خيارات البحث
النتائج 1 - 10 من 1,951
Chemical Speciation, Bioavailability and Risk Assessments of Potentially Toxic Metals in Rainwaters as Indicators of Air Pollution
2023
Adegunwa, Abiodun | Adebiyi, Festus | Asubiojo, Olabode | Ore, Odunayo
Heavy metals contamination of rainwater is a function of the adsorbed metals present in the particulates of the atmosphere in which the rain was formed from and rainwater chemistry is an alternative way of monitoring urban air pollution for predominant metal species. Three distinct sampling sites (residential, industrial and commercial) were investigated in the south western part of Nigeria for one year. After acid digestion, quantification was done using a double-beam Atomic Absorption Spectrophotometer (AAS). The obtained results showed that heavy metals were predominantly present as free metal ion in the commercial and industrial areas but Mn and As mainly occurred in the suspended fraction. Residential area presented major fractions as bound to organic complexes except Cu and Cd which were principally available as suspended fraction. The health risks associated with the intake of the studied rainwaters indicated susceptibility to possible carcinogens upon consumption due to total RI > 10-4. Ecological risk assessment equally shown a very high level of ecological risks related with the metals due to RI ˃ 600. Sequel upon this, there is need for better sensitization of the citizenry to the sources and control of these pollutants.
اظهر المزيد [+] اقل [-]Emission Risk Assessment of Toxic Gases of Floating Roof Storage Tanks
2022
Doregar Zavareh, Razieh | Dana, Tooraj | Roayaei, Emad | Monavari, Seyed Masoud | Jozi, Seyed Ali
Events such as the emission of toxic gases are possible on floating roof storage tanks. Since gasoline is a high-consumption and volatile product stored in adjacent oil depots or large cities, it is necessary to assess their emission risk. Given that the multi-criteria methods allow the identification of and assessment of the indicators well and allow the participation of expert experts, so the FAHP method has been used to identify and assess the risk before the emission of toxic gases. The results showed the importance of 7 factors among 36 factors, 3 of which were related to equipment error. The DOW'S CEI method was used to assess the emission risk if the event occurred. This method provides safe boundaries based on Emergency Response Planning Guidelines (ERPGs), where the results indicate the settlement placement around the oil repository in the range of the predicted concentration at all three levels of ERPG.
اظهر المزيد [+] اقل [-]Lake Hydro Geochemistry: An Implication to Chemical Weathering, Ion-exchange Phenomena and Metal Interaction
2019
Dutta, G. | Gupta, S. | Gupta, A.
Present study aims to unravel the hydro geochemical interaction of sediment and water of Saheb bandh lake, West Bengal, India with an emphasis on heavy metal assessment. Lake water belongs to Ca2+–HCO3− type hydro geochemical faces and water-rock interaction primarily controls the lake water chemistry. Based on different Hydro chemical characteristics it is suggested that silicate weathering is the major hydro geochemical process operating in Saheb bandh lake water. Regarding point source contribution of pollutants the average value of NO3-N, TP and Hg are much higher in inlet water (7.5 mg/L, 1.29 mg/L and 8.5 μg/L) than the lake water (1.5 mg/L, 0.05 mg/L and 0.42 μg/L). Risk assessment indices suggest advanced decline of the sediment quality. Water-sediment interaction of heavy metals reveals that Cd, As, Pb and Hg metals enter into lake water as a result of not only natural processes but also of direct and indirect activities of humans. This study recommends that continuous monitoring of these metals in water and sediment and other aquatic biota of Saheb bandh should be directed to assess the risk of these vital heavy metals in order to maintain the safe ecology in the vicinity of this lake.
اظهر المزيد [+] اقل [-]Ambient Air Quality and Health Impact of Exposure to Outdoor Air Pollution in the Moroccan Population: A Systematic Review
2023
Bouchriti, Youssef | Ait Haddou, Mohamed | Kabbachi, Belkacem | Achbani, Abderrahmane | Cherrat, Zakariae | Rida, Jamila | Sine, Hasnaa | Gougueni, Hicham | Amiha, Rachid | Ezaidi, Sarrah
Evidence of the health impact of air pollution in Morocco is scarce. We aimed to test our hypothesis that exposure to air pollutants has a significant impact on the health of Moroccans. For this systematic review, we searched PubMed, ScienceDirect, LILACS, and ProQuest databases, Google Scholar, and forward and backward citations for studies published between the database inception and August 16, 2022. All studies and reports that measure air quality in Morocco and its health impact were included, without language restrictions. This study is registered on PROSPERO under number CRD42020163948. Studies were selected based on inclusion and exclusion criteria rather than their methods. The data was extracted, coded, and prepared for future examination. After that, descriptive and thematic analyses were carried out. Of 1230 records identified, 31 were eligible, all of which had annual air pollutant concentrations in excess of WHO Air Quality Guidelines. The health impact was demonstrated in five studies. The most studied pathologies were asthma, respiratory and cardiac infections in children under 12 years and adults. In addition to heavy metals, the most investigated pollutants were PM10, O3, SO2, and NOx. The significant association between exposure to air pollutants and health in the Moroccan population has been demonstrated, even if it is not causal. Future research should quantify the health impact of pollution in other Moroccan cities.
اظهر المزيد [+] اقل [-]Analysis of Heavy Metal Contents and Non-carcinogenic Health Risk Assessment through Consumption of Tilapia Fish (Oreochromis niloticus)
2020
Tayebi, L. | Sobhanardakani, S.
Due to the fish are often at the top of the aquatic food chain and may accumulate large amounts of heavy metals from the water, this study was conducted to determine of Cd, Cr, Pb and Ni contents in the muscle of imported tilapia fish marketed in the city of Hamedan in 2017. In so doing, totally, 27 muscle samples from nine different brands of tilapia fish were randomly collected from the market basket of the study area. After preparation and processing the samples in the laboratory, the concentration of metals, was determined using inductively coupled plasma-optical emission spectrometer. The results showed that the mean concentrations (mg/kg) of Cd, Cr, Pb, and Ni in samples were 0.26 ± 0.09, 1.54 ± 0.15, 0.55 ± 0.11, and 0.67 ± 0.20 respectively. Also, the mean contents of Cd and Pb were higher than the maximum permissible levels (MPL) established by the World Health Organization (WHO). The computed health risk index values showed that no potential health risk for adults and children via consuming the muscle of tilapia fish at the current consumption rate for the study area. Based on the results, due to the mean contents of Cd and Pb in the muscle samples of tilapia fish were higher than the MPL, therefore, serious attention to the reduction of the discharge of hazardous substances in the aquatic ecosystems and also periodic monitoring of chemical residue particularly toxic heavy metals in the high-demand food is recommended.
اظهر المزيد [+] اقل [-]Carcinogen Risk Assessment of Mutagen X in Chlorinated Drinking Water in West of Tehran, Using Probabilistic Approaches
2020
Bagheban, M. | Karyab, H. | Baghdadi, M. | Mohammadi, A. | Akbarpour, B. | Keshtkar, A.
The present study aims at evaluating the risk of Mutagen X (MX) (3-chloro-4-(dichloromethyl)-5-hydroxy-2 (5H)-furanone) and adverse health effects, associated with direct ingestion of chlorinated drinking water in west of Tehran, supplied by chlorinated drinking water from surface and underground water sources. For one year, MX concentrations in tap water samples has been measured for consumers in four different zones in western Tehran. It has been found that average MX concentration in the whole study area is 24.16 ng/L, with the highest concentration being in Zone 1 with a value of 38 ng/L. Also, the role of water sources, seasonal changes, and effective factors such as Total Organic Carbon (TOC) have been evaluated on MX formation. The highest of excess lifetime cancer risk (ELCR), estimated as 0.0037E-05, belongs to Zone 1, which uses surface water to supply drinking water, while the lowest can be seen in Zone 4, being 0.0021E-05. This latter zone utilizes underground water as the water source. In all zones, the highest risk of excessive cancer is related to winter, ranging from 0.0045E-5 in Zone 1 to 0.0023E-5 in Zone 4. The estimated number of cancer cases for Zones 1 to 4 have been 0.012, 0.016, 0.016, and 0.004, respectively, based on their population. The estimated average risk and the number of ELCR, caused by exposure to MX, through direct ingestion of drinking water have been 0.0030E-5 and 0.047, respectively, in the entire studied area for the duration of one year.
اظهر المزيد [+] اقل [-]Evaluating the Accumulation and Consumption Hazard Risk of Heavy Metals in the Fish Muscles of Species Living in the Waters of the Persian Gulf, Iran
2020
Norouzi, M.
The aim of this study was to determine the levels of Cd, As, Hg, Pb, and Cr in the edible part of eleven most consumed fish species collected from the north-east coast of Persian Gulf, Iran, during 2017. An inductively coupled plasma atomic emission spectroscopy (ICP-AES) instrument was used to measure the concentration of heavy metals. The results were compared within acceptable limits for human consumption set by various health institutions. The order of heavy metals about total accumulation was Cr>As>Pb> Cd> Hg. The mean heavy metals concentrations of fish species muscle decreased in the order of Acanthopagrus latus> Planiliza subviridis> Lutjanus lemniscatus > Alectis indica> Epinephelus areolatus> Otolithes ruber> Epinephelus chlorostigma> Lethrinus crocineus> Euryglossa orientalis > Cynoglossus arel > Grammoplites suppositus. Probably the difference in the concentration of metals between samples depends on fish species, diet, and habitat. These species were declared to exhibit a low probability of causing non-cancerous diseases. The comparison of the accumulation and hazard risk of consuming the five heavy metals existing in the eleven species that were sampled from the coasts of Khuzestan, Maah-shar Harbour, with the WHO and USEPA guidelines showed that although consuming these fish species does not threaten the consumers' health, pregnant women and children should be cautious about consuming them. The HI was calculated for 70 kg body weight of adults and 14.5 kg body weight of children. The amount of optimal consumption is different for different weights of consumers.
اظهر المزيد [+] اقل [-]Surface water quality, public health, and ecological risks in Bangladesh—a systematic review and meta-analysis over the last two decades
2023
Bilal, H. | Li, X. | Iqbal, Muhammad Shahid | Mu, Y. | Tulcan, R. X. S. | Ghufran, M. A.
Water quality has recently emerged as one of the utmost severe ecological problems being faced by the developing countries all over the world, and Bangladesh is no exception. Both surface and groundwater sources contain different contaminants, which lead to numerous deaths due to water-borne diseases, particularly among children. This study presents one of the most comprehensive reviews on the current status of water quality in Bangladesh with a special emphasis on both conventional pollutants and emerging contaminants. Data show that urban rivers in Bangladesh are in a critical condition, especially Korotoa, Teesta, Rupsha, Pashur, and Padma. The Buriganga River and few locations in the Turag, Balu, Sitalakhya, and Karnaphuli rivers have dissolvable oxygen (DO) levels of almost zero. Many waterways contain traces of NO3, NO2, and PO4-3 pollutants. The majority of the rivers in Bangladesh also have Zn, Cu, Fe, Pb, Cd, Ni, Mn, As, and Cr concentrations that exceed the WHO permissible limits for safe drinking water, while their metal concentrations exceed the safety threshold for irrigation. Mercury poses the greatest hazard with 90.91% of the samples falling into the highest risk category. Mercury is followed by zinc 57.53% and copper 29.16% in terms of the dangers they pose to public health and the ecosystem. Results show that a considerable percentage of the population is at risk, being exposed to contaminated water. Despite hundreds of cryptosporidiosis cases reported, fecal contamination, i.e., Cryptosporidium, is totally ignored and need serious considerations to be regularly monitored in source water.
اظهر المزيد [+] اقل [-]Anthropogenic risk assessment of riverine habitat using geospatial modelling tools for conservation and restoration planning: A case study from a tropical river Pranhita, India
2023
Kantharajan, Ganesan | Govindakrishnan, Panamanna Mahadevan | Chandran, Rejani | Singh, Rajeev Kumar | Kumar, Kundan | Anand, Arur | Krishnan, Pandian | Mohindra, Vindhya | Shukla, Satya Prakash | Lal, Kuldeep Kumar
Acetylcholinesterase activity in the terrestrial snail<em> Xeropicta derbentina</em> transplanted in apple orchards with different pesticide management strategies
2011
Mazzia, Christophe | Capowiez, Yvan | Sanchez-Hernandez, Juan C. | Köhler, Heinz-R. | Triebskorn, Rita | Rault-Léonardon, Magali | Abeilles et Environnement (AE) ; Institut National de la Recherche Agronomique (INRA)-Avignon Université (AU) | Unité de recherche Plantes et Systèmes de Culture Horticoles (PSH) ; Institut National de la Recherche Agronomique (INRA) | Universidad de Castilla-La Mancha = University of Castilla-La Mancha (UCLM) | Eberhard Karls Universität Tübingen = Eberhard Karls University of Tuebingen | Steinbeis Transfer-Center for Ecotoxicology and Ecophysiology
International audience | Apple orchards are highly manipulated crops in which large amounts of pesticides are used. Some of these pesticides lack target specificity and can cause adverse effects in non-target organisms. In order to evaluate the environmental risk of these products, the use of transplanted sentinel organisms avoids side-effects from past events and facilitate comparison of multiple sites in a short time. We released specimens of the terrestrial snail <em>Xeropicta derbentina</em> in each 5 of two kinds of apple orchards with either conventional or organic management strategies plus in a single abandoned orchard. After one month, individuals were retrieved in order to measure acetylcholinesterase (AChE) activity. Mean values of AChE activity were significantly reduced in all conventional apple orchards compared to the others. Results show that the measurement of biomarkers such as AChE inhibition in transplated <em>X. derbentina</em> could be useful in the environmental risk assessment of post-authorized pesticides
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