Refinar búsqueda
Resultados 301-310 de 62,084
Measurement of Natural Radioactivity Levels and Evaluation of Radiological Hazard Risks in Areas of Eastern Coastline Sediments of Lake Hawassa in Ethiopia’s Sidama Region
2023
Kebede Kassa, Messele | Tesfaye Deressu, Tilahun
Natural radioactivity levels in the eastern coastline of Lake Hawassa sediment samples of Ethiopia’s Sidama Region have been measured. Sediment samples were collected and analyzed using gamma-ray spectrometery (high purity germanium detector) to evaluate the radioisotopes of 238U (214Pb, 214Bi), 232Th (228Ac, 212Pb), and 40K and their ranges of activity concentrations were 11.70 to 29.73 Bq 〖kg〗^(-1), 19.01 to 58.61 Bq 〖kg〗^(-1), and BDL to 827.21 Bq 〖kg〗^(-1) ,with average values of 16.51 ± 1.20 Bq 〖kg〗^(-1) , 28.17 ± 2.27 Bq 〖kg〗^(-1) ,and 673.95 ± 29.92 Bq 〖kg〗^(-1) (dry mass), respectively. The radiological hazard indices average values (radium equivalent (R_eq) (108.69 Bq 〖kg〗^(-1) ); hazard index (H_ex (0.29); excess lifetime cancer risk (ELCR) (0.23 x 〖10〗^(-3) ); absorbed dose rate (D_R) (52.70 nGyh^(-1) ); annual effective dose equivalent (AEDE) (0.07 mSv〖yr〗^(-1)); and annual gonadal dose equivalent (AGDE) (0.38 mSv〖yr〗^(-1)) were also evaluated and compared to the worldwide-recommended values. All results of radiological hazard indices obtained in this study were lower than their worldwide-recommended values were 370 Bq 〖kg〗^(-1), ≤1, 59 nGyh^(-1), 0.07mSv〖yr〗^(-1), 0.29 × 〖10〗^(-3), and 0.3mSv〖yr〗^(-1) of radium equivalent activity, external hazard index, outdoor absorbed dose rate, outdoor annual effective dose equivalent, excess lifetime cancer risk, and annual gonadal dose equivalent, respectively. This suggests the eastern coastline of Lake Hawassa is safe from radioactive risk for aquatic species and various human activities, and appears as essential radiometric baseline information for further environmental monitoring programs.
Mostrar más [+] Menos [-]Origin of Heavy Metals amongst Nuisance Dust-Fall Particles in Western Iran
2023
Rajabi, Mahdi | Souri, Bubak
The purpose of this study was to evaluated the origin of the heavy metals amongst nuisance dust particles in Sanandaj, Khorrmabad and Andimeshk cities located in different latitudes in western Iran for the dustiest year during last decade. Samples of dust-fall particles were collected with 10 days intervals from these three cities for the duration of June 2012 to July 2013 using Deposit Gauge Method. Concentration of the heavy metals including iron, manganese, zinc, copper, arsenic, chromium, silver, nickel, lead and cadmium were measured using atomic absorption spectroscopy. The Quantification of Contamination index (QC) was applied to evaluate the origin of heavy metals among dust-fall particles collected in three stations. The results revealed that the annual mean rate of dust-fall was 1.73, 2.66 and 3.37 g/m2 per 10 days for Sanandaj, Khorramabad and Andimeshk, respectively. The highest and the lowest amount of dust-fall were obtained for July and February, respectively, while Fe had the highest concentration among the metals studied. The temperature and wind speed were found to be the most correlated meteorological parameters to dust-fall content throughout the three stations. According to QC index; Ag, Cu, Cd, As, Pb, Mn and Zn (except Pb and Mn for Andimeshk) were derived mainly from similar origins such as anthropogenic activities but the increased values of Fe, Ni, and Cr were ascribed to natural processes. Furthermore, Cu had the highest correlation with other heavy metals measured and was determined the most stable metal amongst dust-fall particles for the three studied stations.
Mostrar más [+] Menos [-]Gamma Radiation Profile of the High Background Radiation Area along Southwest Coastal India and its Neighbourhood
2023
Sukumaran Chettiar Rajamma, Soniya | Abraham, Sunila | Panakal John, Jojo
Radioactive contamination of the earth’s biosphere has always been a source of concern. From the health point of view, radiation exposure and dose delivered to human beings are of prime importance. Certain parts of coastal southwest districts of the state of Kerala in India namely Thiruvananthapuram (Trivandrum), Kollam (Quilon) and Alappuzha (Alleppey) are known high background radiation areas (HBRA) owing to the presence of rich quantities of thorium and uranium. Surface soil samples from these districts' HBRAs and adjoining regions were studied for their primordial radionuclide levels using NaI(Tl) based gamma-ray spectrometry. Specific activities of 226Ra, 232Th and 40K nuclides in soil samples from the whole study area were between 4.7 Bq/kg to 130 Bq/kg, 6.5 Bq/kg to 611 Bq/kg and 101 Bq/kg to 1852 Bq/kg, respectively. Important dosimetric parameters namely radium equivalent activity (Raeq), absorbed gamma dose (D), Indoor and outdoor Annual Effective Dose equivalents (AEDin & AEDout), internal and external hazard indices (Hin & Hex) for gamma exposure, and Excess Lifetime Cancer Risk (ELCR) were also determined to assess probable health effects on human beings residing in these regions. A comparison of average specific radioactivities and average indoor annual effective doses between the HBRA and Normal background Radiation Area (NBRA) is presented. Results show that the neighbouring regions have considerably lower radiation dosimetric parameters.
Mostrar más [+] Menos [-]Chemical Fraction and Health Effect of Size Segregate PM at National Highway of Northern India
2023
Tiwari, Rahul | Botle, Akshay | Rajouriya, Kalpana | P Singh, Prabal | Taneja, Ajay
Sampling was conducted on Agra-Delhi national highway NH-2. Samples were collected with the help of Sioutas cascade impactor. During the sampling, PM1.0-0.5 (255.85µg/m3) was higher than PM2.5-1.0 (218.96µg/m3). The AQI value for the average PM2.5 concentration also exceeded the severe AQ limit (401-500). These results showed that PM2.5 pollution has a significant influence on the site as a result of a variety of anthropogenic activities. During the summer season, for PM1.0-0.5 and PM2.5-1.0 highest values (µg/m3) of metals followed the same trend and it was observed as Mg(6.52)> Ca(5.89)> Al(3.64)> while for PM2.5-1.0 it was as Mg(10.12)> Ca(9.5)> Al(5.95) respectively. At roadside, most of these metals are emitted from the resuspension of dust and vehicle activities which causes serious diseases to the human being. Cd, Cr, Cu, Pb, and Zn were highly enriched at national highway sampling sites, highlighting the crustal source, which has a major impact on metals concentration, followed by anthropogenic sources. The present research was conducted to find out the concentration level of metals in PM2.5-1.0 and PM1.0-0.5 particles in Agra, India to find out the health risk assessment at highway site.From the results, it was observed that all metals bound to larger size PM has high bioavailability. From the health risk assessment, it was found that all the metals bound smaller size particles showed higher HQ except in the case of Ni and Al. Cr, Pb showed carcinogenic risk to children and adults in both size fraction of PM except in the case of Ni.
Mostrar más [+] Menos [-]Investigating the Impact of Virtual Education on Air Pollution Indicators in Tehran during the COVID-19 Outbreak
2023
Omidifar, Reza | Mazari, Ebrahim | Ostadalidehaghi, Rezvan
This research aims to investigate the effect of virtual education during the COVID-19 outbreak on air pollution indicators in Tehran. The study uses quantitative methods, including One-Way ANOVA, to analyze the air pollution indicators before and during the COVID-19 pandemic. Data on air pollution indicators in Tehran from 2018, 2019, and 2020 were collected from Tehran Air Control Company and compared using statistical tests. The year 2019 represents virtual education, while 2018 and 2020 represent face-to-face education. The examined indicators include particulate matters with a diameter less or equal than 2.5μ (PM2.5), SO2, NOX (i.e., NO2 and NO), O3, and CO. The results of variance analysis show significant differences in the PM2.5and NOX indices between virtual and face-to-face training days. Follow-up tests by Toki and Scheffé indicate that in 2019, when education was fully virtual, the levels of these pollutants were lower compared to 2018 and 2020. However, there were no significant differences in the SO2, O3, and CO indices during the days of virtual education compared to the years before and after. This suggests that virtual education during the COVID-19 outbreak contributed to pollution reduction by reducing traffic to educational organizations and its indirect effects.
Mostrar más [+] Menos [-]Determination of Dioxins and Polychlorinated Biphenyls Levels in Milk Samples from Capital and North of Iran
2022
Azarchehry, Seyede Pegah | Ataie, Farangis | Hosseinkhani, Saman
High levels of dioxins and dioxin-like compounds in the food and their adverse effects on human health are of increasing concern. Since milk is one of the most essential human nutritional resources, the present study aims at determining dioxins and PCBs in raw milk samples from four farms in North of Iran and raw and pasteurized samples from three farms and five dairy factories in Vicinity of Tehran (capital of Iran). Total toxic equivalence (TEQ) of dioxin and PCBs have been determined, using the DR-CALUX® bioassay. Results reveal that all samples are contaminated with dioxins and PCBs, comparatively. The total dioxins and PCBs levels in raw milk samples from the north range from 4.08 to 0.97 pg/gfat and for the raw samples and pasteurized samples from Tehran Province from 1.89 to 0.63 pg/gfat and 0.1 to 0.03 pg/gfat, respectively. The mean concentration of dioxins/PCBs is higher in samples from the north of Iran. This may be because of the common method of removing domestic and agricultural disposal in this area.
Mostrar más [+] Menos [-]Assessment of Indoor Air Quality in Schools from Anatolia, Turkey
2022
Babaoglu, Ulken Tunga | Ogutcu, Hatice | Erdogdu, Makbule | Taskiran, Funda | Gullu, Gulen | Oymak, Sibel
Air pollution damages children’s health in many different ways, through both chronic and acute effects. The aims of our research are to reveal the indoor air quality levels in schools. Subject and indoor air measurements were performed in 34 primary schools located in the Central Anatolia region. PM10, PM2.5, CO2, CO, CH2O, relative humidity, temperature, and total bacteria and fungus levels were measured. In the urban region, mean PM1 was higher than the other regions(p=0.029). PM10 and PM2.5 were higher in schools in rural areas. According to CO2 measurements, only one school was identified to be below the upper limit recommended by the WHO. Total microorganism concentration was exceeded in 44.1% of classrooms. Indoor PM1, PM2.5, PM10, CO2, total bacteria and fungus levels were high and above recommended limits. Human activities, movements of students could be considered the most important indoor factors for particle matter increase. Indoor parameters could be lowered by organizing the school environment.
Mostrar más [+] Menos [-]Presence of Microplastics in Freshwater Ecosystems: An Unheeded Emerging Concern – A Global Review
2022
Mukhopadhyay, Patralika | Arkkakadavil Valsalan, Shibu
Plastic production has inevitably increased in the past few decades and is one of the diverse material used in today’s world. With this increasing production and wider use, the aquatic ecosystems have become the trash barrel for all kinds of plastic resulting in it becoming a looming spectre to the habitat and functions of both inland and offshore ecosystems. Plastic pollution is considered as an emerging global environmental concern which could significantly affect the biological diversity and may have potential to cause inimical effects on human health. These plastics have shown to gradually degrade into micro fragments and are reported to cause toxic effects on the aquatic organisms. In comparison to the studies on presence of microplastic in marine ecosystems, the studies on the presence of it in freshwater ecosystems have received relatively lesser attention although some studies have shown that the contamination is as grievous as that of in marine environment. This review article focuses on the literature available on the reports of microplastic occurrence, its distribution in freshwater ecosystems across the world and its insidious effects which are of emerging concern. The effect of such microplastic ingestion in both aquatic organisms and the potential health hazards due to such plastic consumption in humans have also been examined. The paper also discusses the existing knowledge gaps so that future research directions can be taken accordingly and the findings in this paper would significantly help all the countries across the world to understand the present plastic pollution scenario and work towards the mitigation of the same.
Mostrar más [+] Menos [-]The Effects of Occupational Noise Pollution and Shift Work on Oxidative Stress Markers in Cement Workers, Iran
2022
Khavanin, Ali | Khajehnasiri, Farahnaz | Shahhoseini, Sara
Both noise and shift work generate oxidative stress, independently; however, in some work places workers are exposed to both at the same time, where their combined effect might increase the oxidative damage. This research is based on the question whether noise and shift work have a synergistic effect on oxidative stress or not. It tries to investigate the effects of these two factors simultaneously, at the biggest cement factory of Iran. For so doing, it enrols 88 male workers, equally in four groups, with one group serving as the control (i.e., Group 1 with 8 hours of fixed shift, exposed to less than 85 dB sound level) and three groups as the cases (Group 2 with 12 hours of rotational shifts, exposed to less than 85 dB sound level; Group 3 with 8 hours of fixed shift, exposed to more than 85 dB sound level; and Group 4 with 12 hours of rotational shifts, exposed to more than 85 dB sound level). Stress oxidative is evaluated by Malondialdehyde (MDA) and Superoxide dismutase (SOD). Finally, the results show that SOD levels (p<0.001) are significantly decreased in Group 4 and Group 3, compared to the control. Also, MDA levels are significantly increased in Group 4 (in which, the workers are exposed to noise and shift work simultaneously) compared to the control (p < 0.001). The current study shows that co-exposure to noise and shift work has a combined effect (a synergistic role) in MDA. Thereore, more attention should be paid to shift workers, who are exposure to noise simultaneously.
Mostrar más [+] Menos [-]Radiological Hazards Associated with 238U, 232Th, and 40K in some selected Packaged Drinking Water in Ilorin and Ogbomoso, Nigeria
2022
Ajibola, Taiye Benjamine | Orosun, Muyiwa Michael | Ehinlafa, Olusegun Emmanuel | Sharafudeen, Fatimah Anike | Salawu, Banji Naheem | Ige, Simon Olatunji | Akoshile, Clement O.
In order to ensure radiation monitoring and protection, investigation and assessment of radiological risks that may be associated with the consumption of packaged table waters commonly consumed in Ogbomoso and Ilorin metropolis, Nigeria, was carried out. The measurements were carried out using a ‘3 x 3’ inch lead-shielded NaI (Tl) detector coupled through coaxial cable to a multichannel analyser. The measured activity concentrations of the natural radionuclides in the packaged drinking water sample are mostly within the recommended limits. The estimated mean Annual Effective Dose was found to be within the acceptable limits of 1 mSv/y for the general populace except for the infants which is slightly higher for some of the samples. The estimated Excess Lifetime Cancer Risk were found to be lower than the world average value of 0.2 x 10-3 in only two of the selected packaged drinking water. This implies the possibility of developing cancer over a lifetime considering seventy years as the average life span is considerably high.
Mostrar más [+] Menos [-]