Children’s exposure to polycyclic aromatic hydrocarbon (PAHs): a review on urinary 1-hydroxypyrene and associated health effects

This article reviewed the published studies on the environmental exposure to polycyclic aromatic hydrocarbons (PAHs) among children and assessed the urinary 1-hydroxypyrene (1-OHP) level as a biomarker of exposure to PAHs. The current knowledge of the potential health effects of increased 1-OHP in children was reviewed. Additionally, the influence of genetic polymorphism on the urinary 1-OHP level was discussed in this review. The assembled data showed that children who are attending schools or living close to industrial and polluted urban areas might have greater exposure to higher concentrations of PAHs with a higher level of urinary 1-OHP when compared to those children living in rural areas. Urinary 1-OHP may be a reliable biomarker for determining the genotoxic effects, oxidative stress and inflammation caused by exposure to PAHs. Strong research evidence indicated that the total body burden of PAHs should be evaluated by biomonitoring of 1-OHP in line with other urinary PAHs metabolites (with 2–3 rings) to evaluate recent total exposure to PAHs. Overall, the study suggests implementing a mitigation plan to combat air pollution to provide a cleaner environment for children.

Evidence for Ovarian and Testicular Toxicities of Cadmium and Detoxification by Natural Substances

Cadmium (Cd) is an environmental toxicant, capable of reducing mitochondrial ATP production and promoting the formation of reactive oxygen species (ROS) with resultant oxidative stress conditions. The ovary and testis are the primary gonads in which female gametes (oocytes) and male gametes (spermatozoa), estrogen and testosterone are produced. These organs are particularly susceptible to Cd cytotoxicity due to their high metabolic activities and high energy demands. In this review, epidemiological and experimental studies examining Cd toxicities in gonads are highlighted together with studies using zinc (Zn), selenium (Se), and natural substances to reduce the effects of Cd on follicular genesis and spermatogenesis. Higher blood concentrations of Cd ([Cd]b) were associated with longer time-to-pregnancy in a prospective cohort study. Cd excretion rate (ECd) as low as 0.8 μg/g creatinine was associated with reduced spermatozoa vitality, while Zn and Se may protect against spermatozoa quality decline accompanying Cd exposure. ECd > 0.68 µg/g creatinine were associated with an increased risk of premature ovarian failure by 2.5-fold, while [Cd]b ≥ 0.34 µg/L were associated with a 2.5-fold increase in the risk of infertility in women. Of concern, urinary excretion of Cd at 0.68 and 0.8 μg/g creatinine found to be associated with fecundity are respectively 13% and 15% of the conventional threshold limit for Cd-induced kidney tubular effects of 5.24 μg/g creatinine. These findings suggest that toxicity of Cd in primary reproductive organs occurs at relatively low body burden, thereby arguing for minimization of exposure and environmental pollution by Cd and its transfer to the food web.

Analysis of Relation Between Lifetime Rates and Incorporation of Plutonium-239 in Atomic Production Workers Regarding Tumor and Non-Tumor Causes of Death

Purpose: The objective of the study was in quantitative assessment of the effect of internal exposure to lifetime in Mayak PA workers based on analyzing dependence of certain lifetime rates on incorporation of plutonium-239 regarding tumor and non-tumor causes of death. Material and methods: The cohort of deceased Mayak PA workers employed in1948–1958 with known Pu-239 body burden comprising 2343 individuals, of them 1739 males and 604 females, was investigated. Using regression analysis we have assessed dependence of general lifetime and lifetime after start of work as well as of proportion of individuals who did not survive until standard age in general and after start of work from incorporated Pu-239 separately for workers of different age regarding tumor and non-tumor causes of death. Statistical values were defined using Statistica software. Results: It was stated that in case of increase of plutonium-239 body burden in males and females reliably increased shortening of lifetime and lifetime after start of work was observed as well as increased proportion of individuals who did not survive until standard lifetime rate and until standard lifetime after start of work. Reliable regression equations for dependence of the studied lifetime values from radionuclide incorporation rate were obtained based on regression analysis. Generally, changes in the studied characteristics of lifetime after start of work were more evident than in general lifetime characteristics. Conclusion: Reliable dependence of shortening of lifetime and lifetime after start of work, of increased proportion of individuals who did not survive until standard lifetime and lifetime after start of work among Mayak PA workers of different gender from incorporation of plutonium-239 regarding tumor and non-tumor causes of death was stated. Dependence of lifetime after start of work on incorporated plutonium-239 was higher than of general lifetime that could be probably due to direct contact of workers with radionuclide after start of work. The results obtained indicate feasibility of using not only general lifetime but also lifetime after start of work in assessment of lifetime among workers who are in contact with production hazardous factors.

Tobacco Smoke Exposure and Urinary Cadmium in Women from Northern Mexico

Cadmium (Cd), a carcinogenic metal also related to reproductive and cardiovascular diseases, is contained in tobacco and elevated concentrations of it in humans have been consistently associated with first-hand tobacco smoke; however, there is scarce and inconclusive evidence of the relationship between Cd and secondhand smoke (SHS) exposure. Our aim was to evaluate the association between exposure to tobacco, both active and SHS, with urinary Cd concentrations in Mexican women. In a cross-sectional analysis that included 998 women living in northern Mexico, we measured the concentration of creatinine-adjusted urinary Cd (µg-cadmium/g-creatinine) using inductively coupled plasma triple quadrupole (ICP-QQQ) in tandem mass spectrometry mode (MS/MS). We gathered tobacco smoking information through an in-person interview and formed seven groups: non-smokers without SHS exposure; non-smokers with SHS exposure; ex-smokers without SHS exposure <1 year of quitting; ex-smokers without SHS exposure ≥1 year of quitting, ex-smokers with SHS exposure <1 year of quitting; ex-smokers with SHS exposure ≥1 year of quitting and current smokers. The interview also yielded sociodemographic characteristics. We used linear multivariable regression models to estimate the association between Cd concentrations and tobacco smoke exposure. Compared to non-smokers without SHS exposure, we found higher Cd concentrations in ex-smokers with SHS exposure <1 year of quitting and current smokers (adjusted geometric means 0.51 vs. 1.01 and 0.69 µg-cadmium/g-creatinine, respectively). Our results do not support a conclusion that SHS exposure is a source of Cd body burden.

Human Body Burden of Heavy Metals and Health Consequences of Pb Exposure in Guiyu, an E-Waste Recycling Town in China

Guiyu accommodates millions of tons of e-waste from overseas and domestic sources each year and is notorious for its e-waste dismantling industry. As a consequence, Guiyu has been described as “the world’s most toxic place” and “junk town”. Informal e-waste recycling activities have caused severe pollution to the local environment and are associated with extensive health problems to the residents. This review provides updated insights on the body burden of heavy metals derived from e-waste and health outcomes resulted from lead (Pb) exposure. The review identified that Guiyu has been highly contaminated by heavy metals, especially Pb. Excessive exposure to Pb has been associated with multi-system and long-term effects in neonates and children, covering nervous, cardiovascular, adaptive immune, and hematologic systems as well as chromosome and DNA damage. Our review indicates strong associations that emphasize the need to develop strong regulations for prevention of exposure and health consequences in Guiyu and similar sites around the world.

Correction of Selenium status as a tool for preventive medicine

Introduction. Due to the many physiological functions of Selenium (Se), its deficiency is associated with a broad spectrum of adverse health effects. This review aims to analyze epidemiological data on the relation of selenium status to public health and the possibility of selenium-containing drugs usage. Material and methods. Based on the literature search in Pubmed, The Cochrane Library, and Google Scholar, epidemiological data on the association between Se status and population health and effects of Se supplementation were analyzed. Results. Meta-analyses indexed in the Cochrane Library demonstrated a significant association between Se status and many pathologies. Specifically, it has been shown that subjects with physiologically high Se body burden are characterized by a 24-31% lower risk of cancer and 36% lower risk of cancer-related mortality. It is also notable that Se supplementation in human immunodeficiency virus-infected women reduced the risk of maternal diarrhoea and low birth mass in offspring. Moreover, Se supplementation in premature newborns and critically low mass newborns significantly decreased the risk of sepsis. Many extensive epidemiological studies also demonstrated the efficiency of improvement in the Se status concerning coronary heart disease and sepsis mortality risk. At the same time, constant monitoring of Se body burden is essential for assessing Se supplementation efficiency and prevention of adverse health effects of Se overload. It is also noted that Se status is considered as the determinant of the efficiency of prevention of cardiovascular diseases and cancer under Se supplementation. Conclusion. Given the high incidence of Se deficiency in Russia (24-45% depending on the region), assessment and improvement of Se status may be considered a valuable tool for population health management.

Developmental Toxicology of Metal Mixtures in Drosophila: Unique Properties of Potency and Interactions of Mercury Isoforms

Mercury ranks third on the U.S. Agency of Toxic Substances and Disease Registry priority list of hazardous substances, behind only arsenic and lead. We have undertaken uncovering the mechanisms underlying the developmental toxicity of methylmercury (MeHg), inorganic mercury (HgCl2), lead acetate (Pb), and sodium arsenite (As). To probe these differences, we used the Drosophila model, taking advantage of three developmental transitions—pupariation, metamorphosis, and eclosion—to differentiate potentially unique windows of toxicity. We elaborated dose response profiles for each individual metal administered in food and accounted for internal body burden, also extending analyses to evaluate combinatorial metal mixture effects. We observed all four metals producing larval lethality and delayed pupariation, with MeHg being most potent. Compared to other metals, MeHg’s potency is caused by a higher body burden with respect to dose. MeHg uniquely caused dose-dependent failure in eclosion that was unexpectedly rescued by titrating in HgCl2. Our results highlight a unique developmental window and toxicokinetic properties where MeHg acts with specificity relative to HgCl2, Pb, and As. These findings will serve to refine future studies aimed at revealing tissue morphogenesis events and cell signaling pathways, potentially conserved in higher organisms, that selectively mediate MeHg toxicity and its antagonism by HgCl2.

Depuration Kinetics and Growth Dilution of Caribbean Ciguatoxin in the Omnivore Lagodon rhomboides: Implications for Trophic Transfer and Ciguatera Risk

Modeling ciguatoxin (CTX) trophic transfer in marine food webs has significant implications for the management of ciguatera poisoning, a circumtropical disease caused by human consumption of CTX-contaminated seafood. Current models associated with CP risk rely on modeling abundance/presence of CTX-producing epi-benthic dinoflagellates, e.g., Gambierdiscus spp., and are based on studies showing that toxin production is site specific and occurs in pulses driven by environmental factors. However, food web models are not yet developed and require parameterizing the CTX exposure cascade in fish which has been traditionally approached through top-down assessment of CTX loads in wild-caught fish. The primary goal of this study was to provide critical knowledge on the kinetics of C-CTX-1 bioaccumulation and depuration in the marine omnivore Lagodon rhomboides. We performed a two-phase, 17 week CTX feeding trial in L. rhomboides where fish were given either a formulated C-CTX-1 (n = 40) or control feed (n = 37) for 20 days, and then switched to a non-toxic diet for up to 14 weeks. Fish were randomly sampled through time with whole muscle, liver, and other pooled viscera dissected for toxin analysis by a sodium channel-dependent MTT-based mouse neuroblastoma (N2a) assay. The CTX levels measured in all tissues increased with time during the exposure period (days 1 to 20), but a decrease in CTX-specific toxicity with depuration time only occurred in viscera extracts. By the end of the depuration, muscle, liver, and viscera samples had mean toxin concentrations of 189%, 128%, and 42%, respectively, compared to fish sampled at the start of the depuration phase. However, a one-compartment model analysis of combined tissues showed total concentration declined to 56%, resulting in an approximate half-life of 97 d (R2 = 0.43). Further, applying growth dilution correction models to the overall concentration found that growth was a major factor reducing C-CTX concentrations, and that the body burden was largely unchanged, causing pseudo-elimination and a half-life of 143–148 days (R2 = 0.36). These data have important implications for food web CTX models and management of ciguatera poisoning in endemic regions where the frequency of environmental algal toxin pulses may be greater than the growth-corrected half-life of C-CTX in intermediate-trophic-level fish with high site fidelity.

A semi-randomized study determining the psychological and physical effects of three types of eye masks on adult women

Background: Warm compresses are one of the nursing techniques clinically used to improve patients’ comfort and promote the treatment efficacy. Here the effects of eye masks (EM), heated eye masks (HEM), and aroma-scented heated eye masks (AHEM) and their potential as a nursing technique to provide comfort were studied.Methods: Participants in this study were 42 healthcare professionals (female, 20–60 years of age), who voluntarily consented to participate. They participated in all three interventions with EM, HEM, and AHEM at an interval of at least 1 week between interventions. Indicators used were low frequency to high frequency ratio (LF/HF), blood flow, axillary temperature, pulse rate, blood pressure, the salivary α-amylase activity (SAA), and the Profile of Mood States Second Edition (POMS).Results: Of 42 participants in total, 32 were included in the analysis. Their mean age was 46.8 years. The blood flow and axillary temperature values significantly increased and the LF/HF values and the pulse rates significantly decreased after the use of EM, HEM, or AHEM. The POMS Total Mood Disturbance (TMD) score and scores for six POMS subscales significantly decreased after the use of EM, HEM, or AHEM.Comparisons among the three groups showed differences in LF/HF. Scores for subscales of POMS also differed among the three groups.Conclusions: These results suggest that the use of EM, HEM, or AHEM intervention is safe with no major body burden. Parasympathetic nerves may be dominant after the EM, HEM, or AHEM interventions The TMD score improved after the EM, HEM, or AHEM intervention. The data suggest that the AHEM use is particularly effective in alleviating depression, dejection, and confusion after the intervention. These findings indicates that the EM, HEM, or AHEM use holds potential as a nursing technique to provide comfort.Trial registration: UMIN Clinical Trials Registry (UMIN000018409Trial registration number: UMIN-CTR R000021207Date of registration: 07/24/2015