scholarly journals Sequential Extractions and Toxicity Potential of Trace Metals Absorbed into Airborne Particles in an Urban Atmosphere of Southwestern Nigeria

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Emmanuel Gbenga Olumayede ◽  
Thompson Faraday Ediagbonya
Keyword(s):  
Trace Metals ◽  
High Volume ◽  
Airborne Particles ◽  
Urban Atmosphere ◽  
Metal Exposure ◽  
Pollution Indices ◽  
Sequential Extractions ◽  
Southwestern Nigeria ◽  
Geochemical Fractions ◽  
Geochemical Phases

The paper investigates the hypothesis that biotoxicities of trace metals depend not only on the concentration as expressed by the total amount, but also on their geochemical fractions and bioavailability. Airborne particles were collected using SKC Air Check XR 5000 high volume Sampler at a human breathing height of 1.5–2.0 meters, during the dry season months from November 2014 to March 2015 at different locations in Akure (7°10′N and 5°15′E). The geochemical-based sequential extractions were performed on the particles using a series of increasingly stringent solutions selected to extract metals (Cd, Cu, Cr, Ni, Pb, Zn, and Mn) into four operational geochemical phases—exchangeable, reducible, organic, and residual—and then quantified using an Atomic Absorption Spectrophotometer. The results showed metals concentration of order Pb > Cr > Cd > Zn > Ni > Cu > Mn. However, most metals in the samples exist in nonmobile fractions: exchangeable (6.43–16.2%), reducible (32.58–47.39%), organic (4.73–9.88%), and residual (18.28–27.53%). The pollution indices show ingestion as the leading route of metal exposure, with noncarcinogenic (HQ) and cancer risk (HI) for humans in the area being higher than 1.0 × 10−4, indicating a health threat.

RESEARCH: Dry Heat Processing of Single-Use Respirators and Surgical Masks

2020 ◽  
Vol 54 (6) ◽  
pp. 410-416
Author(s):  
Joyce M. Hansen ◽  
Scott Weiss ◽  
Terra A. Kremer ◽  
Myrelis Aguilar ◽  
Gerald McDonnell
Keyword(s):  
Microbial Contamination ◽  
Healthcare Providers ◽  
High Volume ◽  
Airborne Particles ◽  
Heat Processing ◽  
Protective Equipment ◽  
Healthcare Facilities ◽  
Dry Heat ◽  
Surgical Masks ◽  
Single Use

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2, has challenged healthcare providers in maintaining the supply of critical personal protective equipment, including single-use respirators and surgical masks. Single-use respirators and surgical masks can reduce risks from the inhalation of airborne particles and microbial contamination. The recent high-volume demand for single-use respirators and surgical masks has resulted in many healthcare facilities considering processing to address critical shortages. The dry heat process of 80°C (176°F) for two hours (120 min) has been confirmed to be an appropriate method for single-use respirator and surgical mask processing.

scholarly journals Distribution patterns of trace metals in soils of Gbonganorileowu Area, southwestern Nigeria

2018 ◽  
Vol 20 (3) ◽  
pp. 577 ◽  
Author(s):  
T.A. Adesiyan ◽  
J.A. Adesiyan ◽  
A.B. Alao-Daniel
Keyword(s):  
Trace Metals ◽  
Distribution Patterns ◽  
Southwestern Nigeria

scholarly journals A Detection of Airborne Particles Carrying Viable Bacteria in an Urban Atmosphere of Japan

2011 ◽  
Vol 5 (3) ◽  
pp. 152-156 ◽  
Author(s):  
Kazutaka Hara ◽  
Daizhou Zhang ◽  
Maromu Yamada ◽  
Hiromi Matsusaki ◽  
Koji Arizono
Keyword(s):  
Airborne Particles ◽  
Urban Atmosphere ◽  
Viable Bacteria

scholarly journals Yttrium Residues in MWCNT Enable Assessment of MWCNT Removal during Wastewater Treatment

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 670 ◽  
Author(s):  
Justin Kidd ◽  
Yuqiang Bi ◽  
David Hanigan ◽  
Pierre Herckes ◽  
Paul Westerhoff
Keyword(s):  
Wastewater Treatment ◽  
Trace Metals ◽  
Inductively Coupled Plasma ◽  
Wastewater Treatment Plants ◽  
Analytical Techniques ◽  
High Volume ◽  
Inductively Coupled ◽  
Multi Walled Carbon Nanotubes ◽  
Plasma Mass Spectrometry ◽  
Walled Carbon Nanotubes

Many analytical techniques have limited sensitivity to quantify multi-walled carbon nanotubes (MWCNTs) at environmentally relevant exposure concentrations in wastewaters. We found that trace metals (e.g., Y, Co, Fe) used in MWCNT synthesis correlated with MWCNT concentrations. Because of low background yttrium (Y) concentrations in wastewater, Y was used to track MWCNT removal by wastewater biomass. Transmission electron microscopy (TEM) imaging and dissolution studies indicated that the residual trace metals were strongly embedded within the MWCNTs. For our specific MWCNT, Y concentration in MWCNTs was 76 µg g−1, and single particle mode inductively coupled plasma mass spectrometry (spICP-MS) was shown viable to detect Y-associated MWCNTs. The detection limit of the specific MWCNTs was 0.82 µg L−1 using Y as a surrogate, compared with >100 µg L−1 for other techniques applied for MWCNT quantification in wastewater biomass. MWCNT removal at wastewater treatment plants (WWTPs) was assessed by dosing MWCNTs (100 µg L−1) in water containing a range of biomass concentrations obtained from wastewater return activated sludge (RAS) collected from a local WWTP. Using high volume to surface area reactors (to limit artifacts of MWCNT loss due to adsorption to vessel walls) and adding 5 g L−1 of total suspended solids (TSS) of RAS (3-h mixing) reduced the MWCNT concentrations from 100 µg L−1 to 2 µg L−1. The results provide an environmentally relevant insight into the fate of MWCNTs across their end of life cycle and aid in regulatory permits that require estimates of engineered nanomaterial removal at WWTPs upon accidental release into sewers from manufacturing facilities.

Direct Identification of Trace Metals in Fine and Ultrafine Particles in the Detroit Urban Atmosphere

2004 ◽  
Vol 38 (8) ◽  
pp. 2289-2297 ◽  
Author(s):  
Satoshi Utsunomiya ◽  
Keld A. Jensen ◽  
Gerald J. Keeler ◽  
Rodney C. Ewing
Keyword(s):  
Trace Metals ◽  
Ultrafine Particles ◽  
Urban Atmosphere ◽  
Direct Identification

scholarly journals The Study of PM10 Concentration and Trace Metal Content in Different Areas of Karachi, Pakistan

2017 ◽  
Vol 60 (1) ◽  
pp. 50-58
Author(s):  
Durdana Rais Hashmi ◽  
Akhtar Shareef ◽  
Farooq Ahmed Khan
Keyword(s):  
Particulate Matter ◽  
Trace Metals ◽  
Absorption Spectrometry ◽  
High Volume ◽  
Ambient Air ◽  
Average Concentration ◽  
Atmospheric Particulate Matter ◽  
Industrial Zone ◽  
Arithmetic Means ◽  
Air Sampler

Atmospheric particulate matter may exert serious health hazards because of its chemicalcharacteristics. Aim of this study was to determine the concentrations of particulate matter (PM) with anaerodynamic diameter <10 mm (PM10), and air transmitted particulate trace metals in different areas ofKarachi’s ambient air, for the period of 01 year viz. June 2011 to June 2012. Furthermore, the present workcompares the levels of particulate matter and trace metals with the proposed limiting values from the U.S.Environmental Protection Agency (65 mg/m3 for PM10). The sampling for PM10 was performed by usinga high volume air sampler. The PM10 levels were determined by gravimetry and the metals by graphitefurnace. Arithmetic means of 361.0 mg/m3 was determined for PM10 in commercial areas, 275.0 mg/m3 inresidential areas, 438.0 mg/m3 in industrial areas and 68.9 mg/m3 in background areas of Karachi. Tracemetal content in PM10, such as lead (Pb) and cadmium (Cd) were also analysed separately during the sameperiod using atomic absorption spectrometry. The average concentration of Pb were found in commercialzone 1.36 mg/m3, in residential zone 1.0 mg/m3, in industrial zone 1.46 mg/m3 and in urban backgroundzone 0.6 mg/m3, whereas; Cd concentration in commercial zone 0.10 µg/m3, in residential zone 0.02 µg/m3,in industrial zone 0.25 µg/m3 and in urban background zone 0.01 µg/m3, respectively.

scholarly journals Evaluation of Trace Elemental Levels as Pollution Indicators in an Abandoned Gold Mine Dump in Ekurhuleni Area, South Africa

2021 ◽  
Author(s):  
Godwin Okereafor ◽  
Mamookho Makhatha ◽  
Lukhanyo Mekuto ◽  
Vuyo Mavumengwana
Keyword(s):  
South Africa ◽  
Trace Metals ◽  
Cation Exchange Capacity ◽  
Major Elements ◽  
Exchange Capacity ◽  
Pollution Indices ◽  
Trace Elemental ◽  
Contamination Levels ◽  
High Degree ◽  
Mine Dump

In the Blesbokspruit area of Ekuhurleni, South Africa, previous gold mining activities resulted in many tailings dump sites. 20 representative soil samples were used in describing the distribution of metals. The soils were very strongly acidic ranging from 3.86 to 4.34 with a low cation exchange capacity (CEC). Based on X-ray fluorescence (XRF) analysis, elemental composition of the soils revealed average values of major elements such as Na2O (0.18%), MgO (0.63%), Al2O3 (6.51%), SiO2 (81.83%), P2O5 (0.04%), SO3 (3.40%), K2O (1.98%), CaO (0.45%), TiO2 (0.51%), Cr2O3 (0.17%), MnO (0.04%), Fe2O3 (3.59%), NiO (0.04%), As2O3 (0.02%), with Rb2O and SrO falling below 0.01%. Trace metals (TM) contamination levels in the soils were evaluated using various pollution indices which revealed that over 60% of the soils were between the high degree and the ultra-high degree of contamination classes. The concentration of various trace metals varies from 860.3–862.6 mg/kg for Cr; 324.9–328.4 mg/kg for Al; 200.9–203.4 mg/kg for As; 130.1–136.2 mg/kg for Fe; 121.9–125.8 mg/kg for Pb; 27.3–30.2 mg/kg for Co; 23.8–26.8 mg/kg for Ni; 7.2–9.2 mg/kg for Ti; 7.1–9.2 mg/kg for Cd; 4.0–5.6 mg/kg for Zn and 0.1–0.6 mg/kg for Cu.

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