Filterable plasma concentration, glomerular filtration, tubular balance, and renal clearance of heavy metals and organic substances in metal workers

To estimate "filterable" plasma concentration (FPx), glomerular filtration, tubular balance, and renal clearance of heavy metals and organic substances, the authors examined the regressions of the 24-hr urinary excretion on glomerular filtration rate [GFR, 24-hr endogenous creatinine (Cn) clearance] in 19 gun-metal foundry workers with blood lead (Pb) concentrations of 25-59 micrograms/dl. It was estimated that the proportion of FPx to total plasma concentration was on average 15, 7, 3, 0.6, 0.06, and 0.008% for Pb, cadmium (Cd), manganese (Mn), zinc (Zn), chromium (Cr), and copper (Cu), respectively. The estimated FPx value was 2.8 X 10(2), 4, 0.08, and 2.8 X 10(4) micrograms/dl for hippuric acid (HA), delta-aminolevulinic acid (ALA), coproporphyrin (CP), and total urinary solutes (TUS), respectively. The estimated glomerular filtration was significantly greater than the zero level for all substances but inorganic mercury (Hg). Similarly, the estimated net tubular secretion was significantly greater than the zero level for Cr, Cu, and TUS; the net tubular reabsorption was significantly greater than the zero level for Pb, ALA, and CP. The renal clearance of "filterable" plasma substance was significantly greater than GFR for Cr, Cu, and TUS and was significantly smaller for Pb, ALA, and CP. Thus the renal excretory mechanisms of substances were classified into four major categories: glomerular filtration for Cd, Mn, Zn, HA, and Cn; glomerular filtration and net tubular secretion for Cr, Cu, and TUS; glomerular filtration and net tubular reabsorption for Pb, ALA, and CP; and no glomerular filtration, i.e., suspected tubular secretion, for Hg.     

Filterable Plasma Concentration,Glomerular Filtration,Tubular Balance,and Renal Clearance of Heavy Metals and Organic Substances in Metal Workers

To estimate “filterable” plasma concentration (FPx), glomerular filtration, tubular balance, and renal clearance of heavy metals and organic substances, the authors examined the regressions of the 24-hr urinary excretion on glomerular filtration rate [GFR, 24-hr endogenous creatinine (Cn) clearance] in 19 gun-metal foundry workers with blood lead (Pb) concentrations of 25–59 μg/dl. It was estimated that the proportion of FPx to total plasma concentration was on average 15,7,3,0.6,0.06, and 0.008% for Pb, cadmium (Cd), manganese (Mn), zinc (Zn), chromium (Cr), and copper (Cu), respectively. The estimated FPx value was 2.8 × 10², 4,0.08, and 2.8 × 10⁴ μg/dl. for hippuric acid (HA), delta-aminolevulinic acid (ALA), coproporphyrin (CP), and total urinary solutes (TUS), respectively. The estimated glomerular filtration was significantly greater than the zero level for all substances but inorganic mercury (Hg). Similarly, the estimated net tubular secretion was significantly greater than the zero level for Cr, Cu, and TUS; the net tubular reabsorption was significantly greater than the zero level for Pb, ALA, and CP. The renal clearance of “filterable” plasma substance was significantly greater than GFR for Cr, Cu, and TUS and was significantly smaller for Pb, ALA, and CP. Thus the renal excretory mechanisms of substances were classified into four major categories: (1) glomerular filtration for Cd, Mn, Zn, HA, and Cn; (2) glomerular filtration and net tubular secretion for Cr, Cu, and TUS; (3) glomerular filtration and net tubular reabsorption for Pb, ALA, and CP; and (4) no glomerular filtration, i.e., suspected tubular secretion, for Hg.     

Acute Lethal Toxicity of Heavy Metals to the Seeds of Plants of High Importance to Humans

Laboratory experiments were conducted to assess the effects of highly toxic and dangerous metals (Pb, Cd, Hg) and essential microelements (Cr, Cu, Ni, Zn) on the seed germination process in vetch and eight plant species of major importance to human consumption. The degree of metal toxicity was determined on the basis of acute LC50 values calculated by means of two different methods. All the metals were found to inhibit the germination process, but in a varying, species-dependent degree. Of all the plant seeds under study, the most sensitive to the presence of the examined metals during germination were the seeds of cress (Cu, Pb, Hg), rye (Ni, Zn, Cd) and barley (Cr), while vetch (Cr, Ni, Zn, Cd, Pb, Hg), rape (Cr, Cu) and pea (Ni, Cd) were found to be least affected.     

Circadian rhythms in the urinary excretion of metals and organic substances in "healthy" men

Circadian rhythms in the urinary excretion of metals and organic substances were examined in ten "healthy" men under conditions of water loading and restriction. Four characteristic rhythms were observed: (1) decreased excretion during the night for lead and urinary flow rate; (2) decreased excretion of hippuric acid, delta-aminolevulinic acid, coproporphyrin, creatinine, and total urinary solutes during the night and morning hours; (3) increased excretion of mercury and zinc during the morning hours; and (4) no significant variation for copper. Excretion of lead, hippuric acid, delta-aminolevulinic acid, and total urinary solutes was significantly correlated with urinary flow rate and creatinine excretion, which suggested that their circadian rhythms were the consequence of reduced glomerular filtration and increased reabsorption by the distal tubule and collecting duct during the night and morning hours. Similarly, it was suggested that the mercury and zinc rhythms resulted partly from increased reabsorption during the night hours; the coproporphyrin rhythm reflected reduced glomerular filtration of coproporphyrinogen during the night and morning hours.     

Circadian rhythms in the urinary excretion of heavy metals and organic substances in metal workers in relation to renal excretory mechanism: profile analysis

Summary Circadian rhythms in the urinary excretion of eleven heavy metals and organic substances were examined under free, water-restrictive and water-loading conditions for 6 d (2 d for each of the three conditions) in twenty metal workers exposed to lead, zinc and copper. Circadian rhythms were found for all heavy metals and organic substances as well as for urinary flow (UF) rate, creatinine (Cn) and total urinary solutes (TUS). The Cn rhythm was significantly unparallel to the OF rhythm under the water-loading condition, indicating that the two rhythms were essentially different from each other. Circadian rhythms of the eleven urinary substances were then related to the Cn and OF rhythms, using profile analysis. The results indicated that the rhythms in the manganese, chromium, copper and beta-2-microglobulin excretion depend on the Cn rhythm, i.e. the rhythm of glomerular filtration; the rhythms in the hippuric acid, delta-aminolevulinic acid and TUS excretion are on the OF rhythm, i.e. the rhythm of reabsorption by the distal tubule and collecting duct. On the other hand, the rhythms in the lead, inorganic mercury, cadmium, zinc and coproporphyrin excretion were considered as reflecting complex renal excretory mechanisms.     

Biological monitoring of toxic metals in urine by simultaneous inductively coupled plasma-atomic emission spectrometry

A simple and rapid method for the simultaneous determination of 11 metals (As, Be, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, and Zn) in urine by inductively coupled argon plasma-atomic emission spectrometry is presented. Acidification of the urine was the only sample preparation required. Background correction was applied to ensure accuracy. Analytical calibration was based on matrix matching using a "simulated urine" solution. Detection limits in the low mg/L range and linearity over three orders of magnitude were obtained for all 11 metals. In the Occupational Health Laboratory, this procedure has been applied for routine screening of workers for occupational exposure to toxic metals.     

Determination of normal concentration levels of Cd,Pb, Hg,Cu, Zn and Se in urine of the population in the Czech Republic

Knowledge of normal levels of concentrations of trace elements (Cd, Pb, Hg, Cu, Zn, and Se) in the population serves, among others, in design of regulations concerning health protection, determination of exposition limits and prevention of diseases caused by deficiency of trace elements. Concentrations of the named elements in urine of the Czech population were determined by means of atomic absorption spectrometry. The urine has been collected during 1996-2000 from 1192 individuals (816 males and 376 females, average age 34.6 years) and 2008 children (1052 boys and 956 girls, average age 9.9 years). Mineralization in a microwave digestion system was used in sample preparation. The accuracy of results was checked by means of the Control Materials Seronorm 403,125 and BioRad 69,041. Values of concentrations of the trace elements in urine found for adult (medians) were 0.36 microgram Cd.g-1 creatinine, 10.6 micrograms Cu.g-1 creatinine, 0.68 microgram Hg.g-1 creatinine, 3.3 micrograms Pb.g-1 creatinine, 6.2 micrograms Se.g-1 creatinine, and 397 micrograms Zn.g-1 creatinine, respectively. Statistically significant differences between men and women have been found in the concentrations of Cu and Hg. In the juvenile population following concentrations have been found: 0.29 microgram Cd.g-1 creatinine, 16.1 micrograms Cu.g-1 creatinine, 0.32 microgram Hg.g-1 creatinine, 4.8 micrograms Pb.g-1 creatinine, 10.2 micrograms Se.g-1 creatinine and 460 micrograms Zn.g-1 creatinine. Statistically significant differences between boys and girls were found only in Cu and Hg concentrations. Concentrations of the studied elements correspond to the published values concerning population not exposed professionally.     

Heavy metals in three lakes in West Poland.

Concentrations of heavy metals (Ni, Cr, Co, Zn, Mn, Pb, Cd, Cu, Hg, Fe) as well as macronutrients (P, Ca, Mg) were measured in water, bottom sediments, and plants of three lakes in West Poland (southwest of Poznan). The plants collected were Nymphaea alba, Nuphar luteum, Ceratophyllum demersum, Phragmites communis, Typha latifolia, and Schoenoplectus lacustris. These plants contained elevated levels of Co, Zn, Pb, Cd, Cr, and Hg. Analyses of water and bottom sediments indicated that the lakes were polluted with Zn, Cd, Cu, and Pb and partly with Ni and Hg. Strong positive correlations were found between concentrations of Cd in water and in plants, between concentrations of Cd in bottom sediments and in plants, between concentrations of Cr in water and in plants, between concentrations of Cr in bottom sediments and in plants, and between concentrations of Fe in water and in plants, indicating the potential of plants for pollution monitoring for these metals. A negative correlation was found between biomass production and Pb and Mn content in water and Pb and Mn content in bottom sediments. Cr and Cd accumulated in plants at a higher rate from bottom sediments than from water. The accumulation rate of Fe in plant tissues was higher with an increase in Fe in water than with an increase in Fe in bottom sediments.     

Uptake of lead, cadmium, and other metals in the liver and kidneys of cattle near a lead-zinc mine in Kabwe, Zambia

Concentrations of lead, cadmium, and other metals in the liver and kidneys of cattle near a lead-zinc mine in Kabwe (Zambia), which is ranked among the 10 worst polluted places on earth, were compared with other Zambian towns. Metal concentrations were measured in the liver and kidneys of 51 cattle from Kabwe and other Zambian towns. The maximum metal concentrations, expressed in mg/kg and dry weight, in the liver or kidneys were 398.4 (Cu), 252.6 (Zn), 77.81 (Cr), 19.37 (Cd), 7.57 (Ni), 1.8 (Pb), 1.04 (Co), 0.112 (Hg), and 0.05 (As). Concentrations of Pb and Cd in Kabwe cattle were higher than levels in other Zambian towns. The mean concentration of Cd exceeded benchmark values in offal destined for human consumption. Levels of Ni and Cr may also pose public health concerns. Concentrations of Pb and Cr, Pb and Cu, Cd and Zn, Cd and Hg, Zn and Cu, Cu and Co, as well as Co and Ni were positively correlated. The present study also highlighted the dangers of exposure of animals and humans to a mixture of toxic metals.     

Element differences and evaluation of the dietary intake from farmed oysters and mussels collected at different sites along the Croatian coast of the Adriatic Sea

Concentrations of the macroelements Ca, Mg, K and Na, microelements Cr, Cu, Fe, Mn and Zn and toxic metals As, Cd, Hg and Pb were determined in oysters and mussels collected at farming sites in the northern, central and south Adriatic Sea. Mean concentrations in oysters were (mg kg⁻¹): As 4.51, Ca 1551, Cd 1.44, Cu 53.6, Cr 0.23, Fe 45.9, Hg 0.047, K 2476, Mg 895, Mn 2.80, Na 7148, Pb 0.52, Zn 675. Mean values in mussels were (mg kg⁻¹): As 4.71, Ca 601, Cd 0.37, Cu 1.91, Cr 0.29, Fe 49.6, Hg 0.026, K 2246, Mg 1043, Mn 2.49, Na 7992, Pb 0.58, Zn 28.8. Significant differences in the concentrations of toxic metals and elements were found in oysters and mussels among farming sites. Obtained Cd, Hg and Pb concentration in oysters and mussels were lower than the limit levels set by the European Community. However, Cd concentration exceeded the limit level of 1 mg kg⁻¹ in oysters from all locations except Lim Bay. The estimated daily intakes (EDIs) indicate that oysters are a good source of Ca, Cu and Zn. The higher Cu and Zn concentrations than the toxicity reference values suggest a risk for consumers if larger quantities of oysters are consumed frequently.     

Blood and urinary levels of metals and metalloids in the general adult population of Northern France: The IMEPOGE study, 2008–2010

Background

The assessment of human chemical risks related to occupational or environmental exposure to pollutants requires the use of both accurate exposure indicators and reference values. The objective of this study was to evaluate the blood and urinary levels of various metals and metalloids in a sample of adults aged 20–59 years of the general population of Northern France, a formerly heavily industrialised area that retains some industrial activity.

Trends in metals in urban and reference lake sediments across the United States, 1970 to 2001

Trends in metals concentrations in sediment cores from 35 reservoirs and lakes in urban and reference settings were analyzed to determine the effects of three decades of legislation, regulation, and changing demographics and industrial practices in the United States on concentrations of metals in the environment. Decreasing trends outnumber increasing trends for all seven metals analyzed (Cd, Cr, Cu, Pb, Hg, Ni, and Zn). The most consistent trends are for Pb and Cr: For Pb, 83% of the lakes have decreasing trends and 6% have increasing trends; for Cr, 54% of the lakes have decreasing trends and none have increasing trends. Mass accumulation rates of metals in cores, adjusted for background concentrations, decrease from the 1970s to the 1990s, with median changes ranging from -46% (Pb) to -3% (Hg and Zn). The largest decreases are from lakes in dense urban watersheds where the overall metals contamination in recently deposited sediments has decreased to one-half its 1970s median value. However, anthropogenic mass accumulation rates in dense urban lakes remain elevated over those in lakes in undeveloped watersheds, in some cases by as much as two orders of magnitude (Cr, Cu, and Zn), indicating that urban fluvial source signals can overwhelm those from regional atmospheric sources.     

Observations on metal concentrations in tilapia (Oreochromis mossambicus) in reservoirs of south Sri Lanka

Samples of the muscle and liver of tilapia (Oreochromis mossambicus) obtained from the five reservoirs in four catchments in southern Sri Lanka in 1998 were analyzed for 16 elements: As, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr, and Zn by inductively coupled plasma emission spectrophotometry, and Hg by atomic absorption spectrophotometry. The concentrations of Cr, Ni, and Pb were below the detection limits of the instrumental techniques employed in all samples. The elements As, Ca, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Sr, and Zn were detected in the muscle and liver tissue, with Cd detected in some liver samples. There were no statistically significant differences between the individual concentrations of any of the metals and the site from which the tilapia were collected (P>0.05). Furthermore, no statistically significant correlations were found between total length of fish and metal concentration. No elements were found at concentrations of toxicological concern. However, a principal component analysis suggests that the populations of tilapia in the reservoirs may be exposed to different regimes of metals, possibly associated with different catchment land-use patterns.     

Historical Characteristics of Contamination and Risk of Heavy Metals in Weishan Lake,China

Combined with the dating analysis of ²¹⁰Pb and ¹³⁷Cs, the historical concentration and risk of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn in the core sediment of Weishan Lake were determined. Pollution concentrations, enrichment factor, geo-accumulation index, and ecological risk index of these metals and C/N ratio indicate that the natural inputs prevailed till early 1900s. From late 1970s onwards, the risk posed by these metals was significantly increased. Cu and Hg might cause adverse biological effects. The increase of soil erosion and wastewater discharge in the watershed promoted input and accumulation of these metals in the lake. The coal and petroleum industry in the catchment led the more accumulation of Hg, Cd and Cu in the lake.     

Heavy Metals in Livers of Waterbirds from Spain

Wetlands tend to accumulate heavy metals from local sources, such as Pb shot used for waterfowl hunting, and from regional sources, such as atmospheric deposition and riverine or marine inputs. We determined concentrations of six heavy metals (Cr, Mn, Cu, Zn, Cd, and Pb) in livers of waterbirds shot by hunters in five Spanish wetlands to study the different factors that can contribute to the accumulation of these metals (sex, age, diet, grit, and Pb shot ingestion). Differences among wetlands were observed only for Cr, Cu, and Cd. Differences among species were observed for all the metals, and Cu was notably higher in pochards (Aythya and Netta genus) than in other waterfowl. Cu, Zn, and Cd concentrations increased with age, and only Pb showed differences related to sex, with males having higher concentrations than females. Most metals other than Pb were correlated with each other. Lead was dependent on Pb shot ingestion. Grit ingestion positively correlated with concentrations of Cr and to a lesser extent with Mn, Zn, and Cd. Ingestion of grit or shot may obscure relationships between metals and diet. Herbivorous species, which had more grit in the gizzard, had higher Cr, Zn, and Cd concentrations. Granivorous birds, which have the highest rates of Pb shot ingestion, had the highest concentrations of Pb. Grit and Pb shot ingestion are both important sources of heavy metals for waterbirds. Lead was the single metal studied whose concentrations exceeded toxicity thresholds. Received: 5 March 2002/Accepted: 12 June 2002     

Heavy Metal Toxicity and Differential Effects on the Hyperglycemic Stress Response in the Shrimp Palaemon elegans

Agricultural and industrial activities cause heavy metal pollution of the aquatic environment. The sensitivity of crustaceans to heavy metals is well documented. However, the hormonal and metabolic target of physiological functions affected by sublethal toxicity and stress responses have been scarcely investigated. Exposure of Palaemon elegans to increasing concentrations of heavy metals dissolved in artificial sea water resulted in an order of toxicity tested by LC₅₀ for 96 h in intact and eyestalkless animals in which Hg is the most toxic, followed by Cd, Cu, Zn, and Pb. Eyestalkless animals were found to be more sensitive than intact individuals. Heavy metals affect the blood glucose levels, yet manipulative stress does not. The intermediate sublethal concentrations of Hg, Cd, and Pb produced significant hyperglycemic responses within 3 h, while the highest concentrations elicited no hyperglycemia in 24 h. In contrast, animals exposed to Cu and Zn showed hyperglycemia even at high concentrations. This difference in response between Cu or Zn and the nonessential heavy metals Cd, Hg, or Pb can probably be explained by the physiological roles of the former in crustaceans and by tolerance adaptations. Involvement of the crustacean hyperglycemic hormone (cHH) was tested by routine bioassay on eyestalkless individuals; each group was injected with a two-eyestalk-equivalent extract from control animals or from shrimp exposed to high concentrations of Cd, Hg, Pb, or low concentrations of Cu or Zn. All showed a hyperglycemic response within 2 h. In contrast, extracts of eyestalk removed from animals that had developed a full hyperglycemic reaction after exposure to low concentrations of Hg, Cd, Pb, or high concentrations of Cu and Zn were depleted of cHH as shown by the attenuation of the response after injection of the extracts into eyestalkless animals. This generalized and predictable sublethal response can be used as a quantitative physiological biomarker for water quality monitoring assessment. Received: 22 September 1999/Accepted: 9 March 2000     

Toxicity of heavy metals using sperm cell and embryo toxicity bioassays with Paracentrotus lividus (Echinodermata: Echinoidea): comparisons with exposure concentrations in the Lagoon of Venice,Italy

Sperm cell and embryo toxicity tests using the Mediterranean sea urchin Paracentrotus lividus Lmk were performed to assess the toxicity of As3+, Cd2+, Cr3+, Ni2+, Pb2+, Cu2+, Zn2+, and Hg2+. The aim of this study was to improve information about the comparative sensitivity of sea urchin bioassays to the heavy metals, which are an important cause of contamination in the ecosystem of the Lagoon of Venice. Considering the data in mM/L, the order of toxicity is Hg2+ > Cu2+ > Zn2+ > As3+ > or = Cr3+ > or = Cd2+ > or = Pb2+ > or = Ni2+ for the sperm cell test and Hg2+ > or = Pb2+ > Cu2+ > Zn2+ > Cd2+ > Ni2+ > As3+ > or = Cr3+ for the embryo test. New toxicity data for metals expressed as median effective concentration (EC50) and no-observed-effect concentration (NOEC) are reported for the Mediterranean species. Accurate observations of embryotoxic effects at increasing metal concentrations were done, detecting some different behaviors in metal toxicity. Toxicity data compared with water column and pore-water concentrations recorded in the Lagoon of Venice (Italy) demonstrate the potential ability of bioassays using sea urchin to detect important contaminants in this ecosystem.     

Assessment of Metals Pollution on Agricultural Soil Surrounding a Lead–Zinc Mining Area in the Karst Region of Guangxi, China

Soil samples were collected on farmland in a lead-zinc mining area in the Karst region of Guangxi, China. The contamination of the soil by eight metals (Cd, Hg, As, Cu, Pb, Cr, Zn, Ni) was determined. Among all these metals, Cd is the most serious pollutant in this area. Zn, Hg as well asPb can also be measured at high levels, which may affect the crop production. All other metals contributed marginally to the overall soil contamination. Besides the evaluation of single metals, the Nemerow synthetic index indicated that the soil is not suitable for agricultural use.     

公路旁土壤中重金属污染分布及潜在生态危害的研究

[目的]研究公路旁土壤中重金属污染的分布及潜在生态危害。[方法]以319国道龙岩市新罗区路段为研究区,对耕作土采样,用原子吸收光谱法和分光光度法分析土壤中重金属Cd、Pb、Cu、Zn和Cr含量,并与对照区比较,同时采用Lars Hakanson指数法评价重金属的潜在生态危害。[结果]研究区表层土壤cd[(1.48±0.60)mg/kg]、Pb[(160.17±55.99)mg/kg]、cu[(38.44±12.16)mg/kg]、Zn[(80.35±6.60)mg/kg]、Cr[(79.50±23.58)mg/kg]含量显著高于对照区(P<0.001),Cd和Pb为重度污染(100％),Cu和Cr为轻微污染(分别占监测点位的55.8％和35.3％);土壤对重金属元素的吸收及污染程度:Pb>Cd>Cu>Cr>zn。潜在生态危害综合指数为253.0,主要污染为Cd,达到很强的生态危害,其次是Pb、Cu、Cr和Zn,均为轻微生态危害;潜在生态危害地带自公路起向其两侧扩散范围约为150 m。[结论]公路旁土壤中重金属以Cd、Pb污染为主,属于中等生态危害,污染物主要来源于机动车辆燃料和轮胎中所含微量重金属成分。     

Bioaccumulation of heavy metals in mullet (Mugil cephalus) and oyster (Crassostrea madrasensis) from Pulicat lake, south east coast of India

The accumulation of six heavy metals (Cr, Cd, Cu, Zn, Pb and Ni) in sediment, water and in tissue parts of Mugil cephalus and Crassostrea madrasensis was studied in two locations of Pulicat lake, Southeast coast of India, which receives considerable quantity of effluents from industries located in North Chennai coastal region. The results reveal that the metal concentration in water is decreasing in the following order of Zn > Ni > Cu > Cr > Pb > Cd both in lake and barmouth and highest concentration was observed for Zn (32.5 μg L(-1) in lake and 25.2 μg L(-1) in bar mouth). Metals were highly concentrated in sediments when compared to water and biota. Metals abundance in sediments has following sequential order of Cr > Ni > Zn > Cu > Pb > Cd and the accumulation pattern in barmouth showed minor variation indicating the following pattern of Zn > Ni > Cr > Cu > Pb > Cd. The geoaccumulation index (I(geo)) for Pulicat lake sediments indicate that the sediments are extremely contaminated with Cd and moderately contaminated with Cu and Ni. Bioaccumulation of heavy metals in Mugil cephalus and Crassostrea madrasensis showed marked differences in the accumulation patterns. It is observed that Zn, Cu and Pb are accumulated in elevated concentrations in various parts of the fish and oyster when compared with other metals.