A flow cytometry based oligotrophic pollutant exposure test to detect bacterial growth inhibition and cell injury.

Toxicity of chemical pollutants in aquatic environments is often addressed by assays that inquire reproductive inhibition of test microorganisms, such as algae or bacteria. Those tests, however, assess growth of populations as a whole via macroscopic methods such as culture turbidity or colony-forming units. Here we use flow cytometry to interrogate the fate of individual cells in low-density populations of the bacterium Pseudomonas fluorescens SV3 exposed or not under oligotrophic conditions to a number of common pollutants, some of which derive from oil contamination. Cells were stained at regular time intervals during the exposure assay with fluorescent dyes that detect membrane injury (i.e., live-dead assay). Reduction of population growth rates was observed upon toxicant insult and depended on the type of toxicant. Modeling and cell staining indicate that population growth rate decrease is a combined effect of an increased number of injured cells that may or may not multiply, and live cells dividing at normal growth rates. The oligotrophic assay concept presented here could be a useful complement for existing biomarker assays in compliance with new regulations on chemical effect studies or, more specifically, for judging recovery after exposure to fluctuating toxicant conditions.

PPAR beta a player in astrocyte metabolism and morphology

AbstractPPARP is a nuclear receptor responding in vivo to several free fatty acids, and implicated in cell metabolism, differentiation and survival. PPARp is ubiquitously expressed but shows high expression in the developing and adult brain. PPARp is expressed in different cell types such as neurons and astrocytes, where it might play a role in metabolism. To study this nuclear receptor the laboratory engineered a PPARP -/- mouse model. The aim of my PhD was to dissect the role of PPARP in astrocytes.Experiments in primary culture revealed that cortical astrocytes from PPARP -/- mouse have an impaired energetic metabolism. Unstimulated PPARP -/- astrocytes exhibit a 30% diminution in glucose uptake, correlating to a 30% decrease in lactate release and intracellular glucose. After acute stimulation by D- aspartate mimicking glutamate exposure, both WT and -/- astrocytes up-regulate their metabolism to respond to the increasing energy needed (ATP) for glutamate uptake. According to the Astrocyte Neuron Lactate Shuttle Hypothesis (ANLSH), the ratio between glucose uptake/ lactate release is 1. However, stimulated PPARp -/- astrocytes display a higher increase in lactate release than glucose uptake which remains lower than in WT. The extra glucose equivalents could come from the degradation of intra cellular glycogen stores, which indeed decrease in PPARP -/- cells upon stimulation. Lower glucose metabolism correlates with a decreased acute glutamate uptake in PPARP -/- astrocytes. Reciprocally, we also observed an increase of glutamate uptake and ATP production after treatment of WT astrocytes with a PPARp agonist. Glutamate transporter protein expression is not affected. However, their trafficking and localization might be altered as PPARp -/- astrocytes have higher cholesterol levels, which may also affect proper transporter structure in the membrane.Metabolism, transporter localization and cholesterol levels are respectively linked to cell mobility, cell cytoskeleton and cellular membrane composition. All three functions are important in astrocytes to in vivo acquire star shaped morphology, in a process known as stellation. PPARP -/- astrocytes showed an impaired acquired stellation in presence of neurons or chemical stimuli, as well as more actin stress fibers and cell adhesion structures. While non stellation of astrocytes is mainly an in vitro phenomenon, it reveals PPARp -/- primary astrocytes inability to respond to different exterior stimuli. These morphological phenotypes correlate with a slower migration in cell culture wound healing assays.This thesis work demonstrates that PPARp is implicated in cortical astrocyte glucose metabolism. PPARp absence leads to an unusual intracellular glycogen use. Added to the effect on acute glutamate uptake and astrocyte migration, PPARp could be an interesting target for neuroprotection therapies.RésuméPPARP est un récepteur nucléaire qui a pour ligands naturels certains acides gras libres. Il est impliqué dans le métabolisme, la différentiation et la survie des cellules. PPARP est ubiquitaire, et a une expression élevée dans le cerveau en développement ainsi qu'adulte. PPARp est exprimé dans différents types cellulaires tels que les neurones et les astrocytes, où il régule potentiellement leurs métabolismes. Pour étudier ce récepteur nucléaire, le laboratoire a créé un modèle de souris PPARp -/-. L'objectif de ma thèse est de comprendre le rôle de PPARp dans les astrocytes.Les expériences montrent un défaut du métabolisme énergétique dans les astrocytes corticaux primaires tirés de souris PPARp -/-. Sans stimulation, l'entrée du glucose dans les astrocytes PPARP -/- est diminuée de 30% ce qui correspond à une diminution de 30% du relargage du lactate. Après stimulation par du D-Aspartate qui mime une exposition au glutamate, les astrocytes WT et -/- augmentent leur métabolisme en réponse à la demande accrue en énergie (ATP) due à l'entrée du glutamate. D'après l'Astrocyte Neuron Lactate Shuttle Hypothesis (ANLSH), le ratio entre le glucose entrant et le lactate sortant est de 1. Cependant le relargage du lactate dans les astrocytes PPARP-/- est plus élevé que l'entrée du glucose. L'apport supplémentaire de glucose transformé en lactate pourrait provenir de la dégradation des stocks de glycogène intracellulaire, qui sont partiellement diminués après stimulation dans les cellules PPARP -/-. Un métabolisme plus faible du glucose corrèle avec une réduction de l'import du glutamate dans les astrocytes PPARp -/-. Réciproquement, nous observons une augmentation de l'import du glutamate et de la production d'ATP après traitement avec l'agoniste pour PPARp. Bien que l'expression des transporteurs de glutamate ne soit pas affectée, nous ne pouvons pas exclure que leur localisation et leur structure soient altérées du fait du niveau élevé de cholestérol dans les astrocytes PPARp -/-.Le métabolisme, la localisation des transporteurs et le niveau de cholestérol sont tous liés au cytosquelette, à la mobilité, et à la composition des membranes cellulaires. Toutes ces fonctions sont importantes pour les astrocytes pour acquérir leur morphologie in vivo. Les astrocytes PPARP -/- présentent un défaut de stellation, aussi bien en présence de neurones que de stimuli chimiques, ainsi qu'un plus grand nombre de fibres de stress (actine) et de structures d'adhésion cellulaire. Bien que les astrocytes non stellaires soient principalement observés in vitro, le défaut de stellation des astrocytes primaires PPARp -/- indique une incapacité à répondre aux différents stimuli extérieurs. Ces phénotypes morphologiques corrèlent avec une migration plus lente en cas de lésion de la culture.Ce travail de thèse a permis de démontrer l'implication de PPARP dans le métabolisme du glucose des astrocytes corticaux. L'absence de ce récepteur nucléaire amène à l'utilisation du glucose intracellulaire, auquel s'ajoutent les effets sur l'import du glutamate et la migration des astrocytes. PPARp aurait des effets neuroprotecteurs, et de ce fait pourrait être utilisé à des fins thérapeutiques.

Smoke Free Spaces: Progress in reducing exposure to second-hand smoke in Northern Ireland incorporating the five year review of smoke-free legislation

This report provides an overview of progress in reducing Second Hand Smoke (SHS) exposure in Northern Ireland that incorporates the five year review of smoke-free legislation, but also extends to a consideration of SHS exposure in non-work environments.  The report considers aspects of inequalities in SHS exposure in particular according to social disadvantage and with a focus on vulnerable subgroups of the population.

Effective exposure to solar UV in building workers: influence of local and individual factors.

Excessive exposure to solar UV light is the main cause of skin cancers in humans. UV exposure depends on environmental as well as individual factors related to activity. Although outdoor occupational activities contribute significantly to the individual dose received, data on effective exposure are scarce and limited to a few occupations. A study was undertaken in order to assess effective short-term exposure among building workers and characterize the influence of individual and local factors on exposure. The effective exposure of construction workers in a mountainous area in the southern part of Switzerland was investigated through short-term dosimetry (97 dosimeters). Three altitudes, of about 500, 1500 and 2500 m were considered. Individual measurements over 20 working periods were performed using Spore film dosimeters on five body locations. The postural activity of workers was concomitantly recorded and static UV measurements were also performed. Effective exposure among building workers was high and exceeded occupational recommendations, for all individuals for at least one body location. The mean daily UV dose in plain was 11.9 SED (0.0-31.3 SED), in middle mountain 21.4 SED (6.6-46.8 SED) and in high mountain 28.6 SED (0.0-91.1 SED). Measured doses between workers and anatomical locations exhibited a high variability, stressing the role of local exposure conditions and individual factors. Short-term effective exposure ranged between 0 and 200% of ambient irradiation, indicating the occurrence of intense, subacute exposures. A predictive irradiation model was developed to investigate the role of individual factors. Posture and orientation were found to account for at least 38% of the total variance of relative individual exposure, and were also found to account more than altitude on the total variance of effective daily exposures. Targeted sensitization actions through professional information channels and specific prevention messages are recommended. Altitude outdoor workers should also benefit from preventive medical examination.

Pregnancy outcome following maternal exposure to statins: a multicenter prospective study

Introduction Statin use in women of childbearing age is increasingly common. However, published data on pregnancy outcome after exposure to statins are scarce and conflicting. This contribution addresses the safety of statin use during pregnancy.Materials and Methods In a multi-centre (n = 11), prospective study we compared the outcomes of 249 women exposed during the 1st trimester of pregnancy to simvastatin (n = 124), atorvastatin (n = 67), pravastatin (n = 32), rosuvastatin (n = 18), fl uvastatin (n = 7) or cerivastatin (n = 1) with a control group exposed to agents known to be non-teratogenic (n = 249). Data were collected by members of the European Network of Teratology Information Services during individual risk counselling.Results The difference in the rate of major birth defects between the statinexposed and the control group was statistically insignificant (4.0% versus 2.7% OR 1.5; 95% CI 0.5-4.5, p = 0.44). The crude rate of spontaneous abortions (12.8% versus 7.1%, OR 1.9, 95% CI 1.0-3.6, p = 0.04) was higher in the exposed group. However, after adjustment to maternal age and gestational age at initial contact, the difference became insignificant. The rate of elective pregnancy-termination (8.8% versus 4.4%, p = 0.05) was higher and the rate of live births was lower in the exposed group (77.9% versus 88.4%, p = 0.002). Prematurity was more frequent in exposed pregnancies (16.1% versus 8.5%; OR 2.1, 95% CI 1.1- 3.8, p = 0.02). Nonetheless, gestational age at birth (median 39 weeks, IQR 37-40 versus 39 weeks, IQR 38-40, p = 0.27) and birth weight (median 3280 g, IQR 2835-3590 versus 3250 g, IQR 2880- 3600, p = 0.95) did not differ between exposed and non-exposed pregnancies.Conclusion This study did not detect a teratogenic effect of statins. Its statistical power however is not sufficient to reverse the recommendation of treatment discontinuation during pregnancy.

Long-Lasting Protection of Activity of Nucleoside Reverse Transcriptase Inhibitors and Protease Inhibitors (PIs) by Boosted PI Containing Regimens.

BACKGROUND: The accumulation of mutations after long-lasting exposure to a failing combination antiretroviral therapy (cART) is problematic and severely reduces the options for further successful treatments. METHODS: We studied patients from the Swiss HIV Cohort Study who failed cART with nucleoside reverse transcriptase inhibitors (NRTIs) and either a ritonavir-boosted PI (PI/r) or a non-nucleoside reverse transcriptase inhibitor (NNRTI). The loss of genotypic activity <3, 3-6, >6 months after virological failure was analyzed with Stanford algorithm. Risk factors associated with early emergence of drug resistance mutations (<6 months after failure) were identified with multivariable logistic regression. RESULTS: Ninety-nine genotypic resistance tests from PI/r-treated and 129 from NNRTI-treated patients were analyzed. The risk of losing the activity of ≥1 NRTIs was lower among PI/r- compared to NNRTI-treated individuals <3, 3-6, and >6 months after failure: 8.8% vs. 38.2% (p = 0.009), 7.1% vs. 46.9% (p<0.001) and 18.9% vs. 60.9% (p<0.001). The percentages of patients who have lost PI/r activity were 2.9%, 3.6% and 5.4% <3, 3-6, >6 months after failure compared to 41.2%, 49.0% and 63.0% of those who have lost NNRTI activity (all p<0.001). The risk to accumulate an early NRTI mutation was strongly associated with NNRTI-containing cART (adjusted odds ratio: 13.3 (95% CI: 4.1-42.8), p<0.001). CONCLUSIONS: The loss of activity of PIs and NRTIs was low among patients treated with PI/r, even after long-lasting exposure to a failing cART. Thus, more options remain for second-line therapy. This finding is potentially of high relevance, in particular for settings with poor or lacking virological monitoring.

Naturally acquired antibodies to merozoite surface protein (MSP)-1(19) and cumulative exposure to Plasmodium falciparum and Plasmodium vivax in remote populations of the Amazon Basin of Brazil

To infer recent patterns of malaria transmission, we measured naturally acquired IgG antibodies to the conserved 19-kDa C-terminal region of the merozoite surface protein (MSP)-1 of both Plasmodium vivax (PvMSP-1(19)) and Plasmodium falciparum (PfMSP-1(19)) in remote malaria-exposed populations of the Amazon Basin. Community-based cross-sectional surveys were carried out between 2002 and 2003 in subjects of all age groups living along the margins of the Unini and Jaú rivers, Northwestern Brazil. We found high prevalence rates of IgG antibodies to PvMSP-1(19) (64.0 - 69.6%) and PfMSP-1(19) (51.6 - 52.0%), with significant differences in the proportion of subjects with antibodies to PvMSP-1(19) according to age, place of residence and habitual involvement in high-risk activities, defining some groups of highly exposed people who might be preferential targets of malaria control measures. In contrast, no risk factor other than age was significantly associated with seropositivity to PfMSP-1(19). Only 14.1% and 19.3% of the subjects tested for antibodies to PvMSP-1(19) and PfMSP-1(19) in consecutive surveys (142 - 203 days apart) seroconverted or had a three fold or higher increase in the levels of antibodies to these antigens. We discuss the extent to which serological data correlated with the classical malariometric indices and morbidity indicators measured in the studied population at the time of the seroprevalence surveys and highlight some limitations of serological data for epidemiological inference.

Measuring an effect size from dichotomized data : contrasted results whether using a correlation or an odds-ratio

It is well known that dichotomizing continuous data has the effect to decrease statistical power when the goal is to test for a statistical association between two variables. Modern researchers however are focusing not only on statistical significance but also on an estimation of the "effect size" (i.e., the strength of association between the variables) to judge whether a significant association is also clinically relevant. In this article, we are interested in the consequences of dichotomizing continuous data on the value of an effect size in some classical settings. It turns out that the conclusions will not be the same whether using a correlation or an odds ratio to summarize the strength of association between the variables: Whereas the value of a correlation is typically decreased by a factor pi/2 after each dichotomization, the value of an odds ratio is at the same time raised to the power 2. From a descriptive statistical point of view, it is thus not clear whether dichotomizing continuous data leads to a decrease or to an increase in the effect size, as illustrated using a data set to investigate the relationship between motor and intellectual functions in children and adolescents

Urban transmission of Chagas disease in Cochabamba, Bolivia

Chagas disease is a major public health problem in Bolivia. In the city of Cochabamba, 58% of the population lives in peripheral urban districts ("popular zones") where the infection prevalence is extremely high. From 1995 to 1999, we studied the demographics of Chagas infections in children from five to 13 years old (n = 2218) from the South zone (SZ) and North zone (NZ) districts, which differ in social, environmental, and agricultural conditions. Information gathered from these districts demonstrates qualitative and quantitative evidence for the active transmission of Trypanosoma cruzi in urban Cochabamba. Seropositivity was high in both zones (25% in SZ and 19% in NZ). We observed a high risk of infection in children from five to nine years old in SZ, but in NZ, a higher risk occurred in children aged 10-13, with odds ratio for infection three times higher in NZ than in SZ. This difference was not due to triatomine density, since more than 1,000 Triatoma infestans were captured in both zones, but was possibly secondary to the vector infection rate (79% in SZ and 37% in NZ). Electrocardiogram abnormalities were found to be prevalent in children and pre-adolescents (SZ = 40%, NZ = 17%), indicating that under continuous exposure to infection and re-infection, a severe form of the disease may develop early in life. This work demonstrates that T. cruzi infection should also be considered an urban health problem and is not restricted to the rural areas and small villages of Bolivia.

The effect of a smoking ban introduction to environmental tobacco smoke exposure in Swiss hospitality workers : Abstracts of the 23rd Annual Conference of the International Society of Environmental Epidemiology (ISEE), September 13-16, 2011, Barcelona, Spain

Background and Aims: To protect the population from environmental tobacco smoke (ETS) Switzerland introduced a nationwide rather heterogeneous smoking ban in May 2010. The exposure situation of non-smoking hospitality workers before and after implementation of the new law is being assessed in a prospective cohort study. Methods: Exposure to ETS was measured using a novel method developed by the Institute for Work and Health in Lausanne. It is a passive sampler called MoNIC (Monitor of NICotine). The nicotine of the ETS is fixed onto a filter and transformed into salt of not volatile nicotine. Subsequently the number of passively smoked cigarettes is calculated. Badges were placed at the workplace as well as distributed to the participants for personal measuring. Additionally a salivary sample was taken to determine nicotine concentration. Results: At baseline Spearman's correlation between workplace and personal badge was 0.47. The average cigarette equivalents per day at the workplace obtained by badge significantly dropped from 5.1 (95%- CI: 2.4 to 7.9) at baseline to 0.3 (0.2 to 0.4) at first follow-up (n=29) three months later (p<0.001). For personal badges the number of passively smoked cigarettes declined from 1.5 (2.7 to 0.4) per day to 0.5 (0.3 to 0.8) (n=16).Salivary nicotine concentration in a subset of 13 participants who had worked on the day prior to the examination was 2.63 ng/ml before and 1.53 ng/ml after the ban (p=0.04). Spearman's correlation of salivary nicotine was 0.56 with workplace badge and 0.79 with personal badge concentrations. Conclusions: Workplace measurements clearly reflect the smoking regulation in a venue. The MoNIC badge proves to be a sensitive measuring device to determine personal ETS exposure and it is a demonstrative measure for communication with lay audiences and study participants as the number of passively smoked cigarettes is an easily conceivable result.

Identifying pesticide use patterns among flower growers to assess occupational exposure to mixtures

Objectives Exposure assessment to a single pesticide does not capture the complexity of the occupational exposure. Recently, pesticide use patterns analysis has emerged as an alternative to study these exposures. The aim of this study is to identify the pesticide use pattern among flower growers in Mexico participating in the study on the endocrine and reproductive effects associated with pesticide exposure. Methods A cross-sectional study was carried out to gather retrospective information on pesticide use applying a questionnaire to the person in charge of the participating flower growing farms. Information about seasonal frequency of pesticide use (rainy and dry) for the years 2004 and 2005 was obtained. Principal components analysis was performed. Results Complete information was obtained for 88 farms and 23 pesticides were included in the analysis. Six principal components were selected, which explained more than 70% of the data variability. The identified pesticide use patterns during both years were: 1. fungicides benomyl, carbendazim, thiophanate and metalaxyl (both seasons), including triadimephon during the rainy season, chlorotalonyl and insecticide permethrin during the dry season; 2. insecticides oxamyl, biphenthrin and fungicide iprodione (both seasons), including insecticide methomyl during the dry season; 3. fungicide mancozeb and herbicide glyphosate (only during the rainy season); 4. insecticides metamidophos and parathion (both seasons); 5. insecticides omethoate and methomyl (only rainy season); and 6. insecticides abamectin and carbofuran (only dry season). Some pesticides do not show a clear pattern of seasonal use during the studied years. Conclusions The principal component analysis is useful to summarise a large set of exposure variables into smaller groups of exposure patterns, identifying the mixtures of pesticides in the occupational environment that may have an interactive effect on a particular health effect.

Decreased PM10 exposure attenuates age-related lung function decline: genetic variants in p53, p21, and CCND1 modify this effect.

BACKGROUND: Decreasing exposure to airborne particulates was previously associated with reduced age-related decline in lung function. However, whether the benefit from improved air quality depends on genetic background is not known. Recent evidence points to the involvement of the genes p53 and p21 and of the cell cycle control gene cyclin D1 (CCND1) in the response of bronchial cells to air pollution. OBJECTIVE: We determined in 4,326 participants of the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA) whether four single-nucleotide polymorphisms in three genes [CCND1 (rs9344 [P242P], rs667515), p53 (rs1042522 [R72P]), and p21 (rs1801270 [S31R])] modified the previously observed attenuation of the decline in the forced expiratory flow between 25% and 75% of the forced vital capacity (FEF(25-75)) associated with improved air quality. METHODS: Subjects of the prospective population-based SAPALDIA cohort were assessed in 1991 and 2002 by spirometry, questionnaires, and biological sample collection for genotyping. We assigned spatially resolved concentrations of particulate matter with aerodynamic diameter < or = 10 microm (PM(10)) to each participant's residential history 12 months before the baseline and follow-up assessments. RESULTS: The effect of diminishing PM(10) exposure on FEF(25-75) decline appeared to be modified by p53 R72P, CCND1 P242P, and CCND1 rs667515. For example, a 10-microg/m(3) decline in average PM(10) exposure over an 11-year period attenuated the average annual decline in FEF(25-75) by 21.33 mL/year (95% confidence interval, 10.57-32.08) among participants homozygous for the CCND1 (P242P) GG genotype, by 13.72 mL/year (5.38-22.06) among GA genotypes, and by 6.00 mL/year (-4.54 to 16.54) among AA genotypes. CONCLUSIONS: Our results suggest that cell cycle control genes may modify the degree to which improved air quality may benefit respiratory function in adults.

In-vitro cell exposure studies for the assessment of nanoparticle toxicity in the lung: a dialog between aerosol science and biology

The introduction of engineered nanostructured materials into a rapidly increasing number of industrial and consumer products will result in enhanced exposure to engineered nanoparticles. Workplace exposure has been identified as the most likely source of uncontrolled inhalation of engineered aerosolized nanoparticles, but release of engineered nanoparticles may occur at any stage of the lifecycle of (consumer) products. The dynamic development of nanomaterials with possibly unknown toxicological effects poses a challenge for the assessment of nanoparticle induced toxicity and safety.In this consensus document from a workshop on in-vitro cell systems for nanoparticle toxicity testing11Workshop on 'In-Vitro Exposure Studies for Toxicity Testing of Engineered Nanoparticles' sponsored by the Association for Aerosol Research (GAeF), 5-6 September 2009, Karlsruhe, Germany. an overview is given of the main issues concerning exposure to airborne nanoparticles, lung physiology, biological mechanisms of (adverse) action, in-vitro cell exposure systems, realistic tissue doses, risk assessment and social aspects of nanotechnology. The workshop participants recognized the large potential of in-vitro cell exposure systems for reliable, high-throughput screening of nanoparticle toxicity. For the investigation of lung toxicity, a strong preference was expressed for air-liquid interface (ALI) cell exposure systems (rather than submerged cell exposure systems) as they more closely resemble in-vivo conditions in the lungs and they allow for unaltered and dosimetrically accurate delivery of aerosolized nanoparticles to the cells. An important aspect, which is frequently overlooked, is the comparison of typically used in-vitro dose levels with realistic in-vivo nanoparticle doses in the lung. If we consider average ambient urban exposure and occupational exposure at 5mg/m3 (maximum level allowed by Occupational Safety and Health Administration (OSHA)) as the boundaries of human exposure, the corresponding upper-limit range of nanoparticle flux delivered to the lung tissue is 3×10-5-5×10-3μg/h/cm2 of lung tissue and 2-300particles/h/(epithelial) cell. This range can be easily matched and even exceeded by almost all currently available cell exposure systems.The consensus statement includes a set of recommendations for conducting in-vitro cell exposure studies with pulmonary cell systems and identifies urgent needs for future development. As these issues are crucial for the introduction of safe nanomaterials into the marketplace and the living environment, they deserve more attention and more interaction between biologists and aerosol scientists. The members of the workshop believe that further advances in in-vitro cell exposure studies would be greatly facilitated by a more active role of the aerosol scientists. The technical know-how for developing and running ALI in-vitro exposure systems is available in the aerosol community and at the same time biologists/toxicologists are required for proper assessment of the biological impact of nanoparticles.

Sulfur isotope analysis of cinnabar from Roman wall paintings by elemental analysis/isotope ratio mass spectrometry - tracking the origin of archaeological red pigments and their authenticity

The most valuable pigment of the Roman wall paintings was the red color obtained from powdered cinnabar (Minium Cinnabaris pigment), the red mercury sulfide (HgS), which was brought from mercury (Hg) deposits in the Roman Empire. To address the question of whether sulfur isotope signatures can serve as a rapid method to establish the provenance of the red pigment in Roman frescoes, we have measured the sulfur isotope composition (delta(34) S value in parts per thousand VCDT) in samples of wall painting from the Roman city Aventicum (Avenches, Vaud, Switzerland) and compared them with values from cinnabar from European mercury deposits (Almaden in Spain, Idria in Slovenia, Monte Amiata in Italy, Moschellandsberg in Germany, and Genepy in France). Our study shows that the delta(34) S values of cinnabar from the studied Roman wall paintings fall within or near to the composition of Almaden cinnabar; thus, the provenance of the raw material may be deduced. This approach may provide information on provenance and authenticity in archaeological, restoration and forensic studies of Roman and Greek frescoes. Copyright (c) 2010 John Wiley & Sons, Ltd.