Preface

Heavy metals have become phenomenal globally. Although extracted from soil/rock as mineral deposits, they are applied industrially in the manufacture of both industrial and consumer goods, reagent chemicals, and engineering materials but are mostly applied in medicine and pharmaceuticals. There is yet no acceptable definition but the greatest problem with heavy metals is environmental contamination, population exposure, and toxicity.

Environmental pollution occurs through the release of heavy metals anthropogenically into water, farmland, and air, and eventually the food web.

Most metals are medically useful but in excess of the healthy limit cause health problems. The increase in non-communicable diseases such as cancer, renal disease, and organ failure may be attributed to exposure to heavy metals.

The chapter "Heavy metal contamination and remediation of water and soil with case studies from Cyprus" examines the heavy metal contamination and remediation of water and soil using a case study. Sewage waters (municipal, agricultural, or industrial) and pesticides are heavy metal laden. Natural resources from the composition of rock formations are the area of study. Heavy metals are found in fruits and vegetables grown on contaminated soil and water and necessitate public health concern globally. Phytoaccumulation, phytostabilization, phytodegradation, phytovolatilization, and hydraulic control methods are also discussed. The author suggested that agricultural soil and water must be carefully investigated before agricultural activities and that acceptable sampling and laboratory analyses should be executed and evaluated accordingly.

The chapter "Sorption of phosphorus, nickel and lead from aqueous solution using manganese oxides coated materials" looks at the rapid development of X-rays in industries such as plating, petrochemicals, and fertilizers, which has led to the discharge of contaminants like phosphorus and heavy metals into the environment. Phosphorus is the key nutrient for the growth of algal and other biological organisms, which cause eutrophication. Methods to eliminate heavy metals from wastewater are chemical precipitation, electrochemical reduction, ion exchange, membrane separation, reverse osmosis, and adsorption. Adsorption involves batch experiments. Both the Freundlich and Langmuir isotherms give a fit to the experimental data for adsorption. To study surface properties of the adsorbents, scanning electron microscopy and X-ray diffraction methods and Brunauer– Emmett–Teller analyses are used. The pseudo-first-order and pseudo-second-order equations as well as the intraparticle diffusion model were determined to test adsorption kinetics and rate constants derived from the three kinetic models being calculated. The pseudo-second-order kinetic model was better appropriated.

The chapter "A role for heavy metal toxicity and air pollution in respiratory tract cancers" reviews cigarette smoke and the health problems it causes: associated lung, nasopharyngeal, and laryngeal cancers, which are connected to its cadmium and lead content. Biomass smoke contents are hazardous, including carbon monoxide, nitrous oxides, sulfur oxides (principally from coal), formaldehyde, and polycyclic organic compounds (notably benzo[a]pyrene). They are implicated in low birth weight, increased infant perinatal mortality, pulmonary tuberculosis, nasopharyngeal and laryngeal cancer, cataracts, and lung cancer, while the harmful effects of free radicals are balanced by the antioxidant action of antioxidant enzymes and non-enzymatic antioxidants that help in the process of detoxification.

The chapter "Mercury toxicity in public health" describes mercury's physical properties, natural and anthropogenic sources, and the differences between liquid and gaseous mercury. Gaseous mercury is poisonous due to the nature of absorption into blood. Mercury 2+ is more poisonous due to high solubility. Exposure and poisoning types are discussed, including Minamata disease.

The chapter "Health risks of potentially toxic metals contaminated water" reviews routes of groundwater and aquatic contamination by toxic metals leaching from toxic industrial waste dumps and municipal landfills, and the leaching of agricultural chemicals from soils. Potentially toxic metals contaminating vegetables, fruits, seafood, and drinking water are the most recognized sources of ingestion by the general public. Toxic metals (Cd, Cu, Pb, Zn, Cr(III), Cr(VI), and Hg) enrich antibiotic-resistant microbes, particularly bacteria by co-selection, because it promotes antibiotic resistance in bacteria even in the absence of antibiotics. Co-selection occurs by co-resistance and cross-resistance.

The chapter "Toxicologic characteristics of nanodisperse manganese oxide" analyzes physical–chemical properties, biological accumulation, and morphological–functional properties at various exposure types. The author experimentally researched nanodisperse MnO2 water suspension at intragastric, inhalation, and skin-resorptive levels in small rodents (mice and Wistar rats) with various exposure periods. Profound and detailed characteristics of the toxic effects exerted by this substance were found, which determined the target organs and revealed dose-dependent effects. Growth in development and commercialization of nanoindustries and nanotechnological products in the production chain means that such products and technologies are considered to belong to the market segment of new technologies (the sixth technological structure). MnO2 nanoparticles damage the membranes of astrocytes and neurons and disturb the neurotransmitter ratio. The author detected pathomorphologic brain disorders—hyperemia, subarachnoid hemorrhages, brain edema with perivascular and pericellular spaces dilatation, focuses of nerve fibers, demyelinization, and focal dystrophic changes in vessel endothelium.

The chapter "Intracellular iron concentration and distribution have multiple effects on cell cycle events" reviews how iron depletion causes inhibition of cellular proliferation and cell cycle arrest at different parts of the cell cycle. The chapter explains why in some tissues, particularly rapidly growing cancer cells, iron depletion causes cell cycle arrest and apoptosis, a form of programmed cell death. Other neoplastic tissues are more prone to the toxic effects of iron, which can induce autophagic cell death (termed ferroptosis) via reactive oxygen species resulting in lysosomal degradation of cellular constituents.

The editors John Kanayochukwu Nduka and Mohamed Nageeb Rashed thank the Author Service Manager Ms. Dolores Kuzelj and IntechOpen, UK. The assistance of

**V**

Andrea Koric is also noted. We are also grateful to the authors for their hard work and worthy contributions; we have learnt a lot reviewing their chapters. We also

Editor John Kanayochukwu Nduka is grateful to his wife Ogochukwu and children

**John Kanayochukwu Nduka**

Nnamdi Azikiwe University, Awka, Anambra, Nigeria

**Mohamed Nageeb Rashed** Department of Chemistry,

> Faculty of Science, Aswan University,

> > Egypt

Environmental Chemistry and Toxicology Research Unit,

Pure and Industrial Chemistry Department,

thank our families for their understanding.

Chimerem-mma, Onyinye, and Chisom.

Andrea Koric is also noted. We are also grateful to the authors for their hard work and worthy contributions; we have learnt a lot reviewing their chapters. We also thank our families for their understanding.

Editor John Kanayochukwu Nduka is grateful to his wife Ogochukwu and children Chimerem-mma, Onyinye, and Chisom.

#### **John Kanayochukwu Nduka**

Environmental Chemistry and Toxicology Research Unit, Pure and Industrial Chemistry Department, Nnamdi Azikiwe University, Awka, Anambra, Nigeria

#### **Mohamed Nageeb Rashed**

Department of Chemistry, Faculty of Science, Aswan University, Egypt

**1**

Section 1

Environmental Toxic

Heavy Metal Pollution

and Possible Remediating

Techniques

### Section 1
