Metal Levels In Water Research Articles

Comparisons of heavy metals levels in water, sediment and crayfish under rice-crayfish co-culture and pond culture modes with correlation analysis and health risk assessment

Comparisons of heavy metals levels in water, sediment and crayfish under rice-crayfish co-culture and pond culture modes with correlation analysis and health risk assessment

Determination of Some Heavy Metals in Water and Sediment Samples from Maska Dam, Katsina State, Nigeria

Water and sediment samples collected from Maska dam in dry and wet seasons were analysed for some heavy metals namely, Cd, Cu, Ni and Zn. After sample digestion, micro-wave Plasma atomic absorption spectroscopy (MPAES) was used to determine the concentrations of the metals. The concentrations were analysed statistically using one way analysis of variance (Anova). The levels of metals in water and sediment were compared with local and international regulatory authorities. From the result of analysis, the concentrations of the metals in (mg/L) were as follows: 0.03±0.01 for Cd, 0.186±0.003 for Cu, 0.19±0.005 for Ni and 0.193±0.003 for Zn, 0.027±0.002 for Cd, 0.057±0.002 for Cu, 0.114±0.002 for Ni and 0.141±0.001 for Zn in water samples in dry and wet seasons. Likewise, the concentration of the metals in sediment in dry and wet seasons were, 0.0196±0.002 for Cd, 0.143±0.003 for Cu, 0.166±0.044 for Ni and 0.766±0.044mg/kg for Zn in dry season. Similarly, 0.019±0.001 for Cd, 0.143±0.004 for Cu, 0.160±0.09 for Ni and 0.451±0.003mg/kg for Zn were obtained in wet season. The concentrations of Cu and Zn were below the permissible limits of WHO/SON while Cd and Ni were above the permissible limit of WHO/SON in water samples. However, the concentrations of all the metals were below the permissible limits of NOAA and USEPA. The result of statistical analysis indicated no significant difference at P greater than 0.05 (P>0.05).

Threat of heavy metal pollutants and parasites to freshwater fish with special reference to their risk of cancer to humans in Egypt

Understanding how pollution and parasite infection work together to stress their hosts' health raises the possibility of a danger to aquatic life and humans. This study examined two freshwater fish species, Clarias gariepinus, and Oreochromis niloticus, at El-Abbasa Fish farm in Sharkia Governorate of Egypt. to determine their heavy metal content, parasite frequency, and potential health risks. Parasitological investigations revealed higher parasite prevalence in C. gariepinus, with trematodes being the most prevalent. Histopathological examinations displayed severe alterations in infected fish, including gill necrosis, intestinal damage, liver degeneration, and muscle necrosis. Moreover, heavy metal analysis. Heavy metals levels in water, Fe, Zn, Pb, Cu, As, and Cd levels were 0.95 ± 0.04, 0.75 ± 0.03, 0.14 ± 0.02, 0.09 ± 0.01, 0.07 ± 0.01, and 0.03 ± 0.01 mg/L, respectively. Sediment samples showed Cd as the lowest (2.38 ± 0.94 μg/g dry wt. basis) and Fe as the highest (241.01 ± 6.39 mg/kg dry wt. basis). The sequence of heavy metal concentrations in both water and sediment was Fe > Zn > Pb > Cu > As > Cd. Significant differences were found among metals in water and sediment (p < 0.05). Heavy metal concentrations in fish tissues followed the order liver > muscles > gills > intestine Iron was the most abundant, while cadmium was the lowest is the order in which bio-accumulation factors (BAF) between water and fish tissues followed a descending order: BAF-Liver < BAF-Gills < BAF-Intestine < BAF-Muscles. The sequence of heavy metal accumulation in tissues was BAF-Fe > BAF-Pb > BAF-Cd > BAF-As > BAF-Cu > BAF-Zn, indicating varying degrees of accumulation across different metals and tissues and bio-sedimentation (BSF) of metals in fish tissues are the order of heavy metal concentration within tissues was BSF-Cd > BSF-As > BSF-Fe > BSF-Zn > BSF-Cu > BSF-Pb. Additionally, data were recoded to reflect histological changes in several fish organs. The estimated daily intake of heavy metals (EDI-HMs) was far lower than the permissible tolerated daily intake (PTDI) limits, which were set by international authorities at 70 kg of body weight. As the hazard index value is below 1, the THQ and HI associated with the consumption muscle of fish demonstrate negligible non-carcinogenic harm to residents' health. Contrarily, As, and Cd pose a cancer threat for kids and adults who eat muscular fish, and it needs to be viewed as a warning sign from the perspective of data indices and human health.

Physicochemical Characteristics and Heavy Metals Assessment in Water and Sediments of Obodo Oilfield in Warri South Local Government Area of Delta State, Nigeria

This study investigated the physicochemical characteristics and heavy metals levels in water and sediments of Obodo Oilfield in Warri South Local Government Area of Delta State using standard laboratory-approved APHA and ASTM methods. Results indicated traces of heavy metals present in the water and sediments. Temperature and TDS in the water samples were within the DPR established limits while TSS, Chemical Oxygen Demand, Salinity and Biochemical Oxygen Demand were higher than the control and well above the DPR established limits. The heavy metals present in the soil were all still within the permissible DPR limits, except for Cadmium which was higher than the control and DPR established limit. The results showed that the water and soil within the environment may have been considerably polluted and degraded by the operations of oil and gas production in the region. The study recommends that the activities of the oil and gas production companies be checked to ensure they are operating within the environmental standard regulations of the country and that the Government and necessary bodies should be proactive in checkmating illegal bunkering activities as they have become the major source of oil spills in the region.

Adverse Effects of Toxic Metal Pollution in Rivers on the Physiological Health of Fish.

Toxic metal pollution influences the lives of diverse aquatic organisms and humans who consume contaminated aquatic products. However, its potential impacts on aquatic organism health and, thus, ecological health, have been neglected in many regions. This research was carried out to contribute to filling that knowledge gap. Three freshwater fish species in the Nhue–Day River basin, Vietnam, have been chosen to study the bioaccumulation of metals (Zn, Cu, Pb, and Cd) in the tissues (livers, kidneys, gills) and their effects on fish physiological health (changes in the oxidative-GST activity, and physiological biomarkers-energy reserves, respectively) from 2013 to 2017. The extensive results revealed significant spatial and temporal variations in metal concentrations in tissues of common carp (Cyprinus carpio), silver carp (Hypothalmic molitrix), and tilapia (Oreochromis niloticus), and well correlated to their concentration in the water (p < 0.05). Fish bioaccumulated metals in the following order: Zn > Cu > Pb > Cd, with more in the kidneys and livers (spring and summer) than in other tissues. Metal accumulation in O. niloticus and C. carpio was higher than in H. molitrix. Biomarker responses (except for glycogen variation) were also higher during warm seasons. Changes in metal levels in water and fish tissues caused variations in biomarkers in the respective fish tissues, particularly in the livers, as demonstrated by significant correlations of metal concentrations in water and fish tissues to biochemical and physiological responses (p < 0.05). The findings suggest that metal pollution in the river basin adversely impacts the physiological health of both wild and cultured fish. Seasonal shifts in the levels of metal accumulation and biomarkers could be connected to species-specific differences in physiology and the levels of metals in environments. This biomarker set is simple but effective in assessing the impact of metal pollution on fish health and, hence, the aquatic ecosystem. This is one of the first biomonitoring studies to assist in designing better water management strategies for the Nhue–Day River basin.

Heavy metals concentrations in water, sediment, water hyacinth (Eichhornia crassipes) and Frillfin Goby (Bathygobius soporator, Cuvier and Valenciennes, 1837) from Ologe Lagoon, Southwest, Nigeria

The level of heavy metals in water, sediment, water hyacinth (Eichhornia crassipes) and frillfin goby (Bathygobius soporator) from Ologe Lagoon and its tributaries were monitored because of the importance of the water bodies to the socio-economic well-being of the rural population. Physico-chemical parameters and selected heavy metals (Fe, Zn, Cu, Pb and Cd) contents of water, sediment, E. crassipes and B. soporator from six sampling stations in Ologe Lagoon were measured monthly from February to November, 2015. The range of concentration of heavy metals in sediment are: Fe (454±112-2756±1213mg/kg), Zn (3.89±3.08-18.7±6.83mg/kg), Cu (7.68±5.65-36.8±16.9mg/kg), Pb (6.24±2.56-11.2±4.45mg/kg) and Cd (0.42±0.17-0.92±0.42mg/kg). Heavy metal concentration in E. crassipes were 68.5±16.5-987±86.8mg/kg, 13.2±6.40-162±46.2mg/kg, 0.56±0.25-6.54±1.45mg/kg, 5.06±2.41-12.2±4.71mg/kg and 0.28±0.22-1.21±0.49mg/kg for Fe, Zn, Cu, Pb and Cd respectively. The concentrations of heavy metals in the muscle of B. soporator in wet season were: Fe, 8.30±2.29 mg/kg; Zn, 0.78±0.28 mg/kg; Cu, 16.20±6.20 mg/kg; Pb, 2.21±0.33mg/kg; Cd, 0.16±0.05mg/kg while in dry season, they were: Fe, 27.19±7.28 mg/kg; Zn, 24.47±6.27 mg/kg; Cu, 0.18±0.16 mg/kg; Pb, 1.72±0.07mg/kg; Cd, 0.19±0.03mg/kg. Hardness and turbidity showed significant (p&lt;0.05) spatial variation. Concentrations of Fe, Zn and Cu in sediment varied significantly (p&lt;0.05) among the sampling sites but Pb and Cd did not. The heavy metal content of water hyacinth from the six sampling stations exhibited significant (p&lt;0.05) spatial variation except Cd. The concentrations of Fe, Zn and Cu in B. soporator were significantly (p&lt;0.05) affected by season but Pb and Cd were not. Although only Pb exceeded the FAO/WHO maximum permissible limits in the tissue of B. soporator, regular monitoring of Ologe Lagoon is advocated in order stern further deterioration of the ecosystem and to protect the rural population that depend on it for sustenance.

Factors that influence the toxicity levels of metals in water and soils: a case study of Lake Nike, Enugu, Nigeria

Factors that influence the toxicity levels of metals in water and soils: a case study of Lake Nike, Enugu, Nigeria

Determination of Heavy Metal Levels in Water, Sediment and Some Tissues of Carp (Cyprinus carpio L.1758) Living in the in Oymapınar Dam Lake’s (Antalya)

Bu çalışma 2017 yılında Oymapınar Baraj Gölü’nde yürütülmüştür. Çalışma kapsamında göl suyunda, sedimentinde ve gölde yaşayan sazanın (Cyprinus carpio L.,1758) kas, karaciğer ve solungaç dokularındaki bazı ağır metallerin konsantrasyonlarının belirlenmesi amaçlanmıştır. Göl suyunda Mo (&amp;lt;0.0008) her mevsim, Cu (&amp;lt;0.0006) ilkbahar ve sonbahar mevsimlerinde analiz limitinin altında kalmıştır. Suda en fazla biriken metal Fe, en az biriken metaller ise Cd ve Cr olmuştur. Mevsimsel olarak yapılan değerlendirmede Cd, Cu, Mn, Ni ve Se’un sonbahar mevsiminde, Cu, Fe ve Zn’nun kış mevsiminde ve Pb’un yaz mevsiminde artış gösterdiği tespit edilmiştir. Buna karşın Cd, Cu, Fe, Mn ve Zn’nun yaz mevsiminde, Cr, Ni ve Se’un ilkbahar mevsiminde ve Pb’un kış mevsiminde azaldığı saptanmıştır. Göl sedimentinde tüm metaller her mevsimde belirlenmiştir. Sedimentte de en fazla biriken metal Fe, en az biriken metal ise Cd olmuştur. Mevsimsel olarak yapılan değerlendirmede Mo (sonbahar mevsiminde) hariç tüm metallerin miktarlarının yaz mevsiminde arttığı belirlenmiştir. Buna karşın Cu, Mn, Ni, Cr, Fe, ve Zn’ nun ilkbahar mevsiminde, Cd ve Pb’nun sonbahar mevsiminde, Se’un kış mevsiminde ve Mo’in yaz mevsiminde azaldığı belirlenmiştir. Balıklarda analizi yapılan tüm metaller her mevsimde her dokuda belirlenmiştir. Elde edilen sonuçlar genellendiğinde metallerin kasta kış mevsiminde, karaciğerde ilkbaharda ve solungaçta yaz mevsiminde arttığı, kasta ilkbaharda ve solungaçta ise sonbaharda azaldığı saptanmıştır. Karaciğerdeki metal azalışı mevsimsel olarak birbirine benzerlik göstermektedir. Su ve balık dokularında belirlenen değerler, Çevre ve Şehircilik Bakanlığı, EPA, WHO, EU, EC, TGK ve FAO’nun verdiği ağır metallerin kabul edilebilir sınırları ve su kalite sınıfı değerleri ile kıyaslanmıştır. Sedimentte belirlenen konsantrasyonlar sediment kalite kriterlerine göre değerlendirilmiştir.

Long-Term Impact of Wastewater Irrigation on Soil Pollution and Degradation: A Case Study from Egypt

There is consensus on the impact of wastewater irrigation on soil properties and heavy metal accumulation. The studies that show the impact of temporal changes as a result of different long-term additions of wastewater on the heavy metal accumulation and degradation of soil are extremely limited. This study was carried out to assess heavy metal contamination in soils irrigated with wastewater for more than 30 years in Egypt. A total number of 12 irrigation water samples and 12 soil profiles were collected during 2020 and were chemically characterized. The results showed that soils irrigated with wastewater over the long term contained significantly higher concentrations of heavy metals compared to fields irrigated with fresh water. Heavy metal levels in water and soil samples were within the permissible limits, with the exception of Cd concentration in water (0.03 mg L−1). Continuous cultivation for a long period of time (30 years) using raw urban wastewater application has led to the adverse effect of increasingly available Pb concentration (5.44 mg kg−1). Similar temporal behavior was seen for Cd and Fe, which increased by 0.98 and 11.2 mg kg−1, respectively, after 30 years. The heavy metals in wastewater-irrigated soils significantly increased in clayey soils, as compared to sandy soils irrigated from the same source. Our findings provide important information for decision makers in Egypt and similar countries for the development of a strategy for the use of wastewater in irrigation for sustainable agricultural management.

Spatial Variation and Risk Assessment of Arsenic and Heavy Metals in Surface Water and Suspended Particulate Matter in Tail Reaches of the Yellow River, China

To determine the pollution levels and potential toxic risks of arsenic (As) and heavy metals (Cr, Ni, Cu, Zn, Pb and Cd) in water and suspended particulate matter (SPM) in tail reaches (including freshwater reach and low-salinity reach) of the Yellow River as the Flow-Sediment Regulation Project (FSRP) has been carried out for approximately 15 yr, the surface water and SPM were sampled at pre-flood (April) and post-flood seasons (October). Results showed that similar changes of As and metal levels in water and SPM were observed along the tail reaches at pre-flood or post-flood season. Compared to pre-flood season, the levels of As, Cu, Cr and Ni in freshwater reach and the concentrations of Cr and Ni in low-salinity reach rose greatly at post-flood season. The levels of As and metals in SPM of freshwater reach or low-salinity reach at pre-flood season were significantly higher than those at post-flood season (P < 0.01). The pollutions of As and metals in surface water of tail reaches at pre-flood or post-flood season were not serious. The SPM in freshwater reach at pre-flood season were polluted by Cd, As, Cr, Cu and Ni while those in low-salinity reach were polluted by Cd and Cr. The SPM in freshwater reach at post-flood season were polluted by Cd and Pb while those in low-salinity reach were polluted by Cd and Cr. Cd was identified as heavy metal of primary concern at both pre-flood and post-flood seasons. Combined with the existed data reported in present research, this study found that the toxic risk of As and metals in SPM of tail reaches at pre-flood season was higher than that at post-flood season, implying that the implementation of FSRP during flooding season, to a great extent, reduced the toxic risk of these elements. With the long-term implementation of FSRP, the pollution levels of As and metals (particularly for Cd) in SPM of tail reaches might be elevated and the potential toxic risk primarily produced by Cr, Ni and As might be increased if effective measures were not taken in future.

Atomic Absorption Spectrophotometric Determination of Elements in Water, Fish and Sediment of Atabong River, Nigeria

Water pollution is a serious environmental problem. It comprises of the damages done to the physical, chemical and biological properties of water due to anthropogenic activities. Such damages could have serious detrimental effects on the quality and suitability of the water and even the aquatic organisms in the water, for any use. In view of this, levels of Pb, Ni, Mn, Cr and Cd were evaluated in water, fish (<i>Brycinus nurse</i>) and sediment from Atabong River in Okobo, Nigeria, during the dry and wet seasons in order to ascertain the suitability of the water and fish for human use. Samples were digested according to standard methods and analysed using Unicam 939/935 atomic absorption spectrophotometer. Physicochemical parameters were also quantified in the water samples using standard procedures. The results revealed variable levels of the investigated physicochemical parameters in the water samples from each of the sampling stations. For instance, dissolved oxygen (DO) ranged from 4.2 to 5.25 mg/L in the two seasons. Trace metals levels in water followed the trend: Cr > Ni > Mn = Cd > Pb, and Cr > Ni > Cd > Mn >Pb for dry and wet seasons, respectively. In sediment, the trend was: Mn > Cd > Cr > Ni > Pb, and Cr > Cd > Ni > Mn > Pb for dry and wet seasons, respectively. In fish, it was: Cr > Mn = Cd > Ni > Pb and Mn > Ni > Cr = Cd > Pb. The trace metals levels in water, fish and sediment were below the permissible limits stipulated by WHO and USEPA. Bioaccumulation factor analysis revealed the trend: Pb > Mn > Ni > Cr > Cd for dry season and Mn > Pb > Ni > Cd > Cr for wet season with regards to fish pollution status. Health risk assessment due to consumption of fish, water and dermal contact with the water, showed low risk as the hazard quotient and hazard index were less than unity in each case. In conclusion, the analysed fish, water and sediment contained variable levels of the investigated trace metals and the levels were below the limits that could cause toxicity in humans consuming the water and fish at the time of the study. For the purpose of monitoring and documentation, periodic investigation of the investigated trace metals in the river system is highly recommended.

Heavy metal levels in water, brown algae (Cystoseira barbata), and eelgrass (Zostera marina) from the Southern Black Sea coast of Bulgaria

The heavy metals concentration in algae and marine water can be used as a bioindicator of an ecosystem pollution. In the present study, we determined the levels of the elements As, Pb, Cd, Hg, Mn, Zn, and Al in brown algae of the species Cystoseira barbata (Agardh, 1820), eelgrass Zostera marina (Linnaeus, 1753) and also in cooled seawater. The samples were collected during the summer period of 2020 from the region of the Southern Bulgarian Black Sea coast. Our results showed low levels of heavy metals in seawater and much higherin the studied plant species, especially of aluminum in brown algae.

Health risk assessment of heavy metals in irrigated fruits and vegetables cultivated in selected farms around Kaduna metropolis, Nigeria

ABSTRACT This study assessed heavy metals levels in water, soil, fruits (banana, pawpaw) and vegetables (cucumber, cabbage and garden egg) from Bashama, Danmani and Danbushiya farms within Kaduna metropolis, Nigeria. A total of 63 samples (water (9), soil (9), fruits and vegetables (45)) were randomly collected, processed and analyzed for heavy metals using a microwave plasma atomic emission spectrometer. The heavy metal concentration in soil was found to be highest for Fe (57.30–63.51) mg/kg and the least was observed for Cu (0.45–1.45) mg/kg. High levels of Pb (0.02–0.03) mg/l, Cd (0.07–0.1) mg/l and Fe (3.23–3.42) mg/l were determined in the irrigation water exceeding the World Health Organization (WHO) standard. Some of the heavy metals (Fe, Zn and Cu) found in the various fruits and vegetables were essentials metals. Toxic metals like Pb and Cd were also present with concentrations above the World Health Organization permissible limit of 0.2 and 0.1, respectively. In the fruits and vegetables examined, the average mean concentration of metals showed significant variations with Fe having highest concentration of (7.82 mg/kg) in most of the samples from the farms. Health risk assessment of heavy metals from the fruit and vegetable samples indicated that all metals are within hazard quotient limit of less than 1 except for Cd, while for the hazard index, all the metals surpass limit of 1 which showed that the samples are likely to be of health concern. For permissible maximum tolerable daily intake in the metals studied, Cd has the highest concentration. The activities around these farms play a significant role in elevating the concentration of Cd and Pb in the fruits and vegetables a little above the WHO set standard of 0.3 mg/kg and 0.2 mg/kg, respectively. Measures to reduce the concentration of heavy metals in fruits and vegetables should be carried out in further works to avoid their health risk in human.

Heavy Metal and Microbial Contaminants of Some Vegetables Irrigated With Goo Reservoir Water, Navrongo, Ghana

Globally, the safety of vegetables for consumption is becoming an increasing concern to consumers because of the risk associated with eating of vegetables contaminated with heavy metals and microbial organisms. An assessment of the extent of microbial contamination and also levels of heavy metals and the risk associated with the consumption of the vegetables irrigated with polluted Goo reservoir water in the Navrongo municipality was carried out. Site A used the channel flooding irrigation method whilst site B used watering cans for watering during the latter part of the dry season when the pressure of the water is low. A total of 128 vegetables samples were taken for microbial and heavy metals determination each. Samples of leafy vegetable and fruit vegetables were randomly taken from the two sites for microbial and heavy metal analysis. The reservoir was divided to North, South, East and West and water samples taken from each location. The concentrations of heavy metals in the reservoir exceeded the Food and Agricultural Organization (FAO) recommended levels of metals in water for irrigation. Site B recorded the highest microbial counts likewise heavy metal contaminants in the sampled vegetables. Levels of cadmium in the vegetables exceeded the World Health Organization/FAO permissible levels. Copper (Cu) had the highest concentration in both sites. Faecal Coliform (FC) levels in the vegetables were above the International Commission on Microbiological Specifications for Food (ICMSF) allowable limits. The high quantities of Total Coliform, Faecal Coliform, E. coli, helminthes eggs and salmonella contamination of the vegetables indicate high risk of getting diseases through the consumption of these vegetables. The hazard quotient of all the metals exceeded one in both sites except Zinc (Zn). The hazard index (HI) of heavy metals studied was above one in both sites, indicating they could have adverse health effect to human life. The analysis showed there was significant difference in microbial counts and levels of heavy metals in the vegetables in the two different sites. The consumers of these vegetables were at risk of contracting water-borne diseases like typhoid fever, cholera among others and also a high risk of heavy metal poisoning especially from cadmium.

The influence of high energy milling to the adsorption of Cd(II) and Zn(II) ions on activated zeolite

Natural zeolite is believed to be able to effectively reduce heavy metal levels in water. However, due to the weakness of natural zeolites which have a low surface area and impurity so that the adsorption ability of heavy metals becomes less optimal. Increasing the surface area by using high energy milling is expected to optimize the ability of adsorption. In this study, the particle size of natural zeolite was reduced by using high energy milling then activated with HCl and NH4Cl. The adsorption process was carried out by mixing activated zeolite and activated zeolite milling(activated zeolite fine powder) in a solution of metal ions Zn(II) and Cd(II). SEM-EDX analysis showed a change in surface morphology size on activated zeolite milling and GSA indicated an increase in surface area from 69.48 m2/g to 97.9 m2/g. Activated zeolite tends to having a little bigger in ability of adsorption to Cd(II) ions and Zn (II) ions than activated zeolite milling in highest variation of concentration, 800 ppm. In optimum contact time of adsorption, activated zeolite could adsorp Cd(II) ions shorter nevertheless longer to Zn(II) ions than activated zeolite milling. Both of the zeolites have ability to adsorp Zn(II) ions more than Cd(II) ions.

Assessing the spatial and temporal variability and related environmental risks of toxic metals in Lake Asejire, south-western Nigeria

Lake Asejire in Nigeria is polluted with untreated effluent from nearby aquacultural, urban, agricultural and industrial zones. The metal laden effluent pose a hazard to the health of fish and fish consumers in the lake. This study aimed to (1) assess the spatial and seasonal variations in the levels of cadmium, cobalt, copper, iron, lead, nickel, mercury and zinc in water, sediments and gills and stomach tissues of mud catfish, Clarias gariepinus and Nile tilapia, Oreochromis niloticus; and (2) evaluate environmental risks posed by heavy metals in Lake Asejire. Potential ecological risks of heavy metals were assessed using the pollution loading, geoaccumulation and potential ecological risk indices. Levels of Fe, Co, Cu, Cd, Pb, Ni and Zn were high in water and sediments and in some cases exceeded the Nigerian Standards for Drinking Water Quality and World Health Organisation threshold values. There were significant (p < 0.05) seasonal variations in the levels of all metals in water and sediments. Significantly high Fe, Co, Cd, Pb, Ni and Zn levels recorded in gills and stomach tissues of mud catfish and Nile tilapia relate well with metal levels in water and sediments. The geoaccumulation index reflected heavy Cu and Zn contamination in sediments whereas Cd pose serious ecological risks to aquatic organisms in the lake. Accurate assessment of the spatial and temporal variability of heavy metal levels in Lake Asejire is crucial for pollution control and environmental management.

Risk assessment of human exposure to lead and cadmium in maize grains cultivated in soils irrigated either with low-quality water or freshwater

Maize is the third important cereal crop after wheat and rice, especially in Egyptian villages. It is used in baking as a substitution component in wheat products and a main component in snacks for children. The target of this study was to estimate the risk assessment of lead (Pb) and cadmium (Cd) in maize grains cultivated in the agricultural soil irrigated by the contaminated water in comparison with that irrigated by freshwater. Lead (Pb) and cadmium (Cd) levels in irrigation water, soils and maize grains collected from different sites in Egypt were determined using ICP-OES. The studied samples were collected from 5 agricultural sites irrigated with freshwater (Nile River water and groundwater) as well as 4 agricultural sites irrigated with low-quality water (contaminated by sewage and industrial wastewater). Results exhibited that the levels of Pb and Cd in soil and maize grains were significantly affected by their levels in irrigation water; where, the levels of Pb and Cd in soil and maize grains irrigated by low-quality water possessed the multiple concentrations in comparison with those irrigated by freshwater. Specific water sources such as Kafr-Dokhmais and Al-Nasiria sites, Kafr El-Sheikh governorate had the highest levels of metals in the samples of irrigation water, soil and maize grains (p < 0.05). Metals levels in water and soil samples were within the permissible limits except Cd in low-quality water samples. Levels of Pb in maize grains irrigated by low-quality water were above the permissible limits (0.20 mg kg−1), while Cd levels were within the permissible limits (0.1 mg kg−1) except Al-Nasiria samples. Levels of Pb and Cd in maize grains irrigated by low-quality water were 19–30 folds those of maize grains irrigated by freshwater. The risk assessment of Pb and Cd levels in maize grains was estimated by daily intake of metals (DIM) and health risk index (HRI). All determined HRI was <1 indicating a non potential health risk for both adults and children.

Effects of selected heavy metals on morphology of Oreochromis niloticus and Clarias gariepinus along Ruiru River, Kenya

Abstract. Ouma KO, Otieno SA, Sharma RR 2019. Effects of selected heavy metals on morphology of Oreochromis niloticus and Clarias gariepinus along Ruiru River, Kenya. Bonorowo Wetlands 9: 86-101. The objective of this study was to determine the levels of heavy metals in tilapia and catfish species along Ruiru River. Sediments, water, and fish samples were collected using systematic random sampling techniques. Three sites were established at downstream of river, 1000 meters of Ruiru Town. The other three were established at upstream of river, 1000 meters of Ruiru Town. Fish samples were transported to the laboratory at National Museums of Kenya for identification. An atomic absorption spectrophotometer was used to examine metals. Fish gills and livers were also examined for histopathological changes. Using one-way analysis of variance, researchers analyzed data on heavy metal levels in water, sediments, and fish gills, livers and muscles. Correlation coefficients were also calculated to assess the relationship between fish length and weight and metal concentrations in fish liver, gills, and muscles, as well as between levels of heavy metals in water and in sediments. In April, 0.167±0.014 mg/L, August, 0.054±0.003 mg/L, and December, 0.222±0.101 mg/L (F = 2.10, p = 0.202), mean chromium levels in water were not statistically significant, but were statistically significant at the downstream sites 0.236±0.019 mg/L, 0.058±0.001 mg/L, and 0.222±0.101 mg/L during the three months (F = 125.63, p&lt;0.001). Significant positive correlations between the levels of iron in sediments and water were found at both upstream and downstream sites, with r = 0.7319, p = 0.025, and r = 0.8506, p = 0.0037, respectively. The linkage between lead levels in sediments and water at upstream sites was not significant (r = 0.343, p = 0.366), while it was significant (r = 0.7523, p = 0.019) at downstream sites. Chromium levels in sediments and water at upstream sites indicated a positive but non-significant connection (r=0.5339, p=0.138). In the downstream sites, there was a substantial positive correlation between chromium levels in sediments and water (r = 0.9787, p&lt;0.001). Metals accumulated in fish tissues in the following order: liver&gt;gills&gt;muscle, and Clarias gariepinus tissues from downstream sites exhibited higher amounts of metals than Oreochromis niloticus tissues from the same sites. In all tissues, both kinds of fish exhibited higher levels of iron than lead, with chromium being the lowest. The liver and gills of fish from the upstream research sites had normal features on histology. Hepatocytes with larger nuclei were found in the livers of fish from downstream sites. The secondary lamellae of the gills had degenerated and fused. Metal levels in sediments were found to be greater than in water, according to the study. Fish from the downstream sites also showed morphological alterations in the liver and gills. The study's findings suggest that people who eat such fish may be exposed to metal poisoning. The National Environment Management Authority should implement measures to reduce industrial trash flow into the Ruiru River, according to the report.

Waste management: impact on metal accumulation and speciation in Aba River channel, Nigeria

ABSTRACT The impact of indiscriminate disposal of waste materials on the quality of Aba River was examined in this research. Levels of Cd, Pb, Cu, Ni, Fe, Zn, Cr, and Mn were determined in water and sediments from Aba River. Modified BCR sequential extraction procedure was employed for the fractionation of metals in sediments. Levels of toxic metals in water (Cd, Pb, Ni, and Cr) were higher than their recommended limits for potable water. However, mean levels of all the metals except Fe were within their safe limits in sediment. Levels of all the metals in sediments were also higher than in water significantly at p < 0.05. Results showed that Cd, Pb, Ni, and Cr existed mostly in the non-residual fractions while essential elements (Cu, Fe, Zn, and Mn) existed mainly in the residual fraction. Consequently, toxic metals were more mobile and bio-available than the essential ones in Aba River. Cd, Pb, and Ni were metals with serious potential health risk to those exposed to the River. Principal component analysis revealed natural and anthropogenic factors as being responsible for the accumulation of metals in the studied Aba River.

Assessment of Heavy Metals Level in Water and Sediments from Lake Njoboliyo, Yola-South, Adamawa State, Nigeria

Assessment of Heavy metals levels in Water and Sediment from Lake Njoboliyo, Yola-south, Adamawa State, Nigeria was conducted for the period of five months (January-May, 2018). Data were collected in three different sites bi-weekly in triplicate. The concentrations of heavy metals in water ranges during the period of the research were Cadmium (0.0144mg/l to 0.0256mg/l), chromium (0.0133mg/l to 0.0222mg/l), Copper (0.0133mg/l to 0.0244mg/l), Iron (1.3411mg/l to 4.2600mg/l), Zinc (0.0114mg/l to 0.4956mg/l). There was significant difference (P&lt;0.05) for all the heavy metals between sites and Months. All the heavy metals observed in the water samples were higher than the WHO except Copper which was within WHO permissible limits, indicating that the pollution of Lake Njoboliyo is moderate. The concentration of heavy metals in sediment ranges during period of study were Cadmium ranged between 0.0267mg/kg and 0.0700mg/kg, Chromium ranged between 0.0144mg/kg and 0.0467mg/kg, Copper ranged between 0.0166mg/kg and 0.3533mg/kg, Iron ranged between 26.1167mg/kg and 28.8644mg/kg, Zinc ranged between 0.1333mg/kg and 0.3878mg/kg, There was significant difference (P&lt;0.05) for all the heavy metals between sites and Months. All the heavy metals recorded in the sediment were within the permissible limit recommended by WHO and FEPA except Cadmium, indicating that the pollution of Lake Njoboliyo is moderate. Keywords: heavy metals, sediment, water, Lake Njoboliyo DOI : 10.7176/JNSR/9-14-03 Publication date :July 31 st 2019