应用10%抽样法判定高砷暴露区的研究

Study of using 10% sampling method to identify the high arsenic exposure area

目的 研究以 10 %抽样率检测井水中砷浓度判定高砷暴露区 (村、屯 )的方法是否具有代表性。方法 选择山西、内蒙 31个已确定的高砷暴露村 ,应用现场快速检测试剂盒对压把井井水中砷浓度进行测定。根据各村水井分布图 ,按东、南、西、北、中将每村划分为 5个区 ,应用盲法在每个区中随机抽样。以水砷浓度 >0 .0 5 mg/ L作为超标井 ,计算抽样超标率。与实际超标率进行比较 ,评价 10 %抽样法对实际检出率的代表性。结果 在水井实际超标率不低于 5 %的情况下 ,10 %抽样法检出率与实际检出率之间差异无显著性 ,可以较好的代表实际检出率。而在实际超标率低于 5 %时 ,此方法对实际情况的代表性较差。结论 10 %抽样法在实际超标率 >5

Objective To study the representation of 10% sampling method in the area with high arsenic concentration. Methods All the pump well water was detected arsenic concentration in the 31 villages suffered with arsenicosis of Shanxi and Inner Mongolia. The actual exposure rate (Q) was calculated. 10% wells were sampled randomly from each of the five parts in the villages with wells. If arsenic concentration was more than 0.05 mg/L, the well was definited as high arsenic well, then 10% sample exposure rate (R) was calculated. The relationship between Q and R was analyzed. Results Given the exposure rate was not less than 5%, there was no significant difference between R and Q. On the contrary, if the rate was below 5% or even less, R could not represent Q. Conclusions The 10% sampling rate could represent the actual one perfectly, when the actual exposure rate was more than 5%.