山区公路边儿童铅蓄积状况及其影响因素研究

Blood Lead Level and Influencing Factors for Children Living in Area near Highway in Mountain Region

目的探讨山区公路边儿童铅蓄积状况与相关因素,为制定儿童铅中毒防治策略提供科学依据。方法于2006年12月—2007年4月,随机整群抽取山区公路边8～12岁儿童118名(暴露组)和远离公路的同年龄段儿童51名(对照组)为研究对象。监测山区公路边(污染区)和远离公路(对照区)的土壤和农作物的含铅量;按拟定的调查表调查儿童的基本情况;采集儿童指端末梢血,用石墨炉原子吸收光谱法测定血铅,比较两组儿童血铅水平;分析铅中毒对儿童智力、体格发育的影响;并对影响儿童血铅水平的相关因素进行调查分析。结果污染区土壤和农作物的平均含铅量[(96.89±15.05)mg/kg,(0.86±0.29)mg/kg]显著高于对照区[(29.83±1.41)mg/kg,(0.17±0.03)mg/kg;土壤:P<0.01;农作物:P<0.01];暴露组血铅水平[(85.38±27.76)μg/L]显著高于对照组[(68.28±18.02)μg/L,t=4.0427,P<0.01];暴露组中铅中毒儿童的语文成绩平均分和语文、数学成绩高分率显著低于非中毒儿童(P<0.05);暴露组中铅中毒儿童的IQ值比非中毒儿童平均低0.66,身高、体重上等率分别低4.45%,10.60%,但差异无统计学意义(P>0.05);男性、大年龄、居住地(或就读学校)与公路距离近是山区公路边儿童发生铅中毒的主要影响因素(P<0.05或P<0.01)。结论车辆尾气铅污染是引起山区公路边儿童铅中毒的主要原因;铅中毒对儿童学习成绩产生负性影响,且对儿童智商和体格发育有一定影响;铅中毒与性别、年龄、居住地(或就读学校)与公路距离等因素有关。

Objective To know the blood level and the influencing factors for the children living in the area near highway in the mountain region. Methods From December,2006 to April,2007 ,one hundred and eighteen children aged 8-12 years （exposed group） living in the area near highway in the mountain region and fifty-one children aged 8-12 years （control group） living in the area far away from the highway were selected by random cluster sampling. Lead level of the soil and crops on the highway-sides （pollution area） and the area far away from the highway （control area） was determined. The basic situation was investigated by the questionnaire, the blood lead level was determined by graphite furnace atomic absorption spectrometry. The influence of lead on children＇ s intelligence, physical growth and the influencing factors for blood lead level were analyzed. Results The average lead level of the soil [（96.89±15.05） mg/kg] and crops [（0.86±0.29） mg/kg] in the polluted area was significantly higher compared with the control [soil lead： （29.83±1.41）mg/kg, crops lead：（0.17±0.03） mg/kg], and revealed statistical significance respectively （P〈0.01 and P〈0.01）. The blood lead level in the exposed group [（85.38±27.76）μg/L] was significantly higher than that in the control group [ （68.28±18.02 ）μg/L], and revealed statistical significance（ t=4.042 7, P〈0.001）. In the exposure group, the lead poisoning children＇s language average score and the high score rate of language and mathematics was obviously lower than those in the nonpoisoning children＇ s （P〈0.05）. No significant difference was seen in IQ test between the two groups. The short distance from living places （or school） to the highway was the main influencing factors for lead poisoning. Conclusion Lead pollution caused by automobile exhaust is considered as the main cause of lead poisoning for the children living in the area near highway in the mountain region.