Lead poisoning

Lead poisoning is a non-communicable chronic disease caused by cumulative absorption of lead. Typical symptomatic childhood lead poisoning is not common. Although most children do not show signs of brain lesions, they have persistent behavioral and cognitive problems that seriously affect health and learning. When symptoms such as irritability, loss of appetite, personality changes, and abdominal colic appear, the blood lead level is generally around 50 μg/dL, which already constitutes severe lead poisoning, but these symptoms are easily attributed to other causes. If not recognized at this stage, the blood lead level can easily rise above 100 μg/dL, at which point the symptoms typically manifested in children are increased intracranial pressure, causing projectile vomiting, altered consciousness, and convulsions; this is extremely severe lead poisoning. In adults, if lead poisoning continues at a blood lead concentration of 50-60 μg/dL, it can lead to renal failure, slowed reactions, peripheral nervous system disorders, and gout. Lead poisoning is not easily cured, and its harm to the human body persists for a long time even after blood lead levels decrease. Lead toxicity mainly inhibits enzymes containing sulfhydryl groups within cells, thereby causing disorders in the body's biochemical and physiological functions, inducing small artery spasm, damaging capillary endothelial cells, affecting energy metabolism, leading to porphyrin metabolism disorders, hindering the synthesis of methemoglobin, altering the normal properties of red blood cells and their membranes, and inhibiting the resynthesis of phosphocreatine in muscles, thus producing a series of pathological changes. Among these, changes in the nervous system, kidneys, hematopoietic system, and blood vessels are more significant.