China 
Africa 
Explore chapters and articles related to this topic
Utilization of Coal Mine Waste in Vegetation
Published in Karra Ram Chandar, B. C. Gayana, P. Shubhananda Rao, Mine Waste Utilization, 2022
Chaitanya Vikas, Karra Ram Chandar
Trace elements, specifically metals, are found in ore bodies and released into the environment during the mining, milling and smelting processes. These elements often create toxicity problems in soils and contaminate surface and ground waters, creating exposure risks to humans, wild life and aquatic organisms. Once soils are contaminated with metals, metal levels are relatively static and will not be removed by natural processes (Bradshaw 1997). Chemical properties of mine wastes are considered the greatest restraint to plant growth. Trace elements considered essential for plant growth include B, Ca, Co, Cu, Fe, Mn, Mo, Si, Se and Zn. The important metallic micronutrients that are essential for plant growth are Fe, Mn, Cu and Zn.
Occupational Health and Safety in Mines
Published in Debi Prasad Tripathy, Mine Safety Science and Engineering, 2019
Metal toxicity is the toxic effect of specific metals in certain forms and doses. Generally, all the heavy metals are toxic in nature, but not all are particularly toxic. Some trace metals in high doses can also be toxic. Heavy metals are metals with a relatively high density (>5 g/cm3), atomic number, or atomic weight. Trace metals are metals that naturally occur at low levels (<1,000 ppm) in the environment. The trace elements are chromium, cobalt, copper, iron, magnesium, selenium, and zinc. They are required for maintaining good health in people and are used for various purposes in daily life. Depending on the general characteristics of heavy metals, their usage varies. Generally, they are categorized into six groups based on their usage, as shown in Figure 8.6.
Igneous Petrology and the Nature of Magmas
Published in Dexter Perkins, Kevin R. Henke, Adam C. Simon, Lance D. Yarbrough, Earth Materials, 2019
Dexter Perkins, Kevin R. Henke, Adam C. Simon, Lance D. Yarbrough
Trace elements are elements present in very small amounts, amounts even smaller than amounts of minor elements. The amount of any trace element that can enter a growing crystal depends mostly on ionic charge and radius. Some trace elements enter growing crystals in the early stages of crystallization, but others may remain in a magma until the latest stages of crystallization. Trace elements are even more selective than minor elements about the minerals they enter and generally have insignificant effects on rock and mineral properties. Because trace elements are present in very small amounts, petrologists commonly report them in parts per million (ppm) or parts per billion (ppb) instead of weight %. 1 ppm = 0.0001 wt%. Furthermore, when plotting trace element analyses, petrologists normalize the raw data by dividing by the composition of some reference standard. Normalization means that the range of values becomes small enough so that we may plot all trace elements on a single graph.
Influence of biochar on trace element uptake, toxicity and detoxification in plants and associated health risks: A critical review
Published in Critical Reviews in Environmental Science and Technology, 2022
Natasha Natasha, Muhammad Shahid, Sana Khalid, Irshad Bibi, Muhammad Asif Naeem, Nabeel Khan Niazi, Filip M. G. Tack, James Anthony Ippolito, Jörg Rinklebe
Trace elements occur naturally in the environment. However, since the industrial revolution, human activities have redistributed trace elements in the Earth’s crust to essentially all environmental compartments, and in particular to soil (Anwar et al., 2020; Palansooriya et al., 2020; Tack, 2010). More than 10 million contaminated soil sites have been recognized globally with >50% of these sites polluted by trace elements (Carré et al., 2017; Desjardins et al., 2018). The European Environmental Agency (EEA) reported more than 342,000 highly contaminated sites in EEA member countries (EEA, 2011); contaminants mainly included trace elements. In the USA and Europe, about 106 ha of land is contaminated by trace elements (Lewandowski et al., 2006). In China, the Ministry of Natural Resources estimates that > 7 × 107 ha of agricultural lands is contaminated with trace elements (Ministry of Environmental Protection (MEP), 2014).
Occurrence, Origin and Risk Assessment of Trace Elements in High Geological Background Impacted Soil-crop Systems in Yunnan, China
Published in Soil and Sediment Contamination: An International Journal, 2022
Weihong Lu, Siliang Huang, Naiming Zhang, Fangyan Li, Jianwen Wang, Dongjin Han, Hong Yu, Jiaqi Li, Li Bao
Trace elements (TEs) is a general term for chemical elements found in relatively small concentrations in the plant, soil and water. However, an excess of TEs in the soil can result in the food chain contamination through crops (especially cereals and vegetables, etc.) causing potential harm to environmental organisms, including the health of animals and humans (Antoniadis et al. 2019; Guo et al. 2014; Li et al. 2018; Xu et al. 2015). In the past decade, with the rapid industrialization, urbanization, and the use of high-intensity agriculture, increased anthropogenic activities have aggravated the problem of TEs contamination of farmland soils in certain areas (Cai et al. 2019; Jin et al. 2019; Shahid et al. 2021). According to the “National Survey Bulletin of Soil Pollution Status” in China, the over-standard rate of farming sites has reached 19.4%, especially for cadmium (Cd), lead (Pb), arsenic (As), mercury (Hg), and chromium (Cr) (Chen et al. 2017; Lu et al. 2020; Ministry of Environmental Protection, 2014). In China, the total area of polluted cultivated land has reached 2.3 × 107 hm2 (Chen et al. 2017; Yang et al. 2018; Zhao, Huang, and Qian 2007). Therefore, the food safety and health risk assessment of TEs have received substantial attention for possible toxicity in the human food chain.
Sentinel species for biomonitoring and biosurveillance of environmental heavy metals in Nigeria
Published in Journal of Environmental Science and Health, Part C, 2022
Cecilia Nwadiuto Amadi, Chiara Frazzoli, Orish Ebere Orisakwe
Some chemical elements are essential to human health, some are non-essential, and some are toxic.3 Essential trace elements are required for normal healthy body functions and their deficiency induces adverse health effects. They play important and specific roles as components of enzyme systems (e.g. copper (Cu), manganese (Mn), selenium (Se) and zinc (Zn), vitamins (e.g. cobalt (Co), and hormones (e.g. iodine (I)). Among the non-biologically essential elements, which have no known functions in the body, some may exert some positive biological effects at low doses, e.g. chromium (Cr) and vanadium (V). Toxic chemical elements, such as arsenic (As), cadmium (Cd), mercury (Hg), nickel (Ni), and lead (Pb), are known to have harmful effects on living organisms. All trace elements, including the essential ones, exert adverse effects if present above certain threshold intake levels.4