by Mass Transit Railway. For all target groups of people, the findings of this study show that the exposures to VOCs may lead to lifetime risks higher than 1 x 10(-6). Seven indoor environments were selected for the measurement of human exposure and the estimation of the corresponding lifetime cancer risks. The lifetime risks with 8-h average daily exposures to individual VOCs in individual environments were compared. People in a smoking home had the highest cancer risk, while students in an air-conditioned classroom had the lowest risk of cancer. Benzene accounted for about or more than 40% of the lifetime cancer risks for each category of indoor environment. Nonsmoking and smoking residences in Hong Kong had cancer risks associated with 8-h exposures of benzene above 1.8 x 10(-5) and 8.0 x 10(-5), respectively. The cancer risks associated with 1,1-dichloroethene, chloroform, methylene chloride, trichloroethene, and tetrachloroethene became more significant at selected homes and restaurants. Higher lifetime cancer risks due to exposure to styrene were only observed in the administrative and printing offices and air-conditioned classrooms. Higher lifetime cancer risks related to chloroform exposures were observed at the restaurant and the canteen.     

不同成长背景的华裔大学生性观念和性行为调查

目的:了解不同成长背景的现代华裔大学生性观念和性行为的状况。方法:对暨南大学不同成长背景的华裔本科生群体进行问卷调查,比较来自港澳台、海外、大陆城市、大陆乡村的男生和女生的性观念和性行为的差异。结果:大多数大学生认为目前大学生婚前性行为很普遍,57%的学生接受婚前性行为,61.7%的学生可以接受配偶以往的性经历。婚前性行为发生比例外招生高于大陆学生,3.45%的女大学生经历过意外妊娠。生理需要是大学生婚前性行为的主要诱因,婚前性行为对大学生的主要困扰是意外妊娠。结论:当代大学生的性观念很开放,成长环境对性观念和性行为有较大的影响。大学生的避孕知识需加强。     

Using WHOQOL-BREF to evaluate quality of life among Turkish elders in different residential environments

Objective  This study used the Brief Version of The World Health Organization’s Quality of Life Questionnaire (WHOQOL-BREF) to assess and compare the quality of life in older people who live at home and older people who live in public assisted-living facilities for the elderly. Design  Cross-sectional. Setting  Data were collected by a research nurse in each home and in the assisted living facility. Participants  Participants were 60 years old and older. The sample included 37 people who were living in a public assisted-living facility and 37 elderly people living in their own homes. Measurement  The WHOQOL-BREF was used to measure participants’ quality of life. Results  The groups were similar according to gender, literacy, existence of chronic diseases, and general perceived health. However, quality of life scores for social relationships and environment domains were lower in those living in an assisted living facility than those living in their own homes. The scores for elderly females staying in the assisted living facility were lower compared to the scores of males in the facility. Conclusion  The results suggest that social and environmental domains of life quality are low in elderly assisted living facilities. Social activities should be diversified for elderly people staying in assisted living facilities to improve social relationships. Physical and psychological health of females in assisted living facilities should be comprehensively supported by professionals. Alternatively, elderly people may be professionally supported to live in their own homes.     

Lead content of deciduous teeth of children in different environments.

The lead content of teeth of children in five different environments has been measured to determine the relative contribution of different sources of lead. The importance of lead paint in children living in dilapidated housing is clearly observed, but no effect attributable to automobile exhaust or industrial emissions is apparent. High lead levels were found among children living in new public housing projects within the high lead area of the city, even though a lead paint problem presumably should not exist in the projects themselves. The data are analyzed to determine the frequency with which excessive lead contents occur in the problem area in comparison to a low risk area.     

不同职业放射暴露环境工作人员染色体和微核发生变化的影响因素分析

目的 探讨不同职业放射暴露环境工作人员外周血淋巴细胞染色体发生畸变和微核发生变化的危险因素,为评价各类职业放射暴露环境工作人员健康水平提供依据。方法 收集2012年宝鸡市372名职业放射暴露环境工作人员(医用X线诊断139名,工业探伤106名,烟厂卷接工95名,工业同位素应用32名)的一般人口学、工龄、职业放射暴露环境及染色体和微核变化的数据。采用χ²检验、多因素logistic回归等方法进行统计分析。结果 不同年龄组职业放射暴露环境工作人员的微核率之间差异有统计学意义(P＜0.05)。不同工龄组的ace畸变率、染色体型畸变率、染色体畸变总率和微核率之间差异有统计学意义(P＜0.001);不同职业放射暴露环境工作人员的无着丝粒断片(acentric fragment, ace)畸变率和染色体型畸变率差异有统计学意义(P＜0.05)。年龄和放射工龄是职业放射暴露环境工作人员发生ace畸变(OR=1.064,95%CI：1.018～1.112)、染色体型畸变(OR=1.064,95% CI：1.021～1.108)、染色体总畸变(OR=1.038,95% CI：1.006～1.071)和外周血淋巴细胞产生微核(OR=1.064,95% CI：1.037～1.091)的危险因素,随着年龄和放射工龄增加,其发生ace畸变、染色体型畸变、染色体总畸变和外周血淋巴细胞产生微核的风险增加。烟厂卷接工的放射暴露环境是发生染色体型畸变、染色单体畸变和染色体总畸变的危险因素。烟厂卷接工发生ace畸变、染色体型畸变、染色单体畸变和染色体总畸变的危险分别是医用X线诊断的3.679(95%CI：1.310~10.335)、3.637(95%CI：1.405~9.413)、3.649(95%CI：1.488~8.951)、3.794(95%CI：1.795~8.017)倍。人均年有效剂量与职业放射暴露环境工作人员外周血淋巴细胞发生变化无关。结论 职业放射暴露环境对工作人员的外周血淋巴细胞产生一定的影响。年龄和放射工龄也与外周血淋巴细胞发生改变有关。与其他职业放射暴露环境相比,烟厂卷接工作环境是外周血淋巴细胞发生改变的主要危险因素。     

Streptozotocin diabetes in rats after acclimation to cold environment

To investigate the effects of acclimation to a cold environment on the alteration of glucose and fat metabolism in diabetes, the levels of blood glucose, triacylglycerol, nonesterified fatty acid, and immunoreactive insulin were measured before and on the 3rd and 14th days after streptozotocin treatment in cold-acclimated (4 degrees C) and warm-acclimated (24 degrees C; control) rats. The cold-acclimated rats showed no hyperglycemia on the 14th day after streptozotocin treatment, whereas the control diabetic rats maintained high blood glucose levels. Triacylglycerol levels did not increase in the cold-acclimated diabetic rats, whereas the control diabetic rats showed markedly high triacylglycerol levels. Immunoreactive insulin levels remained constantly low in both cold-acclimated and control diabetic rats. It was concluded that acclimation to cold changed some of the metabolic consequences of diabetes caused by streptozotocin in rats.     

不同工作环境人群PM2.5暴露水平与肺功能的研究

目的评价太原市交通警察和疾病预防控制中心(CDC)人员工作环境PM2.5暴露水平,探讨工作环境PM2.5暴露与人群肺功能的关系。方法选用外勤交通警察(暴露组)、CDC人员(对照组)为研究对象,应用环境检测和时间-活动日记相结合的方法连续采样1周,计算研究对象工作时间内PM2.5暴露剂量和潜在暴露剂量。同时对研究对象进行问卷调查,于环境PM2.5检测1周结束后检测肺功能。结果交通警察工作交通路口的PM2.5浓度([0.132±0.049)mg/m3]高于CDC办公室内PM2.5浓度([0.100±0.044)mg/m3],交通警察8 h工作时间内的暴露剂量、潜在暴露剂量分别为(1.060±0.23)mg和(1.690±0.37)mg,均高于CDC人员[均为(0.798±0.19)mg];男性交通警察最大呼气流量(PEF)和第1秒钟用力呼气量/用力肺活量(FEV1.0/FVC)分别为(4.70±0.28)L/s和0.82±0.03,低于男性CDC人员[PEF和FEV1.0/FVC分别为(6.53±0.41)L/s和0.92±0.02];上述差异均有统计学意义(P0.05)。结论交通警察的PM2.5暴露剂量和潜在暴露剂量均高于CDC人员,男性交通警察的肺功能下降可能与长期暴露于机动车尾气有关。     

Cardiovascular disease occurrence in two close but different social environments

Background  

Cardiovascular diseases estimate to be the leading cause of death and loss of disability-adjusted life years globally. Conventional risk factors for cardiovascular diseases only partly account for the social gradient. The purpose of this study was to compare the occurrence of the most frequent cardiovascular diseases and cardiovascular mortality in two close cities, the Twin cities.     

Rapid infection of pigs following exposure to environments contaminated with different levels of Salmonella typhimurium

Pigs reared in an environment free of Salmonella species or on farms with low levels of infection may acquire infection during transport to the abattoir or while held in lairage. We designed a study to determine if pigs could become infected with S. Typhimurium when placed in a contaminated environment similar to that observed in commercial lairage. In addition, quantitative examination of salmonellae in all environmental and animal samples was undertaken. In order to simulate a naturally contaminated environment, animals experimentally infected with a challenge strain of S. Typhimurium (PT12) were used to seed the trial pen environment with salmonellae. In trial 1, pigs were exposed to a highly contaminated environment (5.4 log(10) CFU/100 cm(2)) for 2, 3, or 24 hours. Following these exposure periods, pigs were euthanized and samples including gastrointestinal and associated lymphoid tissue were analyzed for the challenge strain. S. Typhimuirum PT12 was detected in at least one sample type analyzed from each pig after exposure for > or =2 hours. The most frequently contaminated samples were tonsils (100% positive), followed by segments of the ileocecal junction (94.4% positive) and cecal contents (89% positive). Quantitative analysis conducted on cecal contents and ilocaecal junction segments revealed that similar numbers of organisms (1.1-2 log (10) /g) were isolated at all timepoints. In trial 2, pigs were exposed to a less contaminated environment (2.65 log (10) CFU/100 cm(2)) for periods of 1, 3, 6, or 24 hours. S. Typhimuirum PT12 was not detected in any sample from pigs euthanized after exposure of 1 hour. The challenge strain was recovered from the cecal contents of pigs after exposures of 3, 6, and 24 hours, and from the tonsil of one pig after exposure for 6 hours. These results highlight the need to reduce the environmental load of Salmonella spp. in lairage holding pens in order to reduce the numbers of infected pigs entering the slaughter process.     

Effect of pendimethalin on growth and photosynthetic activity of Protosiphon botryoides in different nutrient states

The effect of pendimethalin on the green alga Protosiphon botryoides was investigated. Results indicate that specific growth rate, cell number, chlorophyll a level, and dry weight yield significantly decrease with increasing pendimethalin concentrations, while protein and carbohydrate contents increase significantly. On the other hand, photosynthetic activity decreases whereas dark respiration increases with high pendimethalin concentrations. High doses of pendimethalin exhibited no clear trend with 77 K fluorescence (Fv/Fm). Increasing nitrate and phosphate levels led to a decrease in cell number, chlorophyll a, and dry weight as compared with the control at high doses of pendimethalin. The results obtained revealed that N:P < 1 increases the inhibitory effect of high doses of the herbicide.     

巨尾阿丽蝇卵不同发育时间形态变化及基因表达

目的探讨巨尾阿丽蝇(Aldrichina grahami)卵不同发育时间的形态变化与基因表达差异规律。方法从巨尾阿丽蝇成虫产完卵开始记为0 h, 每隔4 h取1次卵, 直至幼虫孵出, 用扫描电镜观察不同发育时期形态学变化特点;提取0、4、8、12、16 h的蝇卵RNA, 应用Real-time PCR比较循环阈值(CT值)法测定bicoid、slalom、几丁质合成酶(chitin synthase)基因相对表达量, 用SPSS 19.0软件对CT值及时间进行曲线拟合。结果扫描电镜结果显示, 发育0～4 h时, 巨尾阿丽蝇卵变化不明显, 卵孔周围有突起, 8 h卵孔周围变光滑, 卵孔可见, 12 h卵孔消失, 周围皱缩, 16 h卵孔周围皱缩明显, 18 h发育为幼虫;RT-PCR结果显示, bicoid基因在发育0～8 h表达变化不明显、12 h 表达水平最高, CT值为(4.19±0.04);slalom基因4 h表达水平最低、12 h表达最高, CT值分别为(4.05±0.01)、(6.20±0.03);chitin synthase基因8 h表达量最高、12 h最低, CT值分别为(5.80±0.01)、(4.38±0.02);不同发育阶段各基因CT值不同, 差异均有统计学意义(均P<0.05)。结论巨尾阿丽蝇卵形态结构随发育时间而发生变化, 不同发育时期bicoid、slalom、chitin synthase基因表达量存在差异。     

Wind turbine noise, annoyance and self-reported health and well-being in different living environments

Objectives

To evaluate the prevalence of perception and annoyance due to wind turbine noise among people living near the turbines, and to study relations between noise and perception/annoyance, with focus on differences between living environments.

Methods

A cross‐sectional study was carried out in seven areas in Sweden across dissimilar terrain and different degrees of urbanisation. A postal questionnaire regarding living conditions including response to wind turbine noise was completed by 754 subjects. Outdoor A‐weighted sound pressure levels (SPLs) were calculated for each respondent. Perception and annoyance due to wind turbine noise in relation to SPLs was analysed with regard to dissimilarities between the areas.

Results

The odds of perceiving wind turbine noise increased with increasing SPL (OR 1.3; 95% CI 1.25 to 1.40). The odds of being annoyed by wind turbine noise also increased with increasing SPLs (OR 1.1; 95% CI 1.01 to 1.25). Perception and annoyance were associated with terrain and urbanisation: (1) a rural area increased the risk of perception and annoyance in comparison with a suburban area; and (2) in a rural setting, complex ground (hilly or rocky terrain) increased the risk compared with flat ground. Annoyance was associated with both objective and subjective factors of wind turbine visibility, and was further associated with lowered sleep quality and negative emotions.

Conclusion

There is a need to take the unique environment into account when planning a new wind farm so that adverse health effects are avoided. The influence of area‐related factors should also be considered in future community noise research.Wind power is a relatively new form of electricity generation that has a low impact on the environment compared with other power sources¹ and is also favoured by the public, at least by those who do not have a wind turbine project in their own community.² One disadvantage is the noise that inevitably emits from the rotor blades. Typically, sound power levels of a modern wind turbine range from 98–104 dB(A) at a wind speed of 8 m/s, which result in 33–40 dB(A) at a dwelling 500 m away, though this depends on meteorological and ground conditions. Sound pressure levels (SPLs) of this low magnitude are not considered a problem when it comes to other sources of community noise, such as road traffic and aircraft, but two circumstances increase the risk of negative perception of the sound from wind turbines: the sound character and the localisation. The sound is amplitude modulated by the pace of the rotor blades, which gives a rhythmical swishing sound. Such sounds are known to be more easily perceived than an even sound³ and possibly also are more negatively appraised. In a rural environment the turbines are prominent and, because the rotor blades move in an otherwise fairly still environment, they are likely to draw visual attention.We do not know the prevalence of perception and possible effects of wind turbine noise at a generalised level because only a few studies have been carried out. In an investigation of the impact of wind turbines on people living near them in a flat landscape, a dose‐response relation between A‐weighted SPL and annoyance due to wind turbine noise was found.⁴ The relation was, however, moderated by the respondents'' attitude to the visual impact of the turbines on the landscape. In a Danish study, also carried out in a flat landscape, the angle from the subject to the hub of the wind turbine was more correlated to perception of the noise than SPL was.⁵ There are therefore reasons to believe that the prevalence of noise annoyance may be influenced by the variation in visibility of the wind turbines between different landscapes, such as a flat landscape and a hilly ground.In one study, interviews with 15 subjects revealed additional possible associations between landscape and perception of wind turbine noise.⁶ The subjects'' personal values relating to the living environment appeared to influence how the noise from the wind turbines was perceived. Some, who considered the countryside as a place for economic growth and technical achievements, were indifferent to noise exposure from the wind turbines. Others, who emphasised that the countryside should be a quiet and peaceful place for relaxation, felt that the noise intruded their privacy and hence had a negative impact on their quality of life. People in the latter category would presumably seek living environments consistent with their needs, and may therefore be overrepresented in areas they perceive as quiet and peaceful. It could therefore be hypothesised that exposure from wind turbines would be more negatively appraised in an area that is perceived as unspoiled than in an area where several human activities take place.