Health Effects Of Environmental Contaminants Research Articles

Metoprolol elicits neurobehavioral insufficiency and oxidative damage in nontarget Nauphoeta cinerea nymphs.

Metoprolol, a drug for hypertension and cardiovascular diseases, has become a contaminant of emerging concern because of its frequent detection in various environmental matrices globally. The dwindling in the biodiversity of useful insects owing to increasing presence of environmental chemicals is currently a great interest to the scientific community. In the current research, the toxicological impact of ecologically relevant concentrations of metoprolol at 0, 0.05, 0.1, 0.25, and 0.5 μg/L on Nauphoeta cinerea nymphs following exposure for 42 consecutive days was evaluated. The insects' behavior was analyzed with automated video-tracking software (ANY-maze, Stoelting Co, USA) while biochemical assays were done using the midgut, head and fat body. Metoprolol-exposed nymphs exhibited significant diminutions in the path efficiency, mobility time, distance traveled, body rotation, maximum speed and turn angle cum more episodes, and time of freezing. In addition, the heat maps and track plots confirmed the metoprolol-mediated wane in the exploratory and locomotor fitness of the insects. Compared with control, metoprolol exposure decreased acetylcholinesterase activity in insects head. Antioxidant enzymes activities and glutathione level were markedly decreased whereas indices of inflammation and oxidative injury to proteins and lipids were significantly increased in head, midgut and fat body of metoprolol-exposed insects. Taken together, metoprolol exposure induces neurobehavioral insufficiency and oxido-inflammatory injury in N. cinerea nymphs. These findings suggest the potential health effects of environmental contamination with metoprolol on ecologically and economically important nontarget insects.

Comparative Assessment of Physical Development of Children and Adolescents Living in Territories with Different Levels of Anthropogenic Load

Introduction: Correlations are considered as a reliable indicator of adaptive variability in populations. Objective: To make a comparative assessment of physical development of children and adolescents living in areas with different levels of anthropogenic load. Material and methods: We analyzed the structure of correlations between morphological and functional indicators of children and adolescents (n = 5,137) and the level of anthropogenic load (from relatively satisfactory to critical) in four territories for the years 2018–2021. We measured body length and weight, chest circumference, right and left hand grip strength, vital capacity of the lungs, heart rate, systolic and diastolic blood pressure, and sexual size dimorphism, and then calculated the body mass index and body surface area. The variability of somatic and functional indices was examined separately in age-standardized groups of 9, 13 and 15-year-old boys and girls. Significant differences in the frequencies of statistical correlations in each group and in different environmental clusters were determined. Results: We established a statistical decrease in body length by 0.82 % and in right and left handgrip strength by 5.22 % and 9.68 %, respectively, accompanied by an increase in body weight by 5.02 %, chest circumference by 1.26 %, and vital capacity by 5.56 %, all associated with an increase in the level of anthropogenic load in the area. In environmental clusters with intense and critical load, we noted a decrease in systolic and diastolic blood pressure by 4.54 % and 5.89 %, respectively, and an increase in the heart rate by 2.81 %. We found an increase in the total number of age and sex-specific intrasystemic (anthropometric) and intersystemic (anthropometric/hemodynamic) morphofunctional correlations from 186 in clean areas to 228 in heavily polluted ones. Health effects of environmental contamination was the most pronounced in 9-year-old children of both sexes. Conclusion: An increase in the frequency of significant intrasystemic and intersystemic correlations of morphological and functional indicators in children and adolescents with the increase in environmental load indicates tension of adaptive mechanisms in the body; the effect of interactions between environmental pollution and anthropogenic parameters in age and sex groups is attributed to greater sensitivity in the male cohort.

Variable Selection in High Dimensional Data with Interactions

A common research area in statistical machine learning has been variable selection in high dimensional settings. In recent years, numerous effective approaches have been created to deal with these challenges. In order to improve the prediction accuracy of the model for the given dataset, this study sought to present a double approach variable selection method when pairwise interactions between the explanatory variables exist and to choose the smallest explanatory variable set (considering interactions among them). In this study, a double step method consolidating Random Forest and Adaptive Elastic Net was further examined to mimic potential health effects of environmental contamination. When there were existing interactions in the data or none at all, the double step approach was compared to the single-step adaptive elastic net method and two-step CART paired with the adaptive elastic net method. Using significant statistical tests like RMSE, R2 , and the quantity of the variable chosen for the final model, the success of the strategies was measured. The double step RF+AENET approach produces a simple, constrained model. Despite the complex association between exposure variables, it has the lowest false detection rate for null interactions. A set of variables that have correlation with the result are effectively retained by the screening and variable reduction processes in the RF step of the RF+AENET approach. The double step RF+AENET performs prediction better than a single technique and chooses a sparse model that is close to the true model. Thus, it can be said that when there are pairwise interactions between variables in the simulated biological dataset, the double step technique is a better method for model prediction and parameter estimation. Keywords: Adaptive Elastic Net, Random Forest, Variable Selection, CART.

Per- and Polyfluoroalkyl Substances and Risk of Myocardial Infarction and Stroke: A Nested Case-Control Study in Sweden.

Background:Per- and polyfluoroalkyl substances (PFAS) are widespread and persistent pollutants that have been associated with elevated cholesterol levels. However, data on incident cardiovascular disease (CVD) is lacking.Objectives:We investigated the association of exposure to PFAS with risk of myocardial infarction and stroke and, subsidiary, with baseline blood lipids.Methods:This population-based nested case–control study included first incident myocardial infarction and stroke cases with matched controls from two Swedish cohorts: the Swedish Mammography Cohort-Clinical (SMC-C) and the Cohort of 60-year-olds (60YO). Baseline blood sampling occurred during 2003–2009 and 1997–1999 with follow-up through 2017 and 2014 for the SMC-C and the 60YO, respectively. Eight plasma PFAS concentrations were measured using targeted liquid chromatography–triple quadrupole mass spectrometry. Five of these were quantifiable in both cohorts; individual values and their standardized sum were categorized into tertiles based on the controls. First incident myocardial infarction () and ischemic stroke () cases were ascertained via linkage to the National Inpatient Register and the Cause of Death Register. Controls were randomly selected from each cohort after matching for age, sex, and sample date. Baseline blood lipids were measured in plasma or serum after overnight fasting.Results:Among the 1,528 case–control subjects, the mean (standard deviation) age was 66 (7.7) y and 67% of them were women. In multivariable-adjusted analyses, the third tertile of the standardized sum of five PFAS associated with higher cholesterol and lower triglyceride levels among controls at baseline (). The corresponding results were [95% confidence interval (CI): 0.53, 0.93] for CVD, 0.60 (95% CI: 0.39, 0.92) for myocardial infarction, and 0.83 (95% CI: 0.46, 1.50) for stroke.Discussion:This study indicated that exposure to PFAS, although associated with increased cholesterol levels, did not associate with an increased risk of myocardial infarction, stroke, or their composite end point. The findings improve our knowledge on potential health effects of environmental contaminants in the CVD context. https://doi.org/10.1289/EHP9791

Older Adults' Perceptions of Nutrition as Protective Against Detrimental Effects of Environmental Pollution

The aging process makes older adults vulnerable to the detrimental health effects of environmental contaminants. Our study assessed older adults' perceptions regarding diet as protective against environmental contaminants, levels of concern about exposure to environmental contaminants, and interest in learning about protective food-related strategies. A needs assessment to collect such information had not been conducted among older adults. Health fair survey results showed that respondents perceived diet as beneficial against contaminants, were concerned about health implications of exposure, and were interested in learning how to protect health through diet-related strategies. Results suggest that a nutrition-focused curriculum addressing how dietary strategies can help protect against environmental contaminants is needed for Extension professionals.

Informing 21st-Century Risk Assessments with 21st-Century Science.

SummaryUnderstanding and preventing adverse impacts from chemicals in the environment is fundamental to protecting public health, and chemical risk assessments are used to inform public health decisions in the United States and around the world. Traditional chemical risk assessments focus on health effects of environmental contaminants on a chemical-by-chemical basis, largely based on data from animal models using exposures that are typically higher than those experienced by humans. Results from environmental epidemiology studies sometimes show effects that are not observed in animal studies at human exposure levels that are lower than those used in animal studies. In addition, new approaches such as Toxicology in the 21st Century (Tox21) and exposure forecasting (ExpoCast) are generating mechanistic data that provide broad coverage of chemical space, chemical mixtures, and potential associated health outcomes, along with improved exposure estimates. It is becoming clear that risk assessments in the future will need to use the full range of available mechanistic, animal, and human data to integrate multiple types of data and to consider nontraditional health outcomes and end points. This perspective was developed at the “Strengthening the Scientific Basis of Chemical Safety Assessments” workshop, which was cosponsored by the U.S. Environmental Protection Agency and the National Institute of Environmental Health Sciences, where gaps between the emerging science and traditional chemical risk assessments were explored, and approaches for bridging the gaps were considered.

Nigerian bonny‐light crude oil induces alteration in testicular stress response proteins and caspase‐3 dependent apoptosis in albino wistar rats

In the past few decades, there has been much concern about the adverse health effects of environmental contaminants in general and Crude Oil in particular around the Niger Delta region of Nigeria where all the crude Oil exploration is taking place. Studies have shown the repro-toxic effects of Bonny-light crude oil (BLCO). However, the insight into the mechanisms of gonadal toxicity induced by BLCO is not well known. In this study, we sought to elucidate the mechanism(s) underpinning the gonadal effects within hours of exposure to BLCO. Experimental rats were divided into five groups of four each. Animals were orally administered with a single dose of BLCO (800 mg/kg body weight) and killed at 0, 6, 12, 24, and 72 h post-treatment. The levels and time-course of induction of stress response proteins and apoptosis-related proteins like cytochorome C, caspase 3 and procaspase 9, Fas-FasL, NF-kB and TNF-α were determined to assess sequential induction of apoptosis in the rat testis. DNA damage was assessed by TUNEL assay. Administration of BLCO resulted in a significant increase in the levels of stress response proteins and apoptotis- related proteins as early as 6 h following exposure. Time-dependent elevations in the levels of the proteins were observed. The DNA damage was measured and showed time-dependent increase in the TUNEL positive cells of testicular cells. The study demonstrates induction of testicular apoptosis in adult rats following exposure to a single dose of BLCO.

Vascular endothelium as a target of diesel particulate matter-associated toxicants

As the layer of cells separating all systemic organs from circulating xenobiotics, the vascular endothelium is gaining increasing attention as a major target of toxicants, even those brought into the body by inhalation. Endothelial cell dysfunction is central to many major cardiovascular outcomes, including atherosclerosis and related outcomes of myocardial infarction and stroke. Injured endothelial cells exhibit reduced dilatory properties, express adhesion molecules critical to inflammation, and fail to release platelet inhibitor molecules nitric oxide and prostacyclin. Exposures to a variety of air pollutants have been shown to negatively impact endothelial function. Vasodilation is impaired by diesel emissions (Knuckles et al. 2008), particulate matter (Nurkiewicz et al. 2006), and ozone (Chuang et al. 2009). Increased vascular inflammation is induced by particulate matter and combustion-source emissions (Yatera et al. 2008; Lund et al. 2011). Clearly oxidative stress is a factor (Cherng et al. 2011), and nitric oxide synthase uncoupling has been reported (Knuckles et al. 2008; Nurkiewicz et al. 2009), but intracellular signaling and transcriptional alterations have not been studied in as much detail. As a result, much of the intracellular mechanisms underlying endothelial dysfunction remain unknown. In the current issue of Arch Tox, Mattingly and Klinge (2011) have observed that diesel-derived particle components can inhibit normal estrogen signaling in human umbilical vein endothelial cells. Moreover, engine operating conditions alter the chemistry and therefore the potency of the diesel engine extracts. The highlighted manuscript points to a number of interesting and compelling findings related to potential disruption of nuclear-mitochondrial gene regulation, principally highlighted by the reduced expression of NRF-1, an essential nuclear gene that enhances mitochondrial biogenesis (Klinge 2008). These findings are of additional interest because there is very little known about gender-related susceptibility with regard to the cardiovascular health effects of air pollution. Based on the findings of the present paper, one might speculate that chemical components of diesel particulates would nullify the known cardiovascular health benefits of estrogen signaling. Part of the difficulty in assessing these mechanisms relates to the fact that inhalation exposures lead to systemic effects that arise from neural alterations, release of inflammatory mediators, and bioavailable components of the PM itself. Direct exposure of endothelial cells to most air pollutants, including diesel particles, is poorly justified as the lung is an exceptional barrier. The compelling findings of disruption of mitochondrial biogenesis in the present study should motivate exploration of cardiometabolic disruption of diesel and related airborne contaminants using more relevant and complementary exposure methods. While the use of extracts is a suitable tool for reductionist research, uptake and distribution kinetics for the numerous chemicals in the extracts (Sumanasekera et al. 2007) has not been well characterized. Gerde et al. (2001) demonstrated systemic delivery of PM-associated benzo[a]pyrene and a number of soluble metal components of PM can readily access the circulation (Wallenborn et al. 2007). Likely, the same is true of many components of PM, even those not so soluble, as numerous dissolution mechanisms may be at play in macrophages and select regions of the lung environment. Thus, it is rational to consider the vascular endothelial toxicity of extractable components of diesel PM, which consist largely of organic compounds, provided consideration is given to the dose and complex chemistry involved. Mattingly and Klinge provide a stellar example of how to approach this problem, by utilizing diesel PM extracts derived from an engine under varied operating conditions. From previously published work, they have a solid understanding of the chemistry of the diesel particulate extract (Sumanasekera et al. 2007). However, the results must be considered in light of the absence of dosimetry information and the immense complexity of the extract mixtures. In our attempt to understand the systemic vascular health effects of environmental contaminants, the questions of dosimetry and kinetics will be as important as ever. Hopefully, resources for conducting such research will be available in coming years, so that the sophisticated cell biological approaches explored by Mattingly and Klinge can be more fully developed for risk assessment and regulatory science purposes.

Birth Cohort Studies Conducted by Peking University, China

S-31C2-3 Background/Aims: Large birth cohort study with long-term follow-up is a powerful and feasible way to assess the impact of environment, genetics, and environment-genetics interaction on different health outcomes of both pregnant women and their offspring, by prospectively collecting extensive data and specimen during various periods from preconception to childhood or even later life. Methods: Peking University Institute of Reproductive and Child Health have conducted 3 large birth cohort studies. Results: First cohort study includes about 230,000 children, whose mother had participated in a previous folic acid intervention study to prevent the occurrence of neural tube defects in China. Women entered the program either at premarital health assessment or at any stage of pregnancy. Second cohort includes 17,000 children, whose mother had participated in a 3-armed randomized controlled trial to assess the impact of iron-folic acid and multi-micronutrient supplementations on mortality, morbidity, and complications during pregnancy, labor, and delivery in China. Women were enrolled before 20 weeks of gestational age, women's venous blood and baby's cord blood were collected, and children born to the enrolled women are being followed up. Third cohort study is now enrolling women, and is planned to enroll 10,000 women before or during early pregnancy, to collect women's venous blood, and follow these enrolled women up to 42 days postpartum. For all 3 cohort studies, maternal and children's data about demographic, relevant obstetric and pregnancy outcomes, folic acid supplements taking, and body growth were collected at the time of entry, subsequent prenatal visits, delivery, or at the follow-up. Conclusion: These cohort studies provide exciting opportunities to explore the cause and prevention measures for various interested health outcomes including the adverse health effects of environmental contaminants.

Methoxychlor induces apoptosis via mitochondria- and FasL-mediated pathways in adult rat testis

In the past few years, there has been much concern about the adverse health effects of environmental contaminants in general and organochlorine in particular. Studies have shown the repro-toxic effects of long-term exposure to methoxychlor, a member of the organochlorine family. However, the insight into the mechanisms of gonadal toxicity induced by methoxychlor is not well known. In the present study we sought to elucidate the mechanism(s) underpinning the gonadal effects within hours of exposure to methoxychlor. Experimental rats were divided into six groups of four each. Animals were orally administered with a single dose of methoxychlor (50 mg/kg body weight) and killed at 0, 3, 6, 12, 24, and 72 h post-treatment. The levels and time-course of induction of apoptosis-related proteins like cytochorome C, caspase 3 and procaspase 9, Fas–FasL and NF-κB were determined to assess sequential induction of apoptosis in the rat testis. DNA damage was assessed by TUNEL assay and flowcytometry. Administration of methoxychlor resulted in a significant increase in the levels of cytosolic cytochrome c and procaspase 9 as early as 6 h following exposure. Time-dependent elevations in the levels of Fas, FasL, pro- and cleaved caspase 3 were observed. The DNA damage was measured and showed time-dependent increase in the TUNEL positive cells, and also by flowcytometry of testicular cells. The study demonstrates induction of testicular apoptosis in adult rats following exposure to a single dose of methoxychlor.

Large prospective birth cohort studies on environmental contaminants and child health – Goals, challenges, limitations and needs

The adverse health effects of environmental contaminants (ECs) are a rising public health concern, and a major threat to sustainable socioeconomic development. The developing fetuses and growing children are particularly vulnerable to the adverse effects of ECs. However, assessing the health impact of ECs presents a major challenge, given that multiple outcomes may arise from one exposure, multiple exposures may result in one outcome, and the complex interactions between ECs, and between ECs, nutrients and genetic factors, and the dynamic temporal changes in EC exposures during the life course. Large-scale prospective birth cohort studies collecting extensive data and specimen starting from the prenatal or pre-conception period, although costly, hold promise as a means to more clearly quantify the health effects of ECs, and to unravel the complex interactions between ECs, nutrients and genotypes. A number of such large-scale studies have been launched in some developed counties. We present an overview of "why", "what" and "how" behind these efforts with an objective to uncover major unidentified limitations and needs. Three major limitations were identified: (1) limited data and bio-specimens regarding early life EC exposure assessments in some birth cohort studies; (2) heavy participant burdens in some birth cohort studies may bias participant recruitment, and risk substantial loss to follow-up, protocol deviations limiting the quality of data and specimens collection, with an overall potential bias towards the null effect; (3) lack of concerted efforts in building comparable birth cohorts across countries to take advantage of natural "experiments" (large EC exposure level differences between countries) for more in-depth assessments of dose-response relationships, threshold exposure levels, and positive and negative effect modifiers. Addressing these concerns in current or future large-scale birth cohort studies may help to produce better evidence on the health effects of ECs.

Health Effects of Environmental Contamination due to Volcanic Ash from Mount Etna (Sicily, Italy) in Autumn 2002

MM4-PD-08 Introduction: During autumn 2002, a large eruption of Mount Etna (Sicily, Italy) occurred. Ash fell over the city of Catania (about 400,000 inhabitants) and the resident population experienced a public health emergency for several days. Unusually high levels of suspended particulate matter, PM10, (over 100–200 μg/m3) were recorded. The local population was alerted and the Department of Civil Protection issued emergency preventive measures. The aim of the study was to evaluate the acute health effects on mortality and hospital admissions in the area around the volcano. Methods: A time-series approach was adopted for the analysis of data (time unit = day). Health outcomes during the eruption period were compared with those from the same period of the previous year (1-day shift forward to take into account the day of the week effect). Relative risks (RR) and their 95% confidence intervals (CI) were computed. Poisson regression was used to evaluate the association between daily average PM10 and daily counts of hospital admissions for cardiovascular diseases. Results: The study observed a total of 106 days of observation for each year, corresponding to 59 days of eruption and 47 days of noneruption. No effects on overall and cause-specific mortality were observed during the eruption period. Mortality for respiratory diseases (RR = 0.46; 95% CI = 0.26–0.82) as well as hospital admissions for trauma (RR = 0.77; 95% CI = 0.67–0.88) was significantly decreased. Increases in hospital admissions for cardiovascular diseases were observed: ischemic heart diseases, RR = 1.31; 95% CI = 1.10–1.56; myocardial infarction, RR = 1.34; 95% CI = 1.02–1.76, and cerebrovascular diseases, RR = 1.24; 95% CI = 1.05–1.47. The excesses were stronger among the elderly. Daily admissions for cardiovascular diseases were not associated with PM10 levels. Discussion and Conclusions: The effects of the eruption were limited to a temporary increase in cardiovascular morbidity, especially among the elderly, possibly as a consequence of in acute stress. This phenomenon has been reported following other natural disasters. The decrease in mortality for respiratory diseases and the decrease in hospital admissions for trauma were probably a result of the precautionary measures taken during the emergency period. When planning public health measures during natural disasters, special attention should be given to risk communication.

A database for environmental contaminants in traditional foods in northern and arctic Canada: Development and applications

The potential health effects of environmental contaminants in traditional food has become a concern among northern communities because of the presence of environmental contaminants in the Arctic ecosystem. Exposure assessments are needed but they require comprehensive dietary information and contaminant data. Over the last 10 years, there has been considerable effort to monitor the level of contaminants in fish and wildlife collected from different regions in northern and Arctic Canada. The development of a database and its application for dietary contaminant exposure assessment are described. We conducted an extensive literature review on levels of environmental contaminants in northern and Arctic Canada. The ranges of levels of four contaminants of major concern (chlordane, mercury, polychlorinated biphenyls and toxaphene) in 81 species of marine mammals, terrestrial mammals, birds, fish and plants are summarized. These data represent 69% of the 117 species of fish, wildlife and plants mentioned in our dietary interviews conducted in the northern communities. A significant percentage of the foods had contaminant levels exceeding the guidelines used by Health Canada for market food consumed by the ‘southern’ populations. Mathematic modelling of the distributions of the data showed that contaminant levels in most food groups are log‐normally distributed and have a typical coefficient of variation of about 100%. Examples are presented to demonstrate the use of the data for contaminant exposure assessment. Average contaminant exposure levels estimated using the database for two communities are comparable to those obtained previously using community specific data. With the current knowledge of environmental contaminant levels in the northern traditional food system, it may be feasible to conduct preliminary risk assessment of dietary exposure of environmental contaminants when some diet information for a community is available. Further sampling and analysis may be needed only for confirmation purposes.

Human health and the environment in eastern and central Europe.

More than 40 environmental health scien? tists, from 15 countries of Eastern, Central, and Western Europe and the United States, gathered from 12-15 April 1993 at Charles University in Prague, the Czech Republic, to participate in the con? ference, Human Health and the Envir? onment in Eastern and Central Europe. This conference, convened by the Conte Institute for Environmental Health, represented a unique nongovernmental effort by international scientists to develop a regional approach to research on the health effects of environmental contamination in

Rapid toxicity testing based on mitochondrial respiratory activity

The need exists for rapid and inexpensive methods to determine the health effects of environmental contaminants on biological systems. One of the current research approaches for assessing cytotoxicity is to monitor the respiratory activity of the mitochondrion, a sensitive, nonspecific subcellular target site. Detected changes in mitochondrial function after the addition of a test chemical could be correlated to toxic effects. Mitochondrial respiration can be characterized by three indices: state 3 and state 4 respiratory rates, and the respiratory control ratio (RCR). State 4, the idle or resting state, results when coupled mitochondrial respire in a medium containing inorganic phosphate and a Kreb's cycle substrate in the absence of a phosphate acceptor such as adenosine diphosphate (ADP). In the presence of ADP the respiration rate increases to a maximum (state 3), accompanied by phosphorylation of ADP to adenosine triphosphate (ATP). The ratio of state 3 to state 4, or RCR, indicates how tightly the oxidative phosphorylation process is coupled. The synthesis of ATP by mitochondria is influenced by a number of compounds, most of which are either uncouplers or inhibitors.