首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
Environmental Science and Pollution Research - Dengue fever (DF) is one of the world’s most important vector-borne illnesses. In 2017, Egypt experienced a dengue outbreak. This study aimed to...  相似文献   

2.
Environmental Science and Pollution Research - To identify level of job satisfaction among physicians at secondary and tertiary care levels. Random sample of 450 secondary and 523 tertiary care...  相似文献   

3.
Environmental Science and Pollution Research - Tramadol abuse is an increasingly alarming phenomenon among Egyptian Community especially among workers and drivers. Study profile and factors...  相似文献   

4.
Environmental Science and Pollution Research - Adolescent females are often environmentally exposed to pesticides by living near agricultural fields, by using pesticides at home, or by having...  相似文献   

5.
Concentrations of inorganic, methyl- and butyltin compounds were quantified by a hydride derivatization/atomic absorption technique for eleven short sediment cores sampled from Lake Maryut, Alexandria, Egypt. All samples contained inorganic Sn concentrations ranging from 1875 to 8190 ng g(-1) dw, the highest levels occurring in the eastern portion of the lake. Methyltin concentrations were also highest in the eastern lake, decreasing considerably in the western lake. Mono- and dimethyltins were found at all sites, the former species being the highest in concentration. Trimethyltin was much lower than either, and was absent from four out of 11 sites. An opposite trend was observed for the butyltin species, their concentration being highest in the west lake, decreasing eastward. Mono- and dibutyltin were almost equal in concentration. Although tributyltin was absent from one site in the lake, it was much higher in concentration than the two other species, particularly in the western lake. In general, methyl- and butyltin concentrations decreased with depth in the cores. Methyltin compounds appear to form within the lake mainly by methylation of inorganic Sn, and butyltin compounds are derived from anthropogenic sources. No significant correlations were found between organic C and concentrations of methyltin species. A significant negative correlation was found between total butyltin concentrations and organic C in surficial sediments.  相似文献   

6.
Fourteen locations were sampled along the Alexandria coast to assess the occurrence and fate of alkyllead compounds in water, sediments and biota. Tetraalkyllead was not observed in any of the samples analyzed. PbMe(3)(+) dominated the methyllead species in water (constituting 62-64% of total alkyllead) reaching 1506 ng kg(-1) opposite the alkyllead production plant. PbEt(3)(+) dominated the ethyllead species constituting 18-20% of total alkyllead species with a maximum concentration of 902 ng kg(-1) PbEt(2)(+2) > PbMe(2)(+2) > PbMe(2)Et(+) > PbMeEt(2)(+) appeared mostly in nearshore stations with maximum levels being reached opposite to the alkyllead production plant and traffic light locations on the highway running parallel to the seashore, especially during summer. Seasonal variations were mainly related to traffic activity. The average concentration ratio of PbMe(3)(+) : PbEt(3)(+) is 3.2 +/- 2.4 reflecting the use of PbMe(4) as a petrol additive. Alkyllead compounds behaved nonconservatively on reaching seawater due to their removal from solution by uptake onto suspended particles. The PbMe(3)(+) :PbMe(2)(+2) concentration ratio in sediments fluctuated between 30:1 for nearshore to 5:1 for offshore samples while that for PbEt(3)(+) :PbEt(2)(+) was 1.6:1 and 2.9:1 for the same areas. Methylethyllead species were not detected in offshore sediments. Low triand dialkyllead levels were observed for anaerobic sediments. Alkyllead species concentration in biota inhabiting the coastal waters of Alexandria increased in the following order: Mixed plankton < Mugil capito (pelagic fish) < Mullus burbatus (demersal fish) < Donax trunculus (bivalve) < Ulva rigida (algae) < Neptunus pelagicus (crab) indicating higher levels in demersal rather than pelagic organisms. The maximum concentration factors for crabs are: 2850, 4985, 12970 and 6690 for PbMe(3)(+), PbEt(3)(+), PbMe(2)(+2) and PbEt(2)(+2), respectively, during summer. Alkyllead concentrations in some individuals reached high levels. These levels are considered hazardous with respect to the future discharge strategy of alkyllead to coastal waters, rendering these compounds more bioavailable. However, a health hazard criterion has not yet been established.  相似文献   

7.
Indoor particulate matter samples were collected in 17 homes in an urban area in Alexandria during the summer season. During air measurement in all selected homes, parallel outdoor air samples were taken in the balconies of the domestic residences. It was found that the mean indoor PM2.5 and PM10 (particulate matter with an aerodynamic diameter ≤2.5 and ≤10 μm, respectively) concentrations were 53.5 ± 15.2 and 77.2 ± 15.1 µg/m3, respectively. The corresponding mean outdoor levels were 66.2 ± 16.5 and 123.8 ± 32.1 µg/m3, respectively. PM2.5 concentrations accounted, on average, for 68.8 ± 12.8% of the total PM10 concentrations indoors, whereas PM2.5 contributed to 53.7 ± 4.9% of the total outdoor PM10 concentrations. The median indoor/outdoor mass concentration (I/O) ratios were 0.81 (range: 0.43–1.45) and 0.65 (range: 0.4–1.07) for PM2.5 and PM10, respectively. Only four homes were found with I/O ratios above 1, indicating significant contribution from indoor sources. Poor correlation was seen between the indoor PM10 and PM2.5 levels and the corresponding outdoor concentrations. PM10 levels were significantly correlated with PM2.5 loadings indoors and outdoors and this might be related to PM10 and PM2.5 originating from similar particulate matter emission sources. Smoking, cooking using gas stoves, and cleaning were the major indoor sources contributed to elevated indoor levels of PM10 and PM2.5.

Implications: The current study presents results of the first PM2.5 and PM10 study in homes located in the city of Alexandria, Egypt. Scarce data are available on indoor air quality in Egypt. Poor correlation was seen between the indoor and outdoor particulate matter concentrations. Indoor sources such as smoking, cooking, and cleaning were found to be the major contributors to elevated indoor levels of PM10 and PM2.5.  相似文献   

8.

Introduction  

In Egypt, the picture of threats to humans and the environment from the exposure to organic pollutants is still incomplete. Thus the objectives of this study were to assess the occurrence and distribution of polychlorinated biphenyls (PCBs), organochlorine pesticides, and chlorpyrifos in sediments and mussels of Abu Qir Bay and their risks for environment and human health.  相似文献   

9.
Environmental Science and Pollution Research - This study is the first in forming an integrated up-to-date spatial analysis linking heavy metal contamination among three different compartments of...  相似文献   

10.
Field studies were conducted at USDA Beltsville Agricultural Research Center, Beltsville, Maryland, in 1984 and 1985 using open-top chambers to acquire information on the responses of 12 soybean (Glycine max L. Merr.) cultivars to O3 stress and to examine the interactions between maturity groups and O3 stress. Cultivars representing Groups III, IV, and V were exposed for approximately 3 months to charcoal-filtered air (CF) and nonfiltered air plus 40 nl litre(-1) O3 (NF + O3). Ozone was added 6 h d(-1), 5 d week(-1) for 13 weeks. The CF effectively reduced the accumulative oxidant exposure (AOX) to less than 1.0 microl litre(-1) h and the NF + O3 treatment approximately doubled the ambient AOX (16.7 microl litre(-1) h) to about 30 microl litre(-1) h. The AOX estimates the total O3 exposure above 30 nl litre(-1) during an entire growing season. Plant growth rates and relative growth rates were reduced by 17.0 and 14.4%, respectively, when averaged over cultivars. Based on growth rates, the Group III cultivars were the most affected by O3 stress. Averaged over cultivars, leaf expansion rates, leaf conductance, and transpiration rates were lower in the NF + O3 treatment compared to the CF control; however, wide variation was found with the stomatal results from field observations. Combined over years and cultivars, grain yield was reduced by an average of 12.5% by O3 stress with 3 of 12 cultivars showing significant reductions. Grain protein content was increased by 0.7% by O3 stress, but cultivar differences were equal to the differences caused by the O3 treatments. Grain oil content was unchanged by the O3 treatments. Group IV cultivars showed the greatest decrease in grain yield due to O3 stress. Multiple regression analyses were calculated using the difference between the CF and NF + O3 treatment as a measure of O3 stress. Significant positive relationships were found among net assimilation rates, plant growth rates, relative growth rates, and leaf expansion rates, which suggest that growth analysis characteristics would be useful in addition to yield in air pollution tolerance improvement studies with soybeans.  相似文献   

11.
Environmental Science and Pollution Research - Cleaning products are mixtures of many chemical ingredients that are known to contain sensitizers, disinfectants, and fragrances, as well as strong...  相似文献   

12.
Chlorine has been utilized in the early stages of water treatment processes as disinfectant. Disinfection for drinking water reduces the risk of pathogenic infection but may pose a chemical threat to human health due to disinfection residues and their by-products (DBP) when the organic and inorganic precursors are present in water. In the last two decades, many modeling attempts have been made to predict the occurrence of DBP in drinking water. Models have been developed based on data generated in laboratory-scale and field-scale investigations. The objective of this paper is to develop a predictive model for DBP formation in the Alexandria governorate located at the northern west of Egypt based on field-scale investigations as well as laboratory-controlled experimentations. The present study showed that the correlation coefficient between trihalomethanes (THM) predicted and THM measured was R 2?=?0.88 and the minimum deviation percentage between THM predicted and THM measured was 0.8 %, the maximum deviation percentage was 89.3 %, and the average deviation was 17.8 %, while the correlation coefficient between dichloroacetic acid (DCAA) predicted and DCAA measured was R 2?=?0.98 and the minimum deviation percentage between DCAA predicted and DCAA measured was 1.3 %, the maximum deviation percentage was 47.2 %, and the average deviation was 16.6 %. In addition, the correlation coefficient between trichloroacetic acid (TCAA) predicted and TCAA measured was R 2?=?0.98 and the minimum deviation percentage between TCAA predicted and TCAA measured was 4.9 %, the maximum deviation percentage was 43.0 %, and the average deviation was 16.0 %.  相似文献   

13.
Environmental Science and Pollution Research - In this study, the risk of Aspergillus (Asp.) positivity and its respiratory health impacts on wastewater treatment plant (WWTP) workers were studied....  相似文献   

14.
The natural radioactivity of soil samples from Assiut city, Egypt, was studied. The activity concentrations of 28 samples were measured with a NaI(Tl) detector. The radioactivity concentrations of 226Ra, 232Th, and 40K showed large variations, so the results were classified into two groups (A and B) to facilitate the interpretation of the results. Group A represents samples collected from different locations in Assiut and characterized by low activity concentrations with average values of 46.15?±?9.69, 30.57?±?4.90, and 553.14?±?23.19 for 226Ra, 232Th, and 40K, respectively. Group B represents samples mainly collected from the area around Assiut Thermal Power Plant and characterized by very high activity concentrations with average values of 3,803?±?145, 1,782?±?98, and 1,377?±?78 for 226Ra, 232Th, and 40K, respectively. In order to evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity (Raeq), the absorbed dose rate (D), the annual effective dose rate (E), the external hazard index (H ex), and the annual gonadal dose equivalent (AGDE) have been calculated and compared with the internationally approved values. For group A, the calculated averages of these parameters are in good agreement with the international recommended values except for the absorbed dose rate and the AGDE values which are slightly higher than the international recommended values. However, for group B, all obtained averages of these parameters are much higher by several orders of magnitude than the international recommended values. The present work provides a background of radioactivity concentrations in the soil of Assiut.  相似文献   

15.
ABSTRACT

This study investigated medical waste practices used by hospitals in Oregon, Washington, and Idaho, which includes the majority of hospitals in the U.S. Environmental Protection Agency's (EPA) Region 10. During the fall of 1993, 225 hospitals were surveyed with a response rate of 72.5%. The results reported here focus on infectious waste segregation practices, medical waste treatment and disposal practices, and the operating status of hospital incinerators in these three states. Hospitals were provided a definition of medical waste in the survey, but were queried about how they define infectious waste. The results implied that there was no consensus about which agency or organization's definition of infectious waste should be used in their waste management programs. Confusion around the definition of infectious waste may also have contributed to the finding that almost half of the hospitals are not segregating infectious waste from other medical waste. The most frequently used practice of treating and disposing of medical waste was the use of private haulers that transport medical waste to treatment facilities (61.5%). The next most frequently reported techniques were pouring into municipal sewage (46.6%), depositing in landfills (41.6%), and autoclaving (32.3%). Other methods adopted by hospitals included Electro-Thermal-Deac-tivation (ETD), hydropulping, microwaving, and grinding before pouring into the municipal sewer. Hospitals were asked to identify all methods they used in the treatment and disposal of medical waste. Percentages, therefore, add up to greater than 100% because the majority chose more than one method. Hospitals in Oregon and Washington used microwaving and ETD methods to treat medical waste, while those in Idaho did not. No hospitals in any of the states reported using irradiation as a treatment technique. Most hospitals in Oregon and Washington no longer operate their incinerators due to more stringent regulations regarding air pollution emissions. Hospitals in Idaho, however, were still operating incinerators in the absence of state regulations specific to these types of facilities.  相似文献   

16.
Heavy fuel oil and ash samples were collected from the Assiut thermal power plant in Egypt and subjected to gamma spectrometry analysis for natural radioactivity contents. Considerable results were observed where the ash contains nearly 1,000 times natural radionuclides more than raw oil. The results were confirmed by measuring the samples via using different devices in different institutions. All ash samples had radium equivalent activities and external hazard index values more than 370 Bq/kg and unity respectively. The mean absorbed dose rate was10,650 nGy/h which is nearly 190 times higher than the global average value of 55 nGy/h. The corresponding annual external effective dose is estimated to be 13 mSv/year, which is nearly 30 times higher than that in areas of natural background radiation (0.46 mSv/year).  相似文献   

17.
King C  Salem B 《Ambio》2012,41(5):490-503
Under increasing water scarcity, collective groundwater management is a global concern. This article presents an interdisciplinary analysis of this challenge drawing on a survey including 50 large and small farms and gardens in a village in an agricultural land reclamation area on the edge of the Western Desert of Egypt. Findings revealed that smallholders rely on a practice of shallow groundwater use, through which drainage water from adjacent irrigation areas is effectively recycled within the surface aquifer. Expanding agroindustrial activities in the surrounding area are socio-economically important, but by mining non-renewable water in the surrounding area, they set in motion a degradation process with social and ecological consequences for all users in the multi-layered aquifer system. Based on the findings of our investigation, we identify opportunities for local authorities to more systematically connect available environmental information sources and common pool resource management precedents, to counterbalance the degradation threat.  相似文献   

18.

Waterpipe (aka hookah) tobacco smokers are exposed to toxicants that can lead to oxidative DNA and RNA damage, a precursor to chronic disease formation. This study assessed toxicant exposure and biomarkers of DNA [8-oxo-7, 8-dihydro-2′-deoxyguanosine (8-oxodG)] and RNA [8-oxo-7,8-dihydroguanosine (8-oxoGuo)] oxidative damage during smoking of flavored and non-flavored waterpipe tobacco. Thirty waterpipe smokers completed two counterbalanced 2-h lab waterpipe smoking sessions (flavored vs. non-flavored waterpipe tobacco). Urinary concentrations of 8-oxodG and 8-oxoGuo and expired carbon monoxide (eCO) were measured before and after the smoking sessions. A significant increase in the urinary concentrations of 8-oxodG (from 2.12 ± 0.83 to 2.35 ± 0.91 ng/mg creatinine, p = 0.024) and 8-oxoGuo (from 2.96 ± 0.84 to 3.45 ± 0.76 ng/mg creatinine, p = 0.003) were observed after smoking the non-flavored and flavored waterpipe tobacco, respectively. Our results also showed that the mean ± SD of eCO increased significantly after smoking the flavored (from 1.3 ± 1.1 to 20.3 ± 23.6 ppm, p < 0.001) and non-flavored waterpipe tobacco (from 1.8 ± 1.2 to 24.5 ± 26.1 ppm, p < 0.001). There were no significant differences in the means of 8-oxodG (p = 0.576), 8-oxoGuo (p = 0.108), and eCO (p = 0.170) between the flavored and non-flavored tobacco sessions. Smoking non-flavored and flavored waterpipe tobacco leads to oxidative stress and toxicant exposure. Our findings add to the existing evidence about the adverse effects of waterpipe tobacco smoking (WTS) and the need for strong policies to inform and protect young people from the risks of WTS.

  相似文献   

19.
Environmental Science and Pollution Research - North Africa currently accounts for about 40% of Africa’s total CO2 emissions, and the industrial sector is one of the energy-intensive sectors...  相似文献   

20.
The effects of clouds (amount, type and height) on the surface UV-B radiation have been investigated at Qena, Egypt (26°17′, 32°10′, 96 m asl) using 2 years data (2004–2005) carried out by South Valley University (SVU)-meteorological research station. Thus, the characteristics of cloud's statistical property during the study period were employed to evaluate the general feature of the region of this study. However, ≈86% of all the observations were ⩽2 octas and the overcast conditions (8 octas) were very rarely over the study region (only 0.2% of all cases). These observations included 10% low-level clouds, 3.16% mid-level clouds and 7.59% high-level clouds. The dominated types of these clouds are stratocumulus (8.9%) and cirrus (5.8%).The hourly values of cloudless sky UV-B radiation (UV-B0) and consequently the cloud modification factor (CMF) were estimated. An empirical model was developed for CMF as a function of the amount of cloud at low- and mid-level and high-level clouds. The correlation coefficients were equal to 0.985 and 0.987, respectively. In addition, a general expression of the CMF for situations those are considered as the effect of different clouds was found. The efficiency of this model has been tested in combination with a cloudless sky empirical model using independent data set. For this purpose, the hourly values of UV-B at selected cloudless and cloudy days were estimated. A good agreement was observed between the measured and the predicted values of our model. The mean value of the correlation coefficients of these selected days was 0.98.In addition, the attenuation of UV-B radiation could be determined by considering low- and mid-level and high-level clouds. The reduction of UV-B radiation as a function of cloud amount was non-linear for the both cases. At cloud amount of 100%, UV-B radiation was reduced by 83% on average by the high-level clouds.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号