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Lead is a heavy metal that can affect the human hematological system. However, reports are limited on the dose-response relationship between blood lead levels (BLLs) and hematological parameters in children. This study aimed to explore the dose-response relationship between BLLs and hematological measurements among children in China.A cross-sectional design was used. A total of 743 children aged 5-8 years were recruited from two counties in central China. The BLLs and blood levels of iron, zinc, and calcium were determined, and hematological parameters were measured.All hematological measurements and BLLs were logarithm-transformed to ensure a normal distribution. The geometric mean of the BLLs of all children was 82.4 μg/L. Forty-one percent of the children had BLLs ≥ 100 μg/L. The lead-poisoning percentages of the children were significantly associated with gender, age, district of residence, and environmental lead exposure level. Multivariate linear regression analyses showed no significant linear correlation between BLL and each hematological parameter among the children with BLLs ≥ 100 μg/L. The analyses also revealed a small increase in red blood cell count (RBC) with increasing BLLs in the BLLs 100 μg/L group (β = 0.03, P = 0.048). A negative association was noted between BLLs and blood platelet (PLT) count in the children with BLLs 100 μg/L (β = -0.90, P 0.001). Logistic regression analyses showed that BLLs were significantly associated with decreased hemoglobin (Hb) levels, RBC counts, PLT counts and mean corpuscular hemoglobin (MCH) after adjusting for potential confounders. Such analyses also revealed a dose-response relationship between the BLLs and hematological parameters (Hb level, RBC count, and PLT count). The children with BLLs ≥ 100 μg/L were 2.72, 2.51, and 3.76 times more likely to achieve decreased RBC counts, Hb levels and PLT counts, respectively, compared to those with BLLs 100 μg/L. Compared with children with BLLs 100 μg/L, those with BLLs ≥ 100 μg/L were 3.16 and 4.38 times more likely to show decreased Hb levels and PLT counts respectively in the high-level lead-exposure group and 4.33 times more likely to achieve a decreased PLT count in the low-level lead-exposure group. The individuals with BLLs of the highest quartile were 3.65, 5.87, and 29.23 times more likely to exhibit decreased Hb levels, RBC counts, and PLT counts, respectively, than the children with BLLs of the lowest quartile.Our findings suggested a negative association between BLLs and hematological indicators (Hb level, RBC count, PLT count and MCH). A strong negative, non-linear dose-response relationship was also showed between BLLs and hematological parameters (Hb level, RBC count, and PLT count).

Pregnancy is a critical stimulator of bone mineral resorption. We used to find the MTHFR gene polymorphisms are related with blood lead levels among pregnant women. Pregnancy-stimulated bone turnover may be associated with MTHFR gene polymorphisms too. In this article, we aimed to determine the relationship between MTHFR gene polymorphisms and bone turnover rates among the pregnant women. The participants including pregnant and non-pregnant women were selected and recruited during their routine prenatal or physical examination from July to October in 2012. A total of 1000 participants, including 250 pregnant women in the first, second, and third trimesters and 250 non-pregnant women, were enrolled in the study. Finally, after excluding 27 participants unable to provide blood samples, 973 eligible participants (i.e., 234,249, and 248 pregnant women in the first, second, and third trimesters, respectively, and 242 non-pregnant women) were included in the research. The MTHFR gene 1298CC homozygote carriers were more susceptible to yield higher plasma homocysteine levels than the 1298AA/AC carriers, with standardized coefficients of 0.086 (P

To evaluate the relationship of delta-aminolevulinic acid dehydratase (ALAD) activity, urinary delta-aminolevulinic acid (ALAU) level and blood zinc protoporphyrin (ZPP) concentration to low blood lead (PbB) levels, these biomarkers were determined for all subjects enrolled from a rural area of southeast China where people had low levels of exposure to lead. The mean values of PbB, ALAD, ALAU and ZPP were 67.11 microg/L (SD: 1.654, range: 10.90-514.04), 339.66 nmol ml(-1)h(-1) (1.419, 78.33-793.13), 20.64 microg/L (1.603, 2.00-326.00), and 0.14 micromol/L (3.437, 0.01-2.26), respectively. ALAD was inversely associated with low levels of PbB. ZPP was inversely related to low levels of PbB but positively related to relatively higher levels of PbB. Alcohol drinking contributed to low ALAD in men. Women had higher ZPP than men. ALAU had no significant association with PbB. In conclusion, ALAD possibly has a non-linear relation with low to moderate levels of PbB. At moderate levels of PbB, ZPP increases with increasing levels of PbB. ALAU is not suitable as an indicator for low levels of lead exposure.

Our research on adverse effects of lead exposures on physical and neurobehavioral health of children aged 6-12years in 4 villages, labeled as K, M, L, and X, in rural China, was reported in this article. Lead in blood (PbB), urine (PbU), hairs (PbH), and nails (PbN) were measured by graphite furnace atomic absorption spectrometry. Abbreviated Symptom Questionnaire of Conner's instruments and Revised Raven's Standard Progressive Matrices were applied to evaluate childhood attention deficit/hyperactivity disorders (ADHD) and intelligences. Geometric means (SD) of PbB, PbU, PbH and PbN concentrations were 71.2 microg/L (1.56), 11.7 microg/g (1.75), 12.5 microg/g (2.82), and 25.3 microg/g (2.79), respectively. 54 (17.0%) children had PbB levels ofor =100 microg/L. Boys, 6-10 years old, and living in village K were 2.11, 2.48, and 9.16 times, respectively, more likely to be poisoned by lead than girls, aged 11-12 years, and residing in X. 18 (5.7%) and 37 (11.7%) subjects had ADHD and mental retardations, respectively. Inverse relationships between intelligences and natural log transformed PbU and PbH levels were observed with respective odds ratios (95%CI) of 1.79 (1.00-3.22) and 1.46 (1.06-2.03) or 1.28 (1.04-1.58) and 1.73 (1.18-2.52) by binary or ordinal logistic regression modeling. ADHD prevalence was different by gender and age of subjects. PbU, PbH, and PbN related to PbB positively with respective correlation coefficients of 0.530, 0.477, and 0.181. Receiver operating characteristic (ROC) curves of the three measurements revealed areas under curves (AUCs) being 0.829, 0.758, and 0.687, respectively. In conclusion, children had moderate levels of lead exposures in this rural area. Intelligence declines were associated with internal lead levels among children. ROC analysis suggests PbU an internal lead indicator close to PbB.

Few studies have focused on the accuracy of using the Integrated Exposure Uptake Biokinetic (IEUBK) model in Chinese children with site- and age-specific exposure data. This study aimed to validate the accuracy and sensitivity of the IEUBK model in lead risk assessment of Chinese children aged 61-84 months old. A total of 760 children were enrolled from two respective counties in Central China by using random cluster sampling method. Blood lead levels (BLLs) of all subjects were determined using graphite furnace atomic absorption spectrometry, as well as that in the environmental media, such as air, drinking water, soil, dust and food. Age- and site-specific time-activity patterns and water consumption were evaluated by using questionnaires for children. Exposure parameters including outdoor and indoor activity time, ventilation rate and water consumption in this study were different from the default values of the IEUBK model. Statistical analysis revealed no significant differences between the predicted and observed BLLs. Diet and soil/dust lead intake contributed approximately 83.39% (57.40%-93.84% range) and 15.18% (3.25%-41.60% range) of total lead intake, respectively. These findings showed that the IEUBK model is suitable for lead risk assessment of Chinese children aged 61-84 months old and diet acts as an important lead source.

BackgroundPregnancy is an important stimulus of bone lead release. Elevated blood lead levels (BLLs) may cause adverse pregnancy outcomes for mothers and harmful lead effects on fetuses. However, the reports about maternal BLL changes during pregnancy are conflicting to some extent. This article is to explore the variations in BLLs among pregnant women. The relationships of BLLs with methylenetetrahydrofolate reductase (MTHFR) gene C677T, A1298C, and G1793A polymorphisms, which are associated with bone resorption, were also studied. A total of 973 women, including 234, 249, and 248 women in their first, second, and third trimesters, respectively, and 242 non-pregnant women, were recruited at the Wuhan Women and Children Medical Health Center.MethodsBLLs were determined using a graphite furnace atomic absorption spectrometer. Single-nucleotide polymorphisms of MTHFR were identified with the TaqMan probe method.ResultsThe geometric mean (geometric standard deviation) of BLLs was 16.2 (1.78) μg/L for all participants. All the studied MTHFR alleles were in Hardy-Weinberg equilibrium. Multiple-linear regression analysis revealed the following results. Among the pregnant women, those that carried MTHFR 677CC (i.e. wild-genotype homozygote) and 1298CC (i.e. mutant-genotype homozygote) exhibited higher BLLs than those that carried 677CT/TT (standardized β = 0.074, P = 0.042) and 1298AC/AA (standardized β = 0.077, P = 0.035) when other covariates (e.g., age, no. of children, education and income, etc.) were adjusted. The BLLs of pregnant women consistently decreased during the pregnancy and these levels positively correlated with BMI (standard β = 0.086-0.096, PConclusionsThe 1298CC mutant-type homozygote in the MTHFR gene is a risk factor for high BLLs among low-level environmental lead-exposed Chinese pregnant women, whose BLLs consistently decreased during gestation.

BACKGROUND: Cadmium (Cd) is a heavy metal that can cause renal tubular dysfunction in humans. Women are among the high-risk group for Cd health effects. Determining the thresholds of Cd-induced renal effects is important. Thus, in this article, we aimed to identify the benchmark dose (BMD) and its low limit (BMDL) levels as the Cd thresholds for Chinese women. METHODS: Epidemiologic investigation was performed in county A and county B to obtain data on Cd exposure and its renal effect on respondents. Levels of Cd (UCd), β2-microglobulin (UB2M), and N-acetyl-β-D-glucosaminidase (UNAG) were measured in morning urine samples. The BMD approach was mainly performed. RESULTS: Results of the BMD approach were similar whether the method was conducted for the two sets of data (collected in CA and CB, respectively) separately or cooperatively. The BMD/BMDL values of UCd for all subjects were 1.07/0.44 and 2.12/0.53 µg/g cr based on UB2M and UNAG, respectively, given a predetermined BMR of 0.05. CONCLUSIONS: The presented thresholds of Cd-induced renal effects (i.e., the BMDLs of UCd) are close to the counterpart values reported in Japan, Sweden and Belgium.

Lead (Pb) levels, delta-aminolevulinic acid dehydratase (ALAD) activities, zinc protoporphyrin (ZPP) levels in blood, and urinary delta-aminolevulinic acid (ALA) and coproporphyrin (CP) concentrations were measured for 318 environmental Pb exposed children recruited from an area of southeast China. The mean of blood lead (PbB) levels was 75.0μg/L among all subjects. Benchmark dose (BMD) method was conducted to present a lower PbB BMD (lower bound of BMD) of 32.4μg/L (22.7) based on ALAD activity than those based on the other three haematological indices, corresponding to a benchmark response of 1%. Childhood intelligence degrees were not associated significantly with ALAD activities or ALA levels. It was concluded that blood ALAD activity is a sensitive indicator of early haematological damage due to low-level Pb exposures for children.

To explore the risk factors on relapsing tuberculosis related to smear positive pulmonary tuberculosis which had been cured for five years.Patients with smear positive pulmonary tuberculosis registered in 1995 from ten countries in Hubei province were studied and logistic regression was used for data analysis.The 5-year relapse rate of smear positive pulmonary tuberculosis was 3.85 percent. Risk factors related to relapse would include being non-modeled county, negative smear after treated for three months, the class of retreatment, management of non-DOTS, method of chemotherapy and patients that did not get treated by the tuberculosis institute, with odds ratios of 0.15, 4.62, 3.68, 5.88 and 6.47, respectively.Effect standard, regulation DOTS and the centralized management measure might have had effects on decreasing the relapse rate.