Lead intoxication: A summary of the clinical presentation among Thai patients

Abnormal erythrocyte-related parameters in children with Pb, Cr, Cu and Zn exposure

The link between exposure to a particular heavy metal or metalloid and the development of anemia is well established. However, the association between combined exposure to multiple heavy metal(loid)s and anemia in children is still lacking in evidence. In this study, a total of 266 children aged 3 to 7 were recruited from Guiyu, China. Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure blood heavy metal(loid) concentrations. Blood cell count, hemoglobin (HGB), mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), hematocrit (HCT), and red blood cell distribution width (RDW) were measured by an automated hematology analyzer. Erythrocyte-related parameters were negatively correlated with the Cu and Cu/Zn ratios and positively correlated with Cr, Ni, Zn, and Se by Spearman correlation analysis. Only blood Cu level was negatively correlated with HGB [β = -2.74, (95% Cl: -4.49, -0.995)], MCH [β = -0.505, (95% Cl: -0.785, -0.226)], MCV [β = -1.024, (95% Cl: -1.767, -0.281)], and MCHC [β = -2.137, (95% Cl: -3.54, -0.734)] by multiple linear regression analysis. The Bayesian Kernel Machine Regression (BKMR) model analysis indicated a negative correlation between the combined exposure to Cu, Zn, Pb, and Cr and MCH and MCV. The single-factor analysis showed a considerable statistical difference only with Cu on MCV, MCH, and HGB. Furthermore, the interaction analysis highlighted the interdependent effects of Cu and Zn, Pb and Zn, and Cr and Zn on MCH and MCV levels. Additionally, the oxidation and/or antioxidation reactions may play a significant role in the development of metal(loid)-induced anemia risk. It is crucial to investigate the effects of co-exposure to multiple heavy metal(loid) elements on anemia, especially the interrelationships and mechanisms among them.

Cross-sectional audit of blood lead levels in regular outpatient haemodialysis patients dialysing in north London

AIM

Blood lead was measured and found to be high in one haemodialysis patient with atypical abdominal pain and peripheral neuropathy. This prompted an audit of blood lead concentrations in prevalent haemodialysis patients under the care of a University Teaching hospital.

METHODS

Blood lead was determined in 271 prevalent adult haemodialysis patients regularly dialysing three times a week, in five dialysis centres and/or on the home dialysis programme. All samples were carefully collected into lead-free plastic containers, and measured by graphite furnace atomic absorption spectrometry.

RESULTS

25.5% of haemodialysis patients had abnormal blood lead concentrations (>200 microg/L), compared with 59% with high-normal values of 100-200 microg/L, and only 15.5% with normal values (<100 microg/L). Blood lead increased with haemodialysis vintage (r = 0.38, P < 0.001), the use of a single carbon filter and reverse osmosis water purification device unit (r = 0.29, P < 0.001), but reduced by urine output (r = -0.44, P < 0.001).

CONCLUSION

Despite UK government legislation to reduce permissible lead contamination of drinking water, blood lead was increased in 84.5% of prevalent haemodialysis patients. Single reverse osmosis machines and carbon filters may not be as effective at filtering out possible lead contamination compared with large industrial reverse osmosis devices and carbon filters, and thus blood lead testing should be considered for home haemodialysis patients, particularly in those areas where monochloramines are used to sterilize domestic water supplies.