On the Use of Hair Analysis for Assessing Arsenic Intoxication

Review on Toxicology Testing in Hair

BACKGROUND

Hair toxicology is a useful tool for detecting long-term drug use. This method offers several advantages, including the ability to trace historical patterns of drug intake. However, drug incorporation into hair is complex, influenced by numerous factors such as hair structure, physiological differences, external contamination, and the chemical properties of drugs. A comprehensive understanding of these factors is critical to accurately interpret hair toxicology results in both clinical and forensic settings.

CONTENT

The anatomy of hair plays a vital role in drug incorporation. Drugs can enter the hair via diffusion from the bloodstream, by passive deposition through sweat or sebum bathing the hair, or through external contamination. The analysis of drug incorporation has evolved significantly over time, and it is now possible to detect drug exposure even after a single ingestion. However, several factors such as decontamination protocols, extraction methods, melanin content (hair color), growth rates, contamination from drug particulates, and cosmetic hair treatments may affect the accuracy of hair toxicology results. Guidelines by expert societies have been published, but variations in sample preparation and analysis techniques remain.

SUMMARY

While hair toxicology holds promise for detecting long-term drug exposure, many variables must be considered to ensure accurate interpretation. Differences in physiological properties and external factors can complicate the results. Harmonized protocols and advanced techniques are necessary to minimize biases, particularly regarding racial differences in drug incorporation. Future research should aim to further harmonize methodologies and address these challenges to enhance the reliability of hair toxicology testing.

Assessing air quality impacts of gas stations through heavy metal analysis in dust and employees' scalp hair in Erbil City

This research focused on examining the occurrence of heavy metals, including Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Hg, Pb, and V, within the dust and scalp hair of individuals working at gas stations within Erbil province, as well as residents living in rural areas of Hawraman, away from polluted sources. The measurements of metals were performed in a laboratory environment utilizing an XRF device, including the Thermo Scientific Genius 9000 model. The findings revealed significantly higher concentrations of heavy metals in dust particles and hair samples collected from gas station workers compared to those from clean rural areas. The values derived from the Geo-accumulation index (IGEO) and Pollution Load Index (PLI) suggest that pollution from gas stations ranged from uncontaminated to moderate, reaching severe levels. Specifically, the PLI at gas stations reached an elevated level of 7.02, decreasing to 0.49 in rural areas. A strong connection has been identified between the concentrations of metallic elements in the dust particles and worker's hair samples. Workers with over 22 years of experience had higher metal levels in their hair, while those aged 20-30 had lower levels than those over 55.

Biomonitoring of inorganic arsenic species in pregnancy

Exposure assessment of inorganic arsenic is challenging due to the existence of multiple species, complexity of arsenic metabolism, and variety of exposure sources. Exposure assessment of arsenic during pregnancy is further complicated by the physiological changes that occur to support fetal growth. Given the well-established toxicity of inorganic arsenic at high concentrations, continued research into the potential health effects of low-level exposure on maternal and fetal health is necessary. Our objectives were to review the value of and challenges inherent in measuring inorganic arsenic species in pregnancy and highlight related research priorities. We discussed how the physiological changes of pregnancy influence arsenic metabolism and necessitate the need for pregnancy-specific data. We reviewed the biomonitoring challenges according to common and novel biological matrices and discussed how each matrix differs according to half-life, bioavailability, availability of laboratory methods, and interpretation within pregnancy. Exposure assessment in both established and novel matrices that accounts for the physiological changes of pregnancy and complexity of speciation is a research priority. Standardization of laboratory method for novel matrices will help address these data gaps. Research is particularly lacking in contemporary populations of pregnant women without naturally elevated arsenic drinking water concentrations (i.e. <10 µg/l).

A State-of-the-Science Review on Metal Biomarkers

PURPOSE OF REVIEW

Biomarkers are commonly used in epidemiological studies to assess metals and metalloid exposure and estimate internal dose, as they integrate multiple sources and routes of exposure. Researchers are increasingly using multi-metal panels and innovative statistical methods to understand how exposure to real-world metal mixtures affects human health. Metals have both common and unique sources and routes of exposure, as well as biotransformation and elimination pathways. The development of multi-element analytical technology allows researchers to examine a broad spectrum of metals in their studies; however, their interpretation is complex as they can reflect different windows of exposure and several biomarkers have critical limitations. This review elaborates on more than 500 scientific publications to discuss major sources of exposure, biotransformation and elimination, and biomarkers of exposure and internal dose for 12 metals/metalloids, including 8 non-essential elements (arsenic, barium, cadmium, lead, mercury, nickel, tin, uranium) and 4 essential elements (manganese, molybdenum, selenium, and zinc) commonly used in multi-element analyses.

RECENT FINDINGS

We conclude that not all metal biomarkers are adequate measures of exposure and that understanding the metabolic biotransformation and elimination of metals is key to metal biomarker interpretation. For example, whole blood is a good biomarker of exposure to arsenic, cadmium, lead, mercury, and tin, but it is not a good indicator for barium, nickel, and uranium. For some essential metals, the interpretation of whole blood biomarkers is unclear. Urine is the most commonly used biomarker of exposure across metals but it should not be used to assess lead exposure. Essential metals such as zinc and manganese are tightly regulated by homeostatic processes; thus, elevated levels in urine may reflect body loss and metabolic processes rather than excess exposure. Total urinary arsenic may reflect exposure to both organic and inorganic arsenic, thus, arsenic speciation and adjustment for arsebonetaine are needed in populations with dietary seafood consumption. Hair and nails primarily reflect exposure to organic mercury, except in populations exposed to high levels of inorganic mercury such as in occupational and environmental settings. When selecting biomarkers, it is also critical to consider the exposure window of interest. Most populations are chronically exposed to metals in the low-to-moderate range, yet many biomarkers reflect recent exposures. Toenails are emerging biomarkers in this regard. They are reliable biomarkers of long-term exposure for arsenic, mercury, manganese, and selenium. However, more research is needed to understand the role of nails as a biomarker of exposure to other metals. Similarly, teeth are increasingly used to assess lifelong exposures to several essential and non-essential metals such as lead, including during the prenatal window. As metals epidemiology moves towards embracing a multi-metal/mixtures approach and expanding metal panels to include less commonly studied metals, it is important for researchers to have a strong knowledge base about the metal biomarkers included in their research. This review aims to aid metals researchers in their analysis planning, facilitate sound analytical decision-making, as well as appropriate understanding and interpretation of results.

Morphological and chemical profiling for forensic hair examination: A review of quantitative methods

Within the past two decades, there have been many studies for quantitative analysis on human hair samples. Microscopical and chemical analysis techniques have been used to analyze various aspects of hair regarding biological, chemical, anthropological, cosmetic, and forensic applications. Studies have attempted to develop quantification methods to increase the evidentiary value of hair in forensic casework. The literature reviewed in this paper provides some of the current techniques used for forensic examinations and quantitative methods. Although microscopical analysis has been scrutinized in the past, using chemical and microscopical techniques can provide a myriad of information. The extraction of DNA from hair provides high-value evidence; however, it may not be readily available and may yield inconclusive results. Hair analysis can be used for many forensic applications such as comparison, toxicology, and exposure analysis. In this article, we will review published research material regarding chemical and microscopical techniques for human hair analysis. Aspects considered for this review were the sample size requirement for analysis and the destructive nature of the instrumental method. This review will focus on both macro and micro quantitative methods for human hair analysis.

Characterization of the Toxicological Impact of Heavy Metals on Human Health in Conjunction with Modern Analytical Methods

Increased environmental pollution, urbanization, and a wide variety of anthropogenic activities have led to the release of toxic pollutants into the environment, including heavy metals (HMs). It has been found that increasing concentrations of HMs lead to toxicity, mineral imbalances, and serious diseases, which are occurring more and more frequently. Therefore, testing has become imperative to detect these deficiencies in a timely manner. The detection of traces of HMs, especially toxic ones, in human tissues, various biological fluids, or hair is a complex, high-precision analysis that enables early diagnosis, addressing people under constant stress or exposed to a toxic environment; the test also targets people who have died in suspicious circumstances. Tissue mineral analysis (TMA) determines the concentration of toxic minerals/metals at the intracellular level and can therefore determine correlations between measured concentrations and imbalances in the body. Framing the already-published information on the topic, this review aimed to explore the toxicity of HMs to human health, the harmful effects of their accumulation, the advantages vs. the disadvantages of choosing different biological fluids/tissues/organs necessary for the quantitative measurement of HM in the human body, as well as the choice of the optimal method, correlated with the purpose of the analysis.

As and F − cooccurrence in drinking water: critical review of the international scenario, physicochemical behavior, removal technologies, health effects, and future trends

Drinking water contaminated with As andF − is increasingly prevalent worldwide. Their coexistence can have negative effects due to antagonistic or synergistic mechanisms, ranging from cosmetic problems, such as skin lesions and teeth staining, to more severe abnormalities, such as cancer and neurotoxicity. Available technologies for concurrent removal include electrocoagulation ~ adsorption > membranes > chemical coagulation > , and among others, all of which have limitations despite their advantages. Nevertheless, the existence of competing ions such as silicon > phosphate > calcium ~ magnesium > sulfate > and nitrate affects the elimination efficiency. Mexico is one of the countries that is affected by As andF − contamination. Because only 10 of the 32 states have adequate removal technologies, more than 65% of the country is impacted by co-presence problems. Numerous reviews have been published concerning the elimination of As orF − . However, only a few studies have focused on the simultaneous removal. This critical review analyzes the new sources of contamination, simultaneous physicochemical behaviors, available technologies for the elimination of both species, and future trends. This highlights the need to implement technologies that work with actual contaminated water instead of aqueous solutions (55% of the works reviewed correspond to aqueous solutions). Similarly, it is necessary to migrate to the creation of pilot, pre-pilot, or prototype scale projects, because 77% of the existing studies correspond to lab-scale research.

Assessment of Arsenic in Hair of the Inhabitants of East Croatia—Relationship to Arsenic Concentrations in Drinking Water

The problem of elevated arsenic concentrations in water and environment is an increasing public health concern. The aim of the study was to assess the arsenic content in human hair in selected areas of eastern Croatia and to compare them with measured values after installation of a new water supply system. The hair samples were taken in the areas of wider Osijek and Vinkovci area and analyzed using the ICP–MS method. These data were also compared with data for Vinkovci previously published in 2004. Depending on the investigated area, the median concentrations ranged from 0.02 to 0.9 µg g−1, whereby this last value exceeded the upper range of the reference value (0.319 µg g−1). The arsenic concentrations from the Našice, Osijek and Vinkovci areas were within or slightly above the maximum allowed reference range. The highest median values in hair samples were detected in Čepin, with arsenic-contaminated potable water, while in areas where the water source was changed, the values were significantly lower. The results add to the conclusion that there has been significant reduction in hair arsenic concentrations in the population that was given access to clean, uncontaminated water from other regional sources.

Repeated poisoning of the life partner by thallium - a case of questionable Munchausen by adult proxy syndrome with ensuing attempted murder

After the use of thallium as rat poison was banned, the knowledge about the severe and treacherous course of poisonings with this toxic metal has widely been lost. In the present case, the male victim sustained two insidious poisoning attacks in 2017 and 2020 by the perpetrator, his female life partner. In the first poisoning episode, he suffered from increasing heavy pain of the abdomen, stinging pain of both legs, persistent obstipation, hyperesthesia, and, after about 2 weeks, tuft-wise loss of hair as typical symptoms of the thallium poisoning. Within 7 weeks, he was successively examined in six hospitals with a wide variety of diagnostic methods, but a conclusive explanation of the complaints was not found. The possibility of a metal intoxication was then suggested by the perpetrator who privately arranged the analysis of a blood sample with the result of 175 µg/l thallium. Although a criminal poisoning was assumed, the perpetrator was not identified. After the victim left the perpetrator, she subtly executed a second poisoning attack with thallium sulfate (blood level 1230 µg/l after 1 day, urine level 4760 µg/l after 10 days, and hair concentrations 3.26-0.49 from proximal to distal in 9 segments). The perpetrator was sentenced to 10.5 years imprisonment for grievous bodily harm and attempted murder. Because of the behavior of the perpetrator, a Munchausen by proxy syndrome was discussed as a motivation of the first poisoning but was excluded by the psychiatric expert because of a missing antisocial personality disorder.

Three Primary Cancers in a Veteran With Agent Orange and Agent Blue Exposures

A Vietnam War veteran's exposures likely contributed to his cancer diagnoses, but these associations are confounded by his substance use, particularly cigarette smoking.

Arsenic exposure and metabolism in relation to blood pressure changes in pregnant women

Arsenic is concerned with cardiovascular diseases including hypertension, atherosclerosis, and endothelial dysfunction. However, what effects the arsenic exposure and the arsenic metabolism have on hypertensive disorders of pregnancy (HDP) and blood pressure changes during pregnancy remain largely unknown. Our goal was to assess the associations of arsenic exposure and arsenic metabolism with HDP and blood pressure changes in pregnant women through a prospective birth cohort study. A total of 1038 women who were pregnant (52 HDP, 986 non-HDP participants) were included. Arsenic species of spot urine samples collected at three trimesters were measured, which included inorganic arsenic (iAs), monomethylated arsenic (MMA), and dimethylated arsenic (DMA). Arsenic metabolism was evaluated as the percentages of iAs, MMA, and DMA respectively (i.e., iAs%, MMA%, and DMA%). Outcomes were HDP and systolic, diastolic, and mean arterial pressure changes during pregnancy. We employed mixed linear models to investigate the relationships between arsenic exposure and arsenic metabolism with changes in blood pressure during pregnancy. Poisson regression with a robust error variance with generalized estimating equations (GEE) estimation was used so that the associations of arsenic exposure and arsenic metabolism with HDP could be estimated. In this study, there was a significant relationship between the concentrations of urinary DMA and the weekly change in systolic blood pressure (SBP) (β = -0.10; 95% CI: -0.15, -0.05), diastolic blood pressure (DBP) (β = -0.07; 95% CI: -0.11, -0.02) and mean arterial pressure (MAP) (β = -0.08; 95% CI: -0.12, -0.04). Higher DMA% was accompanied with lesser weekly increase in SBP (β = -0.05; 95% CI: -0.10, 0.00), DBP (β = -0.06; 95% CI: -0.10, -0.01) and MAP (β = -0.06; 95% CI: -0.09, -0.01) during pregnancy. There was a positive association with the highest tertile of iAs% and weekly change of SBP (β = 0.08; 95% CI: 0.03, 0.13), DBP (β = 0.07; 95% CI: 0.03, 0.11) and MAP (β = 0.07; 95% CI: 0.03, 0.11). No association was found between each arsenic specie and arsenic metabolism marker in the first trimester and risk of HDP. Arsenic exposure and arsenic metabolism during pregnancy potentially change blood pressure of pregnant women. These findings may be significance as even modest elevation of blood pressure can increase the risk of cardiovascular disease.

Feeding Arsenic-Containing Rice Bran to Growing Pigs: Growth Performance, Arsenic Tissue Distribution, and Arsenic Excretion

This research was conducted to study the growth performance, arsenic (As) tissue distribution, and As excretion of pigs fed As-containing rice bran. Twenty gilts (26.3 kg) were randomly assigned to 3 dietary treatments (n = 6 or 7) with Diets I, II, and III containing 0, 36.7, and 73.5% rice bran and 0, 306, and 612 ppb As, respectively. Pigs were fed for 6 weeks, and their growth performance and daily activities were examined. Fecal, blood, and hair samples were collected immediately before and after the 6-weeks. At the end of the 6-weeks, pigs were slaughtered; the liver, kidney, muscle, and urine samples were collected. No pig showed any unhealthy signs throughout the trial. The average daily feed intake, average daily gain, and final body weight of Diet III pigs were lower (p ≤ 0.001) than Diet I pigs. The gain to feed ratios were not different among the treatments. The fecal, hair, kidney, and urinary As concentrations of both Diets II and III pigs were higher than Diet I pigs. The hair As concentration of Diet III pigs was higher than Diet II pigs, but no difference was found in the fecal, urinary, kidney, or muscle As concentrations between Diets II and III pigs. The blood and muscle As concentrations were below 10 ppb. These results suggest that 73.5% dietary rice bran inclusion compromised growth performance, whereas the 36.7% inclusion did not. The fecal As data imply that dietary As was poorly absorbed by the gastrointestinal tract. The tissue As data indicate that the absorbed As was rapidly cleared from the blood with some retained in various organs and others eliminated via urine. The hair As concentration was much higher than that of liver and kidney. The muscle As data suggest that the pork produced from the pigs fed a typical As-containing rice bran as used in this study is safe for human consumption.

Arsenic and birth outcomes in a predominately lower income Hispanic pregnancy cohort in Los Angeles

Prenatal arsenic exposure has been associated with reduced fetal growth and increased risk for preterm birth, but most studies have been conducted in highly exposed populations outside the U.S. or in non-Hispanic populations in the rural U.S. The objectives of the current study were to: 1) examine the impact of early pregnancy exposure to arsenic on birth weight and gestational age at birth in a predominately lower income Hispanic pregnancy cohort in urban Los Angeles and 2) compare multiple biomarkers of arsenic exposure (blood, urine, and hair) assessed in early pregnancy (mean ± SD gestational age at biospecimen collection: 14 ± 4 weeks). Total arsenic (blood, hair) was measured by ICP-MS and speciated arsenic (urine) was measured by HPLC coupled to ICP-MS. Associations between log₂-transformed arsenic measures and birth outcomes were evaluated using multivariable linear regression. A doubling in hair arsenic was associated with a 72.2 g (95% CI: -144.3, -0.1, P = 0.05) lower birth weight, after adjusting for potential confounders and gestational age at birth. A similar but non-significant trend was observed for blood arsenic, but not urine arsenic. The inverse association between hair arsenic and birth weight was more pronounced among infants whose mothers gained greater amounts of weight during pregnancy (P_interaction = 0.02). The association between urinary monomethyl arsenic and GA at birth differed by pre-pregnancy BMI (P_interaction<0.01). This study provides evidence that even at relatively low levels of exposure, arsenic exposure (measured in hair samples collected in early pregnancy) may adversely affect fetal growth in this understudied population, particularly in combination with greater gestational weight gain. Future studies with larger sample sizes are needed to confirm these findings and to further investigate some of the inconsistencies observed for the different arsenic biomarkers evaluated.

Alluvial and gypsum karst geological transition favors spreading arsenic contamination in Matehuala, Mexico

Arsenic transport in alluvial aquifers is usually constrained due to arsenic adsorption on iron oxides. In karstic aquifers, however, arsenic contamination may spread to further extensions mainly due to favorable hydrogeochemical conditions. In this study, we i) determined the spatial and temporal behavior of arsenic in water in an alluvial-karstic geological setting using field and literature data, ii) established whether a contaminated aquifer exists using field and literature piezometric data and geophysical analysis, iii) studied the local geology and associated arsenic contaminated water sources to specific aquifers, iv) revealed and modeled subsoil stratigraphy, and v) established the extent of arsenic exposure to the population. We found arsenic contamination (up to 91.51 mg/l) in surface and shallow groundwater (<15 m), where water flows from west to east through a shallow aquifer, paleochannels and a qanat within an alluvial-karst transition that favors the spreading and transport of arsenic along 8 km as well as the increase of arsenic exposure to the population (up to 3.6 mgAs/kghair). Results from this study contribute to understanding arsenic transport in semi-arid, mining-metallurgical, and urban environments, where the presence of karst could favor arsenic transport to remote places and exacerbate arsenic exposure and impact in the future.

Ginkgo biloba extract attenuates the disruption of pro-and anti-inflammatory T-cell balance in peripheral blood of arsenicosis patients

Endemic arsenicosis is a public health problem that affects thousands of people worldwide. However, the biological mechanism involved is not well characterized, and there is no specific treatment. Exposure to arsenic may be associated with immune-related problems. In the present work, we performed an investigation to determine whether the Th17/Treg balance was abnormal in peripheral blood mononuclear cells (PBMCs) of patients with arsenicosis caused by burning coal. Furthermore, we investigated the effect of Ginkgo biloba extract (GBE) on the Th17/Treg imbalance in patients with arsenicosis. In this trial, 81 arsenicosis patients and 37 controls were enrolled. The numbers of Th17 and Treg cells, as well as related transcription factors and serum cytokines, were determined at the beginning and end of the study. Patients with arsenicosis exhibited higher levels of Th17 cells, Th17-related cytokines (IL-17A and IL-6), and the transcription factor RORγt. There were lower levels of Treg cells, a Treg-related cytokine (IL-10), and the transcription factor Foxp3 as compared with controls. There was a positive correlation between the levels of Th17 cells and IL-17A and the levels of arsenic in hair. Arsenicosis patients were randomly assigned to a GBE treatment group or a placebo group. After 3 months of follow-up, 74 patients completed the study (39 cases in the GBE group and 35 in the placebo group). Administration of GBE to patient upregulated the numbers of Treg cells and the level of IL-10 and downregulated the numbers of Th17 cells and the levels of cytokines associated with Th17 cells. The mRNA levels of Foxp3 and RORγt were increased and decreased, respectively. These results indicated that exposure to arsenic is associated with immune-related problems. The present investigation describes a previously unknown mechanism showing that an imbalance of pro- and anti-inflammatory T cells is involved in the pathogenesis of arsenicosis and that a GBE exerts effects on arsenicosis through regulation of the pro- and anti-inflammatory T cell balance.