Water toxicants: a comprehension on their health concerns, detection, and remediation

Water is an essential moiety for the human use since a long time. Availability of good-quality water is very essential, as it is used in almost all the industrial, agricultural, and household activities. However, several factors such as increased urbanization and industrialization, extensive use of chemicals, natural weathering of rocks, and human ignorance led to incorporation of enormous toxicants into the water. The water toxicants are broadly classified as inorganic, organic, and radiological toxicants. Inorganic toxicants include heavy metals (As, Cr, Cd, Hg, Ni, Pb) and metalloids, ammonia, nitrate, and fluoride. Uranium is included in radiological toxicants which also causes chemical toxicity. Organic pollutants include polycyclic aromatic hydrocarbons, polychlorinated biphenyls, phenolic compounds, phthalate esters, pesticides, pharmaceutical and personal care products, perchlorates, and flame retardants. These toxicants are harmful for the ecosystem as well as for the human beings causing different types of health complications like lung cancer, nasal cancer, gingivitis, severe vomiting and abdominal pain, hormonal imbalance, skeletal damage, neurotoxicity like Alzheimer and Parkinson disease, renal toxicity, nephrotoxicity, etc. The USEPA and WHO specified the permissible concentration of these pollutants in the drinking water. Determination techniques having high sensitivity, low cost, rapid onsite, and real-time detection of traces of water pollutants are discussed. This review also covers in depth about the remediation techniques, for the control of water toxicants, such as chelation of the heavy metals, intoxication of pollutants using various plants, adsorption of toxicants using different sorbent medias, and photocatalytic breakdown of persistent organic pollutants (POPs).