Blood lead levels among children aged 0 to 6 years in 16 cities of China, 2004-2008 / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The adverse health effects of lead for children under 6 years are well known. Studies to assess the lead exposure among children in China are small in sample size and lack of national representative data. The aim of this study therefore was to describe blood lead levels and identify risk factors for lead exposure among children aged 0 to 6 years living in 16 cities in China.</p><p><b>METHODS</b>We analyzed data from blood lead levels surveillance in China carried out in 16 large cities between 2004 and 2008. A stratified clustered random sampling strategy was used. A total of 69 968 children aged 0 to 6 years were included. We conducted multiple Logistic regression analyses to explore risk factors to high blood lead level.</p><p><b>RESULTS</b>The geometric mean blood lead level of the children was 4.50 µg/dl (median: 4.90 µg/dl; IQR: 3.20 - 7.00 µg/dl). Overall prevalence of blood lead level ≥ 10.00 µg/dl among 0- to 6-year-old children was 7.57%. But the proportion of blood lead level ≥ 5.00 but < 10.00 µg/dl was 42.12%. Blood lead levels were significantly higher in boys (4.63 µg/dl) than in girls (4.35 µg/dl) (P < 0.0001). The geometric mean blood lead levels and prevalence of blood lead level ≥ 10.00 µg/dl increased with age (P < 0.0001 for the two trends). After controlling for sociodemographic, dietary and behavior factors, multivariable analysis indicated that lower maternal education, male gender, younger age, often biting pencil or/and toys, walking or playing for long time on the street, not washing hands before eating are major risk factors for higher lead levels.</p><p><b>CONCLUSIONS</b>The blood lead levels among Chinese children in urban areas are lower than previous studies but close to those of developed countries. However, children with low lead exposure account for almost half and the sociodemographic factors (age, male sex, and low mother education level) continue to be associated with higher blood lead levels.</p>

Blood lead status and influencing factors among preschool children in urban areas of China / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the blood lead status and influencing factors among preschool children in the sampling city.</p><p><b>METHOD</b>Stratified-clustered-random sampling was used. Standardized questionnaire and peripheral blood samples were obtained from 69 968 children aged 0-6 years in fixed kindergartens and communities of Yinchuan, Xi'an, Chengdu, Wuhan, Hefei, Beijing, Harbin, Zhengzhou, Huhhot, Shijiazhuang, Haikou, Dalian, Qingdao, Guangzhou, Nanning and Changsha from 2004 to 2008, respectively. Tungsten atomic absorbtion spectrophotometry was employed to determine the blood lead level of children.</p><p><b>RESULT</b>The proportion of children with blood lead level ≥ 100 µg/L was 7.57% (among which the proportion of high blood lead level, mild lead poisoning, moderate lead poisoning, severe lead poisoning were 91.0%, 2.76%, 3.32%, 2.93%, respectively) and the blood lead level was lower than those of the past studies. The proportion of high blood lead level has steadily declined from 2004 to 2008 [the proportions were 10.03%, 7.85%, 7.40%, 6.91% and 4.78%, respectively (χ(2) = 297.36, P < 0.0001)]. The proportion of children with blood lead level ≥ 100 µg/L in Haikou, Zhengzhou, Guangzhou, Shijiazhuang, Changsha, Xi'an, Wuhan, Hefei, Chengdu, Yinchuan, Harbin, Beijing, Dalian, Huhhot, Nanning and Qingdao were 12.15%, 10.49%, 10.37%, 9.69%, 9.53%, 9.46%, 9.40%, 8.50%, 7.99%, 7.98%, 7.51%, 6.10%, 3.25%, 2.89%, 2.46% and 2.39%, respectively (χ(2) = 768.21, P < 0.0001). By multiple regression method, the risk factors which influenced blood lead status of children were education status of mother, older children, behavior and dietary habit of children, boy, stay for long time in traffic busy areas, the type of housing, taking traditional Chinese and herbal medicine. The protective factors against lead poisoning in children mainly included scattered living, the nutritional status of calcium, iron, zinc, frequent intake of milk, and older mother.</p><p><b>CONCLUSION</b>The blood lead level of children has decreased, but is still higher than those in developed countries. Lead exposure remains a public health issue which affects children most. The blood lead level of children is affected by multiple factors. Government and the whole society should pay attention to interrupt the lead pollutant and to promote nutritional health education. With all these efforts, it is possible to stop the progress of lead exposure and reduce its hazardous effects on the growth and development of children.</p>

Surveillance of childhood blood lead levels in 14 cities of China in 2004-2006 / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the blood lead level in children aged 0-6 years in urban areas of China.</p><p><b>METHODS</b>Fourteen cities were selected as sites under surveillance. A total of 44 045 peripheral blood specimens were collected from 2004 to 2006, during which 15 727, 14 737, and 13 584 specimens were tested in 2004, 2005, and 2006, respectively. Tungsten atomizer absorption spectrophotometer was employed to determine blood lead level.</p><p><b>RESULTS</b>The geometric mean blood lead level in the tested children was 47.10 microg/L with 10.10% > or = 100 microg/L, 46.17 microg/L with 7.78% > or = 100 microg/L, and 47.03 microg/L with 7.30% > or = 100 microg/L in 2004, 2005, and 2006, respectively. The blood lead levels seemed to tend to rise in parallel with the increase of age of the children and were higher in boys (48.84 microg/L, 47.56 microg/L, and 47.78 microg/L in the 3 respective years) than in girls (45.00 microg/L, 44.53 microg/L, and 46.13 microg/L).</p><p><b>CONCLUSION</b>The blood lead levels in children in cities of China are lower than those in previous national studies, but higher than those in developed countries. Childhood lead poisoning remains a public health problem in China.</p>

Study on blood lead level and related risk factors among children aged 0-6 years in 15 cities in China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To observe blood lead level and related risk factors among children aged 0-6 years old living in cities in China and to provide data for policy development to the prevention on environmental lead pollution.</p><p><b>METHODS</b>A stratified-clustered-random sampling method was used. 17 141 peripheral blood samples of 0-6 years old children from 15 cities in China were tested. Tungsten atomizer absorption spectrophotometer was employed to determined the blood lead level. Related factors were also studied using a standardized questionnaire. Data were analyzed on related risk factors that affecting blood lead levels through multiple regression method.</p><p><b>RESULTS</b>The mean blood lead level of 0-6 years old children from 15 cities in China was 59.52 microg/L including 10.45% of those > or =100 microg/L, and 0.62% > or = 200 microg/L. However, the blood lead levels seemed to have had a trend of increase parallel to age among 0-6 years-old children and were higher for boys (59.50 microg/L) than girls (54.95 microg/L). The risk factors which influenceing children's blood lead levels would include the type of housing, parent's education levels, social status and hobby, children's behavior habit, dieting habit and nutritional condition.</p><p><b>CONCLUSION</b>The blood lead levels of children in China were lower than data gathered from former national studies but higher than those from developed countries, suggesting that the. Government and the whole society should be aware of the problem on lead poisoning among children during their childhood.</p>