scholarly journals Heavy metals in Venezuelan marine sediments: concentrations, degree of contamination, and distribution

2021 ◽  
Vol 47 (3) ◽  
Author(s):  
Ruth Ramos ◽  
Alejandra Verde ◽  
Elia M García
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Marine Sediments ◽  
Heavy Metal Contamination ◽  
18Th Century ◽  
Distribution Patterns ◽  
Potential Hazard ◽  
Degree Of Contamination ◽  
Metal Concentrations ◽  
Heavy Metal Concentrations

Venezuelan oil exploration and exploitation activities have been taking place since the 18th century. These long-term activities are closely related to heavy metal contamination because of the increasing input of toxic pollutants. Variations in heavy metal concentrations can cause, among other things, changes in metal distribution patterns, alterations in biogeochemical cycles, and increments in environmental and biological risks. The need for a complete baseline on heavy metal concentrations along the Venezuelan coast is critical. For this reason, we present the concentrations, distribution, and degree of contamination of 9 heavy metals (barium, mercury, copper, nickel, chromium, cadmium, zinc, lead, and vanadium) in marine sediments along the Venezuelan coast. We used the enrichment factor, the geoaccumulation index, and the mean effects range median quotients to evaluate the degree of contamination, comparing areas with and without intervention. Our results indicate that higher concentrations of these heavy metals are associated with places with greater anthropic activity, especially on the central and eastern coasts of Venezuela. Only cadmium showed extremely severe enrichment and a high degree of contamination. The biohazard potential was between 12% and 30% and was primarily associated with locations having high oil activity, which suggests that these places must be monitored, given the potential hazard they represent. This work encompasses the distribution and concentration of 9 heavy metals along the Venezuelan coast and takes relevance as a baseline for heavy metal concentrations and pollution indicators in marine sediments for Venezuela and the Caribbean.

scholarly journals Arsenic and heavy metal concentrations in agricultural soils in South Savo province

2002 ◽  
Vol 11 (4) ◽  
pp. 285-300 ◽  
Author(s):  
V. MÄNTYLAHTI ◽  
P. LAAKSO
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Agricultural Soils ◽  
Mineral Soil ◽  
Soil Samples ◽  
Potential Hazard ◽  
Metal Concentrations ◽  
Limit Values ◽  
Heavy Metal Concentrations ◽  
Target Values

Increasing concentrations of arsenic and heavy metals in agricultural soils are becoming a growing problem in industrialized countries. These harmful elements represent the basis of a range of problems in the food chain, and are a potential hazard for animal and human health. It is therefore important to gauge their absolute and relative concentrations in soils that are used for crop production. In this study the arsenic and heavy metal concentrations in 274 mineral soil samples and 38 organogenic soil samples taken from South Savo province in 2000 were determined using the aqua regia extraction technique. The soil samples were collected from 23 farms.The elements analyzed were arsenic, cadmium, chromium, copper, mercury, nickel, lead and zinc. The median concentrations in the mineral soils were:As 2.90 mg kg –1, Cd 0.084 mg kg –1, Cr 17.0 mg kg –1, Cu 13.0 mg kg –1, Hg 0.060 mg kg –1, Ni 5.4 mg kg –1, Pb 7.7 mg kg –1, Zn 36.5 mg kg –1. The corresponding values in the organogenic soils were:As 2.80 mg kg –1, Cd 0.265 mg kg –1, Cr 15.0 mg kg –1, Cu 29.0 mg kg –1, Hg 0.200 mg kg –1, Ni 5.9 mg kg –1, Pb 11.0 mg kg –1, Zn 25.5 mg kg –1. The results indicated that cadmium and mercury concentrations in the mineral and organogenic soils differed. Some of the arsenic, cadmium and mercury concentrations exceeded the normative values but did not exceed limit values. Most of the agricultural fields in South Savo province contained only small amounts of arsenic and heavy metals and could be classified as “Clean Soil”. A draft for the target values of arsenic and heavy metal concentrations in “Clean Soil” is presented.;

scholarly journals Heavy metal concentrations in vegetables cultivated and sold in Machakos Municipality, Kenya

2021 ◽  
Vol 24 (12) ◽  
pp. 2027-2034
Author(s):  
R.M. Tomno ◽  
L. Kitulu ◽  
J.K. Nzeve ◽  
F. Waswa ◽  
S.N. Mailu ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Contamination ◽  
Public Awareness ◽  
Urban Stream ◽  
County Government ◽  
Human Consumption ◽  
Metal Concentrations ◽  
Heavy Metal Concentrations ◽  
The Mean

Heavy metal contamination of vegetables is a key aspect of food quality assurance since vegetables form a substantial proportion of the daily human diet. Health risks in urban populations due to exposure to heavy metals are on the increase because of the consumption of vegetables irrigated with wastewater. This study analyzed the concentration of Cd, Cu, Pb, Zn and Cr in spinach and kales grown using contaminated water of the Mitheu urban stream and those sold within Machakos municipality. Vegetable samples were collected once per month for a period of four months starting from June to September 2019. The mean heavy metal concentrations obtained were0.013 – 3.19 mg/kg, 0.468 – 1.706 mg/kg, 0.02 – 0.368 mg/kg, 5.78 – 26.7 mg/kg, and 0.104 – 14.0 mg/kg for Cd, Cu, Pb, Zn and Cr respectively in kale samples from the different sampling sites. The heavy metal mean concentrations in spinach were 0.055 – 0.575 mg/kg, 3.79 – 5.55 mg/kg, 0.098 – 1.49 mg/kg, 8.32 – 20.7 mg/kg and 0.368 – 4.43 mg/kg for Cd, Cu, Pb, Zn and Cr respectively. The mean concentrations of Cd, Pb, Zn and Cr in both spinach and kales in some of the sampling sites were above WHO permissible levels for heavy metals in vegetables for human consumption. However, the mean concentration of Cu was below WHO recommended levels. Consumption of these vegetables therefore poses a health risk to the consumers. There is need to create public awareness on the dangers of consuming contaminated vegetables. Additionally, measures to curb heavy metal pollution in Mitheu stream should be taken by the County Government of Machakos.

scholarly journals Heavy Metal Contamination of Irrigation Water, Soil, and Vegetables and the Difference between Dry and Wet Seasons Near a Multi-Industry Zone in Bangladesh

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 583 ◽  
Author(s):  
Minhaz Ahmed ◽  
Masaru Matsumoto ◽  
Akinori Ozaki ◽  
Nguyen Thinh ◽  
Kiyoshi Kurosawa
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Irrigation Water ◽  
Heavy Metal Contamination ◽  
Analysis Data ◽  
Dry Season ◽  
Wet Season ◽  
Metal Concentrations ◽  
Heavy Metal Concentrations ◽  
The Difference

Heavy metal (Cr, Cu, Zn, As, Cd, and Pb) contamination in irrigation water, soil, and vegetables was investigated in farmland adjacent to a multi-industry zone in Bangladesh in dry and wet seasons. In the zone, many factories release wastewater into nearby irrigation canals, and vegetables cultivated with this water could be a major food chain route for human exposure. In the irrigation water and vegetables, heavy metal concentrations exceeded permissible levels in the two seasons, but this was not the case in soil. Zn had the highest concentration, and Cd had the lowest concentration in irrigation water, soil, and vegetables. All heavy metal concentrations were found to be lower in the wet than in the dry season, which is due to the dilution of water by rainfall, lower absorption of heavy metals from the diluted irrigation water, and heavy metal absorption from low concentrated irrigation water and/or soil. The cluster analysis data of irrigation water, soil, and vegetables revealed that the heavy metals in vegetables were considered to be absorbed from irrigation water in the wet season and from soil in the dry season. In the dry season, the high heavy metal concentrations in vegetables might be caused by a high bioconcentration factor (mostly > 20%).

scholarly journals Phytoprevention of Heavy Metal Contamination From Terrestrial Enhanced Weathering: Can Plants Save the Day?

2022 ◽  
Vol 3 ◽  
Author(s):  
Tim Jesper Suhrhoff
Keyword(s):  
Heavy Metals ◽  
Carbon Dioxide ◽  
Heavy Metal ◽  
Heavy Metal Contamination ◽  
Carbon Capture And Storage ◽  
Heavy Metal Accumulation ◽  
Environmental Risks ◽  
Metal Concentrations ◽  
Large Variability ◽  
Heavy Metal Concentrations

Enhanced weathering is a promising approach to remove carbon dioxide from the atmosphere. However, it may also pose environmental risks through the release of heavy metals, in particular nickel and chromium. In this perspective article I explore the potential role of plants in modulating these heavy metal fluxes. Agricultural basaltic soils may be valuable study sites in this context. However, the effect of biomass harvesting on the accumulation of heavy metals is currently not well studied. Mostly caused by different parent rock concentrations, there is a large variability of heavy metal concentrations in basaltic and ultramafic soils. Hence, to minimize environmental risks of enhanced weathering, basalts with low heavy metal concentrations should be favored. Existing phytoremediation strategies may be used to “phytoprevent” the accumulation of nickel and chromium released from enhanced weathering in soils. As a result, elevated nickel and chromium concentrations in rocks must not preclude enhanced weathering in all settings. In particular, hyperaccumulating plants could be used as part of a crop rotation to periodically remove heavy metals from soils. Enhanced weathering could also be employed on fields or forests of (non-hyper) accumulating plants that have a high primary production of biomass. Both approaches may have additional synergies with phytomining or bioenergy carbon capture and storage, increasing the total amount of carbon dioxide drawdown and at the same time preventing heavy metal accumulation in soils.

scholarly journals Spatial Distribution of Heavy Metals in the Surface Sediments of the Southern Coast of Pacitan, Indonesia

2018 ◽  
Vol 18 (1) ◽  
pp. 137 ◽  
Author(s):  
Defri Yona ◽  
Mochamad Arif Zainul Fuad ◽  
Nurin Hidayati
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Spatial Distribution ◽  
Physicochemical Parameters ◽  
Surface Sediments ◽  
Distribution Patterns ◽  
Coastal Areas ◽  
Southern Coast ◽  
Metal Concentrations ◽  
Heavy Metal Concentrations

This study was conducted to analyze the spatial distribution of heavy metals from four different coastal areas in southern Pacitan, Indonesia: Pantai Watu Karung (WK), Pantai Teleng Ria (TL), Pantai Pancer (TP) dan Pantai Soge (SG). Data collected in this study included: temperature, salinity, DO, pH, sediment, organic matter and heavy metals in the sediments (Pb, Hg and Cd). The results showed different distribution patterns of heavy metals. Heavy metal concentrations, especially Pb and Hg, were found to be higher in Pantai Soge, while the concentration of Cd was higher in Pantai Pancer. An ANOVA test showed the distributions of Pb and Cd were significantly different (p < 0.01) between sampling sites. Variability of the physicochemical parameters influenced the variabilities of heavy metal concentrations among sampling sites. Overall, heavy metal concentrations in the study areas are rather low; however, attention is still needed due to heavy activities in the coastal areas of southern Pacitan that can contribute to heavy metal pollution.

scholarly journals Heavy metal contamination in surface water of Mohammedia wetland, Morocco

2021 ◽  
Vol 298 ◽  
pp. 05001
Author(s):  
Halima Jounaid ◽  
El Mehdi El Hachimi ◽  
Nihad Chakri ◽  
Toufik Remmal ◽  
Btissam Elamrani ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Surface Water ◽  
Surface Waters ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Field Observations ◽  
Metal Concentrations ◽  
Industrial Activities ◽  
Heavy Metal Concentrations

Assessing heavy metal concentrations in wetlands and identifying sources of metal contamination are critical steps in protecting wetlands. Using seven sampling stations, we evaluated the spatial variation of some heavy metal concentrations in surface waters of the Mohammedia wetland and a selected segment of the El Maleh wadi that feeds the wetland. Field observations made it possible to identify and map the pollution discharged into El Maleh wadi, carrying heavy metals into the wetland. The analyses showed that the concentrations of lead, manganese, and cadmium far exceed the thresholds relating to fish life in 100% of sampling stations. All the evidence points to heavy metals contamination of surface water in Mohammedia wetland, generated by industrial activities, wastewater discharges, and leachate from the old landfill located upstream.

scholarly journals Heavy Metals in the Soils of Placer Small-Scale Gold Mining Sites in Myanmar

2020 ◽  
Vol 10 (27) ◽  
pp. 200911
Author(s):  
Aung Zaw Tun ◽  
Pokkate Wongsasuluk ◽  
Wattasit Siriwong
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Gold Mining ◽  
Soil Samples ◽  
Small Scale ◽  
Mining Activities ◽  
Mining Operations ◽  
Metal Concentrations ◽  
Mining Sites ◽  
Heavy Metal Concentrations

Background. Artisanal and small-scale mining activities are widely practiced globally. Concentrations of heavy metals associated with gold, such as copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) can increase in the environment as a result of mining activities, leading to environmental pollution and pose toxicity risks to humans and animals. Objectives. The aim of the present study was to investigate soil concentrations of toxic heavy metals in placer small-scale gold mining operations in Myanmar. Methods. Soil samples were collected from three placer small-scale gold mining sites: Site A located in the Hmawbon public protected forest, Site B and Site C, situated in the Nant-Kyin reserved forest around Nar Nant Htun village. At each site, soil samples were collected from four gold mining stages (ore processing, sluicing, panning, and amalgamation). Atomic absorption spectroscopy was utilized to examine the concentrations of As, Cd, Pb, and Hg. Results. The highest heavy metal concentrations were generally found in the amalgamation stages across all the gold mining sites. Across the three mining sites, the maximum heavy metal concentrations in the amalgamation stage were 22.170 mg.kg−1 for As, 3.070 mg.kg−1 for Cd, 77.440 mg.kg−1 for Hg, and 210.000 mg.kg−1 for Pb. Conclusions. The present study examined the concentrations of As, Cd, Hg and Pb in the soil of several small-scale gold mining sites in Banmauk Township, Myanmar. The results demonstrated the presence of high concentrations of heavy metals in the soil of the gold mining sites. Miners in this area work without proper personal protective equipment, and frequent exposure to heavy metals in the soil may cause adverse health effects. The present study provides baseline data for future risk assessment studies of heavy metal contamination in gold mines. Competing Interests. The authors declare no competing financial interests

scholarly journals Distribution and Potential Risk of Heavy Metals in Sediments of the Three Gorges Reservoir: The Relationship to Environmental Variables

Water ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1840 ◽  
Author(s):  
Lei Huang ◽  
Hongwei Fang ◽  
Ke Ni ◽  
Wenjun Yang ◽  
Weihua Zhao ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Environmental Variables ◽  
Three Gorges Reservoir ◽  
Three Gorges ◽  
Metal Concentrations ◽  
Sediment Samples ◽  
Heavy Metal Concentrations ◽  
Sediment Size ◽  
The Three Gorges

In this study, surface sediment samples were taken from the Three Gorges Reservoir (TGR) in June 2015 to estimate the spatial distribution and potential risk of Cu, Zn, Cd, Pb, Cr, and Ni (34 sites from the mainstream and 9 sites from the major tributaries), and correlations with environmental variables were analyzed (e.g., median sediment size, water depth, turbidity, dissolved oxygen of the bottom water samples, and total organic carbon, total nitrogen, and total phosphorus of the surface sediment samples). Results show that the heavy metal concentrations in the sediments have increased over the last few decades, especially for Cd and Pb; and the sites in the downstream area, e.g., Badong (BD) and Wushan (WS), have had greater increments of heavy metal concentrations. The sampling sites from S6 to S12-WS are identified as hot spots for heavy metal distribution and have relatively high heavy metal concentrations, and there are also high values for the sites affected by urban cities (e.g., the concentrations of Zn, Cd, Cr and Ni for the site S12-WS). Overall, the heavy metal concentrations increased slightly along the mainstream due to pollutants discharged along the Yangtze River and sediment sorting in the reservoir, and the values in the mainstream were greater than those in the tributaries. Meanwhile, the heavy metal concentrations were generally positively correlated with water depth (especially for Ni), while negatively correlated with dissolved oxygen, turbidity, and median sediment size. These environmental variables have a great impact on the partition of heavy metals between the sediment and overlying water. According to the risk assessment, the heavy metals in the surface sediments of TGR give a low to moderate level of pollution.

Heavy metals and 137Cs levels in macrophytes and temporal distribution in sediments – application for estuarine environment status assessment (Vistula Lagoon – southern Baltic)

2020 ◽  
Vol 49 (1) ◽  
pp. 68-80
Author(s):  
Tamara Zalewska ◽  
Paulina Brzeska-Roszczyk ◽  
Beata Danowska ◽  
Mariusz Pełechaty
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Stable State ◽  
Temporal Distribution ◽  
Abundant Species ◽  
Vistula Lagoon ◽  
Metal Concentrations ◽  
Heavy Metal Concentrations ◽  
Status Assessment ◽  
The Vistula Lagoon

AbstractThe paper presents the first data on the concentrations of heavy metals (Cd, Pb, Zn, Cu, Ni, Cr, Mn) and 137Cs and their contamination ratios (CR) in the most abundant species of macrophytes in the Vistula Lagoon. No significant differences in the concentrations of heavy metals and 137Cs between macrophyte taxa or the influence of rivers flowing into the Vistula Lagoon on heavy metal concentrations in the area were found. The concentrations of heavy metals in macrophyte taxa varied in the following ranges: Cd – 0.1–0.7 mg kg−1 d.w.; Pb – 0.5–5.0 mg kg-1 d.w.; Zn – 29–390 mg kg-1 d.w.; Cu – 2.5–8.3 mg kg-1 d.w.; Ni – 0.4–6.8 mg kg−1 d.w.; Cr – 0.5–2.8 mg kg−1 d.w.; Mn – 380–8500 mg kg−1 d.w. Since the 1990s, a decline or stable state of heavy metal concentrations in bottom sediments has been observed, reflecting changes in the environment of the Vistula Lagoon. The linear sedimentation rate in the Vistula Lagoon was 3.3 mm y−1. The results presented in the paper can serve as a baseline for assessing changes in the environmental status of the Vistula Lagoon, which may occur as a result of future investments, including building a new navigable canal through the Vistula Spit.

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