Nancy B. Hopf

• Doctor of Philosophy
• Professor (Associate) at University of Lausanne

Propylene glycol ethers (PGEs) are organic solvents commonly found as technical grade on the commercial market, as mixtures of secondary (α‐isomer) and primary (β‐isomer, generally < 5%) alcohols. After handling products containing PGEs, they readily enter the human body where they are metabolized. The minor β‐isomer is oxidized by alcohol dehydrog...

Derivation of occupational biomonitoring levels (OBLs) is needed to effectively utilize biomonitoring for assessing exposures to chemical substances, and consequently, implement risk reduction measures to reduce health risks among workers. OBLs are the appropriate option for chemical substances that can be absorbed through the skin. This methodolog...

Air pollution, a major global issue, comprises various solid and gaseous pollutants in urban environments, including particulate matter (PM) and volatile organic compounds (VOCs). Benzene, toluene, ethylbenzene, and isomeric xylenes (BTEX) constitute about 80% of VOC emissions, primarily from vehicle exhaust, tobacco smoke, petrol, paints, adhesive...

Air pollution, a global environmental and health concern, is being studied for its impact on genome integrity and human health due to the complex composition of urban air and its association with adverse health outcomes. Using alkaline comet assay descriptors and micronucleus frequency from peripheral blood cells as indicators of early biological e...

Exposure assessments to metalworking fluids (MWF) is difficult considering the complex nature of MWF. This study describes a comprehensive exposure assessment to straight and water-based MWFs among workers from 20 workshops. Metal and organic carbon (OC) content in new and used MWF were determined. Full-shift air samples of inhalable particulate an...

(Abstracted from N Engl J Med 2024;390:601–610 In a recent systematic review of randomized controlled trials (RCTs), e-cigarettes were found to be more effective for tobacco smoking cessation than nicotine replacement therapy (NRT). Yet, limited evidence exists on the safety and efficacy of e-cigarettes over standard-of-care cessation counseling an...

Biomonitoring has been widely used in assessing exposures in both occupational and public health complementing chemical risk assessments because it measures the concentrations of chemical substances in human body fluids (e.g., urine and blood). Biomonitoring considers all routes and sources of exposure. An occupational biomonitoring guidance docume...

The BEI® committee developed BEIs to equip Occupational and Environmental Health and Safety professionals to effectively integrate biomonitoring into exposure assessment programs. Biological monitoring is the measure of an exposure biomarker in breath, urine, or blood samples, and reflects total chemical uptake. Most BEI® are derived from TLV–TWA,...

Occupational biomonitoring plays a pivotal role in the assessment and management of chemical workplace exposures. It provides a direct measure of workers’ internal dose of chemicals, integrating all sources and routes of exposure. Biomonitoring can bridge the gap between potential exposure scenarios and real-world implications for worker health. Ne...

In this pilot study on subway workers, we explored the relationships between particle exposure and oxidative stress biomarkers in exhaled breath condensate (EBC) and urine to identify the most relevant biomarkers for a large-scale study in this field. We constructed a comprehensive occupational exposure assessment among subway workers in three dist...

More than eight million premature deaths annually can be attributed to air pollution, with 99% of the world’s population residing in areas below recommended air quality standards. Hence, the present study aimed to examine the association between primary DNA damage and air pollution data among 123 participants enrolled between 2011 and 2015 in Zagre...

Background: Electronic nicotine-delivery systems - also called e-cigarettes - are used by some tobacco smokers to assist with quitting. Evidence regarding the efficacy and safety of these systems is needed. Methods: In this open-label, controlled trial, we randomly assigned adults who were smoking at least five tobacco cigarettes per day and who...

Human health risk assessment is historically built upon animal testing, often following Organisation for Economic Cooperation and Development (OECD) test guidelines and exposure assessments. Using combinations of human relevant in vitro models, chemical analysis and computational (in silico) approaches bring advantages compared to animal studies. T...

Air pollution is regarded as one of the major issues in environmental and public health and has been recognized by leading world authorities as a risk factor associated with adverse health outcomes. Air pollution can alter DNA molecules and consequently human health in either ambient or occupational settings. Exposure to various air pollutants has...

Background Chemicals are not required to be tested systematically for their neurotoxic potency, although they may contribute to the development of several neurological diseases. The absence of systematic testing may be partially explained by the current Organisation for Economic Co-operation and Development (OECD) Test Guidelines, which rely on ani...

Background Semivolatile organic compounds (SVOCs) comprise several different chemical families used mainly as additives in many everyday products. SVOCs can be released into the air as aerosols and deposit on particulate matter during use by dispersion, evaporation, or abrasion. Phthalates are SVOCs of growing concern due to their endocrine-disrupt...

The growing demand for energy, the use of fossil fuels, the increase in traffic, as well as the increase in industrial production greatly contribute to air pollution in cities. It affects the environment and human health. The air in urban areas is a complex and variable mixture of various chemical compounds whose mechanism of action is not fully un...

Air pollution is a persistent serious public health issue worldwide and has been recognized as a leading environmental cause of cancer deaths, so there is an urgent and constant need for continuous prospective studies investigating the effects of air pollution on genome integrity and human health. Considering that the sample of urban air is a very...

Air pollution is acknowledged as one of the most serious public health issues in the world and a leading environmental cause of cancer deaths. Hence, there is an ongoing need for prospective studies investigating the impact of air pollution on genome integrity and human health. Given the fact that urban air is a complex and variable mixture of nume...

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The current evidence on nanomaterial toxicity is mostly derived from experimental studies making it challenging to translate it into human health risks. We established an international cohort (N = 141 workers) within the EU-LIFE project "NanoExplore" to address possible health effects from occupational exposures to nanomaterials. We used a handheld...

BACKGROUND Semivolatile organic compounds (SVOCs) comprise several different chemical families used mainly as additives in many everyday products. SVOCs can be released into the air as aerosols and deposit on particulate matter during use by dispersion, evaporation, or abrasion. Phthalates are SVOCs of growing concern due to their endocrine-disrupt...

Few epidemiological studies use exposure determinants specifically tailored to assess pesticide or plant protection product (PPP) exposures when assessing presumed association between occupational exposure and health outcomes among agricultural workers. This lack of exposure specificity could lead to results that fail to detect an association. It c...

BACKGROUND Chemicals are not required to be tested systematically for their neurotoxic potency, although they may contribute to the development of several neurological diseases. The absence of systematic testing may be partially explained by the current Organisation for Economic Co-operation and Development (OECD) Test Guidelines, which rely on ani...

The environmental impact on health is an inevitable by-product of human activity. Environmental health sciences is a multidisciplinary field addressing complex issues on how people are exposed to hazardous chemicals that can potentially affect adversely the health of present and future generations. Exposure sciences and environmental epidemiology a...

affecting human organs, tissues, cells, and molecules. It is considered responsible for more than 3 million premature deaths annually. Currently ongoing HUMNap project investigates possible associations between air pollutants and biomarkers of exposure and early biological effects. The evaluation of results is divided in two parts. In part 1 we exa...

We aimed at analyzing dose-response relationship between occupational exposure to a mixture of nanomaterials (NMs) and effect biomarkers measured according to the NanoExplore protocol in exhaled breath condensate (EBC, local pulmonary level)) and urine (systemic level) of 141 workers. Two exposure metrics: particle number concentration (PNC) and lu...

Although organic solvents have been associated with CNS toxicity, neurotoxicity testing is rarely a regulatory requirement. We propose a strategy to assess the potential neurotoxicity of organic solvents and predict solvent air concentrations that will not likely produce neurotoxicity in exposed individuals. The strategy integrated an in vitro neur...

Nanotechnology applications are fast-growing in many industrial fields. Consequently, health effects of engineered nanomaterials (ENMs) should be investigated. Within the EU-Life project NanoExplore, we developed a harmonized protocol of an international multicenter prospective cohort study of workers in ENM-producing companies. This article descri...

Glycol ethers are solvents used in a plethora of occupational and household products exposing the users to potential toxic effects. Several glycol ethers derived from ethylene glycol induce hematological toxicity, such as anemia in workers. The exposure effects on blood cells of glycol ethers derived from propylene glycol are unknown in humans. The...

N-Nitrosamines are potent carcinogens and considered non-threshold carcinogens in various regulatory domains. However, recent data indicate the existence of a threshold for genotoxicity, which can be adequately demonstrated. This aspect has a critical impact on selecting the methodology that is applied to derive Occupational Exposure Limits (OELs)....

Increased road traffic and industrial and energy production contribute to urban air pollution worldwide. Consequently, cities are hotspots for air pollution, representing a global health threat, resulting in millions of premature deaths annually. The HUMNap project aims to provide scientifically based data on how air pollution can affect genomic in...

Human biomonitoring (HBM) data measured in specific contexts or populations provide information for comparing population exposures. There are numerous health-based biomonitoring guidance values, but to locate these values, interested parties need to seek them out individually from publications, governmental reports, websites and other sources. Unti...

https://doi.org/10.1016/j.envint.2022.107476

Hydrogen peroxide (H2O2) is a strong oxidizing agent often used in hair coloring and as a component in disinfecting and bleaching processes. Exposures to H2O2 generate reactive oxygen species (ROS) that can cause significant airway irritation and inflammation. Even though workers have reported symptoms associated with sensitivity and irritation fro...

Air pollution is recognized as one of the most serious public health issues worldwide and was declared to be a leading environmental cause of cancer deaths. At the same time, the cytokinesis-block micronucleus (CBMN) assay serves as a cancer predictive method that is extensively used in human biomonitoring for populations exposed to environmental c...

Oxidative stress can contribute to the development of diseases, and may originate from exposures to toxicants commonly found in air pollution and cigarette smoke such as polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). Yet, associations between these exposures and oxidative stress biomarkers are poorly characterized. W...

Human biomonitoring (HBM) is a crucial approach for exposure assessment, as emphasised in the European Commission’s Chemicals Strategy for Sustainability (CSS). HBM can help to improve chemical policies in five major key areas: (1) assessing internal and aggregate exposure in different target populations; 2) assessing exposure to chemicals across l...

Many pathological conditions and certain airway exposures are associated with oxidative stress (OS). Malondialdehyde (MDA) is an end-product of the oxidation of lipids in our cells and is present in all biological matrices including exhaled breath condensate (EBC). To use MDA as a biomarker of OS in EBC, a reference interval should be defined. Thus...

Exhaled breath condensate (EBC) has attracted substantial interest in the last few years, enabling the assessment of airway inflammation with a non-invasive method. Concentrations of 8-Hydroxydesoxyguanosine (8-OHdG) and 8-isoprostane in EBC have been suggested as candidate biomarkers for lung diseases associated with inflammation and oxidative str...

Vodeće svjetske organizacije poput Europske agencije za okoliš, Svjetske zdravstvene organizacije, Međunarodne agencije za istraživanje raka i Globalnog opterećenja bolestima istakle su onečišćenje zraka kao vodeću globalnu zdravstvenu prijetnju odgovornu za 3 – 7 milijuna smrtnih slučajeva godišnje. Zrak u urbanim sredinama kompleksna je i promjen...

Oxidative stress has been associated with various inflammation-related human diseases. It is defined as an imbalance between the production and elimination of reactive oxygen species (ROS). ROS can oxidize proteins, lipids, and DNA, and some of these oxidized products are excreted in urine, such as malondialdehyde (MDA), which is considered a bioma...

Background Underground transportation systems can contribute to the daily particulates and metal exposures for both commuter and subway workers. The redox and metabolic changes in workers exposed to such metal-rich particles have yet to be characterized. We hypothesize that the distribution of nitrosative/oxidative stress and related metabolic biom...

Glycol ethers are organic solvents present in countless products for professional and domestic use. The main toxicological concerns are hematotoxicity, respiratory and reproductive toxicity. The general population can be exposed when using products containing one or several glycol ethers that evaporate or if sprayed, generate aerosols that can be i...

There are several methods for quantifying malondialdehyde (MDA), an oxidative stress biomarker, in exhaled breath condensate (EBC). However, due to the very diluted nature of this biological matrix, a high variability is observed at low concentrations. We aimed to optimize a 2,4-dinitrophenylhydrazine-based method using liquid chromatography couple...

Air pollution is becoming recognised as one of the most serious public health issues worldwide. Rising industrial and energy productions, the burning of fossil fuels and biomass, as well as the rise in road traffic frequency contribute to air pollution in our cities. Urban air is a complex and variable mixture of many different chemicals whose exac...

Data generated by the rapidly evolving human biomonitoring (HBM) programmes are providing invaluable opportunities to support and advance regulatory risk assessment and management of chemicals in occupational and environmental health domains. However, heterogeneity across studies, in terms of design, terminology, 2 Data value chain Data governance...

Major world authorities such as European Environmental Agency, World Health Organization, International Agency for Research on Cancer, and The Global Burden of Diseases highlighted air pollution as leading global health threat responsible for 3 – 7 million deaths annually. Urban air is a variable and complex mixture of many different chemicals with...

Subway particulate toxicity results from in vitro and in vivo studies diverge and call for applied human research on outcomes from chronic exposures and potential exposure biomarkers. We aimed to (1) quantify airborne particulate matter (PM) concentrations (mass and number) and metal concentrations in exhaled breath condensate (EBC), urine, and PM;...

Carrying out exposure studies on children who are not toilet trained is challenging because of the difficulty of urine sampling. In this study, we optimized a protocol for urine collection from disposable diapers for the analysis of phthalate metabolites. The exposure of Swiss children (n = 113) between 6 months and 3 years of life to seven phthala...

The ROBoCoP project is launched within the EU COST Action CA16113 “CliniMARK” aiming to increase the number of clinically validated biomarkers and focused on chronic obstructive pulmonary disease (COPD) biomarker development and validation. ROBoCoP encompasses two consecutive studies consisting of a pilot study followed by a field study. The pilot...

The oxidative potential (OP) measures the ability of pollutants to oxidize a chemical/biological probe. Such assays are starting to gain acceptance as integrative exposure metrics associated with inflammatory-based pathologies. Diseases such as asthma, rhinitis or cancers are reported for workers exposed to oil mist, which are aerosols of metal wor...

Glycol ethers, such as propylene glycol monomethyl ether (PGME) and propylene glycol monobuthyl ether (PGBE) are solvents found in many professional and domestic products. In biomonitoring studies, the type of materials used to collect, store, and transport these samples can greatly influence the analytical results because materials can adsorb the...

Production and handling of engineered nanomaterials (ENMs) can yield worker exposure to these materials with the potential for unforeseen negative health effects. Biomonitoring enables regular exposure and health assessment and an effective risk management. We aimed to identify factors influencing biomonitoring acceptance according to hierarchical...

Bisphenol A (BPA) in vitro skin permeation studies have shown inconsistent results, which could be due to experimental conditions. We studied the impact of in vitro parameters on BPA skin permeation using flow-through diffusion cells with ex-vivo human skin (12 donors, 3–12 replicates). We varied skin status (viable or frozen skin) and thickness (2...

Human biological monitoring is a powerful tool for scientists, policy makers, and occupational health‐care professionals, such as physicians and occupational hygienists, to assess and manage health risks associated with chemical exposures among the general population as well as at the workplace. This chapter will focus on using biological monitorin...

Effect biomarkers can be used to elucidate relationships between exposure to environmental chemicals and their mixtures with associated health outcomes, but they are often underused, as underlying biological mechanisms are not understood. We aim to provide an overview of available effect biomarkers for monitoring chemical exposures in the general a...

Human biomonitoring of oxidative stress relies on urinary effect biomarkers such as 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG), and 8-iso-prostaglandin F2α (8-isoprostane); however, their levels reported for similar populations are inconsistent in the scientific literature. One of the reasons is the multitude of analytical methods with varying d...

Objectives Bisphenol A (BPA) is the most used colour developer in thermal paper for cashiers receipts, labels, and tickets. BPA can migrate onto the skin and be absorbed when handling these papers. BPA is a known endocrine disruptor and is therefore being replaced in thermal paper by some alternatives such as Bisphenol S (BPS), D-8, and Pergafast 2...

Skin exposure to cleaning products in the general and occupational population are a public health concern. Among the most frequently identified amphiphilic organic solvents in cleaning products are propylene glycol monomethyl ether (PGME) and propylene glycol n-butyl ether (PGBE). Internal dose from skin exposure may be efficiently evaluated using...

Introduction: Bisphenol A (BPA) is the most used colour developer in thermal paper products such as cashiers' receipts, followed by Bisphenol S (BPS), Wincon 8 (D-8), and Pergafast 201® (PF201). These chemicals can migrate from the paper onto the skin and possibly be absorbed and metabolised. Until now, D-8 and PF201 have not been analysed in biol...

Recent advances in analytical chemistry have allowed a greater possibility of using quantitative approaches for measuring human exposure to chemicals. One of these approaches is biomonitoring (BM), which provides unequivocal evidence that both exposure and uptake of a chemical have taken place. BM has been a longstanding practice in occupational he...

At the 8th conference of Occupational and Environmental Exposure of the Skin to Chemicals (OEESC) (16–18 September 2019) in Dublin, Ireland, several researchers performing skin permeation assays convened to discuss in vitro skin permeability experiments. We, along with other colleagues, all of us hands-on skin permeation researchers, present here t...

Photocatalytic cement is self-cleaning due to the addition of titanium dioxide (TiO2) nanoparticles, which react with sunlight (UV) and produce reactive oxygen species (ROS). Construction workers using photocatalytic cement are exposed not only to cement particles that are irritants but also to nano TiO2 and UV, both carcinogens, as well as the gen...

Restrictions on the use of bisphenol A (BPA) in consumer products led to its replacement by various bisphenol (BP) analogues, yet young children's exposure to these analogues has been poorly characterized so far. This study aimed to characterize infants' and toddlers' exposure to BPA and 14 emerging BP analogues (i.e., bisphenol AF, bisphenol AP, b...

Isoprostanes are physiopathologic mediators of oxidative stress, resulting in lipid peroxidation. 8-isoprostane seems particularly useful for measuring oxidative stress damage. However, no reference range values are available for 8-isoprosante in exhaled breath condensate (EBC) of healthy adults, enabling its meaningful interpretation as a biomarke...

Oxidative stress reflects a disturbance in the balance between the production and accumulation of reactive oxygen species (ROS). ROS are scavenged by the antioxidant system, but when in excess concentration, they can oxidize proteins, lipids, and DNA. DNA damage is usually repaired, and the oxidized products are excreted in urine. 8-hydroxy-2-deoxy...

Although, photocatalytic cement contains nanosized TiO2, a possibly carcinogen, no exposure assessments exist for construction workers. We characterized airborne nanoparticle exposures during construction activities simulated in an exposure chamber. We collected some construction site samples for regular cement in Switzerland and Thailand for compa...

Oxidative stress is defined as an imbalance between the production and elimination of reactive oxygen species (ROS) are associated with various inflammation-related human disease. ROS can oxidize lipids, which subsequently undergo fragmentation to produce F2-isoprostanes (F2-IsoPs). Eight-isoprostane is one of the most extensively studied F2-IsoPs...

In the field of engineered nanomaterials (ENMs) and other airborne particulate exposure biomonitoring, circulating oxidative stress biomarkers appear promising. These biomarkers could be monitored in different biological matrices. Exhaled breath condensate (EBC) enables their measurements in the respiratory tract, without affecting airway function...

Carbon nanotubes (CNT) trigger fascination as well as anxiety, given their unique physical and chemical properties, and continuing concerns around their possible health effects. CNT exposure assessment is an integral component of occupational and environmental epidemiology, risk assessment, and management. We conducted a systematic review to analyz...

Tolylfluanid (TF) is a sensitizing biocide used in antifouling products and wood preservatives. Paint application is associated with skin exposure; however, the importance of this exposure route is uncertain as TF skin permeation rates are lacking in the peer-reviewed scientific literature. TF is a lipophilic powder that hydrolyses rapidly in conta...

Introduction Environ 25 % des bronchites chroniques obstructives (BPCO) sont liées à des expositions professionnelles, notamment aux particules fines ou ultrafines (PF/PUF) qui peuvent induire un stress oxydant. Le diagnostic et l’évaluation de la sévérité de la BPCO reposent actuellement sur un test d’exploration fonctionnelle respiratoire (spirom...

Introduction L’exposition des employés des EFS à des particules fines et ultrafines (PF/PUF) peut induire un stress oxydant potentiellement responsable de plusieurs pathologies inflammatoires, dont la bronchopneumopathie chronique obstructive (BPCO). L’augmentation des biomarqueurs du stress oxydant à la fois au niveau systémique et local (au sein...

Background: Micronuclei (MNs) are extranuclear DNA-containing bodies and determining MN frequencies is a measure of genomic instability. An age-related increase in MN frequencies in lymphocytes has been quantified, but this effect has not yet been measured in nasal and buccal cells. Methods: We determined the effect of age on the MN frequency di...

Skin exposures are common during cleaning activities, and may contribute to the overall body burden. Cleaning products may contain irritants such as monoethanolamine (MEA) and diethanol amine (DEA). The significance of the skin exposure route is unknown, as no estimates for MEA skin permeation are available. We used in vitro flow-through diffusion...

A biomarker-based approach using micronucleus (MN) (extranuclear DNA-containing bodies) frequencies in buccal cells has been proposed to monitor workers exposed to aero-digestive carcinogens for early detection of occupational cancer. To assess this non-invasive MN approach, we sought to understand: (A) What is the extent of MN frequency increase i...

BACKGROUND Exposure to metal working fluids (MWF) aerosols also known as oil mist has been related to a series of adverse health outcomes (cancer, respiratory diseases). The present project focuses on the effects of occupational exposure to MWF on a panel of exposure and effect biomarkers in an epidemiological study. The assumption is that differen...

Background Exposure to aerosols from metalworking fluids (MWF) has previously been related to a series of adverse health outcomes (eg, cancer, respiratory diseases). Our present epidemiological study focuses on occupational exposures to MWF and a panel of exposure and effect biomarkers. We hypothesize that these health outcomes are caused by partic...

Photocatalytic cement containing nano-TiO2 has been introduced to the construction industry because of its biocidal and self-cleaning properties. Although, TiO2 is classified as possibly carcinogenic to humans, the cancer risk among cement workers is currently unknown. This is partly because an assessment of exposures to airborne photocatalytic cem...

Altered gene expression in pathways relevant to leukaemogenesis, as well as reduced levels of circulating lymphocytes, have been reported in workers that were exposed to benzene concentrations below 1 ppm. In this study, we analysed whole blood global gene expression patterns in a worker cohort with altered levels of T cells and immunoglobulins IgM...