Biological Markers Of Exposure Research Articles

Bisphenol A Negatively Impacts Human Sperm MicroRNA and Protein Profiles

AbstractBisphenol A (BPA), a widely prevalent endocrine disruptor, has detrimental effects on human health and male reproduction. Elevated BPA levels have been linked to reduced sperm quality and production, while paternal exposure may result in poor reproductive outcomes and offspring health. For many years, the effects of BPA exposure in human reproduction were mainly attributed to the deregulation of the hypothalamic–pituitary–gonadal (HPG) axis. In the past decades, other mechanisms of action have been proposed, and studies highlighting epigenetic alterations linked to BPA in sperm emerged. Nevertheless, the impact of BPA on human sperm miRNA and protein profiles and its implications for fertilization and post-fertilization events remain unexplored. This study aimed to investigate the association between BPA concentration in seminal plasma and seminal quality and to examine the alterations in human sperm miRNA and protein expression among men with varying BPA levels in seminal plasma. BPA levels were measured in seminal plasma from 102 Portuguese men, and it was detected in 88% of the samples. No correlation was observed between BPA levels and age or seminal parameters. The small RNA content of 15 normozoospermic samples was evaluated using small RNA sequencing, revealing that 15 miRNAs exhibited a correlation with BPA levels. Gene ontology analysis of their target genes indicated their involvement in embryonic development and response to stress. The proteome of 20 normozoospermic human sperm samples, categorized into four groups based on BPA levels, was accessed by liquid chromatography–mass spectrometry. Data are available via ProteomeXchange with the identifier PXD047280. Sixty-two differentially expressed proteins were identified across groups. The biological processes most affected in samples with higher BPA levels were “protein sumoylation” and “cytoplasmic translation”. The altered miRNAs and proteins identified in spermatozoa from men environmentally exposed to BPA represent potential biological markers of exposure to this endocrine disruptor and may help elucidate cases of idiopathic male infertility, fertilization failure, and abnormal embryo development.

Optimization of a method for collecting infant and toddler urine for non-target analysis using cotton pads and commercially available disposable diapers.

Urine is an abundant and useful medium for measuring biomarkers related to chemical exposures in infants and children. Identification of novel biomarkers is greatly enhanced with non-targeted analysis (NTA), a powerful methodology for broad chemical analysis of environmental and biological specimens. However, collecting urine in non-toilet trained children presents many challenges, and contamination from specimen collection can impact NTA results. We optimized a caregiver-driven method for collecting urine from infants and children using cotton pads and commercially available disposable diapers for NTA and demonstrate its applicability to various children biomonitoring studies. Experiments were first performed to evaluate the effects of processing method (i.e., centrifuge vs. syringe), storage temperature, and diaper brand on recovery of urine absorbed to cotton pads. Caregivers of 11 children (<2 years) used and retained diapers (with cotton pads) to collect their child's urine for 24 h. Specimens were analyzed via a NTA method implementing an exclusion list of ions related to contamination from collection materials. Centrifuging cotton pads through a small-pore membrane, compared to a manual syringe method, and storing diapers at 4 °C, compared to room temperature, resulted in larger volumes of recovered sample. This method was successfully implemented to recover urine from cotton pads collected in the field; between 5-9 diapers were collected per child in 24 h, and the total mean volume of urine recovered was 44.7 (range 26.7-71.1) mL. NTA yielded a list of compounds present in urine and/or stool that may hold promise as biomarkers of chemical exposures from a variety of sources. Infant and children urine is a valuable matrix for studies of the early life exposome, in that numerous biological markers of exposure and outcome can be derived from a single analysis. Depending on the nature of the exposure study, it may be the case that a simple collection method that can be facilitated by caregivers of young children is desirable, especially when time-integrated samples or large volumes of urine are needed. We describe the process for development and results of an optimized method for urine collection and analysis using commercially available diapers and non-target analysis.

Occupational Exposures to Engineered Nanomaterials: a Review of Workplace Exposure Assessment Methods.

The purpose of this review is to consolidate exposure assessment methods for occupational research on engineered nanomaterials (ENMs) published within the past 5years (2015-2020). The three ENMs that generated the highest volume of new research include titanium dioxide, graphene, and aluminum oxide. A multi-metric approach, using both online and offline instruments and analyses, has been found to be a useful method to characterize ENM workplace exposures and was commonly used in the recently published literature. Particle number concentration was the most common online exposure metric used, followed by the metrics of mass and surface area. There are currently no consensus methods for offline analyses of most ENMs. Researchers generally used gravimetric or elemental analyses for carbonaceous nanomaterials, titanium dioxide, and other nanometals, but there was little overlap between other ENM materials reviewed. Using biological markers of exposure, such as urinary oxidative stress biomarkers, as an indication of chronic exposure may also be useful for some ENMs and should be further researched. Generally, similar online instrumentation and offline electron microscopy methods were used for all ENMs. However, this consistency was not observed for offline mass analysis methods within specific ENMs. Consolidation of the most recent methods and results of exposure assessments within this broad material category can guide researchers toward future areas of study. Establishing consensus methods of exposure assessment for each individual ENM is crucial to characterizing workplace exposures, pooling data to fully understand their associated risks, and developing useful occupational exposure limits.

Biological responses in fish exposed to municipal wastewater treatment plant effluent in situ

Abstract Effluents from municipal wastewater treatment plants (MWTPs) are complex mixtures of chemicals including endocrine-disrupting compounds (EDCs) and 17α-ethynylestradiol (EE2). The objective of this study was to evaluate selected responses of two fish species, in two different years, exposed in situ to MWTP effluent. Biological markers of exposure (plasma vitellogenin (VTG) and antioxidant enzymes) were measured in two species of male fish, rainbow trout (Oncorhynchus mykiss) and fathead minnow (Pimephales promelas), caged at sites associated with wastewater outfall. The estrogenicity of the final effluent in 2010 was determined to be 17.0 + 0.4 ng/L estrogen equivalents (EEQ) and reduced to 7.5 + 2.9 ng/L EEQ after infrastructure upgrades. Pharmaceuticals and personal care products in the effluent and surface water in both years confirmed the exposures at each downstream site. Despite the presence of estrogenic compounds in the MWTP effluent, no effluent-caged male fish demonstrated plasma VTG induction. Minnows and trout that received an intraperitoneal injection of 5 mg/g EE2 showed VTG induction at both field sites. In 2012, the liver somatic index (LSI) of both species increased with exposure, as did changes in antioxidant enzymes, and reactive oxygen species (ROS) activity. Multiple biological mechanisms are modified by effluent exposure, and multiple endpoints are needed to assess risk.

Biomarkers of exposure and early effect in three contaminated sites of southern Italy: protocols for etiological epidemiological studies

IntroductionEnvironmental pollution has been progressively becoming one of the main risk factors to human diseases. In particular, populations living in high-contaminated sites are particularly exposed to environmental toxicants, with consequent...

The CHEAR Data Repository

TPS 691: Methods of measurement, design and data analysis, Exhibition Hall, Ground floor, August 28, 2019, 3:00 PM - 4:30 PM Funded by the U.S. National Institute of Environmental Health Sciences, the Children’s Health Exposure Analysis Resource (CHEAR) provides scientific investigators access to laboratory and statistical analyses aimed at incorporating and expanding environmental exposures within their research. To benefit the broader research community, the CHEAR Data Center has created a public data repository that houses deidentified data from studies accepted into the CHEAR program. To date, 26 studies have submitted data containing > 41,000 specimens, > 3,000 mothers and children and 139 environmental chemicals. The goal of this repository is to promote the secondary analysis of pooled CHEAR studies by providing data in a manner that is findable, accessible, interoperable and reusable (FAIR). The repository has been constructed by coupling the open-source Human-aware Data Acquisition Framework with semantic annotation templates that transform CHEAR datasets into machine-readable knowledge graphs. These tools facilitate the ingestion, semantic-mapping, harmonization and accessibility of data (epidemiologic, clinical and biomarker) and metadata across the multiple studies within the CHEAR Program. We demonstrate how users of the public repository have the ability to simultaneously search, view, and download data from multiple CHEAR studies. The repository can be searched based on a number of factors including health outcomes, biological markers of exposure and common covariates. Because data have been harmonized to a common vocabulary (the CHEAR ontology), downloaded datasets automatically contain CHEAR-wide harmonized codes and labels for variables that are present in multiple studies. By selecting common data elements, users can create customized datasets with accompanying codebooks in a format that is easily imported into statistical analysis software. For maximal FAIR impact, we have promoted the CHEAR data, tools and methods through Google dataset search, Github, and Bioportal. The repository will encourage secondary analysis of pooled CHEAR studies, facilitating investigations that leverage larger sample sizes and greater exposure variability.

Validity of different biomonitoring parameters in human urine for the assessment of occupational exposure to naphthalene.

Up to date, information on the validity of human biomonitoring (HBM) parameters of naphthalene exposure is poor. This study was performed to reveal the relation between occupational exposure to naphthalene and biological exposure markers. Therefore, ten lowly and highly exposed workers from the abrasives industry were selected to characterise a broad exposure range. Naphthalene in air was determined by personal air monitoring during one shift. For biological monitoring, pre- and post-shift urine samples collected on 2days of a working week were analysed for 1,2-dihydroxynaphthalene (1,2-DHN), 1- and 2-naphthol, 1- and 2-naphthylmercapturic acid (NMA). The naphthalene concentration in air was in the range of 0.5 to 11.6mg/m3. The biomarkers in urine showed post-shift concentration in the range of 114-51,809µg/L for 1,2-DHN, 0.8-666µg/L for 1-NMA, 2-2698µg/L for 1-naphthol and 4-1135µg/L for 2-naphthol, respectively. 2-NMA was not detected. The urinary levels increased significantly from pre- to post-shift for all analysed parameters and an accumulation over the working week was observed. Significant positive correlations were observed between 1,2-DHN, 1-NMA, 1- and 2-naphthol in post-shift urine samples and personal exposure to naphthalene in the air. 1-NMA and 1,2-DHN, 1- and 2-naphthol have been demonstrated as suitable biomarkers for naphthalene exposure monitoring. Of the determined biomarkers, 1,2-DHN is by far the metabolite with the highest concentration in the urine samples.

Analysis of cause-effect relations of the levels of biological markers of exposure to heavy metals with their personalized loading dose in the areas of wastes’ influence induced by the operation of the metallurgical plant in the past

The article analyses and demonstrates methodical approaches to the practical implementation of the one of key stages in the formation of the evidential base of hazard to health caused by the negative impact of environmental factors. The stage comprises the establishment of the causal dependence (proven relation) of the chemicals’ content in biological media of exposed population on the personalized loading dose. The experiment included the local population (224 cases) living in the area of the exposure of the Dzhidinsky tungsten-molybdenum combine waste (Republic of Buryatia). The cartographic association of the residential areas of the population has been made as well as the approximation of the field study data of environmental factors due to 7 heavy metals has been performed. The total personalized loading dose caused by exposure to lead, cadmium, nickel, chromium, zinc, copper, manganese (the wastes of the metallurgical plant) was calculated. It is evident that the poor quality of the environment leads to the contamination of biological media (blood) by chemicals. More than 90 significant biologically-based mathematical models of the system “exposure - exposure marker” have been received. On the example of cadmium there was established the total dose of 0.0003 mg /(kg*d) for the child population, the excess of which significantly increases chances of both exceeding the concentration of a substance in blood over the control level and leading to the formation of a stable causal relationship with exposure markers of the multimedia load.

Burn Pits Exposure and Chronic Respiratory Illnesses among Iraq and Afghanistan Veterans

Since the beginning of the current conflicts in Southwest Asia, more than 2 million service members have deployed in support of Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) Sharkey (Sharkey et al. 2016). Service members can be exposed to a variety of environmental hazards during deployment including pollutants from unregulated industry, particulate matter from desert environments, exhaust from military vehicles, and emissions from open-air burn pits. Exposure to emissions from burn pits has been a cause for concern because of the potential for respiratory health conditions (asthma, bronchitis, chronic obstructive pulmonary disease, constrictive bronchiolitis) and other chronic health conditions (Sharkey et al. 2016; IOM 2011). Burn pits, widely used in combat zones before 2009, are open areas for burning solid waste. Burn pit emissions can include harmful particulates and chemicals including dioxins, furans, lead, mercury, volatile organic compounds, and polcyclic aromatic hydrocarbons (Liu et al. 2016). Despite considerable media coverage and anecdotal reports from concerned service members, epidemiologic evidence of adverse health effects from burn pits exposure has been lacking until recently. For example, as recently as 2014, Abraham et al. noted that “no study has identified an association between burn pit emissions exposure and post deployment chronic lung conditions.” Similarly, the Institute of Medicine concluded in 2011 that there was insufficient evidence to develop firm conclusions about what long-term health effects might be seen in service members exposed to burn pits. Several factors suggest that this situation is likely to change. First, the number of veterans who have participated in the Airborne Hazards and Open Burn Pit Registry has steadily increased, making it feasible to conduct registry-based epidemiologic studies (Liu et al. 2016). A public law mandated by Congress in in 2013 required the Department of Veterans Affairs to establish a registry for veterans with potential burn pit exposure in Iraq or Afghanistan. Participation in the registry is accomplished by completing its online self-assessment questionnaire, which was designed to obtain a broad picture of the participants’ military exposures and health (Liu et al. 2016). Secondly, two recent epidemiologic studies have found that exposure to burn pits and deployment to Kabul, Afghanistan is associated with chronic respiratory conditions (Liu et al. 2016; Sharkey et al. 2016). Liu et al. (2016) examined associations between assumed geographic and self-reported burn pit emissions exposure and respiratory and cardiovascular outcomes in participants of the Airborne Hazards and Open Burn Pit Registry. The authors found significant dose-response associations for higher risk of self-reported emphysema, chronic bronchitis, or chronic obstructive pulmonary disease with increased days of deployment within 2 miles of selected burn pits (P-trend = 0.01) and self-reported burn pit smoke exposure (P-trend = 0.0005). Sharkey et al. (2016) conducted a retrospective cohort study to investigate associations between deployment to Kabul, Afghanistan and subsequent respiratory health among U.S. military personnel. The study population consisted of personnel who deployed to Kabul, select Operation Enduring Freedom locations, personnel stationed in the Republic of Korea, and U.S.-stationed personnel. A statistically elevated rate of asthma was observed among personnel deployed to Kabul, relative to U.S.-stationed personnel (IRR 1.61; 95% CI, 1.22–2.12), which is consistent with earlier research findings reported by Szema et al. (2010). Thirdly, because of the increasing time elapsed since exposure to burn pits during combat, the latency period may be approaching that sufficient to detect associations with emphysema in epidemiologic studies. It may also be feasible to conduct epidemiologic studies to examine associations with malignancies and pulmonary conditions that are infrequent in the general population (for example, glioblastoma of the brain, constrictive bronchiolitis) (King et al. 2011). A proportionate mortality ratio analysis of data from the Burn Pits 360 degrees registry, which was a hypothesis-generating study, found that deaths from malignancies were over-represented compared to deaths from chronic respiratory conditions (unpublished observations, Sunil Halder, 2018). In addition to additional population-based and registry-based epidemiologic studies of chronic health conditions among veterans exposed to toxic fumes from burn pits, longitudinal studies are needed that include serial measurements of pulmonary function and novel biological markers of exposure to polychlorinated dibeno-p-dioxins/dibenzofurans (Woeller et al. 2016). Individual-level exposure data obtained from microRNAs would reduce misclassification of exposure assessments based upon assumed geographic burn pit emissions exposure and avoid potential recall bias. Other studies are needed that include additional documented burn pit sites integrating particulate matter data, meterological and wind data, and other in-theatre exposures to understand the short- and long-term respiratory health issues associated with open-air burn pit smoke exposure (Smith et al. 2012).

Determination of 1-pyrenol in urine by gas chromatography with mass selective detector

Urinary 1-pyrenol belongs to the biological markers of exposure to the polyaromatic hydrocarbons. Several methods for the determination of 1-pyrenol in urine necessarily include enzymatic hydrolysis, extraction from the biological sample, and derivatization with the silylating agent. Enzymatic hydrolysis and silylation take very long time: 16 hours and 40 minutes respectively. A shorter and more sensitive version of the determination of 1-pyrenol in urine by gas chromatography with mass-selective detection is proposed. Enzymatic hydrolysis with β-glucuronidase is used for 1h to digest the conjugated form of 1-pyrenol (as glucuronide). After the enzymatic hydrolysis, the analyte is extracted from the biological matrix by hexane extraction, followed by evaporation of the extract to dry residue in an inert gas stream. The optimum conditions for liquid extraction are established by varying the ratio of salting out agent : extraction time : extraction ratio. The dry residue is re-dissolved and derivatized in the silylating reagent N, O-bis (trimethylsilyl) trifluoroacetamide (BSTFA) into trimethylsilyl ether at room temperature for 5 minutes. The analysis of the trimethylsilyl extract is carried out by gas chromatography on HP-5MS capillary column with mass-selective detection. The analyte is identified by the retention time and the ratio of the main and confirming ions. The high-accuracy determination is ensured by using the internal standard 1-pyrenol-d 9 . The range of detectable concentrations of the method is from 0.1 to 100 μg/l. Repeatability and interlaboratory precision are 4.4% and 6.4% respectively. The systematic error turns out to be insignificant. The accuracy is 14%. The method is tested on the urine samples of workers with the main professions in the aluminum production industry. Key words : 1-pyrenol, urine, gas chromatography-mass spectrometry, enzymatic hydrolysis, silylation (Russian) DOI: http://dx.doi.org/10.15826/analitika.2019.23.4.007 A.N. Alekseenko, O.M. Zhurba, A.V. Merinov FSBSI East-Siberian Institute of Medical and Ecological Research 12-a district, 3, Angarsk, 665827, Russian Federation

Effects of environmental pollution with aromatic hydrocarbons on endocrine and metabolic functions of the human placenta.

Phenol and 1-hydroxypyrene are biological markers of exposure to polycyclic aromatic hydrocarbons (PAH) that have certain negative effects on parenchymal organs such as the human placenta. The literature presents only few reports regarding the effects of elevated PAH levels on the functions of the human placenta. The aim of the work is to assess the effects of elevated PAH levels in excreted urine on the endocrine and metabolic functions of the human placenta obtained from a normal pregnancy. Tissue material from 50 afterbirths from Płock constituted a study group, whereas 50 afterbirths from Kutno constituted a control group. Immunohistochemical reactions with the peroxidase method using LSAB kits (DAKO, Denmark) were performed. The extent and intensity of reactions were analysed. The levels of phenols and 1-hydroxypyrene in the excreted urine of pregnant women (undergoing delivery) were detected using gas chromatography and colorimetry. The statistical analysis used the PQStat v.1.6.2 software; moreover, t-student and chi-square tests were used. Differences were considered to be significant at the significance level of 95% (p<0.05). The levels of phenol and 1-hydroxypyrene in the excreted urine were demonstrated to be statistically significantly higher in patients living in the area of Płock. Statistically lower expression of placental glutathione transferase and lower immunohistochemical demonstration of the placental phosphatase activity were observed in placentas from Płock. It has been demonstrated that the expression of the oestrogen receptor activity and placental gonadotropin is significantly higher in placentas from areas not contaminated with aromatic hydrocarbons (Kutno). The course of pregnancy in the environment with elevated levels of aromatic hydrocarbons leads to impaired placental functioning and reduced endocrine and metabolic activity of the placenta.

Lower urinary cotinine level is associated with a trend toward more myopic refractive errors in Korean adolescents.

PurposeTo investigate the association between urinary cotinine levels as an objective biological marker for exposure to nicotine and refractive status.Patients and methodsThis cross-sectional study analyzed data from the Korea National Health and Nutrition Examination Survey between 2008 and 2011. A total of 1139 Korean adolescents aged 12-18 years were enrolled. Urinary cotinine concentrations and other potential risk factors for myopia were examined. Correlation analyses and multivariate regression analysis were performed to investigate the association between urinary cotinine level and refractive error.ResultsSpherical equivalent correlated significantly with urinary cotinine concentration (r=0.104, P=0.011). Lower urinary cotinine level was associated with a trend toward more myopic refractive errors (P for trend=0.003). After adjusting for age, sex, area of residence, physical activity, serum 25-hydroxyvitamin D level, parental income level, and receipt of basic livelihood security, subjects with a low urinary cotinine level had a significantly increased risk of myopia <-0.5 D (odds ratio (OR) 1.95, 95% confidence interval (CI) 1.18-3.21), <-3.0 D (OR 2.03, 95% CI 1.29-3.2), and <-6.0 D (OR 2.2, 95% CI, 1.15-4.23) when compared with subjects with a high urinary cotinine level. As urinary cotinine level decreased, the risks of myopia <-0.5 D, <-3.0 D, and <-6.0 D increased significantly (P for trend <0.05).ConclusionA trend toward less myopic refractive error was observed among Korean adolescents with higher urinary cotinine levels. This result provides the epidemiologic evidence implying nicotine as a potential modulator related with refractive development. Further studies with full consideration for myopia-associated risk factors are required to yield clear answers on the direct effect of smoking to the refractive status.

Association between heavy metal and metalloid levels in topsoil and cancer mortality in Spain

Spatio-temporal cancer mortality studies in Spain have revealed patterns for some tumours which display a distribution that is similar across the sexes and persists over time. Such characteristics would be common to tumours that shared risk factors, including the geochemical composition of the soil. The aim of this study was to assess the possible association between heavy metal and metalloid levels in topsoil (upper soil horizon) and cancer mortality in mainland Spain. Ecological cancer mortality study at a municipal level, covering 861,440 cancer deaths (27 different tumour locations) in 7917 Spanish mainland towns, from 1999 to 2008. The elements included in this analysis were Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. Topsoil levels (partial extraction) were determined by ICP-MS at 13,317 sampling points. For the analysis, the data on the topsoil composition have been transformed by the centred logratio (clr-transformation). Principal factor analysis was performed to obtain independent latent factors for the transformed variables. To estimate the effect of heavy metal levels in topsoil composition on mortality, we fitted Besag, York and Mollié models, which included each town’s factor scores as the explanatory variable. Integrated Nested Laplace Approximation (INLA) was used as a tool for Bayesian inference. All results were adjusted for sociodemographic variables. The results showed an association between trace contents of heavy metals and metalloids in topsoil and mortality due to tumours of the digestive system in mainland Spain. This association was observed in both sexes, something that would support the hypothesis that the incorporation of heavy metals into the trophic chain might be playing a role in the aetiology of some types of cancer. Topsoil composition and the presence of potentially toxic elements in trace concentrations might be an additional component in the aetiology of some types of cancer, and go some way to determine the ensuing geographic differences in mortality in Spain. The results support the interest of inclusion of heavy metal levels in topsoil as a hypothesis in analytical epidemiological studies using biological markers of exposure to heavy metals and metalloids.

Validation of a new high-throughput method to determine urinary S-phenylmercapturic acid using low-temperature partitioning extraction and ultra high performance liquid chromatography-mass spectrometry.

A new highly sensitive and environmentally friendly analytical method, using low-temperature partition extraction and ultra-high-performance liquid chromatography with tandem mass spectrometry, without the use of a labeled analyte, was developed and validated to determine and quantify urinary S-phenylmercapturic acid in urine samples. The World Health Organization, in its guidelines for air quality in Europe, recognizes that benzene is carcinogenic to humans and there is no safe level of exposure. Urinary S-phenylmercapturic acid is a sensitive and specific biological marker of exposure to benzene. The new analytical method, extraction, and analysis, were linear in the working range between 0.1 and 200.0μg/L, precise (relative standard deviation lower than 6.0%), accurate (97.0-105.0%), and sensitive. The method's limits of detection and quantification were 0.02 and 0.084μg/L, respectively. The recovery with the low-temperature partition extraction was 96.1%, with relative standard deviation less than 3.8%. The method is simple, accurate, and reproducible, and has been successfully applied in the evaluation of nonoccupational exposure to benzene, by urinary S-phenylmercapturic acid in urine samples.

An Assessment of the Spatial and Temporal Variability of Biological Responses to Municipal Wastewater Effluent in Rainbow Darter (Etheostoma caeruleum) Collected along an Urban Gradient.

Municipal wastewater effluent (MWWE) and its constituents, such as chemicals of emerging concern, pose a potential threat to the sustainability of fish populations by disrupting key endocrine functions in aquatic organisms. While studies have demonstrated changes in biological markers of exposure of aquatic organisms to groups of chemicals of emerging concern, the variability of these markers over time has not been sufficiently described in wild fish species. The aim of this study was to assess the spatial and temporal variability of biological markers in response to MWWE exposure and to test the consistency of these responses between seasons and among years. Rainbow darter (Etheostoma caeruleum) were collected in spring and fall seasons over a 5-year period in the Grand River, Ontario, Canada. In addition to surface water chemistry (nutrients and selected pharmaceuticals), measures were taken across levels of biological organization in rainbow darter. The measurements of hormone production, gonad development, and intersex severity were temporally consistent and suggested impaired reproduction in male fish collected downstream of MWWE outfalls. In contrast, ovarian development and hormone production in females appeared to be influenced more by urbanization than MWWE. Measures of gene expression and somatic indices were highly variable between sites and years, respectively, and were inconclusive in terms of the impacts of MWWE overall. Robust biomonitoring programs must consider these factors in both the design and interpretation of results, especially when spatial and temporal sampling of biological endpoints is limited. Assessing the effects of contaminants and other stressors on fish in watersheds would be greatly enhanced by an approach that considers natural variability in the endpoints being measured.

Use of human milk in the assessment of toxic metal exposure and essential element status in breastfeeding women and their infants in coastal Croatia

Pregnant and lactating women and infants are vulnerable population groups for adverse effects of toxic metals due to their high nutritional needs and the resultant increased gastrointestinal absorption of both, essential and toxic elements. Although breastfeeding is recommended for infants worldwide, as human milk is the best source of nutrients and other required bioactive factors, it is also a pathway of maternal excretion of toxic substances including toxic metals and thus a source of infant exposure. The aim of this research was to assess health risks in breastfeeding women in the coastal area of the Republic of Croatia and their infants (N=107) due to maternal exposure to Cd and Pb via cigarette smoking, and Hg via seafood and dental amalgam fillings, and their interaction with essential elements. Biological markers of exposure were the concentrations of main toxic metals Pb, Cd and Hg in maternal blood and three types of breast milk throughout lactation stages. Biological markers of effects were the levels of essential elements Ca, Fe, Cu, Zn and Se in maternal serum and breast milk. With regard to cigarette smoking as a source of exposure to Cd and Pb, there were effects of smoking on Cd concentration in blood and correlations between the smoking index and Cd concentrations in maternal blood (Ͽ=0.593; P<0.001) and mature milk (Ͽ=0.271; P=0.011) and Pb concentration in transitional milk (Ͽ=0.280; P=0.042). Regarding fish, we found correlations between weekly consumption frequency and total Hg concentrations in maternal blood (Ͽ=0.292; P=0.003) and mature milk (Ͽ=0.303; P=0.003). The number of dental amalgam fillings correlated with total Hg concentrations in colostrum (Ͽ=0.489; P=0.005) and transitional milk (Ͽ=0.309; P=0.018). As for the essential element status, only Se levels in maternal serum decreased by 10% in persons who continued smoking during pregnancy compared to non-smokers. In conclusion, the levels of main toxic metals Cd, Pb and Hg and essential elements Ca, Fe, Cu, Zn and Se in maternal blood and three types of breast milk samples in the studied area of coastal Croatia showed no risk of disrupted essential element levels with regard of toxic metal exposure in both breastfeeding women and their infants.

DYNAMICS OF ACETYLCHOLINESTERASE ACTIVITY AND WATER-SOLUBLE PROTEINS IN THE BRAIN FISH AT DIFFERENT SPEEDS IN THE SUMMER SEASON HEATING OF THE YEAR

The critical thermal maximum (СTM) of the fingerlings of river perch and yearlings of carp are investigated. The range of heating rates of from 0.08 to 46 ° C/h. The values of the two-year carp from KTM for all heating rates were higher than the two-year perch, and the maximum temperature upheaval and loss of coordination of movements observed in carp at the slowest rate, the perch – at the very slow and fast heating rates. The brain enzyme acetyilcholinesterase activity (АChE) and soluble protein content (SPC) of the fishes, subjected heating is determined. Changes of activity АCh and contents SPS are discussed at different rates of heating. On the basis of data on the activity of AChE and content in CPC, one can conclude that in the range of heating rates up to 8? C / h by fish quite easily adaptable to increasing ambient temperature. However, further increasing the heating rate leads to increased cholinergic biosynthetic processes in the brain of the fish, which is reflected in increased activity of AChE and protein content. It is assumed that increasing values of both parameters at a heating rate of 16 and 32 °C/h is the stress response of fish in response to changing ambient temperature. It is possible that the performance of AChE and PCB could potentially be used as a biological marker of exposure to heat different types (natural environment, pre-acclimation, and heating or cooling). Thus, the research activity of AChE and VRB in the brain content of fish at different rate water heating allows to re-evaluate how adaptation possibilities, and physiological and biochemical mechanisms of the reactions of aquatic animals in the course of the temperature adaptations.

Prenatal exposure to endocrine disrupting chemicals and birth weight—A prospective cohort study

ABSTRACTPrenatal exposure to endocrine disrupting chemicals may affect fetal development through disruption of hormonal actions and epigenetic modifications, potentially predisposing individuals to later on-set health risks, such as obesity. The objective of this study was to determine associations between biological exposure markers of various endocrine disrupting chemicals and birth weight in a newly established, prospective mother-child cohort in the Netherlands. Birth weight (n = 91) was obtained from birth records, and exposure to dichlorodiphenyldichloroethylene (DDE), three di-2-ethylhexyl phthalate (DEHP) metabolites, polychlorinated biphenyl-153, perfluorooctanesulfonic acid (PFOS), and perfluorooctanoic acid (PFOA) was determined in cord plasma. For DDE, exposure was also measured in breast milk. Linear regression analysis was used to determine associations between compounds and birth weight, which were stratified for gender and adjusted for a priori defined covariates. Increased exposure to DDE was associated with lower birth weight in boys (>95.89 ng L−1, −325.9 g, 95% CI −634.26 to −17.56), whereas in girls a tendency towards a higher birth weight was observed. Lower birth weights for boys were also observed for high exposure to MECPP, and to a certain extent also for PFOA. MEHHP and PFOS exposure on the other hand were associated with higher birth weights in boys. In girls no effects were observed for these compounds. It can be concluded that prenatal exposure to DDE, perfluorinated alkyl acids, and phthalates was associated with changes in birth weight in this population. Associations were gender specific, and appeared to be non-linear. Since the population was relatively small, results should be interpreted with caution.

Candidate gene biodosimeters of mice and human exposure to ionizing radiation by quantitative reverse transcription polymerase chain reaction.

Understanding of cellular responses to ionizing radiation (IR) is essential for the development of predictive markers useful for assessing human exposure. Biological markers of exposure to IR in human populations are of great interest for assessing normal tissue injury in radiation oncology and for biodosimetry in nuclear incidents and accidental radiation exposures. Traditional radiation exposure biomarkers based on cytogenetic assays (biodosimetry), are time-consuming and do not provide results fast enough and requires highly trained personnel for scoring. Hence, the development of rapid biodosimetry methods is one of the highest priorities. Exposure of cells to IR activates multiple signal transduction pathways, which result in complex alterations in gene-expression. Real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR) has become the benchmark for the detection and quantification of RNA targets and is being utilized increasingly in monitoring the specific genes with more accurately and sensitively. This review evaluates the RT-qPCR as a biodosimetry method and we investigated the papers from 2000 up to now, which identified the genes-expression related the DNA repair, cell cycle checkpoint, and apoptosis induced by ionization radiation in peripheral blood and determined as biodosimeters. In conclusion, it could be say that RT-qPCR technique for determining the specific genes as biodosimeters could be a fully quantitative reliable and sensitive method. Furthermore, the results of the current review will help the researchers to recognize the most expressed genes induced by ionization radiation.

Study of the bile proteome of Atlantic cod (Gadus morhua): Multi-biological markers of exposure to polycyclic aromatic hydrocarbons

PAH metabolites present in bile are well-known biological markers of exposure in fish, and their investigation is recommended by the ICES (International Council for the Exploration of the Sea) and the OSPAR convention (Convention for the Protection of the Marine Environment of the North-East Atlantic) for monitoring purposes.Development of analytical strategies for fish bile is encouraged by the need for more sensitive and informative markers (e.g. capable of tracking the PAH composition of contamination sources) and strengthened by recent results in both fish genomics and proteomics. Herein, the study of the Atlantic cod bile proteome is presented. Preliminary testing for discovering new sensitive markers in the form of expressed proteins affected by PAH exposure (i.e. PAH–protein adducts) is reported. Protein markers were identified using LC–MS/MS analysis, as single biological indicators. Through multivariate analyses, the overall proteome was revealed to be a sensitive multi-biological marker of exposure to PAHs.