BackgroundTo investigate the attention-deficit/hyperactivity disorder (ADHD) status among preschool-aged children in Guiyu, an electronic waste (e-waste) recycling town in Guangdong, China.MethodsTwo hundred and forty-three parents were surveyed regarding ADHD behaviors in their children (aged 3–7 years) based solely on the DSM-IV criteria. The peripheral blood samples were taken from these children to measure blood lead levels (BLLs) and blood cadmium levels (BCLs).Results12.8% of children met the criteria for ADHD, of which the inattentive, hyperactive/impulsive and combined subtypes were 4.5%, 5.3% and 2.9% respectively. Of all children, 28.0% had BLLs ≥ 10 ug/dL and only 1.2% had BCLs ≥ 2 ug/L, levels conventionally considered high. Either modeled by univariate or multivariable analysis, the three ADHD scores (inattentive, hyperactive/impulsive and total scores) calculated from the Parent Rating Scale showed strong positive correlations with BLLs but not with BCLs. Furthermore, children with high BLLs had 2.4 times higher risk of ADHD than those with low BLLs (OR: 2.4 [95% CI: 1.1–5.2]). When each of the 18 categories on the Parent Rating Scale was separately analyzed, children with high BLLs had significant higher risks for positive ADHD symptoms than those with low BLLs in 12 of the 18 categories (ORs ranged from 2.1 [95% CI: 1.1–3.9] to 3.6 [95% CI: 1.7–7.5]).ConclusionsThis study suggests that environmental lead contamination due to e-waste recycling has an impact on neurobehavioral development of preschool children in Guiyu.Electronic supplementary materialThe online version of this article (doi:10.1186/s12887-015-0368-x) contains supplementary material, which is available to authorized users.

Background Primitive electronic waste (e-waste) recycling is ongoing in Guiyu, so toxic heavy metals may continue to threaten the health of children in the area. Objective This study primarily aimed to evaluate the effect of e-waste exposure on haemoglobin (Hb) synthesis in preschool children. Methods Medical examinations were conducted with the permission of children’s guardians and the approval of the Ethics Committee of the Medical College of Shantou University. This study recruited 224 children (aged 3–6 years, exposed group) who lived in Guiyu and 204 children (aged 3–6 years, control group) who lived in a town free of e-waste pollution. Blood levels of lead, Hb, ferritin, folate and vitamin B12 were tested in all children. Furthermore, all children were assessed for thalassemia, and their parents were asked to fill in questionnaires. Results There were no significant differences in the level of ferritin, folate, or vitamin B12 between the exposed and control groups (P > 0.05). No children were identified as having thalassemia in all study participants. Blood lead level (BLL) and the risk of children with BLL ≥ 10 µg/dL in the exposed group were significantly higher than those in the control group (all P < 0.01). Three subgroups of each group were created according to BLL (Group A: < 5.0 µg/dL; Group B: 5.0–9.9 µg/dL; Group C: ≥ 10.0 µg/dL). Hb level decreased with elevated BLL in the exposed group (P = 0.03), but not in the control group (P = 0.14). Hb levels in group B and group C were also significantly lower in the exposed group than in the control group (Group B: 122.6 ± 9.5 g/L versus 125.8 ± 8.2 g/L, P = 0.01; Group C: 120.3 ± 7.3 g/L versus 123.6 ± 8.3 g/L, P = 0.03). In addition, the prevalence of anaemia associated with BLLs above 10 µg/dL and between 5.0 and 9.9 µg/dL were both significantly higher in the exposed group than in the control group (4.0% vs. 0.5%, 5.4% vs. 1.5%, respectively, both P < 0.05). Conclusion Lead exposure more significantly inhibits Hb synthesis in children who live in e-waste dismantling areas than in those who live in non-e-waste dismantling areas. Other toxins released from e-waste may also contribute to the inhibition of Hb synthesis and may lead to anaemia in local children. Further investigations are needed to provide evidence for the development of relevant protective measures.

Background Primitive electronic waste (e-waste) recycling is ongoing in Guiyu, so toxic heavy metals may continue to threaten the health of children in the area. Objective This study aimed to evaluate the effect of e-waste exposure on haemoglobin (Hb) synthesis in preschool children. Methods Medical exams were conducted with the consent of children’s guardians and the approval of the Shantou University Medical College Ethics Committee. This study recruited 224 and 204 children in 3–6 years old from Guiyu (exposed group) and from a town without e-waste pollution (control group), respectively. Blood levels of lead, Hb, ferritin, folate and vitamin B12 were tested in all children. Furthermore, all children were assessed for thalassemia, and their parents were asked to complete questionnaires. Results There was no significant differences in ferritin, folate, or vitamin B12 levels between the exposed and control groups (P > 0.05). All children were excluded thalassemia. Blood lead level (BLL) and the rate of children with BLL ≥ 10 µg/dL were higher in the exposed group than control group (both P < 0.01). Both groups were further divided into three sub-groups according to BLL (Group A: <5.0 µg/dL; Group B: 5.0–9.9 µg/dL; Group C: ≥10.0 µg/dL). Hb levels were negatively correlated with BLL in exposed group (F = 3.52, P = 0.03), but not in control group (F = 1.98, P = 0.14). Hb levels in group B and group C were significantly lower in exposed group than in control group (Group B, P = 0.01; Group C, P = 0.03). In addition, the prevalence of anaemia in children with lead poisoning in exposed group were significantly higher than those in control group (4.0% versus 0.5%, P < 0.05). The prevalence of anaemia in children without lead poisoning and without iron deficiency in exposed group were also higher than those in control group (6.5% versus 2.0%, P < 0.05). Conclusion Lead exposure significantly inhibits Hb synthesis in children living in e-waste dismantling areas compared to those living in non-e-waste dismantling areas. Other toxins released from e-waste may also contribute to the inhibition of Hb synthesis and may lead to anaemia in local children. Further investigations are needed to provide evidence for the development of relevant protective measures.

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