Glucocorticoid hormones in relation to environmental exposure to bisphenols and multiclass pesticides among middle aged-women: Results from hair analysis

Bisphenols and pesticides have been shown to alter circulating glucocorticoids levels in animals, but there is limited human data. Moreover, measurements from biological fluids may not be able to reflect long-term status of non-persistent pollutants and glucocorticoids due to the high variability in their levels. Using hair analysis, we examined the associations between glucocorticoid hormones and environmental exposure to multi-class organic pollutants among a healthy female population aged 25-45 years old. Concentrations of four glucocorticoids, four polychlorinated biphenyl congeners (PCBs), seven polybrominated diphenyl ether congeners (PBDEs), two bisphenols and 140 pesticides and their metabolites were measured in hair samples collected from 196 Chinese women living in urban areas. Due to the low detection frequency of some pollutants, associations were explored only on 54 pollutants, i.e. PCB 180, bisphenol A, bisphenol S and 51 pesticides and their metabolites. Using stability-based Lasso regression, there were associations of cortisol, tetrahydrocortisol, cortisone, and tetrahydrocortisone with 14, 10, 13 and 17 biomarkers of exposure to pollutants, respectively, with bisphenol S, p,p'-dichlorodiphenyldichloroethylene, diethyl phosphate, 3,5,6-trichloro-2-pyridinol, thiamethoxam, imidacloprid, fipronil, tebuconazole, trifluralin, pyraclostrobin and 1-(3,4-dichlorophenyl)-3-methylurea being associated with at least three of the four hormones. There were also associations between cortisone/cortisol molar ratio and pollutants, namely dimethyl phosphate, 3-methyl-4-nitrophenol, carbofuran, λ-cyhalothrin, permethrin, fipronil, flusilazole, prometryn and fenuron. Some of these relationships were confirmed by single-pollutant linear regression analyses. Overall, our results suggest that background level of exposure to bisphenols and currently used pesticides may interfere with the glucocorticoid homeostasis in healthy women.

Exposure assessment to bisphenol A (BPA) and its analogues bisphenol S (BPS) and bisphenol F (BPF) in wild boars by hair analysis

Bisphenols are widely used in various branches of industry for the production of plastics. They penetrate to the natural environment and thus living organisms. As endocrine disruptors, bisphenols have adverse effects on various internal organs and systems. Contrary to humans, the knowledge of the exposure of wild terrestrial mammals to bisphenols is extremely limited. Therefore, this study for the first time assessed the exposure level of wild boars to three bisphenols commonly used in industry (i.e. bisphenol A - BPA, bisphenol S - BPS and bisphenol F - BPF) using hair sample analysis in liquid chromatography-mass spectrometry (LC-MS). The presence of BPA and/or BPS has been noted in the samples collected from >80 % of animals included in the study (n = 54), while the presence of BPF was not found in any sample. At least one of the bisphenols was present in every sample tested. Mean concentrations of BPA and BPS in the hair of wild boars were 151.40 ± 135.10 pg/mg dry weight (dw.) and 29.40 ± 36.97 pg./mg dw, respectively. Concentrations of BPA and BPS in females were statistically higher than in males (p < 0.05). Moreover, statistically significantly higher concentration levels of BPA (and not BPS) in the areas with higher degree of industrialization and higher human population density were also found. This is the first study concerning the use of hair samples to assess the exposure of wild terrestrial mammals to bisphenols. The obtained results show that an analysis of the hair may be a useful tool of biomonitoring bisphenols in wild animals. The presence of BPA and BPS in wild boar hair in relatively high concentration also suggests that these substances may have an influence on the health status not only in humans and aquatic animals, but also in wild terrestrial mammals. However, many aspects connected with this issue are not clear and require further study.

Identification of potential sources

Recent years have seen growing interest in hair sample analysis to detect organic pollutants (OPs). This biological matrix can be analysed non-invasively for biomonitoring of OPs over a wide exposure window. Obtaining hair sample amounts that meet the needs of the analytical methodology required for the determination of the POs of interest can be challenging, especially in infants. As a result, studies assessing organic pollutants in infant hair have been very scarce. We quantified levels of about 60 OPs, including persistent organic pollutants (POPs), in 110 hair samples from a patient cohort (60 mothers and 50 infants) from Santiago de Compostela (north-western Spain). For each participant we examined relationship between OP levels and corresponding epidemiological parameters using correlations, principal component analysis (PCA), hierarchical cluster analysis, and Multivariate analysis of variance (MANOVA). For many OPs we observed significant correlations with place of residence, parity, and maternal age, as well as pet ownership. Evaluation of dietary habits showed significant associations between levels some OPs and the consumption of fish, molluscs, and cereal. There were significant associations between chlorpyrifos and deltamethrin levels and infant birth characteristics such as birthweight and head circumference. Relations between OP levels in the hair of mothers and their infants were also examined, revealing common sources of exposure for dioxin-like polychlorinated biphenyls (DLPCBs), non-dioxin-like polychlorinated biphenyls (NDLPCBs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs). Levels of fluoranthene (F), pyrene (P), endrin, and some PBDEs in maternal hair were significantly correlated with those in infant hair. Our findings identified common sources of exposure to OPs of distinct chemical classes.

Segmental hair analysis as a retrospective testosterone diary: possibilities and pitfalls

Testosterone is thought to be incorporated in growing hair strands so that specific hair segments reflect average free hormone concentrations from the corresponding time period. However, the exact mechanisms of hormone integration in scalp hair have not yet been established and it is not known how testosterone is stored in the hair segments over time. The aim of this study was to investigate the stability of testosterone concentrations in hair as it grows and to determine if segmental hair analysis can be used as a retrospective testosterone diary. Thirty men and 40 women provided two hair samples and 16 saliva samples during a period of three months. Hair growth between the two samplings was measured. Hair samples were cut into 10 mm segments resulting in three segments from the first sampling and six segments from the second sampling. Hair samples were pulverised and extracted with methanol. Hair testosterone concentrations were analysed using an in-house radioimmunoassay. Salivary testosterone was analysed using a commercial enzyme-linked immunosorbent assay (Demeditec). The results demonstrated that there is a degree of segmental hormone conservation over time (rho = 0.405-0.461, p < 0.001, n = 66-67), but also highlighted three potential confounders. Firstly, testosterone concentrations were higher in distal hair segments (mean concentration ratio most distal by most scalp-near was 1.55, SD 0.70), which may be due to continuous hormone integration from sebum and changes in hair matrix composition. Secondly, more frequent hair washing stunted the increase in testosterone concentrations in distal segments (rho = -0.404, p =  < 0.001, n = 66). And lastly, intra- and inter- individual variability in hair growth rate influenced the temporal resolution along the hair, although mean growth rate was indeed 30.0 mm for three months. In a multiple regression model the biological sex, natural hair colour, and relationship status were significant explanatory variables to hair testosterone concentrations. The current results indicate that repeated hair sampling near the hair roots during a study may be preferable to analysing concentration changes between proximal and distal segments within the same hair sample. Also, hair testosterone analysis needs to be adjusted for sex and the natural hair colour.

Are the NPS commonly used? An extensive investigation in Northern Italy based on hair analysis

New psychoactive substances (NPS) are present on the Italian illicit markets, but data from the analysis of biological samples to evaluate their real consumption are rare. For this reason, an epidemiological study was carried out by means of a ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method for the determination of 115 NPS on the keratin matrix. A total of 847 hair samples were collected in 2020 and 2021 and analyzed. The sample donors were in the age range of 18-40 years, from both genders, and were tested either for driving relicensing or for drug withdrawal monitoring. The UPLC-MS-MS system consisted of a Waters ACQUITY UPLC® I-Class, coupled with a Waters XEVO TQ-XS triple quadrupole mass spectrometer. The method was developed and fully validated according to international guidelines. Limits of detection were set as the minimum criterion to identify positive samples. Overall, 56 samples resulted positive for ketamine, 35 for norketamine, 6 for fentanyl, 3 for norfentanyl, 3 for 4-ANPP, 3 for MDMB-4en-PINACA, 2 for N,N-DMT, 2 for 5-chloro AB-PINACA, 1 for α-PHP and 1 for methcathinone. NPS were detected in a small part of samples (8.4%), which seems in contrast with their apparent wide diffusion in Italy, yet it is congruent with similar investigations based on hair analysis. Future studies will be performed to expand the investigated population, especially in terms of age and origin.

Environmental tobacco smoke at home and in public places prior to smoking ban enforcement: Assessment by hair analysis in a population of young adult students

Despite inititatives to reduce tobacco consumption, smoking remains a primary cause of death for both smokers and nonsmokers exposed to environmental tobacco smoke (ETS). The characteristics of some specific groups can make them more exposed to ETS or limit the benefit of prevention measures. This study investigated determinants of ETS in a population of young adult students, considered at higher risk of exposure due to their specific lifestyle. This cross-sectional study involved 90 students aged 20 ± 1.7 years, from the University of Luxembourg, prior to the smoking ban enforcement in public places in the country. Participants reported their tobacco consumption and exposure to ETS at home and/or in public places, and provided a hair sample analyzed for nicotine and cotinine. Nicotine and cotinine were significantly higher in smokers than in nonsmokers' hair in general (median: 2.6 vs. 0.9 ng/mg and 87.1 vs. 22.5 pg/mg respectively). However, nonsmokers exposed to ETS at home and in public places had comparable concentrations to smokers (nic = 2.2 ng/mg; cot = 56.2 pg/mg), whereas unexposed nonsmokers presented significantly lower values (nic = 0.4 ng/mg, cot = 8.5 pg/mg). Nonsmokers exposed to ETS only at home presented higher values than nonsmokers only exposed in public places (nic: 1.3 vs. 0.8 ng/mg, cot: 70.4 vs. 15.0 pg/mg). The study shows the widespread exposure to ETS in this population, the importance of exposure assessment, and the relevance of hair analysis for this purpose. Results suggest that ETS can lead to equivalent exposure to active smoking and that exposure at home can highly contribute to ETS, which is not solved by smoking ban in public places.

Emerging diagnostic methods and imaging modalities in cushing's syndrome

Endogenous Cushing's syndrome (CS) is a rare disease characterized by prolonged glucocorticoid excess. Timely diagnosis is critical to allow prompt treatment and limit long-term disease morbidity and risk for mortality. Traditional biochemical diagnostic modalities each have limitations and sensitivities and specificities that vary significantly with diagnostic cutoff values. Biochemical evaluation is particularly complex in patients whose hypercortisolemia fluctuates daily, often requiring repetition of tests to confirm or exclude disease, and when delineating CS from physiologic, nonneoplastic states of hypercortisolism. Lastly, traditional pituitary MRI may be negative in up to 60% of patients with adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas (termed "Cushing's disease" [CD]) whereas false positive pituitary MRI findings may exist in patients with ectopic ACTH secretion. Thus, differentiating CD from ectopic ACTH secretion may necessitate dynamic testing or even invasive procedures such as bilateral inferior petrosal sinus sampling. Newer methods may relieve some of the diagnostic uncertainty in CS, providing a more definitive diagnosis prior to subjecting patients to additional imaging or invasive procedures. For example, a novel method of cortisol measurement in patients with CS is scalp hair analysis, a non-invasive method yielding cortisol and cortisone values representing long-term glucocorticoid exposure of the past months. Hair cortisol and cortisone have both shown to differentiate between CS patients and controls with a high sensitivity and specificity. Moreover, advances in imaging techniques may enhance detection of ACTH-secreting pituitary adenomas. While conventional pituitary MRI may fail to identify microadenomas in patients with CD, high-resolution 3T-MRI with 3D-spoiled gradient-echo sequence has thinner sections and superior soft-tissue contrast that can detect adenomas as small as 2 mm. Similarly, functional imaging may improve the identification of ACTH-secreting adenomas noninvasively; Gallium-68-tagged corticotropin-releasing hormone (CRH) combined with PET-CT can be used to detect CRH receptors, which are upregulated on corticotroph adenomas. This technique can delineate functionality of adenomas in patients with CD from patients with ectopic ACTH secretion and false positive pituitary lesions on MRI. Here, we review emerging methods and imaging modalities for the diagnosis of CS, discussing their diagnostic accuracy, strengths and limitations, and applicability to clinical practice.

Measurement Tools and Utility of Hair Analysis for Screening Adherence to Antihypertensive Medication

Poor adherence to the prescribed antihypertensive therapy is an understated public health problem and is one of the main causes of the high prevalence of uncontrolled hypertension in sub-Saharan Africa. Medication adherence is vital for the effectiveness of antihypertensive treatment and is key to ameliorating the clinical outcomes in hypertensive patients. However, it has often been ignored because the current methods used to assess medication adherence are not reliable, limiting their utilization in clinical practice. Therefore, the identification of the most accurate and clinically feasible method for measuring medication adherence is critical for tailoring effective strategies to improve medication adherence and consequently achieve blood pressure goals. This review not only explores various available methods for estimating medication adherence but also proposes therapeutic drug monitoring in hair for the measurement of medication adherence to the antihypertensive medication period.

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.

Concordance between substance use self-report and hair analysis in community-based adolescents

Background: Accurate drug use identification through subjective self-report and toxicological biosample (hair) analysis are necessary to determine substance use sequelae in youth. Yet consistency between self-reported substance use and robust, toxicological analysis in a large sample of youth is understudied.Objectives: We aim to assess concordance between self-reported substance use and hair toxicological analysis in community-based adolescents.Methods: Hair results by LC-MS/MS and GC-MS/MS and self-reported past-year substance use from an Adolescent Brain Cognitive Development (ABCD) Study subsample (N = 1,390; ages 9-13; 48% female) were compared. The participants were selected for hair selection through two methods: high scores on a substance risk algorithm selected 93%; 7% were low-risk, randomly selected participants. Kappa coefficients the examined concordance between self-report and hair results.Results: 10% of youth self-reported any past-year substance use (e.g. alcohol, cannabis, nicotine, and opiates), while a mostly non-overlapping 10% had hair results indicating recent substance use (cannabis, alcohol, non-prescription amphetamines, cocaine, nicotine, opiates, and fentanyl). In randomly selected low-risk cases, 7% were confirmed positive in hair. Combining methods, 19% of the sample self-reported substance use and/or had a positive hair sample. Kappa coefficient of concordance between self-report and hair results was low (kappa = 0.07; p = .007).Conclusions: Hair toxicology identified substance use in high-risk and low-risk ABCD cohort subsamples. Given low concordance between hair results and self-report, reliance on either method alone would incorrectly categorize 9% as non-users. Multiple methods for characterizing substance use history in youth improves accuracy. Larger representative samples are needed to assess the prevalence of substance use in youth.

Estimation of the Frequency and Time of Human Exposure to Arsenic by Single Hair Analysis

Arsenic (As) and its compounds are widely used in many applications. Long-term exposure to As can cause acute and chronic poisoning. In severe cases, it can lead to adverse effects, such as gene mutation, cell cancer and fetal malformation. The objective of this study was to accurately estimate As exposure frequency and time. Quantitative analysis of As in single hairs obtained from APL (acute promyelocytic leukemia) patients treated with As₂O₃ was performed by LA-ICP-MS. An informative As concentration distribution profile of single hair was applied to estimate the As exposure frequency and time. As exposure frequency was estimated according to the number of As concentration peaks. As exposure time was estimated according to the hair growth length in combination with the hair growth rate. The validation results demonstrate that this method was more efficient than the traditional method; compared with the traditional method, which provides estimates in months, our model shortened the As exposure time estimate to the range of a few days, which considerably improved the inference accuracy. Therefore, these results can be used for forensic toxicology studies, environmental exposure monitoring, etc.

Hormonal profile changes induced by pesticide mixture exposure in female rats revealed by hair analysis

Pesticide exposure has been associated with hormonal disruption in both animals and humans. However, there is limited knowledge of the combined effects of complex mixtures of pesticides on endogenous hormone levels. Here, we used hair analysis to assess the impact of a pesticide mixture comprising 19 components from multiple chemical classes at eight doses of 0-400 μg/kg body weight (bw) three times per week per component on concentrations of 36 steroid and thyroid hormones in female rats over a 90-day exposure period. We detected 13 hormones in rat hair, namely estradiol (E2), androstenedione (AD), testosterone (T), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), pregnenolone (P5), progesterone (P4), 11-deoxycorticosterone (11-DOC), corticosterone (CORT), 3,3'-l-diiodothyronine (T2), 3,5,3'-l-triiodothyronine (T3), 3,3',5'-l-triiodothyronine (rT3), and 3,5,3',5'-l-tetraiodothyronine (T4). In comparison to the control group, hair E2 concentration was significantly lower in the two highest (200 and 400 μg/kg bw) exposure groups, whereas hair DHEAS and CORT concentrations were significantly higher in the 40 μg/kg bw and the highest exposure groups, respectively. Results from generalized additive models suggest that pesticide exposure resulted in monotonic dose responses in hair E2 concentration, CORT concentration and DHEA/CORT molar ratio but nonmonotonic dose responses in hair T concentration, DHEAS concentration, P4/P5 and DHEA/DHEAS molar ratios. The associations of E2, CORT and DHEA/CORT ratio with exposure intensity were confirmed by their significant linear relationships with hair concentrations of at least 23 of the 25 exposure biomarkers analyzed. Our results demonstrate that exposure to low levels of the pesticide mixture evaluated here can alter hair reproductive and adrenal hormones levels.

Investigating children's chemical exposome - Description and possible determinants of exposure in the region of Luxembourg based on hair analysis

The specific physiology and behaviour of children makes them particularly vulnerable to chemical exposure. Specific studies must therefore be conducted to understand the impact of pollution on children's health. Human biomonitoring is a reliable approach for exposure assessment, and hair, allowing the detection of parent chemicals and metabolites, and covering wider time windows than urine and blood is particularly adapted to study chronic exposure. The present study aims at assessing chemical exposure and investigating possible determinants of exposure in children living in Luxembourg. Hair samples were collected from 256 children below 13 y/o and tested for 153 compounds (140 pesticides, 4 PCBs, 7 BDEs and 2 bisphenols). Moreover, anthropometric parameters, information on diet, residence, and presence of pets at home was collected through questionnaires. Correlations, regressions, t-tests, PLS-DA and MANOVAs, were used to investigate exposure patterns. Twenty-nine to 88 (median = 61) compounds were detected per sample. The highest median concentration was observed for BPA (133.6 pg/mg). Twenty-three biomarkers were detected in ≥ 95% of the samples, including 13 in all samples (11 pesticides, BPA and BPS). Exposure was higher at younger ages (R² = 0.57), and boys were more exposed to non-persistent pesticides than girls. Presence of persistent organic pollutants in most children suggests that exposure is still ongoing. Moreover, diet (e.g. imazalil: 0.33 pg/mg in organic, 1.15 pg/mg in conventional, p-value < 0.001), residence area (e.g. imidacloprid: 0.29 pg/mg in urban, 0.47 pg/mg in countryside, p-value = 0.03), and having pets (e.g. fipronil: 0.32 pg/mg in pets, 0.09 pg/mg in no pets, p-value < 0.001) were identified as determinants of exposure. The present study demonstrates that children are simultaneously exposed to multiple pollutants from different chemical classes, and confirms the suitability of hair to investigate exposure. These results set the basis for further investigations to better understand the determinants of chemical exposure in children.

Micro-segmental hair analysis: detailed procedures and applications in forensic toxicology

PURPOSE

Since the 1980s, the detection sensitivity of mass spectrometers has increased by improving the analysis of drugs in hair. Accordingly, the number of hair strands required for the analysis has decreased. The length of the hair segment used in the analysis has also shortened. In 2016, micro-segmental hair analysis (MSA), which cuts a single hair strand at a 0.4-mm interval corresponding to a hair growth length of approximately one day, was developed. The advantage of MSA is that the analytical results provide powerful evidence of drug use in the investigation of drug-related crimes and detailed information about the mechanism of drug uptake into hair. This review article focuses on the MSA technique and its applications in forensic toxicology.

METHODS

Multiple databases, such as SciFinder, PubMed, and Google, were utilized to collect relevant reports referring to MSA and drug analysis in hair. The experiences of our research group on the MSA were also included in this review.

RESULTS

The analytical results provide a detailed drug distribution profile in a hair strand, which is useful for examining the mechanism of drug uptake into hair in detail. Additionally, the analytical method has been used for various scenarios in forensic toxicology, such as the estimation of days of drug consumption and death.

CONCLUSIONS

The detailed procedures are summarized so that beginners can use the analytical method in their laboratories. Moreover, some application examples are presented, and the limitations of the current analytical method and future perspectives are described.

Molecular imaging of humain hair with MeV-SIMS: A case study of cocaine detection and distribution in the hair of a cocaine user

Human hair absorbs numerous biomolecules from the body during its growth. This can act as a fingerprint to determine substance intake of an individual, which can be useful in forensic studies. The cocaine concentration profile along the growth axis of hair indicates the time evolution of the metabolic incorporation of cocaine usage. It could be either assessed by chemical extraction and further analysis of hair bundels, or by direct single hair fibre analysis with mass spectroscopy imaging (MSI). Within this work, we analyzed the cocaine distribution in individual hair samples using MeV-SIMS. Unlike conventional surface analysis methods, we demonstrate high yields of nonfragmented molecular ions from the surface of biological materials, resulting in high chemical sensitivity and non-destructive characterisation. Hair samples were prepared by longitudinally cutting along the axis of growth, leaving half-cylindrical shape to access the interior structure of the hair by the probing ion beam, and attached to the silicon wafer. A focused 5.8 MeV 35Cl6+ beam was scanned across the intact, chemically pristine hair structure. A non-fragmented protonated [M+ H]+ cocaine molecular peak at m/z = 304 was detected and localized along the cross-section of the hair. Its intensity exhibits strong fluctuations along the direction of the hair’s growth, with pronounced peaks as narrow as 50 micrometres, corresponding to a metabolic incorporation time of approx. three hours.

Profiling steroid and thyroid hormones with hair analysis in a cohort of women aged 25 to 45 years old

OBJECTIVE

Endogenous hormones regulate numerous physiological processes in humans. Some of them are routinely measured in blood, saliva and/or urine for the diagnosis of disorders. The analysis of fluids may, however, require multiple samples collected at different time points to avoid the high variability in the concentration of some hormones. In contrast, hair analysis has been proposed as an interesting alternative to reveal average hormone levels over a longer period. In this work, we developed and validated an analytical method for analyzing 36 endogenous steroid and thyroid hormones and one pineal hormone in human hair using ultra-performance liquid chromatography (UPLC)-tandem mass spectrometry (MS/MS).

METHODS

Sample preparation involved hair decontamination, pulverization, methanol extraction, and purification with C18-solid phase extraction. Extracts were then divided into two portions, respectively injected into an UPLC-MS/MS system, and analyzed using two different instrumental methods. The method was applied to a healthy female population aged 25-45 years.

RESULTS

The method was validated on supplemented hair samples for the 37 targeted hormones, and its application to the population under study allowed to detect 32 compounds in 2-100% of the samples. Complete reference intervals (2.5-97.5th percentiles) were established for estrone, 17β-estradiol, androstenedione, dehydroepiandrosterone, progesterone, 17α-hydroxyprogesterone, cortisone, cortisol and 3,3',5-triiodo-L-thyronine. Hair cortisone, cortisol, tetrahydrocortisone and tetrahydrocortisol concentrations were highly correlated with each other, with Kendall's τ correlation coefficients ranging from 0.52 to 0.68.

CONCLUSION

Allowing the detection of 32 hormones from different chemical classes, the present method will allow to broaden hormonal profiling for better identifying endocrine disorders.

[Clinical applications of hair analysis in the Netherlands]

Hair analysis has been known for its role in forensic science. However, it may also have an important role in the clinical approach of various exposures, for example drugs and heavy metals. In the Netherlands, it is used infrequently probably because clinicians are not familiar with this diagnostic possibility. In this article, we present two cases in which hair analysis proved to be crucial in the diagnosis of two different exposures (tobacco smoking and arsenic). We provide an overview of the various clinical applications of hair analysis and important factors affecting the results of hair analysis.

Population-based biomonitoring of exposure to persistent and non-persistent organic pollutants in the Grand Duchy of Luxembourg: Results from hair analysis

Environmental exposure of humans to pollutants has been associated with adverse health outcomes, but few studies have evaluated the multiple exposure of general populations. In the present study, we used hair analysis to assess the exposure of a general adult population (n = 497) in Luxembourg to 34 persistent and 33 non-persistent organic pollutants from 11 chemical families, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs), organophosphate pesticides (OPPs), and pyrethroid pesticides (PYRs). We detected 24 persistent and 29 non-persistent organic pollutants, with 17 pollutants being detected in more than 50% of hair samples. The median concentrations for pollutants detected in 100% of the samples were 0.37 pg/mg for lindane (γ-HCH), 0.15 pg/mg for hexachlorobenzene (HCB), 14.1 pg/mg for p-nitrophenyl (PNP), and 0.10 pg/mg for trifluralin. Each participant in this study had detectable levels of at least 10 of the pollutants analyzed, and 50% of participants had 19 or more, suggesting the simultaneous exposure to numerous different pollutants among our study population. Significant correlations were often found between pollutants from the same family, with the strongest being found between two PYR metabolites, trans/cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-carboxylic acid (Cl₂CA) and 3-phenoxybenzoic acid (3-PBA). Results from multiple linear regression analyses showed that sex, age and/or body mass index were significantly associated with 15 out of the 17 frequently detected pollutants. The current study is the first nationwide biomonitoring investigating organic contaminants in the Luxembourg population using hair analysis.

Tenofovir and emtricitabine concentrations in hair are comparable between individuals on tenofovir disoproxil fumarate versus tenofovir alafenamide-based ART

Tenofovir disoproxil fumarate (TDF) in combination with emtricitabine (FTC) is the backbone for both human immunodeficiency virus (HIV) treatment and pre-exposure prophylaxis (PrEP) worldwide. Tenofovir alafenamide (TAF) with FTC is increasingly used in HIV treatment and was recently approved for PrEP among men-who-have-sex-with-men. TDF and TAF are both metabolized into tenofovir (TFV). Antiretrovirals in plasma are taken up into hair over time, with hair levels providing a long-term measure of adherence. Here, we report a simple, robust, highly sensitive, and validated high-performance liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS)-based analytical method for analyzing TFV and FTC from individuals on either TDF/FTC or TAF/FTC in small hair samples. TFV/FTC are extracted from ~5 mg hair and separated on a column using a gradient elution. The lower quantification limits are 0.00200 (TFV) and 0.0200 (FTC) ng/mg hair; the assay is linear up to 0.400 (TFV) and 4.00 (FTC) ng/mg hair. The intra-day and inter-day coefficients of variance (CVs) are 5.39-12.6% and 6.40-13.5% for TFV and 0.571-2.45% and 2.45-5.16% for FTC. TFV concentrations from participants on TDF/FTC-based regimens with undetectable plasma HIV RNA were 0.0525 ± 0.0295 ng/mg, whereas those from individuals on TAF/FTC-based regimens were 0.0426 ± 0.0246 ng/mg. Despite the dose of TFV in TDF being 10 times that of TAF, hair concentrations of TFV were not significantly different for those on TDF versus TAF regimens. Pharmacological enhancers (ritonavir and cobicistat) did not boost TFV concentrations in hair. In summary, we developed and validated a sensitive analytical method to analyze TFV and FTC in hair and found that hair concentrations of TFV were essentially equivalent among those on TDF and TAF.

Hair mineral analysis in the population of students living in the Lower Silesia region (Poland) in 2019: Comparison with biomonitoring study in 2009 and literature data

The paper presents a comparative analysis of biomonitoring research results using hair mineral analysis today and 10 years ago. The aim of the present work was to examine the impact of individual factors, on the content of elements in human hair. The mineral analysis of 115 hair samples was carried out using ICP-OES and AAS technique. It was shown that calcium, barium, copper, mercury, magnesium, manganese and selenium content depend on gender and is higher for women. Statistically significant synergistic correlations were identified between the following pairs of elements: (Ca-Mg), (P-S), (Mo-Sb) and (Ba-Pb). The results of the present work were compared with the previous assessment in 2009 on students of the same age. The content of most of the heavy metals in hair was reduced significantly, which is a sign of the improving state of the local environment. The greatest decrease was recorded for silver (96.6%), arsenic (93.4%), mercury (45.1%), lead (67.7%), antimony (55.2%), thallium (10 times) and cobalt (93.7%). The level of the following elements increased: Ba: 27.3%, Cu: 28.5%, Ni: 22.4%, Ti: 191%, Zn: 11.0%. Changes in the content of most heavy metals in hair have been noted, as well as changes of reference ranges, which may indicate an improvement in the state of the environment in Wrocław, Lower Silesia (Poland) over the last 10 years. These results were confirmed by biomonitoring studies carried out with human hair, which was shown to be a reliable biomarker of human exposure to toxic elements.

Evaluation of Drug Abuse by Hair Analysis and Self-Reported Use Among MSM Under PrEP: Results From a French Substudy of the ANRS-IPERGAY Trial

BACKGROUND

We used the Agence nationale de Recherches sur le sida et les hépatites virales (ANRS)-IPERGAY trial to qualitatively and quantitatively measure drug use among men who have sex with men under preexposure prophylaxis using 2 different methods, to better understand and collectively respond to risky practices.

METHOD

We included 69 volunteers of the ANRS-IPERGAY trial. We measured drug use by 2 methods: (1) drug detection by hair analysis and (2) reported drug use by self-reported drug consumption.

RESULTS

New psychoactive substances (NPS) and conventional drugs were detected in 53 of the 69 (77%) volunteers by hair analysis and in 39 of the 69 (57%) volunteers by questionnaires. On the 219 hair segments analyzed, the most commonly used drugs were cocaine in 47 of the 69 (68%), 3,4-methylenedioxymethamphetamine/ecstasy in 31 of the 69 (45%), and NPS in 27 of the 69 (39%). On the 1061 collected questionnaires, the most commonly used drugs were cocaine in 31 of the 69 (45%), 3,4-methylenedioxymethamphetamine/ecstasy in 29 of the 69 (42%), and NPS in 16 of the 69 (23%). Hair analysis detects more conventional drugs and/or NPS use (P < 0.05). Drug use identified by hair was significantly associated with a higher number of sexual partners in the past 2 months (P ≤ 0.001), more often casual partners (P ≤ 0.001), condomless anal sex (P ≤ 0.005), hardcore sexual practices (P ≤ 0.001), a higher number of sexually transmitted infections, and chemsex (P ≤ 0.05).

CONCLUSIONS

Self-report drug use by questionnaires remains the reference tool for harm reduction at the individual level because of its feasibility and low cost. However, hair analysis is more sensitive, objectively assessing consumption, and interesting to understand uses and to be able to collectively respond to risky practices with adapted messages.

Mercury content in the Siberian tiger (Panthera tigris altaica Temminck, 1844) from the coastal and inland areas of the Russia

Being a global pollutant, mercury can originate from both natural as well as anthropogenic sources. Coastal marine atmospheric fog is considered a potential source of ocean-derived monomethylmercury (MMHg) to coastal terrestrial ecosystems. However, the ratio between mercury appearing through natural processes and that from the results of human activity is unclear. We assumed that the total mercury content in the fur of tigers would differ depending on the distance from the sea. Here we show that the average mercury content in tigers from the coast (0.435 ± 0.062 mg kg-1) is significantly different from tigers from the inland area (0.239 ± 0.075 mg kg-1), (p = 0.02). We found that the content of mercury in the fur of tigers is largely dependent of natural processes rather than human activity. We assume that the levels of mercury in coastal ecosystems in the south of the Russian Far East reflect the position of the region relative to the deep faults of the East Pacific Platform. Obtained data indicate that environmental risks associated with mercury pollution currently exist, but do not pose a serious threat to Siberian tigers.

Evaluation of Mercury Contamination in Iranian Wild Cats Through Hair Analysis

Due to its environmental persistence and bioaccumulative properties, mercury is considered highly toxic to humans, ecosystems, and wildlife. The present study aimed to investigate the total mercury (Hg) concentrations in hair samples of 40 wild cats belonging to eight different species collected from various provinces of Iran and to characterize their risk of Hg exposure. Total Hg levels in Iranian wild cats ranged from 62 to 3670 ng/g dw hair, with a median value of 488 ng/g dw hair. The lowest median Hg concentration was found in west Iran (251 ng/g dw hair), while the highest median level was measured in the north-east of the country (736 ng/g dw hair), likely related to its past use in agriculture and potential contamination of industrial effluents. The overall contamination of Iranian wild cats with mercury can be considered generally low, but 20% of the samples reached levels above 1100 ng/g dw hair, set as indicative of an environmental Hg concern according to the U.S. Fish and Wildlife Service. Our data are comparable with other investigations on wildlife worldwide, confirming the suitability of museum collection specimens to assess the environmental levels of Hg. We showed that, while diet and habitat can influence the mercury accumulation in wild cats, complementary factors, such as age, size, and interspecific metabolic differences, should be considered as well in future investigations.

Exposure to polycyclic aromatic hydrocarbons (PAHs) in people living in urban and rural areas as revealed by hair analysis

Some polycyclic aromatic hydrocarbons (PAHs) are carcinogenic and mutagenic to humans. However, little is known about PAH exposure to people living in urban and suburban areas through comparative studies. Some studies have indicated that human hair can be used as a noninvasive biomarker of PAH exposure. Therefore, we collected hair samples from 66 volunteers from Nanjing and Ningbo, China, to detect PAH concentrations in this work. The highest levels in the hair samples were found in phenanthrene > anthracene > naphthalene among the parent PAHs. Sixteen parent PAHs showed higher concentrations in the samples from Nanjing than in the samples from Ningbo. Significantly higher levels of some PAHs were observed in male hair than in female hair in Nanjing, and in hair from smokers than in hair from non-smokers in both Nanjing and Ningbo. In addition, there was a significant effect of the age on the concentration of low-molecular-weight PAHs and ∑PAHs in human hair in both Nanjing and Ningbo. Studying the inter-chemical associations between these PAHs indicated similarities and differences between Nanjing and Ningbo.

Exposure to multiclass pesticides among female adult population in two Chinese cities revealed by hair analysis

The high use of pesticides worldwide and the constant exposure of humans to these toxic-by-design chemicals have drawn the attention on the possible consequences on human health. However, information on the exposure of the general population to pesticides remain very limited in most countries, especially in urban areas. In the present work, hair analysis was conducted to investigate the exposure of 204 urban women living in two Chinese cities (Baoding and Dalian) to 110 pesticides and 30 metabolites of the following families: organochlorines, organophosphates, carbamates, pyrethroids, neonicotinoids, phenylpyrazoles, acid herbicides, urea herbicides and azoles. Results showed that 71 pesticides and 23 metabolites were found in the hair samples, with concentrations ranging up to 1070 pg/mg in hair. In each hair sample, the number of detected chemicals ranged from 25 to 50, demonstrating the cumulative exposure to pesticides among Chinese women in the studied regions. The concentrations of 38 chemicals (e.g., p-nitrophenol, diethyldithiophosphate, λ-cyhalothrin, permethrin, carbendazim and tebuconazole) were significantly different between women in Baoding and Dalian, indicating the regional differences in exposure to pesticide. Using a multiple regression analysis, we found that concentrations of a few dominant pesticides were associated with age, body mass index (BMI), cooking frequency and regions. These results can provide baseline information on exposure of female adult Chinese population to multiple pesticides and support future studies focused on the health effects associated with pesticide exposure.

Cumulative exposure to organic pollutants of French children assessed by hair analysis

Children represent one of the most vulnerable parts of the population regarding the effects of pollutants exposure on health. In this study, hair samples were collected between October 2013 and August 2015 from 142 French children originating from different geographical areas (urban and rural) and analysed with a GC/MS-MS method, allowing for the detection of 55 biomarkers for pesticides and metabolites both persistent and non-persistent from different families, including: organochlorines, organophosphates, pyrethroids, azoles, dinitroanilines, oxadiazines, phenylpyrazoles and carboxamidas; 4 polychlorobiphenyls (PCBs) and 5 polybromodiphenylethers (PBDEs). The number of compounds detected in each sample ranged from 9 up to 37 (21 on average), which clearly highlighted the cumulative exposure of the children. The results also showed a wide range of concentration of the pollutants in hair (often more than 100 times higher in the most exposed child compared to the less exposed), suggesting significant disparities in the exposure level, even in children living in the same area. In addition to the detection of currently used chemicals, the presence of persistent organic pollutants (POPs) in children also suggests that the French population is still exposed to POPs nowadays. PCP, DEP, PNP, 3Me4NP, trans-Cl2CA, 3PBA, fipronil and fipronil sulfone, presented statistically significant higher concentration in the hair of boys compared to girls. PCP, PNP and 3Me4NP presented statistically significant higher concentration in younger children. Finally, this study also suggests that local environmental contamination would not be the main source of exposure, and that individual specificities (habits, diet…) would be the main contributors to the exposure to the pollutants analysed here. The present study strongly supports the relevance of hair for the biomonitoring of exposure and provides the first values of organic pollutant concentration in the hair of French children.

Investigating exposure to endocrine disruptors via hair analysis of pregnant women

The aim of this study was the monitoring of the levels of parabens (PBs) and triclosan (TCS) in head hair samples of women collected during the first months of their pregnancy. Personal details concerning somatometric and demographic characteristics, dietary habits, use of personal care products and the medical and obstetrical history of the pregnant women as well as infants' somatometric characteristics and health condition were recorded through relevant questionnaires. Ninety five hair samples were collected, extracted by solid-liquid extraction and analysed using a liquid chromatography-mass spectrometry system (LC-MS). Analysis revealed high percentage of positive samples for all tested compounds (90-100% except from BePB (15.8%)). The mean concentration levels were 4501.2 pg/mg (17.6-27,437.0 pg/mg) for MePB; 510.1 pg/mg (11.0-4224.5 pg/mg) for EtPB; 22.9 pg/mg (2.1-66.6 pg/mg) for BePB; 237.1 pg/mg (1.8-2513.7 pg/mg) for BuPB and 245.0 pg/mg (8.8-8070.2 pg/mg) for TCS. Statistical analysis of both analytical results and questionnaires' data showed that the frequent use of personal care and hygiene products, such as makeup, hairspray and sunscreens, is correlated with higher levels of PBs in hair of the pregnant women. Additionally, positive correlation was observed between the BePB levels in hair and the infants' height. Finally, no other correlation was observed between endocrine disruptors' levels in maternal hair and infants' somatometric characteristics or health condition. Our study is the first one that determined PBs and TCS levels in hair samples, simultaneously. At the same time, correlation of the detected levels with the use of personal care products was accomplished, leading to significant association of BePB levels in hair of pregnant women with infants' height.