Sources, symptoms and characteristics of childhood lead poisoning: experience from a lead specialty clinic in China

OBJECTIVES: This study explored the sources of lead exposure, identified patients' geographic distribution and evaluated the symptoms of children with elevated blood lead levels (BLLs) referred to a pediatric lead specialty clinic in China. MATERIAL AND METHODS: Data were collected from 515 consecutive outpatients attending the Pediatric Lead Poisoning Clinic in Xinhua Hospital, Shanghai, China, between 2011 and 2016, referred for BLLs ≥5 μg/dL. Atomic absorption spectrometry was used to measure venous BLLs. RESULTS: The mean ± standard deviation age of the patients was 4.1 ± 3.2 years. Their BLLs ranged from 5 to 126 μg/dL. The geometric mean and median BLLs were 24 and 26 μg/dL, respectively. Two hundred and twenty-two children (43.1%) were exposed to industrial lead pollution-mainly from Zhejiang, Jiangsu, Hunan, Henan and Anhui provinces; whereas, 41.4% (213 cases) were induced by folk medicines used widely throughout China. Other nonindustrial sources of lead exposure included lead-containing tinfoil and tin pots. Household lead paint was a rare source. Most patients exhibited nonspecific symptoms, such as hyperactivity, attention difficulty, aggressiveness, constipation and anorexia. CONCLUSIONS: Industrial pollution and folk medicines are important sources of lead exposure in China. Childhood lead poisoning may be difficult to diagnose clinically as symptoms are nonspecific. Thus, blood lead screening may be necessary to identify children at high risk of exposure. Education to raise the awareness of potential sources of exposure resulting in their elimination would be expected to decrease the incidence of children with elevated BLLs.