Quality of life and mental health status of arsenic-affected patients in a Bangladeshi population

Design and application of metal organic frameworks for heavy metals adsorption in water: a review

The growing apprehension surrounding heavy metal pollution in both environmental and industrial contexts has spurred extensive research into adsorption materials aimed at efficient remediation. Among these materials, Metal-Organic Frameworks (MOFs) have risen as versatile and promising contenders due to their adjustable properties, expansive surface areas, and sustainable characteristics, compared to traditional options like activated carbon and zeolites. This exhaustive review delves into the synthesis techniques, structural diversity, and adsorption capabilities of MOFs for the effective removal of heavy metals. The article explores the evolution of MOF design and fabrication methods, highlighting pivotal parameters influencing their adsorption performance, such as pore size, surface area, and the presence of functional groups. In this perspective review, a thorough analysis of various MOFs is presented, emphasizing the crucial role of ligands and metal nodes in adapting MOF properties for heavy metal removal. Moreover, the review delves into recent advancements in MOF-based composites and hybrid materials, shedding light on their heightened adsorption capacities, recyclability, and potential for regeneration. Challenges for optimization, regeneration efficiency and minimizing costs for large-scale applications are discussed.

Drinking water and the implications for gender equity and empowerment: A systematic review of qualitative and quantitative evidence

BACKGROUND

Safe drinking water is a fundamental human right, yet more than 785 million people do not have access to it. The burden of water management disproportionately falls on women and young girls, and they suffer the health, psychosocial, political, educational, and economic effects. While water conditions and disease outcomes have been widely studied, few studies have summarized the research on drinking water and implications for gender equity and empowerment (GEE).

METHODS

A systematic review of primary literature published between 1980 and 2019 was conducted on drinking water exposures and management and the implications for GEE. Ten databases were utilized (EMBASE, PubMed, Web of Science, Cochrane, ProQuest, Campbell, the British Library for Development Studies, SSRN, 3ie International Initiative for Impact Evaluation, and clinicaltrials.gov). Drinking water studies with an all-female cohort or disaggregated findings according to gender were included.

RESULTS

A total of 1280 studies were included. GEE outcomes were summarized in five areas: health, psychosocial stress, political power and decision-making, social-educational conditions, and economic and time-use conditions. Water quality exposures and implications for women's health dominated the literature reviewed. Women experienced higher rates of bladder cancer when exposed to arsenic, trihalomethanes, and chlorine in drinking water and higher rates of breast cancer due to arsenic, trichloroethylene, and disinfection byproducts in drinking water, compared to men. Women that were exposed to arsenic experienced higher incidence rates of anemia and adverse pregnancy outcomes compared to those that were not exposed. Water-related skin diseases were associated with increased levels of psychosocial stress and social ostracization among women. Women had fewer decision-making responsibilities, economic independence, and employment opportunities around water compared to men.

CONCLUSION

This systematic review confirms the interconnected nature of gender and WaSH outcomes. With growing attention directed towards gender equity and empowerment within WaSH, this analysis provides key insights to inform future research and policy.

Demyelination associated with chronic arsenic exposure in Wistar rats

Inorganic arsenic is among the major contaminants of groundwater in the world. Worldwide population-based studies demonstrate that chronic arsenic exposure is associated with poor cognitive performance among children and adults, while research in animal models confirms learning and memory deficits after arsenic exposure. The aim of this study was to investigate the long-term effects of environmentally relevant arsenic exposure in the myelination process of the prefrontal cortex (PFC) and corpus callosum (CC). A longitudinal study with repeated follow-up assessments was performed in male Wistar rats exposed to 3 ppm sodium arsenite in drinking water. Animals received the treatment from gestation until 2, 4, 6, or 12 months of postnatal age. The levels of myelin basic protein (MBP) were evaluated by immunohistochemistry/histology and immunoblotting from the PFC and CC. As plausible alterations associated with demyelination, we considered mitochondrial mass (VDAC) and two axonal damage markers: amyloid precursor protein (APP) level and phosphorylated neurofilaments. To analyze the microstructure of the CC in vivo, we acquired diffusion-weighted images at the same ages, from which we derived metrics using the tensor model. Significantly decreased levels of MBP were found in both regions together with significant increases of mitochondrial mass and slight axonal damage at 12 months in the PFC. Ultrastructural imaging demonstrated arsenic-associated decreases of white matter volume, water diffusion anisotropy, and increases in radial diffusivity. This study indicates that arsenic exposure is associated with a significant and persistent negative impact on microstructural features of white matter tracts.

Arsenic exposure with reference to neurological impairment: an overview

Arsenic (As) toxicity has become a public health and environmental problem, which is a serious issue in certain parts of the world. Many people are exposed to As through contaminated drinking water, food and soil, through occupation, etc. Chronic As exposure is linked to various hostile health effects including skin problems, cancer, diabetes, cardiovascular disease, reproductive and developmental and neurological problems in exposed subjects. Experimental existing data indicate that chronic As exposure affects the nervous system by impairing the nerve and brain tissues of the exposed animals, and clinical studies indicate that As exposure leads to both central nervous system and peripheral nervous system impairments and also causes depression, memory impairment and difficulty in problem solving, affects body coordination, etc. Various prenatal and postnatal studies with respect to As exposure also suggest that developing offspring and young children are susceptible to As exposure. The only solution to this serious health problem is to stop occupational As exposure and provide As free drinking water to the affected population.

The mechanistic basis of arsenicosis: pathogenesis of skin cancer

Significant amounts of arsenic have been found in the groundwater of many countries including Argentina, Bangladesh, Chile, China, India, Mexico, and the United States with an estimated 200 million people at risk of toxic exposure. Although chronic arsenic poisoning damages many organ systems, it usually first presents in the skin with manifestations including hyperpigmentation, hyperkeratoses, Bowen's disease, squamous cell carcinoma, and basal cell carcinoma. Arsenic promotes oxidative stress by upregulating nicotinamide adenine dinucleotide phosphate oxidase, uncoupling nitric oxide synthase, and by depleting natural antioxidants such as nitric oxide and glutathione in addition to targeting other proteins responsible for the maintenance of redox homeostasis. It causes immune dysfunction and tissue inflammatory responses, which may involve activation of the unfolded protein response signaling pathway. In addition, the dysregulation of other molecular targets such as nuclear factor kappa B, Hippo signaling protein Yap, and the mineral dust-induced proto-oncogene may orchestrate the pathogenesis of arsenic-mediated health effects. The metalloid decreases expression of tumor suppressor molecules and increases expression of pro-inflammatory mitogen-activated protein kinase pathways leading to a tumor-promoting tissue microenvironment. Cooperation of upregulated signal transduction molecules with DNA damage may abrogate apoptosis, promote proliferation, and enhance cell survival. Genomic instability via direct DNA damage and weakening of several cellular DNA repair mechanisms could also be important cancer development mechanisms in arsenic-exposed populations. Thus, arsenic mediates its toxicity by generating oxidative stress, causing immune dysfunction, promoting genotoxicity, hampering DNA repair, and disrupting signal transduction, which may explain the complex disease manifestations seen in arsenicosis.

Fluoxetine treatment ameliorates depression induced by perinatal arsenic exposure via a neurogenic mechanism

Several epidemiological studies have reported an association between arsenic exposure and increased rates of psychiatric disorders, including depression, in exposed populations. We have previously demonstrated that developmental exposure to low amounts of arsenic induces depression in adulthood along with several morphological and molecular aberrations, particularly associated with the hippocampus and the hypothalamic-pituitary-adrenal (HPA) axis. The extent and potential reversibility of this toxin-induced damage has not been characterized to date. In this study, we assessed the effects of fluoxetine, a selective serotonin reuptake inhibitor antidepressant, on adult animals exposed to arsenic during development. Perinatal arsenic exposure (PAE) induced depressive-like symptoms in a mild learned helplessness task and in the forced swim task after acute exposure to a predator odor (2,4,5-trimethylthiazoline, TMT). Chronic fluoxetine treatment prevented these behaviors in both tasks in arsenic-exposed animals and ameliorated arsenic-induced blunted stress responses, as measured by corticosterone (CORT) levels before and after TMT exposure. Morphologically, chronic fluoxetine treatment reversed deficits in adult hippocampal neurogenesis (AHN) after PAE, specifically differentiation and survival of neural progenitor cells. Protein expression of BDNF, CREB, the glucocorticoid receptor (GR), and HDAC2 was significantly increased in the dentate gyrus of arsenic animals after fluoxetine treatment. This study demonstrates that damage induced by perinatal arsenic exposure is reversible with chronic fluoxetine treatment resulting in restored resiliency to depression via a neurogenic mechanism.

The Effects of Arsenic Exposure on Neurological and Cognitive Dysfunction in Human and Rodent Studies: A Review

Arsenic toxicity is a worldwide health concern as several millions of people are exposed to this toxicant via drinking water, and exposure affects almost every organ system in the body including the brain. Recent studies have shown that even low concentrations of arsenic impair neurological function, particularly in children. This review will focus on the current epidemiological evidence of arsenic neurotoxicity in children and adults, with emphasis on cognitive dysfunction, including learning and memory deficits and mood disorders. We provide a cohesive synthesis of the animal studies that have focused on neural mechanisms of dysfunction after arsenic exposure including altered epigenetics; hippocampal function; glucocorticoid and hypothalamus-pituitary-adrenal axis (HPA) pathway signaling; glutamatergic, cholinergic and monoaminergic signaling; adult neurogenesis; and increased Alzheimer’s-associated pathologies. Finally, we briefly discuss new studies focusing on therapeutic strategies to combat arsenic toxicity including the use of selenium and zinc.