Key facts

Lead is a cumulative toxicant that affects multiple body systems and is particularly harmful to young children.Lead in the body is distributed to the brain, liver, kidney and bones. It is stored in the teeth and bones, where it accumulates over time. Human exposure is usually assessed through the measurement of lead in blood.Lead in bone is released into blood during pregnancy and becomes a source of exposure to the developing fetus.There is no known level of lead exposure that is considered safe.Lead poisoning is entirely preventable.

重要事实铅是一种累积性毒物，影响身体多个系统，特别对幼童具有危害。身体中的铅分布在大脑、肝脏、肾脏和骨骼。它在牙齿和骨骼中储存下来，随着时间不断累积。人类的接触程度通常通过测量血铅加以估测。骨骼中的铅可在怀孕期间释放到血液里，对发育中的胎儿形成接触来源。没有已知的被认为安全的铅接触水平。铅中毒完全可以得到预防。

Health effects of lead poisoning on children

Lead can have serious consequences for the health of children. At high levels of exposure, lead attacks the brain and central nervous system to cause coma, convulsions and even death. Children who survive severe lead poisoning may be left with mental retardation and behavioural disorders. At lower levels of exposure that cause no obvious symptoms, and that previously were considered safe, lead is now known to produce a spectrum of injury across multiple body systems. In particular lead affects children’s brain development resulting in reduced intelligence quotient (IQ), behavioural changes such as reduced attention span and increased antisocial behaviour, and reduced educational attainment. Lead exposure also causes anaemia, hypertension, renal impairment, immunotoxicity and toxicity to the reproductive organs. The neurological and behavioural effects of lead are believed to be irreversible.

铅中毒对儿童带来的健康影响

铅可对儿童健康具有严重影响。高浓度接触会使铅影响到大脑和中枢神经系统，引起昏迷、抽搐、甚至死亡。从严重铅中毒中恢复过来的儿童可能会留有智力低下和行为紊乱问题。没有引起明显症状并且以往认为是安全的低浓度铅接触，现在已知可在多个身体系统产生一系列伤害。尤其是铅会影响到儿童大脑发育，造成智商（IQ）下降、像是注意力时间缩短以及反社会行为增加等行为改变以及学习成绩下降。铅接触还可引起贫血、高血压、肾功能损害、免疫毒性以及生殖器官毒性。人们认为，由铅带来的神经和行为影响具有不可逆性。

There is no known safe blood lead concentration. But it is known that, as lead exposure increases, the range and severity of symptoms and effects also increases. Even blood lead concentrations as low as 5 µg/dl, once thought to be a “safe level”, may result in decreased intelligence in children, behavioural difficulties and learning problems.

并没有已知的安全血铅浓度。但人们已知，随着铅接触的增加，症状及其影响的范围和严重性也会增加。即便血铅浓度达到5微克/分升这一曾经被认为的“安全水平”，也可能会引起儿童智力下降、行为困难以及学习问题。

Encouragingly, the successful phasing out of leaded gasoline in most countries, together with other lead control measures, has resulted in a significant decline in population-level blood lead concentrations. There are now only 3 countries that continue to use leaded fuel1.

令人鼓舞的是，含铅汽油在多数国家已经成功遭到淘汰，这使人群层面的血铅浓度出现了显著下降。现在只有六个国家继续使用含铅汽油。

Further efforts are required to continue to reduce the use and releases of lead and to reduce environmental and occupational exposures, particularly for children and women of child-bearing age. Interventions include eliminating non-essential uses of lead such as lead in paint, ensuring the safe recycling of lead-containing waste, educating the public about the importance of safe disposal of lead-acid batteries and computers, and monitoring of blood lead levels in children, women of child-bearing age and workers.

需要作出进一步努力，继续减少铅的使用和排放，降低环境风险和职业风险，尤其是降低儿童和育龄妇女面临的风险。干预措施包括消除铅的不必要使用，例如不在涂料中加铅，确保含铅废物的安全回收，向公众宣讲安全处置铅酸电池和计算机的重要性，并监测儿童、育龄妇女和工人的血铅水平。

（来源：世界卫生组织）