为何儿童更易受到铅影响？

Core Points - A kindergarten in Gansu, China, is under investigation due to multiple cases of lead poisoning among children, with 19 children hospitalized across provinces and over 200 samples sent for retesting [1] - Lead is identified as one of the three major heavy metal pollutants, posing significant health risks, especially to children, with the World Health Organization (WHO) stating that lead is the greatest environmental threat to children [2][4] - The ideal blood lead concentration in humans should be zero, as lead has no physiological function and can cause irreversible damage, particularly in children [4][5] Health Impact - Lead poisoning can lead to severe health consequences, including irreversible damage to organs and systems during childhood development, with potential long-term effects such as memory loss and intellectual disabilities [5][6] - Research indicates that for every 10 micrograms per liter increase in blood lead concentration, IQ can decrease by 0.25 to 0.5 points, and a 100 microgram per liter increase can result in a height reduction of 1 centimeter [6] Vulnerability of Children - Approximately one-third of children globally are affected by lead poisoning, with around 800 million children having blood lead levels at or above the warning threshold of 5 micrograms per deciliter; in China, this number is about 31.23 million [7] - Children are more susceptible to lead exposure due to their underdeveloped blood-brain barrier, higher absorption rates through the digestive system, and lower excretion capabilities compared to adults [7] Sources of Lead Exposure - The WHO estimates that the sources of lead exposure in children include indoor and outdoor dust (45%), food (47%), drinking water (6%), and air (1%) [8] - Common sources of lead contamination include traditional practices, such as using lead-containing materials in food preparation and folk remedies that incorporate lead compounds for medicinal purposes [9][10] - Food items, particularly those made using traditional methods or contaminated with lead-based pesticides, can also pose risks, although the primary concern is the "hand-to-mouth" route of exposure through toys and household items [10]