Cadmium, copper and zinc in tissues of deceased copper smelter workers

Workers at a copper and lead smelter in northern Sweden have a multifactorial exposure to a number of heavy metals. The concentrations of cadmium, copper and zinc in liver, lung, kidney and brain tissues have been determined by atomic absorption spectrometry in 32 deceased long-term exposed male lead smelter workers, and compared with those of 10 male controls. Furthermore, copper and zinc levels in hair and nails were determined by energy-dispersive X-ray fluorescence.

The highest cadmium concentrations among both workers and controls were observed in kidney, followed in order by liver, lung and brain. The levels in kidney, liver and lung were all significantly higher in the workers than in the controls (p < 0.03). Among the workers relatively strong positive correlations (p < 0.03) were observed between cadmium concentrations in liver and lung, liver and kidney, liver and brain, and lung and brain. In the exposed workers a positive correlation was observed between cadmium and zinc concentrations in the kidney (r_s = 0.38; p = 0.034). This is probably mainly due to the protein metallothionein, which is stored in the kidney, binding equimolar amounts of these two metals.

The highest concentrations of copper were found in hair and nails among both workers and controls, followed in order by liver, brain, kidney and lung. The tissue concentrations of copper in brain, lung and kidney were all significantly higher among the smelter workers than in the controls (p ≤ 0.036). Copper levels in lung and age at time of death were positively correlated among the exposed workers (r_s = 0.39; p = 0.029). In the same group, positive correlations between copper and zinc concentrations in kidney (r_s = 0.45; p = 0.009) and nails (r_s = 0.68; p < 0.001) were also observed, reflecting possible biological interactions between these two metals.

Among both workers and controls, the highest zinc concentrations were found in hair, followed in order by nails, liver, kidney, brain and lung. Significantly higher tissue concentrations among the workers as compared with the reference group were noted in kidney, liver and brain (p ≤ 0.033).

Neither copper nor zinc concentrations in hair and nails seemed to provide a useful measure of the trace element status of the smelter workers.     

Interrelationships of selenium with other trace elements.

Biological interactions between selenium and a number of other elements occur that render selenium much less toxic than when it is present alone. These elements are arsenic, mercury, cadmium, and copper. Furthermore, the presence of selenium reduces the toxicity of mercury and cadmium. These are general biological interactions and have been found to occur in a number of animal species under a variety of conditions. It has been shown that the reaction products of selenium with mercury and cadmium are less toxic than an equal amount of selenium fed alone to chicks. The presence of arsenic shifts the excretion of selenium to the bile. There is no conclusive evidence that the presence of other elements reduces the absorption or retention of selenium. It is possible that some of the interactions are caused by the formation of a compound by selenium and other elements which has less affinity for active groups on biologically active compounds.--Hill, C.H. Interrelationships of selenium with other trace elements.     

The determination of heavy metals in water,suspended materials and sediments from Langat River,Malaysia

The distributions of heavy metals in the Langat River were studied for a period of six months between September 1984 and February 1985. Heavy metals such as arsenic, cadmium, cerium, cobalt, chromium, caesium, lanthanum, rubidium, antimony, scandium, thorium and zinc were determined in water, suspended materials and sediment samples from the Langat River by neutron activation and atomic absorption spectrometry. The concentrations of arsenic, cadmium, cerium, cobalt, scandium, antimony, and zinc were generally highest in the suspended materials, whereas the concentrations of chromium, rubidium and thorium were always highest in the sediments: Arsenic concentrations in the river were slightly higher than the natural concentration, while other elements were generally at their natural concentration levels. The use of arsenical herbicides in plantations along the river could be a source of arsenic pollution.     

Selenium interactions and toxicity: a review

Selenium is an essential trace element for mammals. Through selenoproteins, this mineral participates in various biological processes such as antioxidant defence, thyroid hormone production, and immune responses. Some reports indicate that a human organism deficient in selenium may be prone to certain diseases. Adverse health effects following selenium overexposure, although very rare, have been found in animals and people. Contrary to selenium, arsenic and cadmium are regarded as toxic elements. Both are environmental and industrial pollutants, and exposure to excessive amounts of arsenic or cadmium can pose a threat to many people’s health, especially those living in polluted regions. Two other elements, vanadium and chromium(III) in trace amounts are believed to play essential physiological functions in mammals. This review summarizes recent studies on selenium interactions with arsenic and cadmium and selenium interactions with vanadium and chromium in mammals. Human studies have demonstrated that selenium may reduce arsenic accumulation in the organism and protect against arsenic-related skin lesions. Selenium was found to antagonise the prooxidant and genotoxic effects of arsenic in rodents and cell cultures. Also, studies on selenium effects against oxidative stress induced by cadmium in various animal tissues produced promising results. Reports suggest that selenium protection against toxicity of arsenic and cadmium is mediated via sequestration of these elements into biologically inert conjugates. Selenium-dependent antioxidant enzymes probably play a secondary role in arsenic and cadmium detoxification. So far, few studies have evaluated selenium effects on chromium(III) and vanadium actions in mammals. Still, they show that selenium may interact with these minerals. Taken together, the recent findings regarding selenium interaction with other elements extend our understanding of selenium biological functions and highlight selenium as a potential countermeasure against toxicity induced by arsenic and cadmium.     

Concentration of Thyrotropic Hormone in Persons Occupationally Exposed to Lead,Cadmium and Arsenic

Thyroid hormones are essential for body homeostasis. The scientific literature contains restricted proofs for effects of environmental chemical factors on thyroid function. The present study aimed at evaluating the relationship between toxicological parameters and concentration of thyrotropic hormone in persons occupationally exposed to lead, cadmium and arsenic. The studies were conducted on 102 consecutive workers occupationally exposed to lead, cadmium and arsenic (mean age 45.08 ± 9.87 years). The estimated parameters characterizing occupational exposure to metals included blood cadmium concentration (Cd-B), blood lead concentration (Pb-B), blood zinc protoporphyrin concentration (ZnPP) and urine arsenic concentration (As-U). Thyroid function was evaluated using the parameter employed in screening studies, the blood thyrotropic hormone concentration (TSH). No differences were disclosed in mean values of toxicological parameters between the subgroup of persons occupationally exposed to lead, cadmium and arsenic with TSH in and out of the accepted normal values. Logistic regression demonstrated that higher blood total bilirubin concentrations (ORu = 4.101; p = 0.025) and higher Cd-B (ORu = 1.532; p = 0.027) represented independent risk factors of abnormal values of TSH in this group. In conclusion, in the group of workers exposed to lead, cadmium and arsenic, higher blood cadmium concentration seems to augment the risk of abnormal hormonal thyroid function.     

Biological monitoring,by in vivo XRF measurements,of occupational exposure to lead,cadmium, and mercury

In vivo X-ray fluorescence (XRF) techniques were used for biological monitoring of lead, cadmium, and mercury. Lead accumulates in bone, the level of which may thus be used for monitoring of exposure. However, there was no close association between lead levels in bone and exposure time, partly because of differences in exposure patterns and partly, probably, because of variations in the toxicokinetics of lead. There are at least two separate bone lead compartments. The average over-all half-time is probably 5–10 yr. The finger bone level may be an index of the lead status of the total skeleton. In lead workers, the mobilization of bone lead causes an “internal” lead exposure and affects the blood lead level considerably. In cadmium workers, in vivo XRF is a sensitive and risk-free method for assessment of accumulation in kidney cortex, the critical tissue as to toxic effects; workers displayed increased levels. However, there was no clear association with duration and intensity of exposure, cadmium levels in urine, or microglobulinuria. Determinations of kidney cadmium may add important information on the state of accumulation and, thus, risk of kidney damage. Workers exposed to elemental mercury vapor, as well as fishermen exposed to methyl mercury, had mercury levels in bone below the detection limit of the XRF method.     

Viral RNA kinetics is associated with changes in trace elements in target organs of Coxsackie virus B3 infection

Trace elements are pivotal for the host defense, as well as potentially important for viral replication and virulence. Studies of sequential changes in viral replication in target organs of infection are sparse and a possible association with changes in specific trace elements is unknown. In this study Balb/c mice were infected with Coxsackie virus B3 (CVB3). Results indicated that sequential changes in viral replication (RT-PCR) were related to changes in trace element (arsenic, copper, iron, selenium and zinc) concentrations (as determined by ICP-MS) on days 3, 5 and 7 of the infection in serum, heart, lung, liver, pancreas, kidney, spleen, intestine and brain. After an initial viral peak on day 3, viral load drastically decreased in all organs, i.e. by >99% (serum), 97% (lung), 98% (liver), 60% (pancreas), 95% (kidney) and 93% (spleen), except in the heart, intestine and brain in which viral load increased after day 3. Selenium decreased in all organs except the heart while arsenic decreased in all organs except the kidney, spleen and brain. Moreover, selenium was negatively correlated to viral load in serum, liver, pancreas and intestine. To conclude, these findings give evidence that trace elements are directly involved in the replication of CVB3.     

In vivo neutron activation analysis of organ cadmium burdens

In vivo neutron activation measurements of liver and kidney cadmium have been mae in 77 exposed workers and 101 referents. Cadmium levels were higher in exposed workers than in referents; both in liver, 25.7 cf. 0.6 μg/g, and kidney, 17.9 cf. 2.7 mg. The 19 referents who never smoked had lower mean organ cadmium burdens than the other referents, the difference achieving statistical significance in the kidney,p<.01. Cigaret smoking was estimated to increase cadmium body burden by 370-140 μg/pack year. These referent cadmium levels are similar to, although slightly below, previous in vivo and autopsy data.

     

The Retention of Cadmium and Selenium Influence in Fowl and Chickens of F1 Generation

The retention of cadmium and selenium influence on Cd retention in the muscle, liver and kidneys of hens, chickens and in eggs was studied. Cadmium (Cd) as cadmium chloride (CdCl(2)) and selenium (Se) as sodium selenite (Na(2)SeO(3)) were added to feed at dosages: group 0-control, group 1-20 mg/kg Cd, group 2-30 mg/kg Cd + 4 mg/kg Se. The birds were exposed to Cd for 8 weeks. Cadmium level in hens and cocks was found highest in the kidneys, followed by the liver and muscle. Se supplementation resulted in Cd increase in the muscle tissue and in the reduction of Cd content in the liver and in significant decrease in the kidneys (p < 0.05). A higher Cd level in the yolk and lower in the white was noted in both experimental groups. Nonsignificant increase of Cd in eggs was noted in experimental groups with Se supplementation. Level of cadmium in organs of 7-day-old chicks hatched from Cd-treated hens in both experimental groups was low but the tendency to accumulate preferentially the Cd in the liver and kidneys was recorded. Supplementation of selenium in hens and cocks was not reflected in the decrease of Cd in these two organs of F(1) chickens but was reflected in increase in the muscle. In spite of relatively high Cd levels in the organs of layers no layer-egg-chickens transfer was observed. It was confirm that kidneys and liver are organs more attacked by dietary cadmium than muscle. Supplementation of low dose of Se resulted in decrease of cadmium deposition in analyzed organs.     

Bacterial resistance to toxic elements

Plasmid-determined resistances to compounds of such toxic elements as antimony, arsenic, bismuth, boron, cadmium, chromium, copper, mercury, lead, nickel, silver, tellurium and zinc occur at high frequencies in natural populations of common bacteria. Considerable study has been made of the resistances to cadmium and to arsenic which result from altered transport and of resistance to mercury which results from biotransformation. However, much remains to be learned about all of these resistances which have potential for use in engineering microbes for applications in biotechnology.     

Zinc,cadmium, mercury and selenium in polar bears (Ursus maritimus) from Central East Greenland

Muscle, liver, and kidney tissues from 38 polar bears (Ursus maritimus) caught in the Scoresby Sound area, Central East Greenland, were analysed for zinc, cadmium, mercury and selenium. In general, cadmium concentrations were low in muscle, liver and kidney tissue, with geometric means (g.m.) of 0.022 (range: <0.015–0.085), 0.841 (range: 0.092–3.29) and 13.1 (range: 1.04–115) g Cd/g wet weight (ww) respectively. This finding can be explained by low cadmium levels in the blubber of ringed seals. The concentration of mercury in muscle tissue was low (g.m. 0.071; range: 0.039–0.193 g Hg/g ww), whereas concentrations in liver and kidney tissue were relatively high (liver: g.m. 7.87; range: 1.35–24.8 g Hg/g ww, and kidney: g.m. 15.2; range: 1.59–66.6 g Hg/g ww). Mercury and cadmium were positively correlated with age in liver and kidney. Zinc was positively correlated with age in kidney, and selenium was correlated with age in liver. Contrary to other marine mammals, polar bears had higher mercury levels in the kidneys than in the liver. In all three tissues polar bears had significantly lower cadmium levels than ringed seals from the same area. Mercury levels were likewise significantly lower in the muscle tissue of polar bears than in ringed seals, whereas levels in the liver and kidney were significantly higher. The previous geographic trend for cadmium and mercury found in Canadian polar bears could be extended to cover East Greenland as well. Hence cadmium levels were higher in Greenland than in Canada, while the opposite was the case for mercury. Greenland polar bears had higher mercury and cadmium contents in livers and kidneys than polar bears from Svalbard. The mercury levels in muscle and liver tissue from polar bears from East Greenland were twice as high as found in bears from western Alaska, but half the levels found in northern Alaska. Cadmium and zinc were partially correlated in kidney tissue, and this was found for mercury and selenium as well. Cadmium and zinc showed molar ratios close to unity with the highest concentrations occurring in kidney tissue, while the levels of zinc exceeded cadmium in muscle and liver tissue by up to several decades. Mercury and selenium showed molar ratios close to unity in liver and kidneys.     

Metal interactions within and between tissues of nestling rooks Corvus frugilegus

We analyzed interactions of concentrations of 11 essential and nonessential elements, including toxic metals within and between internal organs (liver, kidney and lung), muscles and bones of nestling rooks Corvus frugilegus with acute cadmium contamination and elevated level of lead. The number of statistically significant (P ≤ 0.05) metal-metal relationships (positive/negative) within particular tissues was the highest in the kidney (7/6), following in the bone (9/2), liver (6/4), lung (5/2) and muscle (5/2). We found eight significant interactions of lead with other metals, and only two of cadmium (only with lead and cobalt, which probably mirrored a greater ability of lead (than in the case of cadmium) to functional and kinetic interaction with other metals, and/or inhibiting effect of lead or cadmium in co-accumulation. Furthermore, a positive relationship between concentration of cadmium and lead in the kidney could hint at the key importance of this organ in detoxification of both toxic metals. Analyses of relationships of individual metals between examined tissues show only positive results in the case of copper (n = 8), following potassium (n = 3), zinc and iron (in both cases n = 2) and a single ones for calcium and magnesium. We concluded that the lack of significant relationships of individual toxic metals (cadmium or lead) between analyzed tissues could result from high levels of these metals, which destroyed detoxifying capacity of kidney, and ultimately enabled a rapid bioaccumulation of these inorganic contaminations in all tissues of examined nestlings. An explanation of concentration of toxic metals in tissues of animals, especially in the case of their high level, require an identification of the actual level of essential elements associated with physiological status of organism.     

Time course of arsenite-induced copper accumulation in rat kidney

Oral administration of inorganic arsenic has been shown to lead to an accumulation of copper in the kidneys of rats and guinea pigs. However, nothing is known about the characteristics and mechanisms of this organ-specific renal copper accumulation. Many heavy metals accumulate in the kidney, either after environmental or occupational exposure. An additional accumulation of any other trace metals, even essential ones, may therefore be critical for that organ. This prompted us to follow the course of the renal copper accumulation. Rats were given daily subcutaneous doses of sodium arsenite for 12 d. Each second day, three rats were killed by exsanguination and the liver, kidneys, and blood removed and analysed for As, Cu, and other trace elements by atomic emission spectrometry. Results indicate that arsenic and copper accumulate in the kidney cortex synchroneously over time. Arsenic also accumulated in the liver and red blood cells (RBC). Copper levels in the RBC and liver as well as copper excretion into the urine were unaffected. After terminating arsenite administration, there was a slow decline in tissue levels of both arsenic and copper, a phenomenon which was parallel for both metals. Because the copper level in the liver was not affected, it is concluded from this study that renal processes and not hepatic or biliary mechanisms might be responsible for the renal copper accumulation. Furthermore, the strong linear correlation (r=0.85) between arsenic and copper levels in the kidney during and after arsenite administration suggests a functional relationship between arsenic and copper with respect to their retention in the kidney.     

Metabolic deposition of selenium and cadmium into the hair and other tissues of the guinea pig

To better understand the significance of hair trace-element measurements and their relationships with the trace-element levels in body organs and fluids, a series of controlled animal experiments were conducted in which several trace elements were periodically measured during a 90-day chronic exposure to selenium and cadmium. Chronic selenium exposure appeared to be reflected by elevated selenium levels in the hair, kidneys, and liver. Chronic cadmium exposure, although reflected by kidney and liver elevation, appeared not to be reflected by corresponding increases in its concentration in the hair.     

Distribution of elements binding to molecules with different molecular weights in aqueous extract of Antarctic krill by size-exclusion chromatography coupled with inductively coupled plasma mass spectrometry

The distribution of silver, arsenic, cadmium, cobalt, chromium, copper, iron, manganese, nickel, lead, selenium and zinc binding to species with different molecular weight in aqueous extract of krill was studied by on-line size-exclusion chromatography (SEC)/inductively coupled plasma mass spectrometry (ICP-MS). The extract was fractionated in three fractions with different molecular weight (MW) ranges (>20,000 relative molecular mass (rel. mol. mass), 2000-20,000 rel. mol. mass and <2000 rel. mol. mass), which were further analyzed by SEC with columns having different optimum fractionation ranges in order to obtain more detailed information about the MW distribution of the elements. Various distribution profiles for the target elements among different MW ranges were observed. The results obtained indicated that manganese, zinc, silver, cadmium and lead species were mostly distributed in the higher MW range (>20,000 rel. mol. mass). In the case of chromium, iron, cobalt, arsenic and selenium, most of them bind to species with lower MW (<2000 rel. mol. mass). Only copper and nickel species was predominantly present in middle MW range (2000-20,000 rel. mol. mass). Further speciation of arsenic compounds in the small MW fraction was carried out with anion exchange chromatography (AEC) coupled with ICP-MS. The results showed that the dominant arsenic species in this fraction is As(III) (63% of extractable arsenic), while As(V) (13%) and two unknown arsenic species (19% and 5%, respectively) are present in lower amounts.     

Element concentrations in the archiacanthocephalan Macracanthorhynchus hirudinaceus compared with those in the porcine definitive host from a slaughterhouse in La Paz, Bolivia

Concentrations of lead and cadmium, determined by electrothermal atomic absorption spectrometry, and concentrations of the elements barium, cadmium, copper, iron, magnesium, manganese, nickel, lead, selenium and strontium, determined by inductively coupled plasma mass spectrometry, in the acanthocephalan Macracanthorhynchus hirudinaceus and its porcine final host, sampled at a slaughterhouse in La Paz, Bolivia, were compared. Inductively coupled plasma mass spectrometry analysis revealed that most of the elements were found at higher concentrations in the acanthocephalan than in different tissues of its host. The bioconcentration of elements in M. hirudinaceus compared with the host intestine, listed in order of decreasing values, was as follows: Cd > Pb > Ni > Sr = Cu > Mg > Se > Fe = Mn = Ba. Analysis by electrothermal atomic absorption spectrometry showed that M. hirudinaceus contained 85, 85, 56 and 24 times higher lead levels compared with hosts muscle, liver, kidney and intestine, respectively. The mean cadmium concentration of the parasite was 32 times higher than that of the liver and five times higher compared with porcine kidney. The metal distribution within the body of M. hirudinaceus was as follows: cement gland > testes > lemnisci > eggs = tegument for lead and lemnisci > testes > cement gland > tegument > eggs for cadmium. Therefore, the hypothesis that parasites excrete toxic metals with the shells of their eggs seems not to be valid for M. hirudinaceus. It is concluded, that not only eoacanthocephalans and palaeacanthocephalans parasitising fish, but also archiacanthocephalans from mammalian hosts, are able to bioaccumulate metals.     

Human health risks of metals and metalloids in muscle tissue of Synodontis zambezensis Peters, 1852 from Flag Boshielo Dam,South Africa

Muscle tissue from 63 Synodontis zambezensis collected bimonthly in 2013 at Flag Boshielo Dam were analysed for metals and metalloids in a desktop human health risk assessment. The Hazard Quotient, based on a weekly meal of 67 g of fish muscle, exceeded the maximum acceptable level of one for lead, cobalt, cadmium, mercury, arsenic and selenium. The concentrations of these elements were higher in 2013 than those recorded in 2009 and 2012 in other fish species from Flag Boshielo Dam and these may pose a long-term health risk if consumed regularly by impoverished rural communities reliant on fish as a source of protein.     

Trace Elements and Heavy Metals in Hair of Stage III Breast Cancer Patients

This prospective study was designed to compare the hair levels of 36 elements in 52 patients with stage III breast cancer to those of an equal number of healthy individuals. Principal component and cluster analysis were used for source of identification and apportionment of heavy metals and trace elements in these two groups. A higher average level of iron was found in samples from patients while controls had higher levels of calcium. Both patients and controls had elevated levels of tin, magnesium, zinc, and sodium. Almost all element values in cancer patients showed higher dispersion and asymmetry than in healthy controls. Between the two groups, there were statistically significant differences in the concentrations of silver, arsenic, gold, boron, barium, beryllium, calcium, cadmium, cerium, cobalt, cesium, gadolinium, manganese, nickel, lead, antimony, scandium, selenium, and zinc (p?相似文献   

Volatilisation of metals and metalloids by the microbial population of an alluvial soil

In order to assess the microbial contribution to the volatilisation of metal(loid)s by methylation and hydridisation in the environment, we focused on soils of different origin. Here, we describe the biogenic production of volatile metal(loid) species of an alluvial soil with rather low metal(loid) contamination. The production of volatile metal(loid) compounds was monitored in soil suspensions kept under anaerobic conditions over an incubation time of 3 months. In the headspace of the samples, we detected mainly hydrids and methylated derivatives of a broad variety of elements such as arsenic, antimony, bismuth, selenium, tellurium, mercury, tin and lead, with the volatile products of arsenic, antimony and selenium representing the highest portions. Classical cultivation-dependent procedures resulted in the isolation of a strictly anaerobic Gram-positive strain (ASI-1), which shows a high versatility in transforming metal(loid) ions to volatile derivatives. Strain ASI-1 is affiliated to the species Clostridium glycolicum due to its high 16S rDNA sequence similarity with members of that species. As shown by fluorescence in situ hybridisation, strain ASI-1 amounts to approximately 2% of the total microbial flora of the alluvial soil. Since the spectrum of volatile metal(loid) compounds produced by this strain is very similar to that obtained by the whole population regarding both the broad variety of metal(loid)s converted and the preference for volatilising arsenic, antimony and selenium, we suggest that this strain may represent a dominant member of the metal(loid) volatilisating population in this habitat.     

Levels of toxic and essential elements in arctic fox in Svalbard

Concentrations of cadmium, mercury, lead, arsenic, selenium, copper, zinc, manganese and iron in liver, and cadmium in kidneys, were analysed in 95 carcasses of arctic fox (Alopex lagopus) caught in Svalbard during three winter seasons from 1984 through 1986. The hepatic concentration ranges of cadmium, mercury, lead and arsenic were 0.1–2.4, 0.01–2.2, < 0.5–2.9 and 0.01–1.3 g·g^–1 WW, respectively. The range of cadmium concentration in the kidneys was from 0.2 to 13 g·g^–1 WW. Cadmium and mercury concentrations were higher in adult animals than in juveniles. The average concentrations of cadmium and lead were similar to recently published levels in polar bear from Svalbard, but the mercury concentrations were lower. Significant geographical differences were observed between trapping areas. Foxes caught north of Isfjorden had lower levels of liver iron and higher levels of all other elements analysed than those caught south of Isfjorden. The recorded concentrations of heavy metals indicate a moderate degree of exposure, which most likely is of natural origin.Gunnar Norheim died January 9, 1991