Cobalt speciation assay for human serum,Part II. Method validation in a study of human volunteers ingesting cobalt(II) chloride dietary supplement for 90 days

A new analytical method for determining cobalt (Co) species in human serum by size exclusion chromatography with inductively coupled plasma mass spectrometry (SEC-ICP-MS) was applied to serum samples collected from 12 human volunteers who participated in a Co(II) chloride supplement study involving ingestion of 1 mg Co/day for up to 90 consecutive days. The study protocol included determination of serum total Co by acid digestion followed by ICP-MS. Co speciation assay measurements were conducted for up to 13 time points per individual spanning from one to two weeks before dosing began to two weeks after dosing ceased. The Co speciation assay showed good recovery >91% relative to total Co measurements. Undiluted serum demonstrated uniform fractions of large molecular Co defined as Co bound to albumin and other proteins >50 kDa at 96% and the residual as small molecular Co defined as free Co(II) and <1 kDa Co-complexes for individual serum Co concentrations up to 146 μg/L. There were no dose-related changes in Co distribution. Analysis of the same serum samples with tenfold dilution in 0.1 M acetic acid led to a lower fraction of large molecular Co at 87%, with the difference between diluted and undiluted measurements being 8.4%. The difference noted between undiluted and diluted large molecular Co may be attributed to Co release from albumin. Data demonstrated that large molecular Co was the predominant Co species in both undiluted and diluted human serum over a broad range of in vivo Co concentrations, reflecting high albumin–Co binding capacity. These data validate the Co speciation assay and may be employed in understanding further the toxicokinetics and dose-response relationships for Co species.     

Validation of a digestion procedure for ICP-AES and dynamic reaction cell ICP-MS for trace elemental analysis in environmental samples

Due to chloride polyatomic interferences, hydrochloric acid is not recommended for preparation of samples analysed by ICP-MS and separate digestion procedures are used for ICP-MS and ICP-AES. Here we demonstrate that a single digestion procedure using a mixture of HNO₃ and HCl can be used for ICP-AES and dynamic reaction cell (DRC)-ICP-MS. Hotplate, block digester and microwave digestion were investigated. For a quantitative recovery of 26 elements including Ag, Sb and Ti from waters, soils and sediments, the final concentration of 10% (v/v) HCl in the digest is required regardless of the digestion techniques. The method detection limits of 0.3–1.2 μg/L were obtained for chloride-interfering elements As, V, Cr and Se by DRC-ICP-MS using ammonia and oxygen as the DRC gas.     

Concentrations of selected metals in blood,serum, and urine among US adult exclusive users of cigarettes,cigars, and electronic cigarettes

Data from National Health and Nutrition Examination Survey for 2013–2014 were used to compare observed levels of selected metals in blood, serum, and urine among US adults aged ≥20 years for exclusive cigar, cigarettes, and e-cigarette users. Adjusted geometric means for e-cigarette users were found to be higher than for cigar users for blood manganese (10.3 vs. 7.9 µg/L, p = 0.02). Cigar users were found to have lower adjusted geometric means than cigarette users for urine cobalt (0.22 vs. 0.4 µg/L, p = 0.04) and urine antimony (0.03 vs. 0.06 µg/L, p = 0.03). Adjusted levels of blood selenium, serum copper, selenium, and zinc, and urine arsenic, barium, molybdenum, tin, strontium, thallium, tungsten, and uranium were found to be comparable among cigarettes only, cigar only, and electronic cigarettes only users. However, irrespective of the comparative levels of these metals among cigar, cigarette, and e-cigarette users, focus must be to assess the short- and long-term health effects of the exposure to these metals particularly nanoparticles via inhalation from e-cigarette aerosols.     

Rapid release of heavy metals and anions from polyethylene laminated paper cups into hot water

Polyethylene laminated disposable paper cups are commonly used as a container for hot drinks, yet there is limited knowledge on the transfer of contaminants from the cup to the drink. Here we poured 95^?C hot water in 14 cups, to simulate the preparation of hot beverage for daily use. We studied the water composition after 15 min by inductively coupled plasma mass spectrometry (ICP-MS) and ion chromatography. Results show the presence of metals such as vanadium, chromium, copper, cobalt and arsenic at concentration ranging from 0.04 to 1.80 µg/L. Nitrate, nitrite, chloride, bromate, fluoride and sulfate ions were also detected at concentration from 0.003 to 49.21 mg/L. All concentrations are below the WHO maximum permissible limits in drinking water. However, the levels of vanadium at 1.24 µg/L and fluoride ions at 1.03 mg/L are likely to induce a health risk by bioaccumulation after long-term water ingestion. Therefore paper cups composition should be modified to avoid the release of contaminants in hot drinks.

     

Cobalt speciation assay for human serum,Part I. Method for measuring large and small molecular cobalt and protein-binding capacity using size exclusion chromatography with inductively coupled plasma-mass spectroscopy detection

A method utilizing size exclusion liquid chromatography (SEC) was developed to separate and quantify large molecular cobalt (Co) (e.g., albumin-Co) from cyanocobalamin (vitamin B₁₂) and small molecular Co (e.g., glutathione-Co and free Co) in human serum. Highly selective and sensitive detection using inductively coupled plasma–mass spectrometry was coupled with SEC to provide a method with reliable accuracy, precision, recoveries, stability, and a detection limit of 0.037 μg/L in undiluted serum. Other divalent metal cations known to compete with Co(II) for serum albumin-binding sites (such as iron, zinc, manganese, cadmium, copper, nickel, and lead) did not significantly alter Co(II) quantification. Co–protein binding capacity determination of individual serum samples indicated that addition of 2500 μg Co/L to undiluted human serum resulted in approximately 90% distribution to the large molecular Co peak, consistent with Co binding to high-affinity divalent metal binding sites on albumin. Since serum albumin binding partially sequesters biologically active Co(II) ions, this method provides an important tool for better understanding the kinetics and toxicology of Co compounds. Thus, the proposed method might play an important role in establishing Co dose–response relationships that affect the equilibrium concentrations of free ionic Co(II).     

Strontium and its relationship with trace elements Mg,Cu, Co,and Mo in human blood and serum

The aim of the study was to assess the influence of exposure to strontium on human blood and serum concentrations of magnesium, copper, cobalt, and molybdenum. Inductively coupled plasma–mass spectrometry (ICP-MS) was used to analyze the elemental content of whole blood and blood serum of 97 healthy men including 70 workers in a thermal power plant and 27 control subjects from the rural area of Dragash (Kosovo), an environment without pollution. The results showed that chronic moderate exposure to strontium decreases the levels of copper in blood (BCu) and serum (SCu), of cobalt in blood (BCo) and serum (SCo), and of molybdenum in blood (BMo). All changes in blood and serum concentrations of these essential elements were significant but remained within the normal range. The results suggest that strontium may induce adverse health effects in humans.     

Chromium speciation in the blood of metal-on-metal hip implant patients

The objective of this study was to determine the valence state of chromium (Cr) in the blood of individuals with Cr-containing metal hip implants. Serum and red blood cell (RBC) Cr concentrations from 52 patients with Cr-containing total hip arthroplasties were measured preoperatively and at 3, 12, and 24 months postoperatively. Geometric mean and median pre-surgery serum Cr concentrations were consistently below 0.2 µg/L, while geometric mean and median pre-op RBC Cr concentrations were typically about four- to six-fold higher than the serum values. A significant 5- to 13-fold increase was found in the mean and median serum Cr concentrations three months post-surgery, with an 8- to 18-fold rise at 12 and 24 months, respectively. Steady-state serum concentrations were reached between 3 and 12 months. In contrast, there were no marked differences in mean and median RBC Cr concentrations pre- and post-surgery. Slope regression analysis for our data was similar to those reported for Cr(III) in spiked blood samples. The analysis showed that Cr released from hip implants preferentially distributed into serum and not RBC, indicating that the form of Cr present in blood of hip implant patients was in the form of non-toxic Cr(III). Our findings indicate that blood Cr concentrations Cr(III) associated with metal implants do not pose an adverse health risk to patients, which is in agreement with findings published by most investigators.     

Calibration for the determination of 19 trace elements in serum and urine

A fast, high-throughput and accurate method was developed for determination of Al, As, Ba, Cd, Co, Cr, Cs, Cu, Fe, Mn, Ni, Pb, Se, U, Zn, Sb, Sn, I and Hg in urine and serum by inductively coupled plasma mass spectrometry. The samples were directly analyzed after 1/20 (v/v) dilution in 0.4% (v/v) HNO₃ and 0.005% Triton X-100. Three calibration modes were tested: aqueous and matrix matching with urine and serum. The accuracy was tested using reference materials of serum, urine and spiking. Results showed that the use of matrix matching calibration reduced the interferences and improved the recoveries for Al, Co, Pb and I in urine. The matrix matching did not affect the results considerably for serum. When serum was spiked with As, Co, Cs, Pb, U, Hg, I, Ba, Al, Cr and Ni, only matrix matching presented good recoveries. Helium was used as a collision cell gas reducing effectively polyatomic interferences for Al, Mn, Cu, Ni, Cr, Zn, As and Fe. Selection of the best internal standard was carried out for each element. The use of diluted HNO₃ improved the limit of detection. Finally, the method was applied successfully in samples of urine from workers occupationally exposed.     

Neurotoxicity and oxidative stress induced by permethrin in gills of the freshwater mussel Unio ravoisieri

Pyrethroids are contaminants found in the aquatic environment, and their toxicological effects on aquatic organisms have received extensive attention. However, the impact on freshwater bivalve of exposure to these chemicals is still largely unknown. Freshwater mussels Unio ravoisieri were exposed to two nominal permethrin (PM) concentrations C1?=?50?µg/L and C2?=?100?µg/L during 7 days. The measured concentrations of PM using gas chromatography (GC/ECD) in the treated aquariums were, respectively, 28.7–62.3?µg/L. Catalase (CAT), Glutathione-S-transferase (GST), and Acetylcholinesterase (AChE) activities, Glutatione (GSH) and Malondialdehyde (MDA) levels were determined in gills of U. ravoisieri. Significant increase in CAT activity by the lowest concentration and decrease by highest concentration were observed. Additionally, GST activity was increased in a concentration-dependent manner. However, statistically significant decrease in GSH levels (about 39%) was observed only at high concentration of this compound (100?µg/L). PM generated an increase in MDA levels reaching the highest value at the high concentration. AChE activity of mussel ranging from 51% inhibition at lowest concentration 50?µg/L to 89% inhibition at highest concentration 100?µg/L. The results indicated that oxidative stress and cell damage might be one of the main mechanisms of PM toxicity to freshwater mussels.     

Arsenic and other trace elements in groundwater and human urine in Ha Nam province,the Northern Vietnam: contamination characteristics and risk assessment

The contamination characteristics of arsenic and other trace elements in groundwater and the potential risks of arsenic from the groundwater were investigated. Elevated contamination of arsenic, barium and manganese was observed in tube-well water of two villages (Chuyen Ngoai and Chau Giang) in Ha Nam province in the Northern Vietnam. Concentrations of As in the groundwater ranged from 12.8 to 884 µg/L with mean values in Chuyen Ngoai and Chau Giang were 614.7 and 160.1 µg/L, respectively. About 83 % of these samples contained As concentrations exceeding WHO drinking water guideline of 10 μg/L. The mean values of Mn and Ba in groundwater from Chuyen Ngoai and Chau Giang were 300 and 657 μg/L and 650 and 468 μg/L, respectively. The mean value of Ba concentration in groundwater in both Chuyen Ngoai and Chau Giang was about 22 % of the samples exceeded the WHO guideline (700 µg/L). Arsenic concentrations in human urine of residents from Chuyen Ngoai and Chau Giang were the range from 8.6 to 458 µg/L. The mean values of Mn and Ba in human urine of local people from Chuyen Ngoai were 46.9 and 62.8 μg/L, respectively, while those in people from Chau Giang were 25.9 and 45.9 μg/L, respectively. The average daily dose from ingesting arsenic for consuming both untreated and treated groundwater is from 0.02 to 11.5 and 0.003 to 1.6 μg/kg day, respectively. Approximately, 57 % of the families using treated groundwater and 64 % of the families using untreated groundwater could be affected by elevated arsenic exposure.     

Trace element concentration levels in three bird species in Hormod Protected Area,Larestan, Iran

The objective of the present study was to investigate the levels of Cd, Pb, Co, and Cu, in A. chukar, A. griseogularis, and Columba livia, in order to (1) examine the age- and gender-related variation in trace metal accumulation and (2) to determine the significance between metal concentrations in the kidney, liver, and pectoral muscle. Mean concentrations of Cd and Pb in the kidney of A. chukar, A. griseogularis, and C. livia were 3.7, 4.1, and 3.9?µg/g and 15.9, 13.6, and 15.5?µg/g, respectively. In the liver, they were 4.8, 4.3, and 3.9?µg/g and 21.4, 21.3, and 21.1?µg/g, and in the pectoral muscle, 2.3, 2.3, and 2.2?µg/g and 7.1, 7.1, and 7.8?µg/g, respectively. Metal concentrations in three bird species were decreased in the sequence of liver?>?kidney?>?pectoral muscle. Trace metal concentrations in the three species were higher in females than in males. The mean concentrations of Cd in the kidney and liver were higher than the background levels, as well as Pb concentrations in the liver were higher than the toxic level.     

Occurrence and migration of microplastics and plasticizers in different wastewater and sludge treatment units in municipal wastewater treatment plant

● Reduce the quantifying MPs time by using Nile red staining. ● The removal rate of MPs and PAEs in wastewater and sludge were investigated. ● MPs and PAEs were firstly analyzed during thermal hydrolysis treatment. ● The removal of PAEs from wastewater and sludge was mainly biodegradation. Microplastics (MPs) and plasticizers, such as phthalate esters (PAEs), were frequently detected in municipal wastewater treatment plants (MWTP). Previous research mainly studied the removal of MPs and PAEs in wastewater. However, the occurrence of MPs and PAEs in the sludge was generally ignored. To comprehensively investigate the occurrence and the migration behaviors of MPs and PAEs in MWTP, a series of representative parameters including the number, size, color, shape of MPs, and the concentrations of PAEs in wastewater and sludge were systematically investigated. In this study, the concentrations of MPs in the influent and effluent were 15.46±0.37 and 0.30±0.14 particles/L. The MP removal efficiency of 98.1% was achieved and about 73.8% of MPs were accumulated in the sludge in the MWTP. The numbers of MPs in the sludge before and after digestion were 4.40±0.14 and 0.31±0.01 particles/g (dry sludge), respectively. Fourier Transform Infrared Spectroscopy (ATR FT-IR) analysis showed that the main types of MPs were polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), and polystyrene (PS). Six PAEs, including phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DIBP), ortho dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), and bis(2-ethyl) hexyl phthalate (DEHP), were detected in the MWTP. The concentrations of total PAEs (ΣPAEs) in the influent and effluent were 76.66 and 6.28 µg/L, respectively. The concentrations of ΣPAEs in the sludge before and after digestion were 152.64 and 31.70 µg/g, respectively. In the process of thermal hydrolysis, the number and size of MPs decreased accompanied by the increase of the plasticizer concentration.     

Deoxynivalenol impairs proliferation and induces apoptosis in primary murine osteoblasts

The effects of deoxynivalenol in different dose including 100, 200, 500, 1000, and 1500 µg/L on primary cranial osteoblasts from fetal mice were investigated. Fluorescence staining, flow cytometric measurement, 3-(4,5-dimethylthiazol 2-y1)-3,5-di-phenyltetrazolium bromide assay, quantitative PCR, and Western blot were used for the test. Mineralization and proliferation of osteoblasts decreased upon 100 µg/L and higher deoxynivalenol treatment and apoptosis of osteoblasts was increased upon 500, 1000, and 1500 µg/L deoxynivalenol treatment. Karyopyknosis, membrane breakage, and a decreased number of calcium nodes were also observed upon 500 µg/L deoxynivalenol treatment. The mRNA and protein levels of B-cell lymphoma-2-associated X protein were upregulated, B-cell lymphoma-2 protein downregulated with increasing concentrations of deoxynivalenol treatment and their ratio increased. Deoxynivalenol induces apoptosis of osteoblasts, suggesting a mechanism by which deoxynivalenol can affect murine skeletal development.     

Toxicity of cadmium to the green alga Parachlorella kessleri: Producing Cd-loaded algae for feeding experiments

The effects of Cd at environmental concentrations (0–32 µg/L) on the green alga Parachlorella kessleri were investigated. At about 3 µg Cd/L, toxic effects of Cd are becoming evident, much lower than reported previously. At 8 µg/L and higher, pronounced adverse effects on growth, cell morphology, size, and physiological state are seen. Therefore, levels lower than 2 µg Cd/L should be employed to produce Cd-carrying algae for feeding experiments with organisms on the next trophic level, e.g. mussels, to avoid reduced food uptake. These findings also suggest that aquatic ecosystem conditions can be indirectly influenced via the impairment of the nutritional value of algae since they are the basic organisms of aquatic food chains.     

Hair burning and liming in tanneries is a source of pollution by arsenic,lead, zinc,manganese and iron

Heavy metals in the environment may be toxic for human and animals. Tanneries are a source of pollution by heavy metals. There is little information on heavy metals pollution in tanneries, especially on metals produced by the process of hair burning and liming. Liming is the first stage of chemical treatment where animal hair or wool is removed with sodium sulphide and calcium oxide. Here we studied cow, goat, buffalo and sheep hair, conventional liming agents and liming wastewaters from several sources. Samples were acid-digested and aliquots were analysed by atomic absorption spectroscopy following APHA standard method to measure concentrations of arsenic, lead, cadmium, zinc, manganese and iron. Results show that the range of metal contents in hair or wool and liming agents are 1.3–8.2 mg/kg for arsenic, 0.02–21.8 mg/kg for lead, 17.7–121.0 mg/kg for manganese, 7.3–141.1 mg/kg for zinc and 119.6–10613.8 mg/kg for iron. Liming wastewaters contain 1.9–5.6 µg/L arsenic, 0.03–6.05 µg/L lead, 38.6–139.0 µg/L manganese, 144.0–171.5 µg/L zinc and 399.5–1069.0 µg/L iron. Cadmium was below detection limits. This is the first investigation that reveals that hair burning liming operation is a potential source of heavy metals in the environment.     

Tissue distribution of antimony (Sb) in piglets orally given graded levels of Sb (V)

The potential risks from oral intake of soil antimony (Sb) depends mainly on the amount of metal ingested and its bioavailability. Relative bioavailability may be determined by comparing Sb present in soil to a reference compound, taking into account accumulation in different target tissues or excretion. However, due to the lack of scientific knowledge concerning the fate of Sb in the organism, there is a need to study the absorption and distribution of Sb in order to select target tissues for assessment of bioavailability of Sb in soils. Thus, 45 piglets were exposed to a soluble pentavalent antimony salt (KSb(OH)₆), for 15 days at concentrations ranging from 0–1600 µg Sb/kg body weight (BW) per day. Following the exposure period, blood, plasma, liver, spleen, kidneys, hair, bone, bile and urine were obtained to measure Sb concentrations by ICP-MS. Results showed that tissue Sb levels were dose-related. Higher Sb concentrations were found in urine, kidneys, hair, bone and liver. Sb(V) was not detectable in blood and plasma. In the case of highly contaminated soil with soluble forms of Sb in concentrations ranging from 200–1600 µg Sb/kg BW, kidneys, liver and spleen are the most reliable compartments to determine Sb bioavailability from soil. However, for the soils with lower levels of contamination and a low Sb bioaccessibility, urine may serve as a relevant compartment.     

Sediment-associated trace and major metals in the headwaters of a tropical reservoir

Bed sediment samples of the two headwaters of a tropical reservoir in Southwestern Nigeria were analysed for some metal concentrations using ICP-OES for a period of one year. Sediment samples were collected bi-monthly from both the lower and upper reaches of the streams from May 2013 to March 2014. Sediment samples were microwave-digested and analysed using ICP-OES. Concentrations of metals were higher in the lower reach than in the upper reach, and wet season concentrations were higher than in the dry season with the exception of Fe and Mn. The annual mean metal concentrations were as follows: Fe (121.72?±?6.82?µg/g); Mn (9.34?±?2.57?µg/g); Na (6.20?±?2.29?µg/g); K (0.65?±?0.57?µg/g); Mg (8.07?±?1.36?µg/g); Ca (13.92?±?2.85?µg/g); Ba (0.17?±?0.17?µg/g); Al (106.54?±?5.55?µg/g); and Se (0.6?±?0.19?µg/g). These values were lower in comparison with the baseline concentrations of elements on the earth’s crust. Contamination assessment of all the metals investigated in this study showed that metals in the bed sediments of the two headstreams had not reached pollution status with the exception of Se.     

Trace metal concentrations in cigarette brands commonly available in Turkey: relation with human health

In this study, the concentrations of Co, Ni, Fe, Cu, Mn, Pb, Cr, and Cd were determined in 15 cigarette brands from Turkey by flame atomic absorption spectrometry (FAAS). A wet digestion method was employed to cigarette samples. The mean values obtained for Co, Ni, Fe, Cu, Mn, Pb, Cr, and Cd were 1.2, 4.1, 134, 14, 66, 3.7, 5.0, and 1.1?µg?g^?1, respectively, i.e., in the order of Fe?>?Mn?>?Cu?>?Cr?>?Ni?>?Pb?>?Co?>?Cd. The results were compared with the literature values for other international cigarette brands.     

Concentrations of selected metals in chicken eggs from commercial farms in Southern Nigeria

This work presents the results of the determination of concentrations of the trace metals Ni, Zn, Mn, Pb, Cd, Cr, Co, Cu, and Fe in eggs from farms in Southern Nigeria. The mean concentrations (µg?g^?1 fresh weight) ranged from 0.6 to 1.2 for Ni, 3.1 to 8.9 for Zn, 0.45 to 0.65 for Mn, 0.4 to 1.2 for Pb, <0.09 to 0.3 for Cr, 0.1 to 0.3 for Cd, 0.26 to 0.34 for Co, 0.9 to 1.2 for Cu and 19.5 to 24.0 for Fe. The concentrations and estimated dietary intakes of these metals were below the respective statutory limits. The Target Hazard Quotient (THQ) values for the individual metals in all zones are less than 1, i.e., within safe levels. The combined THQ values for the different zones were greater than 1but less than 2, with a significant contribution of cobalt.     

Exposure profiles of mercury in human hair at a terai belt of North India

Human hair is frequently used as a bioindicator of mercury exposure. Mercury (Hg) has for centuries been a useful metal in a variety of applications. Unfortunately, this usefulness is counterbalanced by its neurotoxicological health impact. The US Environmental Protection Agency recommends keeping the hair Hg level <1.0 µg/g. Therefore, an investigation has been performed in order to ascertain the hair Hg levels among the people living at the terai belt of North India. Hair samples were collected from 111 individuals and were placed in an identified plastic bag, stapled to prevent the shift of the hair strand. Samples were analyzed by combustion, gold amalgamation, atomic absorption spectrometry (C-GA-AAS). The mean Hg level in hair was 0.28 µg/g for the whole group ranging from 0.0012 to 1.9091 µg/g. The mean hair Hg levels were 0.16 µg/g for men and 0.12 µg/g for women, indicating that men had higher hair Hg levels than women. Total hair Hg was found to be significantly associated with age, gender and fish consumption frequency. 98 % of the total sample had hair Hg concentrations less than 1.0 µg/g, i.e, within safe dose, whereas only 2 % had Hg concentrations greater than 1.0 µg/g, thereby exceeding the safe dose.