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Trace Metal Content of Hair
Abstract
Cadmium and lead content of hair of males and females was found to he age-dependent. Regression analysis showed two male groups with respect to cadmium, namely those under and those over 12 years of age, while the data revealed only one male group with respect to lead. Analysis of the data also indicated that hair cadmium distribution for females delineated one group below, and one above, 50 years. Females showed hair lead which fell into two groups, one below and the other above 30 years of age. Cadmium and lead in the hair of both sexes showed a high degree of association of the metals (r= 0.4052 (P = .001) for males and r = 0.2563 (P = .02) for females). The data indicate that comparisons of metallic content of hair in humans must be limited to a narrow age range and to one sex.
... oli et al., 1994;Batzevich, 1995 . Concentrations of some elements in hair may depend on age, sex, hair colour and smoking habits, although infor- mation on this subject is scarce and is inconsis- Ž tent Petering et al., 1973;Takeuchi et al., 1982;Bencze, 1990a,b;Ashraf et al., 1994;Chaudhary . et al., 1995;Meng, 1998 . ...
... 982;. Valkovic, 1988;Caroli et al., 1992Caroli et al., , 1994 . Al- though the wide concentration ranges found in the literature may reflect the variety of specific local conditions, those covering up to five orders of magnitude are suspicious, especially for essen- tial elements. For example, the concentration Ž for males and 1.77 g g for females Petering . et al., 1973 . During the next two decades, re- ported concentrations commonly were approxi- y1 Ž mately 1 g g Gross et al., 1976;Creason et al., 1982;Takeuchi et al., 1982;Valkovic, 1988;. Vance et al., 1988 . In the 1990s, reported mean concentrations for unexposed populations de- y1 Ž creased to less than 0.3 g g Leotsinidis and Kondakis, 1990;Ca ...
Double-focusing sector-field, inductively coupled plasma-mass spectrometry was used for the determination of 71 elements in scalp hair and fingernail samples from an urban population group living in the north-east of Sweden. Samples (n = 114 for hair and n = 96 for nails) were taken from subjects without known occupational exposure to metals. From these results, concentration ranges were calculated and compared with published intervals. Statistical analysis was used to elucidate differences according to sex, age and smoking habit. It was found that significant correlations exist between different elements in hair and nails, as well as between hair and nail concentrations for several elements. Strong positive correlation for Hg, Cd, Pb, Sb and Bi levels between these media confirms that both can be used for exposure assessment for these elements. Several examples on the use of distribution patterns for the rare-earth elements (REE) and of Pb isotope ratios for assessment of exposure are given.
... ).Cats from the vicinity of Minamata, Japan.Rodents from areas of heavily mineralized soils in Idaho.Kit foxes from Bakersfield.Schroeder et al. (1970).Rats fed nominally toxic levels of Se; control rats had 0.6 ppm.Kit foxes from the Kesterson Reservoir.Coyotes from the Kesterson Reservoir.Petering et al. (1971). ...
Causal thinking is an everyday activity. We all are confronted with questions of causation, whether to figure out why the car is making a funny noise or why a toddler is running a fever. Our fascination with investigating causes is reflected in the enduring popularity of detective stories and in the frequency of investigative reports in the news.
Because causal inference is commonplace, a book on ecological causal assessment may seem unnecessary. However, causes are not always easy to determine. Ecosystems are complex; the factors we can influence interact with natural factors, random processes, and initial conditions to produce the effects that are observed. Taking corrective action to remedy an environmental problem before knowing its cause could target the wrong thing, depleting scarce resources and missing an opportunity to improve environmental quality.
Formal processes for causal assessment, as described in this book, are particularly helpful when the situation is complex or contentious. A wellarticulated process guides the analysis of available data and optimizes further collection efforts. A transparent process helps others replicate results and is more likely to convince skeptics that the true cause has been identified. A consistent process helps meet legal and regulatory standards for reasonableness and ensures that scientific information contributes to these decisions. Perhaps most importantly, formal methods help to eliminate biases that arise because of the all-too-human tendency to make and defend causal judgments too readily. As aptly articulated by the physicist Richard Feynman, “The first rule of science is not to fool yourself—and you are the easiest person to fool.”
We began this project with a practical purpose—to share useful methods and strategies for identifying causes of undesirable biological effects in specific places. Causal assessment is a challenging, often humbling, but endlessly fascinating endeavor. It begins with the intrigue of a good mystery— why did this effect happen? Success requires the persistence to figure things out and solid strategies for using the information that you have and getting more of the right kind of information that you need. We feel fortunate to have been involved with adapting existing methods and testing new approaches. It has led us to renewed study of our intellectual heritage of science and philosophy, the strengths and foibles of human cognition, and the underlying assumptions of different sampling designs and analytical methods. It has also allowed us to provide scientific assessments and advice on some of the more complex ecological problems of our times.
We have drawn on our personal experiences and those of our colleagues to provide examples and to describe approaches for assessing causes of undesirable biological effects in ecological systems. Some of these effects have captured the public’s attention and concern: collapsing fisheries and bee colonies; bleaching coral reefs; endangered species; dwindling stream life; and kills of fish, birds, and bats. Behind these reports are scientists who monitor our ecological systems and carefully document when something is amiss. In the past 20 years, biological monitoring has become an essential part of the environmental management tool kit. Causal assessment is the next essential tool. When we wonder why a condition has worsened, causal assessment finds the explanation.
We believe that this book provides sound advice for the near term. We hope that it will lead the way to future improvements in methods and applicable scientific knowledge. We also hope that our study of causal assessment in the context of environmental management advances the larger field of causal assessment and provides insights into how we all can improve our causal reasoning.
... ).Cats from the vicinity of Minamata, Japan.Rodents from areas of heavily mineralized soils in Idaho.Kit foxes from Bakersfield.Schroeder et al. (1970).Rats fed nominally toxic levels of Se; control rats had 0.6 ppm.Kit foxes from the Kesterson Reservoir.Coyotes from the Kesterson Reservoir.Petering et al. (1971). ...
... ).Cats from the vicinity of Minamata, Japan.Rodents from areas of heavily mineralized soils in Idaho.Kit foxes from Bakersfield.Schroeder et al. (1970).Rats fed nominally toxic levels of Se; control rats had 0.6 ppm.Kit foxes from the Kesterson Reservoir.Coyotes from the Kesterson Reservoir.Petering et al. (1971). ...
... 13.95mg/kg， 女性是 10.97mg/kg。Petering [20] ...
铱重金属可以在人体内累积，并产生一系列的毒害作用。近年来，头发重金属研究又取得了新的进展，论文综述了近几年人体头发重金属含量与环境、年龄、性别以及参考值的研究进展，提示头发重金属研究使个体识别成为了可能。
Hair samples were taken from mothers and newborns. The mean lead value of infants’ head hair was found to be higher than that found in many older children and was suggestive of placental lead transfer. There was a significant correlation between maternal copper in hair and infants’ lead in hair. As the age of the mother increased the copper levels in the infants’ hair decreased. The mean values of zinc decreased in mothers as parity increased. Mean hair lead values were significantly higher in blacks than in whites. The infants’ hair copper values increased as the parity of the mothers’ increased only in blacks. Zinc and iron content of infants’ hair was higher than mothers’ hair. There may be a need to screen certain populations during pregnancy so that corrective measures can be taken.
This review highlights those aspects of both the present and potential environmental problems of cadmium. Emphasized are properties and analyses; environmental processes; biological aspects of microbial, plant, animal, and human life; and 'safe' levels of exposure.
A study was carried out in 6 districts of Cubatão county, S. Paulo State, Brazil on a sample of 251 children aged between 1 and 10. The concentration of heavy metals (lead and mercury) in hair was tested. The lead concentration in the hair of 229 children was tested, and in 189 (82.5%) levels varying from 2.5 to 71.4 µg/g were detected. The average concentration of the lead found in hair was of 7.25 ± 8.51 µg/g. The concentration of mercury in the hair of 217 children was checked and all of them were found to have levels varying from 0.2 to 3.0 µg/g. The average concentration of mercury was of 0.82 ± 0.48 µg/g. No statistical difference (p > 0.05) was observed between the averages found for lead and mercury in the hair of those who consumed and those who did not consume aquatic organisms.
Both dietary iron and copper were inversely related to lead absorption as indicated by erythrocyte and kidney lead levels, dietary iron having the greatest effect. Kidney copper values were depressed when dietary iron was low, a condition which was worsened by lead. Lead tended to lower heart cytochrome c oxidase especially when dietary copper was low, but also when dietary copper and zinc were high. Lead interfered with hematopoiesis when dietary copper and/or iron were low, the effect being expecially severe when both essential nutrients were low. These results show the importance of copper and iron nutriture and metabolism as factors which reduce lead toxicity, and emphasize the necessity of considering nutritional status in evaluating lead toxicity.
Lead-induced anemia in rats, which is of a microcytic, hypochromic type, has been shown to be a result of an interference with the metabolism of copper and iron. In this complex interaction, copper may be the target upon which ingested lead has its antagonistic effect on hematopoiesis. The depressions in hematocrit and hemoglobin levels resulting from exposure to lead may occur secondarily to the effects of a lead-induced copper deficiency on iron mobilization and utilization. The metabolic fault induced by lead is seen in a reduction of serum iron, elevation of serum iron binding capacity, and increase in liver iron, all manifestations of systemic effects related to an interference with copper metabolism. These results relate many of the characteristics of the lead-induced anemia to those found in the copper-deficiency anemia.
The effects of long-term anticonvulsant therapy on copper (Cu), zinc (Zn), and magnesium (Mg) in the serum and hair were investigated in epileptics. Hair concentrations of Cu in both male and female epileptics, Zn in male epileptics, and Mg in female epileptics were significantly decreased when compared with those of age-matched and gender-matched controls. Hair Cu concentrations were significantly decreased in male epileptics; a significant decrease in hair Mg concentration was observed in female epileptics when compared with schizophrenics. An increased serum Cu concentration was found in female epileptics and a decreased Zn concentration was found in male epileptics. These findings suggest that long-term anticonvulsant therapy could induce alterations in both the metabolism and distribution of Cu, Zn, and Mg.
The analysis of hair for trace elements is potentially a safe, noninvasive and extremely useful diagnostic tool, but it has not yet been proven to be reliable or to reflect the status of trace elements elsewhere in the body. As well, little is known about the normal ranges of concentrations of elements in the hair or about the physiologic and pharmacologic factors that affect the concentrations. Until these problems have been resolved satisfactorily the diagnostic use of hair analysis performed by commercial laboratories cannot be justified in clinical practice.
The effect of daily parenteral administration of cadmium (0.75, 1.5, and 3.0 mg/kg) on the urinary excretion of enzymes has been studied in the young male rat. Aspartate amino-transferase, alkaline phosphatase, γ-glutamyl transpeptidase, and leucine aminopeptidase all showed an initial significant increase around the second day of dosage, the intensity of which was dose related. A second phase of enzymuria occurred later, the onset of which was dose related. High-dose-group animals (3.0 mg/kg) exhibited this increase around Day 15, while the median (1.5 mg/kg) and low- (0.75 mg/kg) dose-group animals developed enzymuria around Days 21 and 38, respectively. This second phase of elevated enzyme levels in the urine was persistent, and is believed to represent the development of renal damage.
A cross-sectional and follow-up study of young women taking oral contraceptive agents revealed a marked increase in serum copper levels. This increase was significant after the taking of oral contraceptive agents for 3 months. No significant effect of oral contraceptive agents on serum zinc and hair levels or copper were observed. There was no correlation between duration of oral contraceptive agent therapy and zinc or copper concentrations in serum or hair. Serum and hair concentration of zinc or copper were also not significantly correlated.
Children in the fourth to sixth grades at two schools were studied and divided in a control group (n = 323) and a learning disability (LD) group (n = 77). The following trace metals were analyzed in the air (7 months) at the two schools and in the children's hair: cadmium, selenium, arsenic, mercury, and lead. Discriminant analysis showed that selenium, mercury, cadmium, diastolic blood pressure, arsenic, and sex (all P < 0.001) were able to correctly classify 79.9% of the cases into LD or control groups. LD females had elevated selenium (P < .05) and lower diastolic blood pressure (P < 0.05) as compared to controls. LD males had elevated selenium (P < 0.001) and cadmium (P < 0.01), and lower systolic and diastolic blood pressure (P < 0.001) and mercury (P < 0.05) as compared to controls. The aerometric data showed that although there was a positive correlation between air and hair, lead, mercury, and selenium the absolute values were well below Federal Standards (PB = 276 ng/m3, Hg = 1.5 ng/m3, Se = 1.75 ng/m3). The data suggest that there is a significant difference between LD and control trace metal hair content and blood pressure, but that the air is not a major source of this effect although it does add to the cumulative trace metal hair content.
Hair cadmium and lead content were related to intelligence tests, motor impairment assessments, and school achievement scores from 149 children aged 5 to 16 yr enrolled in rural Maryland public school systems. Hair cadmium and lead were significantly correlated with both intelligence scores and school achievement scores, but not motor impairment scores. Significant relations with I.Q. were obtained after regressing out demographic factors and were observed, even in children within a normal I.Q. range. Evidence of different effects of cadmium and lead on cognitive development was obtained. Hierarchical regression analyses suggest that cadmium has a significantly stronger effect on verbal I.Q. than does lead and that lead has a stronger effect on performance I.Q. than does cadmium.
The use of human hair analysis technique is far from being the universal tool for monitoring exposures to environmental pollutants and considering the broad spectrum of pollutants encountered in the general environment one can hardly expect that such a screening tool would ever exist. However, for a majority of toxic trace metals this technique has proved to be a well-suited biological marker of occupational and environmental exposure of man. One of the essential conditions for ensuring the realistic evaluation of excessive population exposure is the examination of sufficiently large population groups and the use of group diagnostics methodology in environmental epidemiology studies. The method of hair analysis appears to be ideally suited for use in pilot prospective studies. If an excessive exposure is detected it is recommendable that the epidemiological examination be completed by analyses of other biological materials, most often blood and urine, in order to obtain a closer specification of the degree of exposure in the respective population.
A study was carried out in 6 districts of Cubatão county, S. Paulo State, Brazil on a sample of 251 children aged between 1 and 10. The concentration of heavy metals (lead and mercury) in hair was tested. The lead concentration in the hair of 229 children was tested, and in 189 (82.5%) levels varying from 2.5 to 71.4 micrograms/g were detected. The average concentration of the lead found in hair was of 7.25 +/- 8.51 micrograms/g. The concentration of mercury in the hair of 217 children was checked and all of them were found to have levels varying from 0.2 to 3.0 micrograms/g. The average concentration of mercury was of 0.82 +/- 0.48 microgram/g. No statistical difference (p > 0.05) was observed between the averages found for lead and mercury in the hair of those who consumed and those who did not consume aquatic organisms.
Hair samples of 23 male professional drivers and 20 male university teachers in Hong Kong were collected, and the concentrations of Al, Sb, As, Ca, Cu, Fe, Pb, Mg, Mn, Hg, K, Sr, S, V, and Zn were measured. Both of the target groups fell within the same age group of 35-45. The washing method of using detergent and powder was found to be comparable to that of using ether. Difference in the mean concentration of each detected element in the two groups was tested by the Student's t-test and the Wilcoxon rank-sums test. Hair concentrations of Al, Sb, Pb, Mg, Mn, and K in the "Driver Group" were significantly (p < 0.05) higher than those in the "Teacher Group." On the other hand, As and Hg were found to have a higher concentration in hair of teachers. Interpretation of the findings in terms of the environmental factor and the metabolic rate was attempted.
The relationship between concentrations of cadmium in hair and in the whole body is of interest when discussing which biological sampling materials could be reliable indicators of cadmium accumulation in the body. When whole-body and hair concentrations of cadmium were followed at regular intervals up to 112 days after an intravenous injection of cadmium chloride tagged wih cadmium 109 in mice, a correlation coefficient of .99 was found. Retention of cadmium in different tissues was illustrated by organ assay and whole-body autoradiography and was especially pronounced in kidneys and pancreas.
In a relatively large sample of human population, we find that the hair levels of zinc and copper can be divided into two groups, those individuals under 12 years of age and those over 12 years. In either group the concentrations of zinc and copper in the hair are directly related to the age of the individual; the relationship is linear when the concentration and age are expressed as logarithms. There is an increase during childhood and a slow continuing decrease after maturity. The sexes may differ in their respective need and use of copper.
Analyses for 8 trace metals were made on hair samples of 126 male and 55 female subjects aged 1 to 102 years, most of whom patronized a barber shop. Marked variations were found. Samples of female hair had significantly more magnesium, copper and cobalt than did male hair. Young female hair had more copper, lead and cadmium than did hair from older women. Natural colored hair of females contained more magnesium, copper, lead, nickel and zinc than did natural colored hair of males. Grey hair of women had more magnesium and less cadmium and lead than that of men. In males there was more magnesium and less cadmium in black hair than in hair of other colors, less zinc in blond than in black or red, more lead in brown than in black or red and more nickel in red than in brown hair. In females there was less zinc in blond than in brown or red and less magnesium in brown than in red hair. Concentrations of the essential elements magnesium, zinc, copper, cobalt and chromium in hair did not decline with age in men, and were maintained in women after age 40. Nickel, cadmium and lead did not accumulate with age. It is doubtful that concentrations of these trace metals in hair reflect tissue stores under normal conditions.
In a study performed on 67 lead exposed workers, a correlation was found between levels of lead in hair and the biochemical and clinical findings. A lead level in hair of more than 30 µg/g could be considered as a sign of excessive lead level.
Since 1962 the trace element content of human hair has been studied as a possible means of comparing physical-evidence hair samples. It is recognized that for hair to be of wide value in this application, its trace element content must not change rapidly with time. Limited studies have indicated, however, that changes do occur over relatively long periods of time. These changes may be due to natural growth processes and/or environmental contamination. This study was made to see how extensively the trace element content of hair might be modified by the adsorption of environmental trace elements and to see if solvents could be found that would remove the adsorbed elements. The procedure used was to place a sample of hair in a solution containing measured quantities of an element and a radiotracer. After 16 hr, the sample was removed from the solution, rinsed, and then washed. The radioactivity that remained after the wash was a measure of the quantity of adsorbed element. All solutions were prepared to approximate the composition and pH(3.5-5.5) of perspiration. The elements studied were Na, K, Cl, Br, Cu, Zn, Au, Se, Cr, I, As, Ag, Sb, Co, Fe, Mn, Ca, Ba, and Sr. All elements except Na and K were found to absord, and the extent of adsorption was pH dependent. The elements Zn, Fe, Ba, Co, Mn, and Sb were removed by solutions containing EDTA, but no solvent was found that would remove Au, Ag and Se.
Adsorption and elution of cadmium on human and mouse hair were studied by the use of radioactive isotope technique. Hair with Cd accumulated solely from the hair follicle was obtained from mice injected with cadmium 109. Cadmium adsorption on human hair, when brought into contact with a solution of cadmium chloride tagged with cadmium 109 occurred with an individual variation, ranging from 0 to 100% of Cd present in the solution. This variation seemed to have been the result of individual variation in hair acidity. A nearly complete removal of Cd from the hair could be obtained by using a sufficiently strong solution of an acid. However, the different treatments applied were not effective for separate analysis of exogenous and endogenous hair Cd.
This article has no abstract; the first 100 words appear below.
THE present study explores the quantitative analysis of lead in hair as an aid in the diagnosis of chronic, mild or subacute lead poisoning in children. Hair, one of the lesser known sites for lead accumulation, concentrates more lead per unit weight than any other tissue or body fluid, including bone, blood and urine.¹²³⁴ In healthy persons the concentration of lead in scalp hair may be from two to five times greater than in bone, about ten to fifty times higher than in blood, and from a hundred to five hundred times greater than that excreted in urine.⁵ Hair presents . . .
*Supported in part by a research grant (A-6339) from the Division of Arthritis and Metabolic Disease, National Institutes of Health, United States Public Health Service.
We are indebted to Kevin B. Higgins for technical assistance.
Source Information
BOSTON
† Research associate in clinical pathology, Children's Cancer Research Foundation.
‡ Consultant in neurology, Children's Hospital Medical Center.
§ Clinical professor of pediatrics, Harvard Medical School: chief, Division of Clinical Laboratories, Children's Hospital Medical Center.
Zinc, copper, cadmium, and lead content of hair of a sample of US urban population
- Petering
- D W Yeager