Objective To know the actual level of hair lead levels in children of Xi'an. Methods Hair samples were collected from 203 children aged 7-13 years of an urban primary school and a suburban one during April-June, 2001. The hair lead levels were measured with flame atomic absorption spectrophotometer. Results The geometric mean of hair lead levels of children in urban area was 4.69 ?g/g, while in suburban area it was 1.67 ?g/g. There was a significant difference between them (t=7.78, P=0.001). The younger group had a higher hair lead levels in urban area and suburban area. With age, hair lead levels showed a significant down trend. There was no significant difference had been seen between boys and girls living in the city, but the hair lead levels of rural boys(median 2.92 ?g/g) were higher than rural girls (median 1.52 ?g/g), P=0.02. Rate of high hair lead (13.2%)of urban children, based on the standard (≥10.0 ?g/g), was higher than rural children (1.2%) (?2=9.18, P=0.002). Conclusion The hair lead levels of the children living in urban districts are higher than that in the suburb area of Xi'an city. The rate of high hair lead of urban children was higher than that of the suburban children. The hair lead levels of children aged 7-13 years in Xi'an have showed a down trend with age. There is no significant difference between boys and girls in urban area, but the hair lead levels in suburban boys is higher than that of the suburban girls.

Objective:To investigate the clinical characteristics and the risk of major adverse cardiac events within 1 year of middle-aged and elderly in-patients with acute decompensated and mid-range ejection fraction heart failure(HF)in the medical alliance setting.Methods:A retrospective cohort study was conducted among a total of 180 in-patients with acute decompensated heart failure in Cardiovascular Hexi Hospital Consulting Area of Tianjin Chest Hospital.According to ejection fraction measured by echocardiogram, the in-patients were classified into three groups: heart failure with reduced ejection fraction(HFrEF)group(n=70, 38.9%), HFmEF group(n=50, 27.8%), and heart failure with preserved ejection fraction(HFpEF)group(n=60, 33.3%). Clinical feature and 1-year prognosis between different groups were compared.Results:Univariate Cox regression analysis of 1-year all-cause death and cardiovascular death showed that there was no significant difference between HFrEF group and HFmEF group, HFpEF group and HFmEF group(all P>0.05); 1-year readmission analysis of heart failure showed that 47.1%(33 cases)of HFrEF group was higher than 24.0%(12 cases)of HFmEF group, 48.3%(29 cases)of HFpEF group was higher than HFmEF group( HR=2.307, 2.368, 95% CI: 0.187-4.480, 1.207-4.644, respectively, all P<0.05); The major 1-year cardiovascular events were 57.1%(40 cases)higher in the HFrEF group than 34.0%(17 cases)in the HFmEF group( HR=2.053, 95% CI: 0.187-4.408, P< 0.05). Multivariate analysis showed that the 1-year risk of major cardiovascular events was significantly different between HFmEF group and HFpEF group( HR=0.477, 95% CI: 0.241-0.941, P< 0.05). Pulmonary heart disease( P< 0.05), atrial flutter and/or atrial fibrillation( P< 0.01), New York Cardiology class Ⅳ( P< 0.01)were risk factors for death.Hypertension and cor pulmonale were the risk factors for readmission in patients with heart failure(all P< 0.01). Conclusions:The clinical characteristics of inpatients with HFmEF in the medical alliance setting tended to be consistent with those with HFrEF, while the feature of ischemic heart disease was more prominent in HFmEF.The 1-year risk of heart failure readmission in HFmEF group was significantly lower than that in HFpEF and HFrEF group, and the risk of all-cause mortality and cardiovascular mortality at 1 year was not significantly different among the three groups.