scholarly journals Metal(loid)s in Cucurbita pepo in a Uranium Mining Impacted Area in Northwestern New Mexico, USA

Author(s):  
Christine Samuel-Nakamura ◽  
Felicia S. Hodge ◽  
Sophie Sokolow ◽  
Abdul-Mehdi S. Ali ◽  
Wendie A. Robbins

More than 500 unreclaimed mines and associated waste sites exist on the Navajo Nation reservation as a result of uranium (U) mining from the 1940s through the 1980s. For this study, the impact of U-mine waste on a common, locally grown crop food was examined. The goal of this site-specific study was to determine metal(loid) concentration levels of arsenic (As), cadmium (Cd), cesium (Cs), molybdenum (Mo), lead (Pb), thorium (Th), U, vanadium (V) and selenium (Se) in Cucurbita pepo Linnaeus (squash), irrigation water, and soil using inductively coupled plasma-mass spectrometry. The concentrations of metal(loid)s were greatest in roots > leaves > edible fruit (p < 0.05), respectively. There were significant differences between metal(loid)s in squash crop plot usage (<5 years versus >30 years) for V (p = 0.001), As (p < 0.001), U (p = 0.002), Cs (p = 0.012), Th (p = 0.040), Mo (p = 0.047), and Cd (p = 0.042). Lead and Cd crop irrigation water concentrations exceeded the United States Environmental Protection Agency (USEPA) Maximum Contaminant Levels for drinking water for those metals. Edible squash concentration levels were 0.116 mg/kg of As, 0.248 mg/kg of Pb, 0.020 mg/kg of Cd, and 0.006 mg/kg of U. Calculated human ingestion of edible squash did not exceed Provisional Tolerable Weekly Intake or Tolerable Upper Limit levels from intake based solely on squash consumption. There does not appear to be a food-ingestion risk from metal(loid)s solely from consumption of squash. Safer access and emphasis on consuming regulated water was highlighted. Food intake recommendations were provided. Continued monitoring, surveillance, and further research are recommended.

Plants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 21
Author(s):  
Christine Samuel-Nakamura ◽  
Felicia S. Hodge

This study reports on the harvesting, ingestion, and contamination of American Indian tea Thelesperma megapotamicum grown on the Navajo Reservation in New Mexico. Uranium (U) and co-metal(loid)s (As, Cd, Cs, Mo, Pb, Se, Th, and V) have contaminated local soil and plants. Tea plants were gathered for analysis near U mining impacted areas. The study collected samples of wild tea plants (n = 14), roots (n = 14), and soil (n = 12) that were analyzed with inductively coupled plasma mass spectrometry. Tea harvesting activities, behavior, and ingestion information were collected via questionnaires. Harvesting took place in community fields and near roadways. Results indicate edible foliage concentration levels for Cd exceeded the World Health Organization (WHO) raw medicinal plant permissible level guidelines. Tea samples collected near high traffic areas had significantly greater Cd and Mo concentrations than those collected near low traffic areas (p < 0.001). Tea sample metal(loid) concentration levels ranged from 0.019–7.916 mg/kg. When compared to established food guidelines including the WHO provisional tolerable weekly intake (PTWI), reference dietary intake, recommended dietary allowance, and the tolerable upper limit (UL), Cd exceeded the WHO guidelines but none exceeded the PTWI nor the UL. These findings warrant improved standardization and establishment of universal guidelines for metal(loid) intake in food.


2006 ◽  
Vol 54 (11-12) ◽  
pp. 289-299 ◽  
Author(s):  
S.A. Sari ◽  
Z. Ujang ◽  
U.K. Ahmad

The objective of this study was to investigate the cycling of arsenic in the water column of a post-mining lake. This study is part of a research project to develop health risk assessment for the surrounding population. Inductively Coupled Plasma-Mass Spectrophotometer (ICP-MS) and Capillary Electrophoresis (CE) have been used to analyze the total amount and speciation, respectively. A computer program, called MINTEQA2, which was developed by the United States Environmental Protection Agency (USEPA) was used for predicting arsenic, iron, and manganese as functions of pH and solubility. Studying the pH values and cycle of arsenic shows that the percentage of bound arsenate, As(V) species in the form of HAsO−4 increases with range pH from 5 to 7, as well as Fe(II) and Mn(II). As expected phases of arsenic oxides are FeAsO4 and Mn3(AsO4), as a function of solubility, however none of these phases are over saturated and not precipitated. It means that the phases of arsenic oxides have a high solubility.


Author(s):  
Inna Yu. Tarmaeva ◽  
Anatoliy V. Skalny ◽  
Olga G. Bogdanova ◽  
Andrey R. Grabeklis ◽  
Alexandr I. Belykh

Introduction.The study of the elemental status of the population of individual regions of the Russian Federation with the purpose of scientific development and implementation of measures for elimination of revealed elementosis is a promising direction for preventive medicine.The aim of the studyis to study the elemental status of the adult able-bodied population of the Republic of Buryatia, which was part of the Siberian Federal district (SFD) until 2018.Materials and methods.The analysis was performed by inductively coupled plasma mass spectrometry (ICP-MS) on the basis of the accredited laboratory of “Center of biotic medicine”. (Moscow; ISO 9001: 2008 certificate 54Q10077 from 21.05.2010). The content of chemical elements in the hair of 130 adults (102 women and 28 men) aged 25–50 years was studied. This indicator serves as an indicator in assessing the impact of the environment on the human body. Methods of nonparametric statistics were used for mathematical processing of the data.Results.For women living in the Republic of Buryatia, the maximum values of Zn, increased levels of Cu, Li, Si were revealed; for men — the maximum values of Mg, Cr, Si, increased levels of P, Li, Se, V, Pb. Minimum values were found for P, Fe, V. Elemental status indicates a significant degree of prevalence of essential trace element deficiencies and electrolyte imbalance. The obtained data can be used as reference values for the content of chemical elements in the hair of adults living in the Republic of Buryatia.Conclusions:Elemental analysis of the population of the Republic of Buryatia indicates imbalances among the adult working-age population.


2016 ◽  
Vol 26 (3) ◽  
pp. 368-374 ◽  
Author(s):  
Ajay Kumar ◽  
Saurabh Narang ◽  
Rohit Mehra ◽  
Surinder Singh

Groundwater samples taken from 20 villages of Fazilka district, Punjab, India were analysed for radon concentration using RAD7, which is an electronic radon detector. Radon concentration varies from (1.4 ± 1.0) × 103 Bq/m3 to (4.9 ± 3.0) × 103 Bq/m3, which is much below the safe limits proposed by US Environmental Protection Agency (US EPA) and UN Scientific Committee on the Effects of Atomic Radiation. The mean annual effective dose calculated for these samples was also found to be within the limits provided by WHO and EU council. These samples were also analysed for concentration of certain heavy elements like As, Pb, Zn, Cu, Hg, Ni and Cd using inductively coupled plasma atomic emission spectrometer. Out of these, concentrations of As and Pb were found to exceed the permissible limits suggested by US EPA.


Author(s):  
Radim J. Sram

Thirty years ago, Northern Bohemia in the Czech Republic was one of the most air polluted areas in Europe. After political changes, the Czech government put forward a research program to determine if air pollution is really affecting human health. This program, later called the “Teplice Program”, was initiated in collaboration with scientists from the United States Environmental Protection Agency (US EPA). This cooperation made possible the use of methods on the contemporary level. The very high concentrations of sulphur dioxide (SO2), particulate matter of 10 micrometers or less (PM10), and polycyclic aromatic hydrocarbons (PAHs) present in the air showed, for the first time, the impact of air pollutants on the health of the population in mining districts: adverse pregnancy outcomes, the impact of air pollution on sperm morphology, learning disabilities in children, and respiratory morbidity in preschool children. A surprising result came from the distribution of the sources of pollution: 70% of PM10 pollution came from local heating and not from power plants as expected. Thanks to this result, the Czech government supported changes in local heating from brown coal to natural gas. This change substantially decreased SO2 and PM10 pollution and affected mortality, especially cardiovascular mortality.


Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2562
Author(s):  
Pierre-Marie Coulon ◽  
Peng Feng ◽  
Tao Wang ◽  
Philip A. Shields

The formation of gallium nitride (GaN) semi-polar and non-polar nanostructures is of importance for improving light extraction/absorption of optoelectronic devices, creating optical resonant cavities or reducing the defect density. However, very limited studies of nanotexturing via dry etching have been performed, in comparison to wet etching. In this paper, we investigate the formation and morphology of semi-polar (112¯2) and non-polar (112¯0) GaN nanorods using inductively coupled plasma (ICP) etching. The impact of gas chemistry, pressure, temperature, radio-frequency (RF) and ICP power and time are explored. A dominant chemical component is found to have a significant impact on the morphology, being impacted by the polarity of the planes. In contrast, increasing the physical component enables the impact of crystal orientation to be minimized to achieve a circular nanorod profile with inclined sidewalls. These conditions were obtained for a small percentage of chlorine (Cl2) within the Cl2 + argon (Ar) plasma combined with a low pressure. Damage to the crystal was reduced by lowering the direct current (DC) bias through a reduction of the RF power and an increase of the ICP power.


2019 ◽  
Vol 16 (18) ◽  
pp. 3565-3582 ◽  
Author(s):  
Nicolai Schleinkofer ◽  
Jacek Raddatz ◽  
André Freiwald ◽  
David Evans ◽  
Lydia Beuck ◽  
...  

Abstract. Here we present a comprehensive attempt to correlate aragonitic Na∕Ca ratios from Desmophyllum pertusum (formerly known as Lophelia pertusa), Madrepora oculata and a caryophylliid cold-water coral (CWC) species with different seawater parameters such as temperature, salinity and pH. Living CWC specimens were collected from 16 different locations and analyzed for their Na∕Ca ratios using solution-based inductively coupled plasma-optical emission spectrometry (ICP-OES) measurements. The results reveal no apparent correlation with salinity (30.1–40.57 g kg−1) but a significant inverse correlation with temperature (-0.31±0.04 mmolmol-1∘C-1). Other marine aragonitic organisms such as Mytilus edulis (inner aragonitic shell portion) and Porites sp. exhibit similar results highlighting the consistency of the calculated CWC regressions. Corresponding Na∕Mg ratios show a similar temperature sensitivity to Na∕Ca ratios, but the combination of two ratios appears to reduce the impact of vital effects and domain-dependent geochemical variation. The high degree of scatter and elemental heterogeneities between the different skeletal features in both Na∕Ca and Na∕Mg, however, limit the use of these ratios as a proxy and/or make a high number of samples necessary. Additionally, we explore two models to explain the observed temperature sensitivity of Na∕Ca ratios for an open and semi-enclosed calcifying space based on temperature-sensitive Na- and Ca-pumping enzymes and transport proteins that change the composition of the calcifying fluid and consequently the skeletal Na∕Ca ratio.


2020 ◽  
Vol 36 (4) ◽  
pp. 272-286
Author(s):  
Nahla Kamal ◽  
AH Zaki ◽  
Ahmed AG El-Shahawy ◽  
Ossama M Sayed ◽  
SI El-Dek

The present research investigated the impact of the morphology change of titanate (TiO2) nanostructures on its tissue distribution and toxicity. The TiO2 nanotubes, rods, and ribbons were synthesized by the hydrothermal technique, and the morphology was adjusted by alteration of the hydrothermal duration time. The characterization techniques were X-ray diffraction, high-resolution transmission electron microscopy, dynamic light scattering, and the Brunauer–Emmett–Teller method for measuring the surface area. The intravenously administrated dose (5 mg/kg) was injected as a single dose for 1 day and consecutively for 42 days. The quantitative analysis of accumulated TiO2 nanostructures in the liver, spleen, and the heart was performed using an inductively coupled plasma emission spectrometer, and the organs’ toxicity was estimated by histopathological analysis. The prepared nanostructures exhibited differences in morphology, crystallinity, size distribution, surface area, zeta potential, and aspect ratio. The results revealed a tissue distribution difference between the liver, spleen, and heart of these nanostructures, the distribution order was the liver, spleen, and the heart for all TiO2 nanostructures. The toxicity was induced with different degrees. The nanotubes were the most harmful among the three formats. In summary, changes in the morphology of the TiO2 nanostructures change its distribution and toxicity.


2013 ◽  
Vol 740-742 ◽  
pp. 825-828 ◽  
Author(s):  
Jerome Biscarrat ◽  
Jean François Michaud ◽  
Emmanuel Collard ◽  
Daniel Alquier

Due to its inert chemical nature, plasma etching is the most effective technique to pattern SiC. In this paper, dry etching of 4H-SiC substrate in Inductively Coupled Plasma (ICP) has been studied in order to evaluate the impact of process parameters on the characteristics of etching such as etch rate and trenching effect. Key process parameters such as platen power and ICP coil power prove to be essential to control the SiC etch rate. On the other hand, the ICP coil power and the working pressure mainly master the trenching effect. Our results enlighten that high etch rate with minimal trenching effect can be obtained using high ICP coil power and low working pressure.


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