Please use this identifier to cite or link to this item:
http://hdl.handle.net/123456789/27807
Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.author | Mehwish David | - |
dc.date.accessioned | 2023-11-29T05:21:19Z | - |
dc.date.available | 2023-11-29T05:21:19Z | - |
dc.date.issued | 2023 | - |
dc.identifier.uri | http://hdl.handle.net/123456789/27807 | - |
dc.description.abstract | Environmental pollution is a matter of global concern. With the increasing need for industrialization, the rate of environmental degradation due to pollution is also increasing on daily basis. The brick kiln industry is the fastest growing industry in South Asia with an increased number of bonded laborers. This industry emits enormous amounts of poisonous gases and traces elements directly into the atmosphere that affect all life forms, especially brick kiln workers through external deposition (dermal) as well as through internal route (inhalation and ingestion). In Pakistan, the number of laborers associated with the brick kiln industry is quite high, which raises public health concerns. Several studies have reported that emitted metals are deposited in blood and affect multiple biochemical reactions in humans. Heavy metals are known to alter blood profile, increase production of reactive oxygen and acidic species, decrease antioxidants levels, alter hormone concentrations in blood, bring genotypic effects, as well as modifying gene expression. Heavy metals induce genetic changes by creating single nucleotide polymorphisms (SNPs) in important structural and functional genes, whose altered function might bring physiological conditions in body. Objectives: The present study aims to estimate the metal burden in blood and possible hazardous effects of heavy metals emission from coal clay brick kilns on human health regarding child growth, pubertal development, maternal health, and reproductive health in men. The objectives of the study include: • The evaluation of the socio-demographic, work associated, and general health determinants among brick kiln workers and non-workers, along with an emphasis on the extrinsic and intrinsic deposition of heavy metal burden in soil and biological samples (blood and hair). DRSML QAU Introduction 2 • Finding the comparative environmental health effects of heavy metal burden in blood among brick kilns workers and control individuals, by looking at blood parameters, oxidative stress markers, antioxidant enzymes concentrations, and reproductive hormones profile along with stress response on hypothalamic-pituitary-gonadal (HPG) axis. • Measurement of possible deleterious effects of brick kilns emitted metals on female workers regarding reproductive health indicators, blood and lipid profile, antioxidant status, reproductive hormone concentrations, and direct effect on hypothalamic pituitary adrenal (HPA) axis. • Identification of genetic mutations in the ABCG2 gene in brick kiln workers and control subjects from the Pakistani population. • Investigation of lethal effects of kiln emitted heavy metals on pubertal development and child health by monitoring blood parameters, antioxidant enzyme status of the body, reproductive hormones, induced DNA damage, growth hormone and cortisol concentrations, that eventually may affect development and puberty. Materials and methods: The study involved a total of 1053 participants including men (n=346, n=200), women (n=118, n=114), and children (=n175, n=100 control) from Rawat, Punjab. Information regarding demographic data, personal health information, fertility indicators from women, and body mass index (BMI) was gathered. Hair and blood samples were collected for heavy metal determination through atomic absorption spectroscopy (AAS), external beam PIXE and scanning electron microscope (SEM/EDS). Further, blood was divided into two halves, one half was subjected to hematological and genotoxic analysis (comet assay), while the other half was centrifuged, plasma was obtained and stored at − 20° to study biochemical variables (sodium dismutase, peroxidase, reactive oxygen species, thiobarbituric acid DRSML QAU Introduction 3 reactive species, protein estimation), lipid profile (HDL, LDL, TG, cholesterol), growth hormone (GH), cortisol and concentrations of reproductive hormone (testosterone, luteinizing hormone, follicle-stimulating hormone, oestradiol, progesterone, prolactin) concentrations by immunoassay. To understand the functional changes in the ABCG2 gene, two exons (exons 3 and 5) were selected. The collected blood samples were subjected to DNA extraction, gel electrophoresis and nanodrop, DNA amplification, gel electrophoresis, gene sequencing, and post sequencing analysis using BioEdit, Chromas, and mutation taster. Results: The results showed that about 10% of the adult kiln laborers were underweight and had multiple health issues including skin allergies (1%), asthma (10%), stomach and kidney disorder (5%), and other diseases. Almost 58% of brick workers were addicted to tobacco (p = 0.363) and were working in poor and unhygienic conditions without the use of any personal protective equipment. Examination of blood for heavy metals concentrations through AAS revealed significantly (p<0.001) higher levels of Cd, Cr, and Cr in the working group as compared to the control group. PIXE data further detected higher than permissible levels of Si, P, S, Fe, Co, Ni, Cu, Cl, K, Ca, Ti, Mn, and Zn, in the blood of kiln workers. The SEM/EDS analysis of hair depicted the presence of macro-elements with an average concentration in the order of K > S > Ca > P > Cl. Similarly, a micro-element profile with mean levels in the order of: Rb > Fe > Mn > Cu > Sr > Zn were seen. Analysis of male samples showed a significant increase in platelet count (p=0.010); decreased antioxidant enzyme (p<0.01) and increased oxidants level (p<0.001); increased cortisol levels (p<0.001) were seen in workers in contrast to the control group. The inverse relationship was found between cortisol and pituitary gonadotropins (FSH r = 0.676, LH r = 0.580); cortisol and testosterone (r = 0.832). DRSML QAU Introduction 4 Analysis of female samples showed increased platelet count; decreased antioxidant enzyme and increased oxidants level; amplified total cholesterol, low-density lipoprotein (LDL) and triglyceride (TG); reduced total protein and high-density lipoprotein (HDL); and increased cortisol levels among workers in contrast to control group. A significant decrease (p<0.001) in FSH, LH, estradiol, and progesterone concentration, while a significant increase in prolactin levels was seen among workers groups as compared with control. The findings of correlation studies revealed that blood plasma cortisol levels negatively correlate with FSH (r=-0.872), LH (r=-0.856), estradiol (r=-0.923) and progesterone (r=-0.879) concentrations with significance value of p<0.001. The blood plasma cortisol level positively correlated with prolactin concentration (r=0.874). A total of twenty- eight genetic variations, including 25 novel ones were noted: 24 of them were present in the coding exons, and 1 in the intronic region. Results revealed that mutations were found in both worker and control samples. In addition to three previously reported nonsynonymous single nucleotide polymorphisms, g.91361G>A (rs2231137), g.91461G>A (rs142634180) and g.91521C>T (no rsID), the novel variations found in workers samples were present at genomic position g.91474G>A, g.91482delinsAA, g.91410T>A, g.91414G>A, g.91416C>A (rs142634180), g.91419T>A, g.91427G>A, g.91436T>A, g.91450C>T, g.91454T>A, g.91456C>A, g.91459T>A, g.91461G>A, g.91463G>A, g.91416C>A, g.91427G>C, g.91430G>C, g.91440_91441delinsAA, while those found in control are g.91474G>A, g.91487C>A, g.91507G>A, g.91521C>T, g.91346G>C, g.91416C>A, g.91430G>A, g.80676T>A, g.91446A>T. The V12M variant (rs2231137) has been previously reported and is associated with multiple metabolic diseases. The demographic data for children demonstrated that 70% of boys and 68% of girls were illiterate and early marriage practice was common among them. The biochemical analysis DRSML QAU Introduction 5 of children samples presented a significant decrease in percent hematocrit (HCT) in the brick kiln group in contrast to the control. Further, results showed a significant increase in white blood cells (p<0.05), reactive oxygen species (p<0.001), and decrease in catalase (p<0.001), peroxidase (p<0.001), and sodium dismutase (p<0.01). There was observed a drop in GH levels from 1.66±0.08 ng/mL in control to 0.87±0.13ng/mL in brick kiln children. Similarly, an increase in cortisol concentration from 0.83±0.14 ng/mL in control to 1.81 ± 0.05 ng/mL in brick kiln group was evident. The results of the comet assay showed a decrease in percent DNA in the head and an increase in the tail region among the exposed group in contrast to the control. Conclusion: A high concentration of trace elements and heavy metal burden in brick kiln workers induced multiple health disorders such as respiratory and stomach problems. Likewise, external, and internal deposition of heavy metal in soil and on hair and blood samples of kiln workers was quite elevated as compared to control subjects. Conclusively, it is stated that men, women and children subjected to brick kiln emissions experience heavy metal burden in blood; altered blood profile; decreased antioxidant levels, increased oxidant species production; disturbed lipid profile; and reduced production of LH, FSH, E, P and T, while increased production of cortisol and prolactin in women, respectively. Additionally, we found 28 variants of the ABCG2 gene (a placental gene) in females, indicating its possible altered function in humans. Moreover, we concluded that brick kiln children experience poor hygiene, poor health conditions, and growth spurt in growing boys and girl children that puts them at high risk for the development of metabolic and reproductive disorders. | en_US |
dc.language.iso | en | en_US |
dc.publisher | Quaid I Azam university Islamabad | en_US |
dc.subject | Animal Sciences | en_US |
dc.subject | Zoology | en_US |
dc.title | Effect of Environmental and Occupational Pollutants on Health Status of Brick Kiln Workers: A Molecular and Cellular Based Study | en_US |
dc.type | Thesis | en_US |
Appears in Collections: | Ph.D |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
BIO 7149.pdf | BIO 7149 | 7.46 MB | Adobe PDF | View/Open |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.