Lead and Aquatic Ecosystems, Biomarkers, and Implications for Humankind

Abstract

Lead, a highly toxic metal, is present in all the biotic and abiotic environmental components. Its continuous use for several industrial and domestic purposes has caused rise in its levels, thereby posing serious threats to animal and human health. In aquatic ecosystems, fish are highly susceptible to the deleterious effects of lead exposure. This toxicity is induced mainly by bioaccumulation in tissues which then causes oxidative stress due to the production of reactive oxygen species. In addition to this, lead being a divalent cation can surrogate for calcium at multiple levels affecting various cell signaling pathways. Fish can directly affect humans via food intake. Disorders of different body systems in humans and the role of inflammation due to lead exposure have been proven by various studies. These studies indicate that lead exposure may cause respiratory, neurologic, digestive, cardiovascular, and urinary diseases. Both acute and chronic lead exposure can cause many detrimental systematic effects including hypertension, frank anemia, cognitive deficits, infertility, immune imbalances, delayed skeletal and deciduous dental development, vitamin D deficiency, and gastrointestinal effects. The molecular basis of lead exposure resulting in various systemic effects is being extensively explored. Therefore, the aim of this review is to examine the various harmful effects of lead exposure on aquatic organisms and humans, including bioaccumulation, oxidative stress, and immune responses because of lead-induced toxicity.KeywordsLead toxicityAquatic ecosystemHumankindBlood lead levelReactive oxygen speciesRespiratoryNeurologicDigestiveCardiovascularKidneyOxidative stressInflammationBiomarkers