Urinary Polycyclic Aromatic Hydrocarbon Metabolites Are Associated with Biomarkers of Chronic Endocrine Stress, Oxidative Stress, and Inflammation in Adolescents: FLEHS-4 (2016-2020)

Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants of public health concern. Multiple biological mechanisms have been hypothesized to contribute to PAHs-associated adverse health effects. Little is known about the impact of PAHs on endocrine stress and inflammation in adolescence. We examined 393 Flemish adolescents (14-15 years) cross-sectionally, measured urinary concentrations of hydroxylated naphthalene, fluorene, phenanthrene and pyrene metabolites, and calculated the sum of all measured metabolites. We determined hair cortisol concentration (HCC) as endocrine stress biomarker, leucocyte counts and neutrophil-lymphocyte ratio (NLR) in peripheral blood as inflammatory biomarkers, and urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) concentration as oxidative stress biomarker. Exposure-response associations were analyzed by multiple regression, adjusted for a priori selected covariates. A doubling of 1-hydroxypyrene concentration was associated with a factor of 1.13 (95% CI: 1.03, 1.24) increase in HCC and a factor of 1.07 (95% CI: 1.02, 1.13) increase in 8-oxodG. Doublings of 2- and 3-hydroxyphenanthrene concentrations were associated with a factor of 1.08 (95% CI: 1.02, 1.14) and 1.06 (95% CI: 1.00, 1.12) increase in 8-oxodG, respectively. Doubling of 2-hydroxyphenanthrene and of the sum of 2- and 3-hydroxyfluorene was associated with, respectively, a factor of 1.08 (95% CI: 1.02, 1.14) and 1.06 (95% CI: 1.01, 1.13) increase in NLR. Our results indicate the glucocorticoid pathway as a potential target for PAH exposure in adolescents and suggest oxidative stress, endocrine stress, and inflammation in adolescence as underlying mechanisms and early markers for PAH-related adverse health effects.

Human Biomonitoring of Environmental and Occupational Exposures by GC-MS and Gas Sensor Systems: A Systematic Review

Environmental chemicals and contaminants coming from multiple external sources enter the human body, determining a potential risk for human health. Human biomonitoring (HBM), measuring the concentrations of biomarkers in human specimens, has become an emerging approach for assessing population-wide exposure to hazardous chemicals and health risk through large-scale studies in many countries. However, systematic mapping of HBM studies, including their characteristics, targeted hazardous pollutants, analytical techniques, and sample population (general population and occupationally exposed workers), has not been done so far. We conducted a systematic review of the literature related to airborne hazardous pollutants in biofluids to answer the following questions: Which main chemicals have been included in the literature, which bodily fluids have been used, and what are the main findings? Following PRISMA protocol, we summarized the publications published up to 4 February 2021 of studies based on two methods: gas-chromatography/mass spectrometry (GC/MS) and electronic noses (e-noses). We screened 2606 records and 117 publications were included in the analysis, the most based on GC/MS analysis. The selected HBM studies include measurements of biomarkers in different bodily fluids, such as blood, urine, breast milk, and human semen as well as exhaled air. The papers cover numerous airborne hazardous pollutants that we grouped in chemical classes; a lot of hazardous and noxious compounds, mainly persistent organic pollutants (POPs) and volatile organic compounds (VOCs), have been detected in biological fluids at alarming levels. The scenario that emerged from this survey demonstrates the importance of HBM in human exposure to hazardous pollutants and the need to use it as valid tool in health surveillance. This systematic review represents a starting point for researchers who focus on the world of pollutant biomonitoring in the human body and gives them important insights into how to improve the methods based on GC/MS. Moreover, it makes a first overview of the use of gas sensor array and e-noses in HBM studies.

Exposure Profile to Traffic Related Pollution in Pediatric Age: A Biomonitoring Study

The aim of this study was to trace an exposure profile to traffic-derived pollution during pediatric age. For this purpose, two biomonitoring campaigns for the determination of urinary (u-) methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), tert-amyl methyl ether (TAME), and diisopropyl ether (DIPE) were carried out in two different periods of the year (summer 2017 and winter 2018), among a large sample of healthy children (n = 736; 5–11 years old) living in rural and urban areas in central Italy. The quantification of u-MTBE, u-ETBE, u-TAME, and u-DIPE was performed by HS-SPME-GC/MS technique and information on participants was collected by a questionnaire. u-DIPE concentrations resulted always under the LOQ. u-TAME mean levels were similar in both seasons (18.7 ng L⁻¹ in summer vs. 18.9 ng L⁻¹ in winter), while u-MTBE and u-ETBE levels were, respectively, 69.9 and 423.5 ng L⁻¹ (summer) and 53.3 and 66.2 ng L⁻¹ (winter). Main predictors of urinary excretion resulted the time spent in motor vehicles, being male and younger.

Modelling the Renal Excretion of the Mycotoxin Deoxynivalenol in Humans in an Everyday Situation

The dietary exposure to the mycotoxin deoxynivalenol (DON) can be assessed by human biomonitoring (HBM). Here, we assessed the relation between dietary DON intake and the excretion of its major metabolite DON-15-glucuronide (DON15GlcA) through time, in an everyday situation. For 49 volunteers from the EuroMix biomonitoring study, the intake of DON from each meal was calculated and the excretion of DON and its metabolites was analyzed for each urine void collected separately throughout a 24-h period. The relation between DON and DON15GlcA was analyzed with a statistical model to assess the residence time and the excreted fraction of ingested DON as DON15GlcA (f_{abs_excr}). F_{abs_excr} was treated as a random effect variable to address its heterogeneity in the population. The estimated time in which 97.5% of the ingested DON was excreted as DON15GlcA was 12.1 h, the elimination half-life was 4.0 h. Based on the estimated f_{abs_excr}, the mean reversed dosimetry factor (RDF) of DON15GlcA was 2.28. This RDF can be used to calculate the amount of total DON intake in an everyday situation, based on the excreted amount of DON15GlcA. We show that urine samples collected over 24 h are the optimal design to study DON exposure by HBM.

Oxidative Stress Biomarkers in Urine of Metal Carpentry Workers Can Be Diagnostic for Occupational Exposure to Low Level of Welding Fumes from Associated Metals

Urinary concentrations of 16 different exposure biomarkers to metals were determined at the beginning and at the end of a working shift on a group of workers in the metal carpentry industry. Five different oxidative stress biomarkers were also measured, such as the oxidation products of RNA and DNA metabolized and excreted in the urine. The results of workers exposed to metals were compared to those of a control group. The metal concentrations found in these workers were well below the occupational exposure limit values and exceeded the mean concentrations of the same metals in the urine of the control group by a factor of four at maximum. Barium (Ba), mercury (Hg), lead (Pb) and strontium (Sr) were correlated with the RNA oxidative stress biomarker, 8-oxo-7, 8-dihydroguanosine (8-oxoGuo), which was found able to discriminate exposed workers from controls with a high level of specificity and sensitivity. The power of this early diagnostic technique was assessed by means of the ROC curve. Ba, rubidium (Rb), Sr, tellurium (Te), and vanadium (V) were correlated with the level of the protein oxidation biomarker 3-Nitrotyrosine (3-NO₂Tyr), and Ba, beryllium (Be), copper (Cu), and Rb with 5-methylcytidine (5-MeCyt), an epigenetic marker of RNA damage. These effect biomarkers can help in identifying those workers that can be defined as "occupationally exposed" even at low exposure levels, and they can provide information about the impact that such doses have on their health.

Environmental Tobacco Smoke in Occupational Settings: Effect and Susceptibility Biomarkers in Workers From Lisbon Restaurants and Bars

Environmental tobacco smoke (ETS) has been recognized as a major health hazard by environmental and public health authorities worldwide. In Portugal, smoke-free laws are in force for some years, banning smoking in most indoor public spaces. However, in hospitality venues such as restaurants and bars, owners can still choose between a total smoke-free policy or a partial smoking restriction with designated smoking areas, if adequate reinforced ventilation systems are implemented. Despite that, a previous study showed that workers remained continuously exposed to higher ETS pollution in Lisbon restaurants and bars where smoking was still allowed, comparatively to total smoke-free venues. This was assessed by measurements of indoor PM2.5 and urinary cotinine, a biomarkers of tobacco smoke exposure, demonstrating that partial smoking restrictions do not effectively protect workers from ETS. The aim of the present work was to characterize effect and susceptibility biomarkers in non-smokers from those hospitality venues occupationally exposed to ETS comparatively to non-exposed ones. A group of smokers was also included for comparison. The sister chromatid exchange (SCE), micronucleus (MN) and comet assays in whole peripheral blood lymphocytes (PBLs) and the micronucleus assay in exfoliated buccal cells, were used as biomarkers of genotoxicity. Furthermore, a comet assay after ex vivo challenge of leukocytes with an alkylating agent, ethyl methanesulfonate (EMS), was used to analyze the repair capacity of those cells. Genetic polymorphisms in genes associated with metabolism and DNA repair were also included. The results showed no clear association between occupational exposure to ETS and the induction of genotoxicity. Interestingly, the leukocytes from non-smoking ETS-exposed individuals displayed lower DNA damage levels in response to the ex vivo EMS challenge, in comparison to those from non-exposed workers, suggesting a possible adaptive response. The contribution of individual susceptibility to the effect biomarkers studied was unclear, deserving further investigation.

Human Biomonitoring Data Enables Evidence-Informed Policy to Reduce Internal Exposure to Persistent Organic Compounds: A Case Study

Human biomonitoring (HBM) monitors levels of environmental pollutants in human samples, which often is a topic of concern for residents near industrially contaminated sites (ICSs). Around an ICS area in Menen (Belgium), including a (former) municipal waste incinerator and a metal recovery plant, increasing environmental concentrations of dioxins and polychlorinated biphenyls (PCBs) were observed, causing growing concern among residents and authorities. The local community succeeded in convincing the responsible authorities to investigate the problem and offer research funding. Persistent organic pollutants (POPs) were measured in two consecutive HBM studies (2002-2006 and 2010-2011), in the context of the Flemish Environment and Health Study (FLEHS), as well as in soil and locally produced food. Meanwhile, local authorities discouraged consumption of locally produced food in a delineated area of higher exposure risk. Ultimately, HBM and environmental data enabled tailored dietary recommendations. This article demonstrates the usefulness of HBM in documenting the body burdens of residents near the ICS, identifying exposure routes, evaluating remediating actions and providing information for tailored policy strategies aiding to further exposure reduction. It also highlights the role of the local stakeholders as an example of community-based participatory research and how such an approach can create societal support for research and policy.

Analysis of Multiple Mycotoxins in the Qatari Population and Their Relation to Markers of Oxidative Stress

Mycotoxins are naturally occurring food toxins worldwide that can cause serious health effects. The measurement of mycotoxin biomarkers in biological fluids is needed to assess individuals' exposure. The aim of this study was to investigate the incidence of mycotoxins in the Qatari population. Serum samples from 412 adults and urinary samples from 559 adults were analyzed for the presence of mycotoxin biomarkers. Multimycotoxin approaches have been applied, using liquid chromatography mass spectrometry methods. Samples were further analyzed for the oxidative stress markers and compared with regard to the incidence of mycotoxins. The presence of mycotoxins was identified in 37% of serum samples and in less than 20% of urine samples. It was found that 88% of positive of the samples were positive for only one mycotoxin, while 12% of positive samples had two or more mycotoxins. Trichothecenes and zearalenone metabolites were most commonly detected mycotoxins, followed by aflatoxins, roquefortine C and mycophenolic acid. The presence of mycotoxins was found to positively correlate with oxidative stress markers. The obtained results illustrate the importance of mycotoxin biomonitoring studies in humans and the need to elucidate the underlying mechanisms of mycotoxin-induced toxicity.

Participant Experiences in a Human Biomonitoring Study: Follow-Up Interviews with Participants of the Flemish Environment and Health Study

Communicating individual human biomonitoring results to study participants has been the subject of debate for some time. This debate is dominated by ethical considerations from a researchers’ perspective on whether or not to communicate, thereby overlooking more practice-based questions from a participants’ perspective on what and how to communicate. We conducted a small scale follow-up study based on eleven face-to-face interviews with mothers participating in the third cycle of the Flemish Environment and Health Study (FLEHS III 2012–2015) to investigate how they experienced and interpreted individual biomonitoring results. Key findings indicate that respondents were generally satisfied with participating in the biomonitoring study, but the report-back process especially lacked contextualized information and interactive communication options to better comprehend and cope with personal results. These findings also argue in favor of a more tailored approach in which report-back methods, formats and content are diversified according to the type of results and the preferences of participants. A reflexive research practice with active engagement in follow-up research is crucial to improve participants’ understanding and use of personal biomonitoring results.

Polyphenol Exposure, Metabolism, and Analysis: A Global Exposomics Perspective

Polyphenols are generally known for their health benefits and estimating actual exposure levels in health-related studies can be improved by human biomonitoring. Here, the application of newly available exposomic and metabolomic technology, notably high-resolution mass spectrometry, in the context of polyphenols and their biotransformation products, is reviewed. Comprehensive workflows for investigating these important bioactives in biological fluids or microbiome-related experiments are scarce. Consequently, this new era of nontargeted analysis and omic-scale exposure assessment offers a unique chance for better assessing exposure to, as well as metabolism of, polyphenols. In clinical and nutritional trials, polyphenols can be investigated simultaneously with the plethora of other chemicals to which we are exposed, i.e., the exposome, which may interact abundantly and modulate bioactivity. This research direction aims at ultimately eluting into atrue systems biology/toxicology evaluation of health effects associated with polyphenol exposure, especially during early life, to unravel their potential for preventing chronic diseases.

Challenges to Evidence Synthesis and Identification of Data Gaps in Human Biomonitoring

The increasing number of human biomonitoring (HBM) studies undertaken in recent decades has brought to light the need to harmonise procedures along all phases of the study, including sampling, data collection and analytical methods to allow data comparability. The first steps towards harmonisation are the identification and collation of HBM methodological information of existing studies and data gaps. Systematic literature reviews and meta-analyses have been traditionally put at the top of the hierarchy of evidence, being increasingly applied to map available evidence on health risks linked to exposure to chemicals. However, these methods mainly capture peer-reviewed articles, failing to comprehensively identify other important, unpublished sources of information that are pivotal to gather a complete map of the produced evidence in the area of HBM. Within the framework of the European Human Biomonitoring Initiative (HBM4EU) initiative-a project that joins 30 countries, 29 from Europe plus Israel, the European Environment Agency and the European Commission-a comprehensive work of data triangulation has been made to identify existing HBM studies and data gaps across countries within the consortium. The use of documentary analysis together with an up-to-date platform to fulfil this need and its implications for research and practice are discussed.

Quantitative investigation of the urinary excretion of three specific monoester metabolites of the plasticizer diisononyl adipate (DINA)

Diisononyl adipate (DINA) is a plasticizer used in PVC products as an alternative for restricted phthalate plasticizers. With this study, we provide first data on human DINA metabolism and excretion. We postulated mono(hydroxy-isononyl) adipate (OH-MINA), mono(oxo-isononyl) adipate (oxo-MINA), and mono(carboxy-isooctyl) adipate (cx-MIOA) as specific DINA metabolites based on the known human metabolism of structurally similar adipates and phthalates. Urinary excretion was quantitatively investigated after a single oral dose (113 to 145 µg/kg body weight) to three healthy volunteers using a newly developed online-SPE-LC-MS/MS method with isotope dilution and LOQs between 0.3 - 0.6 µg/L. OH-MINA turned out to be the major of the three metabolites with consistent urinary excretion fractions (F_UEs) of 0.020-0.023 % among all volunteers. Oxo-MINA and cx-MIOA were excreted with lower shares (mean: 0.003 % and 0.009 %, respectively). For all three metabolites, urinary concentrations peaked quickly between 1.4 and 2.3 h post dose with maximum concentrations of 23.1 (OH-MINA), 2.87 (oxo-MINA) and 9.83 µg/L (cx-MIOA). Thus, F_UEs and urinary concentrations were rather low for these specific metabolites, with the major share of the dose presumably being excreted as non-specific metabolites such as adipic acid. In a pilot population (n=35) of German adults without known DINA exposure, we could not detect any of the three metabolites, contrary to the dosage study, indicating to population exposures lower than 50 µg/kg body weight/day. The new HBM method in conjunction with the new F_UEs can be used for objective DINA exposure and risk assessment especially in populations with potentially higher DINA exposures.

Assessment of Exposure to Mycotoxins in Spanish Children through the Analysis of Their Levels in Plasma Samples

In this study, we present, for the first time in Spain, the levels of 19 mycotoxins in plasma samples from healthy and sick children (digestive, autism spectrum (ASD), and attention deficit hyperactivity (ADHD) disorders) (n = 79, aged 2–16). The samples were analyzed by liquid chromatography-mass spectrometry (triple quadrupole) (LC-MS/MS). To detect Phase II metabolites, the samples were reanalyzed after pre-treatment with β-glucuronidase/arylsulfatase. The most prevalent mycotoxin was ochratoxin A (OTA) in all groups of children, before and after enzyme treatment. In healthy children, the incidence of OTA was 92.5% in both cases and higher than in sick children before (36.7% in digestive disorders, 50% in ASD, and 14.3% in ADHD) and also after the enzymatic treatment (76.6 % in digestive disorders, 50% in ASD, and 85.7% in ADHD). OTA levels increased in over 40% of healthy children after enzymatic treatment, and this increase in incidence and levels was also observed in all sick children. This suggests the presence of OTA conjugates in plasma. In addition, differences in OTA metabolism may be assumed. OTA levels are higher in healthy children, even after enzymatic treatment (mean OTA value for healthy children 3.29 ng/mL, 1.90 ng/mL for digestive disorders, 1.90 ng/mL for ASD, and 0.82 ng/mL for ADHD). Ochratoxin B appears only in the samples of healthy children with a low incidence (11.4%), always co-occurring with OTA. Sterigmatocystin (STER) was detected after enzymatic hydrolysis with a high incidence in all groups, especially in sick children (98.7% in healthy children and 100% in patients). This supports glucuronidation as a pathway for STER metabolism in children. Although other mycotoxins were studied (aflatoxins B1, B2, G1, G2, and M1; T-2 and HT-2 toxins; deoxynivalenol, deepoxy-deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol; zearalenone; nivalenol; fusarenon-X; neosolaniol; and diacetoxyscirpenol), they were not detected either before or after enzymatic treatment in any of the groups of children. In conclusion, OTA and STER should be highly considered in the risk assessment of mycotoxins. Studies concerning their sources of exposure, toxicokinetics, and the relationship between plasma levels and toxic effects are of utmost importance in children.

Network Analysis to Identify Communities Among Multiple Exposure Biomarkers Measured at Birth in Three Flemish General Population Samples

Introduction: Humans are exposed to multiple environmental chemicals via different sources resulting in complex real-life exposure patterns. Insight into these patterns is important for applications such as linkage to health effects and (mixture) risk assessment. By providing internal exposure levels of (metabolites of) chemicals, biomonitoring studies can provide snapshots of exposure patterns and factors that drive them. Presentation of biomonitoring data in networks facilitates the detection of such exposure patterns and allows for the systematic comparison of observed exposure patterns between datasets and strata within datasets. Methods: We demonstrate the use of network techniques in human biomonitoring data from cord blood samples collected in three campaigns of the Flemish Environment and Health Studies (FLEHS) (sampling years resp. 2002-2004, 2008-2009, and 2013-2014). Measured biomarkers were multiple organochlorine compounds, PFAS and metals. Comparative network analysis (CNA) was conducted to systematically compare networks between sampling campaigns, smoking status during pregnancy, and maternal pre-pregnancy BMI. Results: Network techniques offered an intuitive approach to visualize complex correlation structures within human biomonitoring data. The identification of groups of highly connected biomarkers, "communities," within these networks highlighted which biomarkers should be considered collectively in the analysis and interpretation of epidemiological studies or in the design of toxicological mixture studies. Network analyses demonstrated in our example to which extent biomarker networks and its communities changed across the sampling campaigns, smoking status during pregnancy, and maternal pre-pregnancy BMI. Conclusion: Network analysis is a data-driven and intuitive screening method when dealing with multiple exposure biomarkers, which can easily be upscaled to high dimensional HBM datasets, and can inform mixture risk assessment approaches.

Chemical Exposure: European Citizens' Perspectives, Trust, and Concerns on Human Biomonitoring Initiatives, Information Needs, and Scientific Results

Over the last few decades, citizen awareness and perception of chemical products has been a topic of interest, particularly concerning national and international policy decision makers, expert/scientific platforms, and the European Union itself. To date, few qualitative studies on human biomonitoring have analysed communication materials, made recommendations in terms of biomonitoring surveillance, or asked for feedback in terms of specific biomonitoring methods. This paper provides in-depth insight on citizens' perceptions of knowledge of biomonitoring, impact of chemical exposure on daily life, and claims on how results of research should be used. Four semi-structured focus groups were held in Austria, Portugal, Ireland, and the United Kingdom (UK). The cross-sectional observational qualitative design of this study allows for better understanding of public concern regarding chemicals, application, and use of human biomonitoring. The main findings of this study include citizens' clear articulation on pathways of exposure, the demand on stakeholders for transparent decision-making, and sensitivity in communication of results to the public. Validated and trustful communication is perceived as key to empowering citizens to take action. The results can be used to facilitate decision-making and policy development, and feeds into the awareness needs of similar and future projects in human biomonitoring. Furthermore, it also brings to light ideas and concepts of citizens' in shaping collaborative knowledge between citizens', experts, scientists, and policy makers on equal terms.

Life-Time Environmental Chemical Exposure and Obesity: Review of Epidemiological Studies Using Human Biomonitoring Methods

The exponential global increase in the incidence of obesity may be partly attributable to environmental chemical (EC) exposure. Humans are constantly exposed to ECs, primarily through environmental components. This review compiled human epidemiological study findings of associations between blood and/or urinary exposure levels of ECs and anthropometric overweight and obesity indices. The findings reveal research gaps that should be addressed. We searched MEDLINE (PubMed) for full text English articles published in 2006-2020 using the keywords "environmental exposure" and "obesity". A total of 821 articles were retrieved; 102 reported relationships between environmental exposure and obesity indices. ECs were the predominantly studied environmental exposure compounds. The ECs were grouped into phenols, phthalates, and persistent organic pollutants (POPs) to evaluate obesogenic roles. In total, 106 articles meeting the inclusion criteria were summarized after an additional search by each group of EC combined with obesity in the PubMed and Scopus databases. Dose-dependent positive associations between bisphenol A (BPA) and various obesity indices were revealed. Both individual and summed di(2-ethylhexyl) phthalate (DEHP) and non-DEHP metabolites showed inconsistent associations with overweight and obesity indices, although mono-butyl phthalate (MBP), mono-ethyl phthalate (MEP), and mono-benzyl phthalate (MBzP) seem to have obesogenic roles in adolescents, adults, and the elderly. Maternal exposure levels of individual POP metabolites or congeners showed inconsistent associations, whereas dichlorodiphenyldichloroethylene (DDE) and perfluorooctanoic acid (PFOA) were positively associated with obesity indices. There was insufficient evidence of associations between early childhood EC exposure and the subsequent development of overweight and obesity in late childhood. Overall, human evidence explicitly reveals the consistent obesogenic roles of BPA, DDE, and PFOA, but inconsistent roles of phthalate metabolites and other POPs. Further prospective studies may yield deeper insights into the overall scenario.

B-Comet Assay (Comet Assay on Buccal Cells) for the Evaluation of Primary DNA Damage in Human Biomonitoring Studies

Many subjects perceive venous blood collection as too invasive, and thus moving to better-accepted procedures for leukocytes collection might be crucial in human biomonitoring studies (e.g., biomonitoring of occupational or residential exposure to genotoxins) management. In this context, primary DNA damage was assessed in buccal lymphocytes (BLs), fresh whole venous, and capillary blood leukocytes, and compared with that in peripheral blood lymphocytes (PBLs)—the most frequently used cells—in 15 young subjects. Mouthwashes were collected after the volunteers rinsed their mouths with normal saline, and BLs were isolated by density gradient centrifugation. Blood samples were collected by venipuncture or by lancet. Anthropometric and lifestyle information was obtained by the administration of a structured questionnaire. As shown in the Bland-Altman plots, the level of agreement between BLs and PBLs lied within the accepted range, we thus enrolled a wider population (n = 54) to assess baseline DNA damage in BLs. In these cells, mean values of tail length (µm), tail intensity (%), and tail moment were 25.7 ± 0.9, 6.7 ± 0.4 and 1.0 ± 0.1, respectively. No significant association was observed between sex and smoking habit with any of the DNA damage parameters. Conversely, underweight subjects displayed significantly higher genomic instability compared with normal weight group (p < 0.05). In conclusion, we successfully managed to set up and update a non-invasive and well-accepted procedure for the isolation of BLs from saliva that could be useful in upcoming biomonitoring studies.

Presence of 19 Mycotoxins in Human Plasma in a Region of Northern Spain

This study was conducted to investigate human exposure to 19 compounds (mycotoxins and their metabolites) in plasma samples from healthy adults (n = 438, aged 19-68 years) from Navarra, a region of northern Spain. Samples were analyzed by LC-MS/MS, before and after enzymatic hydrolysis for the detection of possible glucuronides and/or sulfates (Phase II metabolites). The most prevalent mycotoxin was ochratoxin A (OTA), with an incidence of 97.3%. Positive samples were in the concentration range of 0.4 ng/mL to 45.7 ng/mL. After enzymatic treatment, OTA levels increased in a percentage of individuals, which may indicate the presence of OTA-conjugates. Regarding ochratoxin B, it has also been detected (10% of the samples), and its presence may be related to human metabolism of OTA. Sterigmatocystin was detected with a high incidence (85.8%), but only after enzymatic hydrolysis, supporting glucuronidation as a pathway of its metabolism in humans. None of the other studied mycotoxins (aflatoxins B1, B2, G1, G2 and M1; T-2 and HT-2 toxins; deoxynivalenol, deepoxy-deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol; zearalenone; nivalenol; fusarenon-X; neosolaniol; and diacetoxyscirpenol) were detected in any of the samples, neither before nor after enzymatic treatment. To the best of our knowledge, this is the first report carried out in Spain to determine the exposure of the population to mycotoxins and some of their metabolites using plasma, and the obtained results justify the need for human biomonitoring and metabolism studies on mycotoxins.

Characteristics of Exposure of Reproductive-Age Farmworkers in Chiang Mai Province, Thailand, to Organophosphate and Neonicotinoid Insecticides: A Pilot Study

Exposure to insecticides containing organophosphate (OP) and neonicotinoid (NEO) compounds has been associated with adverse reproductive health outcomes. This study characterized and identified predictors of exposure to OP and NEO among 100 reproductive-age farmworkers from two intensive farming areas in Chiang Mai Province, Thailand, including 50 each from the Fang (FA) and Chom Thong (CT) districts. OP exposure was determined by measuring the urinary concentrations of six dialkylphosphates (DAPs), whereas NEO exposure was determined by measuring the urinary concentrations of NEO compounds and their metabolites (NEO/m). The most frequently detected OPs were diethylphosphate (DEP) and diethylthiophosphate (DETP), with DETP having the highest geometric mean (GM) concentration, 8.9 μg/g-creatinine. The most frequently detected NEO/m were N-desmethyl-acetamiprid (N-dm-ACE), imidacloprid (IMI), and thiamethoxam (THX), with IMI having the highest GM concentration, 8.7 μg/g-creatinine. Consumption of well water was the predominant determinant of OP and NEO exposure in this population. In addition to encouraging workers to use personal protective equipment, exposure of farmworkers to these compounds may be reduced by nation-wide monitoring agricultural insecticides and other pesticides in community drinking water resources.

Biomonitoring of Aflatoxin B1 and Deoxynivalenol in a Rural Pakistan Population Using Ultra-Sensitive LC-MS/MS Method

There are limited data on exposure to mycotoxins in Pakistan. Here, we measured exposure to deoxynivalenol (DON), a common contaminant of wheat, and aflatoxin B1 (AFB1), a known contaminant of rice, using biomarkers of exposure. Wheat (n = 195) and rice (n = 62) samples were analyzed for AFB1 and DON levels, and the corresponding urinary biomarkers were analyzed in urine samples from a rural population (n = 264, aged 4-80 years, male 58%) using ultra-sensitive liquid chromatography-tandem mass spectrometry. AFB1 was detected in 66% of rice (5.04 ± 11.94 µg/kg) and 3% of wheat samples. AFM1 (hydroxylated form of AFB1)was detected in 69% of urine samples, mean 0.023 ± 0.048 ng/mL and DON was detected in 20% of urine samples, mean 0.170 ± 0.129 ng/mL. The maximum probable daily intake for DON derived from the urinary biomarker was 59.8 ng/kg b.w./day, which is below the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives' tolerable daily intake (1000 ng/kg b.w./day). However, for aflatoxin, the derived margin of exposure (MoE) of (13.2) was well below the safe MoE (10,000) suggested by the European Food Safety Authority. The calculated aflatoxin-associated cancer risk of 0.514/105 individuals/year suggests that measures should be taken to reduce the AFB1 contamination in food, particularly rice, in Pakistan.

Human Biomonitoring of Glyphosate Exposures: State-of-the-Art and Future Research Challenges

Glyphosate continues to attract controversial debate following the International Agency for Research on Cancer carcinogenicity classification in 2015. Despite its ubiquitous presence in our environment, there remains a dearth of data on human exposure to both glyphosate and its main biodegradation product aminomethylphosphonic (AMPA). Herein, we reviewed and compared results from 21 studies that use human biomonitoring (HBM) to measure urinary glyphosate and AMPA. Elucidation of the level and range of exposure was complicated by differences in sampling strategy, analytical methods, and data presentation. Exposure data is required to enable a more robust regulatory risk assessment, and these studies included higher occupational exposures, environmental exposures, and vulnerable groups such as children. There was also considerable uncertainty regarding the absorption and excretion pattern of glyphosate and AMPA in humans. This information is required to back-calculate exposure doses from urinary levels and thus, compared with health-based guidance values. Back-calculations based on animal-derived excretion rates suggested that there were no health concerns in relation to glyphosate exposure (when compared with EFSA acceptable daily intake (ADI)). However, recent human metabolism data has reported as low as a 1% urinary excretion rate of glyphosate. Human exposures extrapolated from urinary glyphosate concentrations found that upper-bound levels may be much closer to the ADI than previously reported.

Factors Affecting Arsenic Methylation in Contaminated Italian Areas

Chronic arsenic (As) exposure is a critical public health issue. The As metabolism can be influenced by many factors. The objective of this study is to verify if these factors influence As metabolism in four Italian areas affected by As pollution. Descriptive analyses were conducted on 271 subjects aged 20-49 in order to assess the effect of each factor considered on As methylation. Percentages of metabolites of As in urine, primary and secondary methylation indexes were calculated as indicators for metabolic capacity. The results indicate that women have a better methylation capacity (MC) than men, and drinking As-contaminated water from public aqueducts is associated with poorer MC, especially in areas with natural As pollution. In areas with anthropogenic As pollution occupational exposure is associated with a higher MC while smoking with a poorer MC. Dietary habits and genetic characteristics are probably implicated in As metabolism. BMI, alcohol consumption and polymorphism of the AS3MT gene seem not to influence As MC. Arsenic metabolism may be affected by various factors and in order to achieve a comprehensive risk assessment of As-associated disease, it is crucial to understand how these factors contribute to differences in As metabolism.

Towards Harmonized Biobanking for Biomonitoring: A Comparison of Human Biomonitoring-Related and Clinical Biorepositories

Human biomonitoring (HBM) depends on high-quality human samples to identify status and trends in exposure and ensure comparability of results. In this context, much effort has been put into the development of standardized processes and quality assurance for sampling and chemical analysis, while effects of sample storage and shipment on sample quality have been less thoroughly addressed. To characterize the currently applied storage and shipment procedures within the consortium of the European Human Biomonitoring Initiative (HBM4EU), which aims at harmonization of HBM in Europe, a requirement analysis based on data from an online survey was conducted. In addition, the online survey was addressed to professionals in clinical biobanking represented by members of the European, Middle Eastern and African Society for Biopreservation and Biobanking (ESBB) to identify the current state-of-the-art in terms of sample storage and shipment. Results of this survey conducted in these two networks were compared to detect processes with potential for optimization and harmonization. In general, many similarities exist in sample storage and shipment procedures applied by ESBB members and HBM4EU partners and many requirements for ensuring sample quality are already met also by HBM4EU partners. Nevertheless, a need for improvement was identified for individual steps in sample storage, shipment, and related data management with potential impact on sample and data quality for HBM purposes. Based on these findings, recommendations for crucial first steps to further strengthen sample quality, and thus foster advancement in HBM on a pan-European level are given.

Development of a Sensitive and Reliable UHPLC-MS/MS Method for the Determination of Multiple Urinary Biomarkers of Mycotoxin Exposure

A variety of mycotoxins from different sources frequently contaminate farm products, presenting a potential toxicological concern for animals and human. Mycotoxin exposure has been the focus of attention for governments around the world. To date, biomarkers are used to monitor mycotoxin exposure and promote new understanding of their role in chronic diseases. The goal of this research was to develop and validate a sensitive UHPLC-MS/MS method using isotopically-labeled internal standards suitable for accurate determination of 18 mycotoxin biomarkers, including fumonisins, ochratoxins, Alternaria and emerging Fusarium mycotoxins (fumonisin B1, B2, and B3, hydrolyzed fumonisin B1 and B2, ochratoxin A, B, and alpha, alternariol, alternariol monomethyl ether, altenuene, tentoxin, tenuazonic acid, beauvericin, enniatin A, A1, B, and B1) in human urine. After enzymatic digestion with β-glucuronidase, human urine samples were cleaned up using HLB solid phase extraction cartridges prior to instrument analysis. The multi-mycotoxin and analyte-specific method was validated in-house, providing satisfactory results. The method provided good linearity in the tested concentration range (from LOQ up to 25-500 ng/mL for different analytes), with R2 from 0.997 to 0.999. The limits of quantitation varied from 0.0002 to 0.5 ng/mL for all analytes in urine. The recoveries for spiked samples were between 74.0% and 133%, with intra-day precision of 0.5%-8.7% and inter-day precision of 2.4%-13.4%. This method was applied to 60 urine samples collected from healthy volunteers in Beijing, and 10 biomarkers were found. At least one biomarker was found in all but one of the samples. The high sensitivity and accuracy of this method make it practical for human biomonitoring and mycotoxin exposure assessment.

Urinary Mercapturic Acids to Assess Exposure to Benzene and Other Volatile Organic Compounds in Coke Oven Workers

Coke production was classified as carcinogenic to humans by the International Agency for Research on Cancer. Besides polycyclic aromatic hydrocarbons, coke oven workers may be exposed to benzene and other volatile organic compounds (VOCs). The aim of this study was to assess the exposure to several VOCs in 49 coke oven workers and 49 individuals living in the same area by determining urinary mercapturic acids. Active tobacco smoking was an exclusion criterion for both groups. Mercapturic acids were investigated by a validated isotopic dilution LC-MS/MS method. Linear models were built to correct for different confounding variables. Urinary levels of N-acetyl-S-phenyl-L-cysteine (SPMA) (metabolite of benzene), N-acetyl-S-(2-hydroxy-1/2-phenylethyl)-L-cysteine (PHEMA) (metabolite of styrene), N-acetyl-S-(2-cyanoethyl)-L-cysteine (CEMA) (metabolite of acrylonitrile), N-acetyl-S-[1-(hydroxymethyl)-2-propen-1-yl)-L-cysteine and N-acetyl-S-(2-hydroxy-3-buten-1-yl)-L-cysteine (MHBMA) (metabolites of 1,3-butadiene) were 2-10 fold higher in workers than in controls (p < 0.05). For SPMA, in particular, median levels were 0.02 and 0.31 µg/g creatinine in workers and controls, respectively. Among workers, coke makers were more exposed to PHEMA and SPMA than foremen and engine operators. The comparison with biological limit values shows that the exposure of workers was within 20% of the limit values for all biomarkers, moreover three subjects exceeded the restrictive occupational limit value recently proposed by the European Chemicals Agency (ECHA) for SPMA.