Determination of exposure to lead of subjects from southwestern Poland by human hair analysis

Microchemistry of Single Hair Strands Below and Above the Scalp: Impacts of External Contamination on Cuticle and Cortex Layers

External contamination of hair is the most significant challenge to it becoming an accepted matrix for monitoring endogenous metal exposure and nutritional deficiency. Here we use laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to quantify elemental concentrations in hair strands below and above the scalp in the cuticle and cortex layers to determine the extent of external contamination in a reference population. Evidence of hair strand contamination occurred for barium, calcium, iron, magnesium, and strontium in both the outer cuticle and the inner cortex layers, with increasing concentrations from root to tip. Aluminum, boron, copper, lead, and manganese showed significant contamination in the cuticle layer only, suggesting some protection of the inner cortex. Phosphorus and potassium decreased outside the scalp suggesting loss by washing, while chromium, mercury, selenium, sodium, titanium, and zinc showed no evidence of loss or external contamination above the scalp. The results clearly show that for most elements, hair chemistry above the scalp is unreliable for use in interpretation of endogenous exposures or deficiencies, and that the below-scalp portion provides a more accurate monitoring tool. This is the first paper to provide a reference range of elemental hair chemistry that is not impacted by the external environment.

Exploring the link between toxic metal exposure and ADHD: a systematic review of pb and hg

INTRODUCTION

Attention-Deficit/Hyperactivity Disorder (ADHD) is a recognized neurodevelopmental disorder with a complex, multifactorial origin. Lead (Pb) and mercury (Hg) are highly toxic substances that can potentially impair brain development and have been implicated in the development of ADHD. This systematic review aims to analyze the epidemiological literature regarding the association between Pb and Hg exposure and the diagnosis of ADHD.

METHODS

From November 1983 to June 2, 2023, a comprehensive search was conducted in multiple databases and search engines, including PubMed, Web of Science, Scopus, and Google Scholar. Observational studies (case-control, cohort, and cross-sectional) measuring Pb and Hg levels in various biological samples (blood, hair, urine, nail, saliva, teeth, and bone) of children with ADHD or their parents and their association with ADHD symptoms were included.

RESULTS

Out of 2059 studies, 87 met the inclusion criteria and were included in this systematic review. Approximately two-thirds of the 74 studies investigating Pb levels in different biological samples reported associations with at least one subtype of ADHD. However, most studies examining Hg levels in various biological samples found no significant association with any ADHD subtype, although there were variations in exposure periods and diagnostic criteria.

CONCLUSION

The evidence gathered from the included studies supports an association between Pb exposure and the diagnosis of ADHD, while no significant association was found with Hg exposure. Importantly, even low levels of Pb were found to elevate the risk of ADHD. Further research is needed to explore the comprehensive range of risk factors for ADHD in children, considering its significance as a neurodevelopmental disorder.

Heavy metal concentrations and clinical symptoms in patients diagnosed with schizophrenia related to cigarette smoking

In our study, blood concentrations of lead (Pb), arsenic (As), and cadmium (Cd) and urine concentrations of thallium (Tl) were measured together with related symptoms of heavy metal poisoning in cigarette smoking volunteers diagnosed with schizophrenia, in cigarette smokers not diagnosed with schizophrenia, and in the control group of non-smokers and not diagnosed with schizophrenia volunteers. Our study was performed on 171 volunteers divided into the following subgroups: patients diagnosed with schizophrenia with at least 1 year of continuous cigarette smoking experience (56 participants), cigarette smokers not diagnosed with schizophrenia with at least one year of continuous smoking experience (58), and control group (not diagnosed with schizophrenia and non-smoking volunteers) (57). Smoking durations of cigarette smokers diagnosed with schizophrenia and cigarette smokers not diagnosed with schizophrenia are not similar (p = 0.431). Blood Pb, As, and Cd concentrations and urine Tl concentrations were the highest in the subgroup of cigarette smokers not diagnosed with schizophrenia, followed by the subgroup of cigarette smokers diagnosed with schizophrenia, and the control group. Only blood Pb concentrations were significantly higher (probability value p < 0.05) in the group of cigarette smokers not diagnosed with schizophrenia (5.16 μg/dL), comparing to the group of cigarette smokers diagnosed with schizophrenia (3.83 μg/dL) and to the control group (3.43 μg/dL). Blood Cd and As concentrations and urine Tl concentrations were significantly higher (p < 0.05) in cigarette smokers not diagnosed with schizophrenia than in the control group. The results revealed a statistically significant positive correlation (p < 0.001) in the cigarette smokers in the schizophrenia diagnosed group between blood Pb, blood As, and urine Tl concentrations and the duration of cigarette smoking.

Survey to identify the metal accumulation pathway in humans using hair and nail as biomarkers from fisherfolk population

Human hair and nail samples from Cuddalore fisherfolk populations were used as biomarkers for assessing metal concentrations in humans. Hair samples from 80 participants (47 men and 33 women) and nail samples from 40 participants (21 men and 19 women) were collected, and the concentrations of Cd, Cu, Pb, and Zn were assessed using an atomic absorption spectrophotometer (AAS). Metal data from AAS were compared with the survey questionnaire's personal and dietary parameters. Results indicate that both personal and dietary parameters may influence metal exposure; however, majority of the sources may have originated from metal-contaminated seafood. Higher metal accumulation in communities, especially those which consume seafood on a daily basis, may increase the possibility for them to get affected by metal-related diseases. Based on environmental parameters, people who live ≤500 m from industrial zones accumulate more metals. Further extensive studies with more individuals and more questionnaire parameters are needed to identify the metal accumulation pathway in humans.

Relationships Between Hair Chemical Elements and Nutritional Status in Oldest-Old and Centenarian Populations

Background

Hair chemical elements reflect physical condition over time. Collection, transporting, and storing hair is more convenient than handling blood. Hair elements show higher levels for a long time, which allows for more accurate and sensitive results than using blood. Studies explored the relationships between elements and age, without full consideration of nutritional status, in older people. This study explored the relationships between hair chemical elements and Geriatric Nutritional Risk Index (GNRI) in oldest-old and centenarian populations to provide an updated reference for nutritional evaluation of older people.

Methods

A total of 152 participants over 80 years old underwent home interviews and physical examinations. An inductively coupled plasma mass spectrometer was used to detect hair chemical elements.

Results

Women accounted for 77.0% of participants. Women had lower levels of zinc, and higher levels of selenium, manganese, lead, iron, and copper than men (P<0.05 for all). Ninety-two participants formed the 80-99 year group, and 60 participants formed the 100+ year group. Centenarians had lower levels of selenium, lead, iron, and copper than those aged 80-99 years (P<0.05 for all). Hair selenium levels were positively associated with GNRI (odds ratio: 11.55, 95% confidence interval: 3.42-19.68, P < 0.05) based on a multivariate linear regression analysis. Other chemical elements had no significant associations with GNRI based on a multivariate linear regression analysis.

Conclusion

Chemical elements and nutrient status were altered based on age and gender, and an association existed between hair selenium and nutritional status in older people. Chemical elements may influence and indicate nutritional status in older people.

Source apportionment based on lead isotope ratios: Could domestic dog's blood lead be used to identify the level and sources of lead pollution in children?

Domestic dogs have been proved to be used as "sentinel organisms" to monitor human lead exposure. However, whether dogs' blood can be used to identify the levels and pollution source of children's lead exposure still needs evidence. To evaluate the potential use of domestic dogs' blood lead as an indicator of lead exposure levels and pollution source of children, accompanying with potential environmental media samples, lead concentrations and isotope ratios (expressed as ²⁰⁷Pb/²⁰⁶Pb, ²⁰⁸Pb/²⁰⁶Pb) in blood were investigated and compared between children and dogs, who came from a Pb-Zn smelter area, a coal fired area and a control area without industrial activity. The results showed that there were significant correlations in blood lead levels (BLLs) between children and dogs in the study areas (p < 0.01). The lead isotope ratios (LIRs) in blood of children and dogs were disparate among the three areas, however, the LIRs of dogs were quite correlated with those of children in each area (p < 0.01). With the comparison of LIRs between potential pollution sources (slag, ore, coal, paint) and blood samples, the identified lead sources based on dogs' blood were found to be coincident with those based on children's blood. Ore smelting and coal combustion were the main sources of lead exposure for the dogs and children in the smelting area, and coal combustion was the predominant source for the children and dogs living in the coal burning area and control area. The results showed that dogs' BLLs might be used to estimate children's BLLs, and blood LIRs measurements of dogs' could be used as an alternative for identifying the sources of children's lead exposure. This study further provided relevant evidence for dogs to be sentinels exposed to human lead exposure and an alternative method for source apportionment of children's lead exposure.

Person identification using the composition of elements in human hair

If an individual cannot be identified, it is necessary to conduct a forensic medical examination. In this case, all possible group indexes are investigated. In this study, the content of elements in hair was investigated to identify individuals by territory, age, profession, or gender. The level of 14 micro- and macroelements (Cu, Zn, Co, Fe, Cr, Mn, Cd, As, Pb, Ni, P, Ca, K and Mg) was determined in hair samples of men and women from five age categories (21 to >60) using inductively coupled plasma atomic emission spectroscopy. The samples were analyzed taking into account the health condition, gender, place of residence, occupation, work experience, and age. A correlation between the content of elements in people's hair and their place of residence was observed. The difference in the content of elements in the hair of urban and rural residents was substantial and statistically significant (p<0.05). Moreover, there were significant differences related to age (p<0.0051) and gender (p<0.05). The current research detected significant differences in the content of the chemical elements in the hair of the groups tested, which can be used as personal identification indicators depending on occupation, work experience, and environmental factors.

Examining of Heavy Metal Concentrations in Hookah Smokers

Hookah smoking has been spreading around the world, especially among young adults. The current study aimed to investigate the concentration of heavy metals and elements and clinical symptoms in hookah users in comparison with non-users. To the best of our knowledge, the present study represents the first scientific contribution indicating levels of several heavy metals and elements in urine and blood in hookah users and non-users as well as evaluating clinical symptoms. This research was implemented in Iran among 100 males divided into two groups (50/group): control and hookah users. Heavy metal contamination (lead, cadmium, arsenic, thallium, zinc, and copper) in blood and urine samples was assayed by graphite furnace atomic absorption spectrometry (GFAAS). Duration of hookah use was 7.06 ± 4.57 years. The mean ± SD of lead, arsenic, and thallium concentrations was 3.77 ± 2.22, 8.50 ± 4.34, and 4.22 ± 2.69 μg/L. The mean levels of blood for lead, arsenic, and urinary thallium in hookah users are significantly higher than the control group (p < 0.05). The most frequent clinical symptoms in hookah smokers were constipation and fatigue. Findings from this study might guide the development of policies to regulate hookah smoking and prevent adverse health effects associated with hookah smoking.

Evaluating the use of hair as a non-invasive indicator of trace mineral status in woodland caribou (Rangifer tarandus caribou)

Trace mineral imbalances can have significant effects on animal health, reproductive success, and survival. Monitoring their status in wildlife populations is, therefore, important for management and conservation. Typically, livers and kidneys are sampled to measure mineral status, but biopsies and lethal-sampling are not always possible, particularly for Species at Risk. We aimed to: 1) determine baseline mineral levels in Northern Mountain caribou (Rangifer tarandus caribou; Gmelin, 1788) in northwestern British Columbia, Canada, and 2) determine if hair can be used as an effective indicator of caribou mineral status by evaluating associations between hair and organ mineral concentrations. Hair, liver, and kidney samples from adult male caribou (n_Hair = 31; n_Liver, n_Kidney = 43) were collected by guide-outfitters in 2016–2018 hunting seasons. Trace minerals and heavy metals were quantified using inductively-coupled plasma mass spectrometry, and organ and hair concentrations of same individuals were compared. Some organ mineral concentrations differed from other caribou populations, though no clinical deficiency or toxicity symptoms were reported in our population. Significant correlations were found between liver and hair selenium (rho = 0.66, p<0.05), kidney and hair cobalt (rho = 0.51, p<0.05), and liver and hair molybdenum (rho = 0.37, p<0.10). These findings suggest that hair trace mineral assessment may be used as a non-invasive and easily-accessible way to monitor caribou selenium, cobalt, and molybdenum status, and may be a valuable tool to help assess overall caribou health.

Elemental composition of hair as a marker for forensic human identification

BACKGROUND

Hair is one of the most common evidence types found in criminal investigations. Analysis of human hair reveals the mineral composition accumulated within it over time spent in a specific area, thereby providing additional information for forensic identification.

MATERIALS AND METHODS

To identify patterns of the elemental composition of hair in territories with different natural and anthropogenic features, hair samples of 1238 residents and 217 corpses of Central Kazakhstan were studied. The determination of 14 chemical elements in hair by inductively coupled plasma atomic emission spectrometry were presented. The data were analysed in terms of place of residence, gender, age and condition.

RESULTS

The results showed that the concentration of trace elements like Cu, Fe, Cd, and As significantly differed among all regions (p < 0.05). The composition of hair samples obtained from women significantly differed from those obtained from men for certain major and trace elements (p < 0.05). Concentrations of Ca and Mg in men were significantly lower than in women (p < 0.05) and were decreasing with age (p < 0.05).

CONCLUSIONS

The present investigation revealed a relationship between the elemental composition of hair and the place of permanent residence of a person, formed under the influence of regional industrial complexes, and determining gender and age-related differences. These findings enhance the possibilities of forensic human identification.

Knowledge, Attitude and Practice Study of Health Risks Among E-waste Recyclers in Delhi

BACKGROUND

India is the fifth biggest producer of e-waste in the world, discarding 1.7 million tons in 2014. E-waste gets recycled mainly in the informal sector which means activities are largely unaccounted for. Hazardous chemicals and metals are released during recycling processes (lead (Pb) being the most common). Compared to other developing countries, there are few studies from India on the awareness of recyclers of health risks related to e-waste recycling.

OBJECTIVES

The aim of the present study was to assess the knowledge, attitudes, and practices (KAP) of health-related risks and behaviors among e-waste workers/recyclers belonging to the informal sector in Delhi and to determine the concentration of Pb levels in hair samples from a subset of workers from selected recycling sites.

METHODS

A cross-sectional study was conducted in three e-waste informal recycling sites of Delhi: Seelampur, Mustafabad and Mandoli using an interviewer administered questionnaire among 220 e-waste workers. Percentages were presented for each KAP indicator. Analyses were computed using the statistical software STATA 14.2.

RESULTS

It was observed that 24% of participants had knowledge of the meaning of e-waste and 36% knew the chemicals that could be released from e-waste handling. Personal protective equipment (PPE) was used by only 12% of the workers. Twenty-six percent (26%) perceived occupational injuries (cuts or burns) as mild and 20% perceived coughing immediately after work as mild. Explorative analysis showed a link between worker education level and the type of work practices employed. The median level of Pb concentration among hair samples was 8 mg/kg with inter-quartile range between 5.8 to 12.4 mg/kg.

CONCLUSIONS

Knowledge and practices among e-waste workers regarding the health hazards associated with e-waste recycling were poor with little knowledge of or attention to health risks. A comprehensive remediation package covering sensitization and awareness-building strategies of the health risks associated with informal e-waste recycling should be an urgent priority.

PARTICIPANT CONSENT

Obtained.

ETHICS APPROVAL

Ethics approval was obtained from the Institutional Ethical Committee (IEC), Indian Institute of Public Health-Delhi.

COMPETING INTERESTS

The authors declare no competing financial interests.

Environmental chronic exposure to metals and effects on attention and executive function in the general population

Heavy metals are neurotoxic, associated with brain dysfunction, and have been linked with cognitive decline in adults. This study was aimed to characterize chronic exposure to metals (Cd, Be, Co, Hg, Sn, V, Al, Ba, Cr, Cu, Fe, Li, Mn, Ni, Pb, and Zn) and metalloids (As, B, Sb) and assess its impact on cognitive performance of Tehran's residents, capital of Iran. Scalp hair samples gathered from 200 volunteered participants (110 men and 90 women), aged 14-70 years and quantified by inductively coupled plasma atomic emission spectroscopy (ICP-OES). Attention and executive function, two measures of cognitive performance, were characterized using the trail making test (TMT) part A and B, respectively. Mental flexibility was characterized as the Delta TMT B-A scores and cognitive efficiency or dissimulation as the ration between TMT B and A scores. A comprehensive questionnaire was used to gather information on demographic and socioeconomic as well as lifestyle and health status. The highest and lowest mean concentrations were observed for B (325 μg/g) and As (0.29 μg/g), respectively. Results indicated that chronic metal exposure measured in hair changed significantly based on gender and age (p < 0.05). The levels of Cr, Fe, Ni, Si, Hg, Pb and B were significantly higher in males' hair, whereas those of Ag and Ba were greater in females' hair (p < 0.05). The results of the cognitive TMT test were significantly different between gender and age groups (p < 0.05). Moreover, results revealed that As, Hg, Mn, and Pb levels in hair were significantly associated with poorer participants' performance scores in the TMT test (p < 0.05). Age, gender, cigarette smoking, water-pipe smoking, traffic density in the area of residence, and dental amalgam filling were significant factors affecting the TMT test scores. The results suggest that chronic exposure to metals has detrimental effects on attention, executive function, mental flexibility and cognitive efficiency.

Biomonitoring chronic lead exposure among battery manufacturing workers in Tunisia

The aim of the study was the biomonitoring of the chronic exposure to Pb by measuring its levels in blood, urine, and hair of battery workers. Blood lead (BPb), urinary lead (UPb), hair lead (HPb), and urinary δ-aminolevulinic acid (UALA) levels were determined for 52 workers in a battery plant and compared to those of 20 non-occupational exposed subjects (controls). BPb and UPb levels were determined by graphite furnace atomic absorption spectrometry (GFAAS). HPb levels were measured by triple quadrupole ICP-MS and UALA levels were determined using cation exchanger column. The measured levels were significantly higher compared to the controls exceeding the OSHA cutoff values (p < 0.01). The GM mean levels of BPb, UPb, UALA, and HPb of workers were 715 μg L^-1, 331 μg L^-1, 16.3 mg g^-1, and 234 μg g^-1, respectively. The GM mean levels of BPb, UPb, UALA, and HPb of controls were 93.6 μg L^-1, 36.3 μg L^-1, 1.9 mg g^-1, and 1.8 μg g^-1, respectively. Significant correlations were observed between BPb and UALA (r = 0.630, p = 0.000), UPb and UALA (r = 0.566, p = 0.000), and between BPb and HPb (r = 0.466, p = 0.004). The significant correlation between BPb and HPb suggests the usefulness of hair for assessing occupational exposure particularly when the study area presents medium to high levels of Pb pollution. The association between Pb biomarkers and potential confounding factors revealed significant influence of the occupational factor over smoking and alcohol consumption. The results of this study urge for the reinforcement of the implemented engineering controls and safety measures in order to reduce exposure and to address the health issues related to Pb poisoning.

Trace Element Levels in the Elders over 80 from the Hainan Province of China

Trace elements are key regulators of metabolism and physiological pathways, and their levels change during aging. Hair, as a biological sample, has attracted much attention due to its ease of collection and slow substance metabolism. Also, trace elements in hair can reveal the distribution of essential nutrients and toxic elements in the body pools. Therefore, we investigated the lifestyle and dietary status by questionnaire and measured 8 trace elements in hair and 6 elements in blood of a sample of elders over 80 residing in Hainan province of China. Our data showed that the concentration of Se, Fe and Pb dropped as people grow older, but Mn rose. Changes in trace elements may affect enzyme activity and biological pathways, and are associated with many diseases, including cancer and chronic diseases. In addition, association between age-related diseases and trace elements are increasingly being reported, suggesting that approaches of combining nutrition with longevity studies in the further study will help us to identify the mechanisms whereby trace elements affect the aging process.

Hair chemical element contents and influence factors of reproductive-age women in the West Ujimqin Banner, Inner Mongolia, China

Women have an increased risk for chemical element deficiencies during reproductive age, particularly due to higher chemical element requirements and poor diets. Twenty-one chemical elements (Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Se, Si, Sn, Sr, Ti, V and Zn) in hair samples, which were collected from 71 non-pregnant and 236 pregnant women living in the West Ujimqin Banner, central Inner Mongolia, China, were measured, and the environment, dietary habits and ethnic group influence factors associated with the biomarker were analyzed. The results indicated that the average values of the chemical element contents from hair were greatly different compared to those from other areas, especially the Al, Cd, Pb, Ca and Sr contents. There was no significant difference among the three ethnicities for any element except Mn and Ti in non-pregnant women. Compared to non-pregnant women, in the first trimester group, the levels of nine chemical elements (Ba, Cd, Cu, Pb, Se, Si, Sn and Ti) decreased, while the others increased, and the contents of all of the chemical elements decreased in the second trimester group, while in the third trimester, there was a slight increase. Three chemical elements (Cu, Mn and Zn) displayed a synergistic correlation between each other in the third trimester group, which may protect the placenta from some oxidant damage. The high levels of Cd and Pb in hair likely originate from house renovations and traffic pollution. This study provided basic and useful information on the levels of chemical elements in reproductive-age women, and the results of this study are helpful to control the contents and improve the health of pregnant and non-pregnant women.

Assessment of environmental and occupational exposure to heavy metals in Taranto and other provinces of Southern Italy by means of scalp hair analysis

The monitoring of heavy metals in industrialized areas to study their association with different occupational and environmental factors is carried out in different ways. In this study, scalp hair analysis was used for the assessment of exposure to these metals in the industrial city of Taranto, characterized by a severe environmental pollution. The highest median values were observed for aluminum, barium, cadmium, lead, mercury, and uranium. Moreover, in the industrial area of Taranto, high levels of barium, cadmium, lead, mercury, nickel, and silver were observed in comparison with other Apulia areas. The risk odds ratios (ORs) for observing values above the 50th percentile were elevated for mercury and fish consumption, uranium and milk consumption, lead and female sex, and aluminum and mineral water consumption. No significant increased risk was observed for occupational activities. In a dendrogram of a cluster analysis, three clusters were observed for the different areas of Taranto (Borgo, San Vito, and Statte). A scree plot and score variables plot underline the presence of two principal components: the first regarding antimony, lead, tin, aluminum and silver; the second regarding mercury and uranium. The observed clusters (Borgo, San Vito, and Statte) showed that lead, antimony, tin, aluminum, and silver were the main component. The highest values above the 50th percentile of these minerals, especially lead, were observed in the Borgo area. The observed metal concentration in the Borgo area is compatible with the presence in Taranto of a military dockyard and a reported increase of lung cancer risk among residents of that area.

Human hair analysis in relation to similar environmental and occupational exposure

The aim of this work was to assess the influence of various factors on the elemental composition of the investigated hair samples. The studied population consisted of students of Faculty of Chemistry at Lodz University of Technology and included 95 subjects. The following elements: Co, Cr, Cu, Li, Sr, Pb were determined by inductively coupled plasma time-of-flight mass spectrometry ICP-TOF-MS. The obtained results were elaborated using Statistica ver. 10.0 software. Statistically significant differences were observed for the content of Cr, Li, Pb and Sr as the impact of sex, and Sr-as the effect of cosmetic treatment. Based on the calculated Spearman correlation coefficients, a statistically significant correlation between the concentration of pairs of metals were found for Pb=f(Co, Cr, Cu); Sr=f(Cu); Li=f(Cr), Cr=f(Li, Pb), Co=f(Pb) and Cu=f(Pb, Sr). A statistically negative correlation was obtained for Sr-Li. In the population two groups were distinguished: males and females; smokers and non-smokers.