饮水砷暴露对儿童免疫功能的影响

目的 研究高砷饮水对儿童免疫功能的影响.方法 于2006年选择某高砷饮水地区194名9～13岁小学生作为研究对象,采集家庭饮用水样和空腹晨尿,测定水砷和尿砷含量,按照水砷含量分为对照组(P＜0.05mg/L)、暴露组(≥0.1mg/L),进行T淋巴细胞亚群、免疫球蛋白IgG、IgM、IgA和白细胞介素2(IL-2)测定,并对家庭一般情况、饮水水源情况、儿童健康状况、父母健康及职业暴露情况等进行问卷调查.结果 对照组、暴露组儿童尿砷含量中位数分别为0.02和0.12 mg/L,尿砷与水砷含量呈统计学相关.暴露组儿童T淋巴细胞(CD3~+)、CD4~+、CD8~+亚群百分含量均值和CD4~+/CD8~+的均值低于对照组,经t检验,暴露组CD~(4+)亚群百分含量和CD4~+/CD8~+显著低于对照组(P<0.05),而两组间T淋巴细胞(CD3~+)、CD8~+亚群百分含量差异均无统计学意义(P＞0.05).暴露组男生T淋巴细胞CD~(4+)亚群百分含量显著低于对照组(P＜0.05),暴露组女生CD4~+亚群百分含量和CD4~+/CD8~+显著低于对照组(P<0.05).暴露组儿童血清IgG含量高于对照组(P<0.05),血清IgM含量低于对照组(P<0.05),血清IgA含量两组间差异无统计学意义(P>0.05);对照组和暴露组男生血清免疫球蛋白含量分布情况与全体学生近似,女生血清免疫球蛋白含量差异无统计学意义.两组儿童白细胞介素2含量差异无统计学意义(P>0.05).结论 长期饮用砷含量在0.1 mg/L以上的高砷水对儿童的免疫功能可能造成不利影响.儿童外周血T淋巴细胞亚群是水砷暴露非常敏感的健康效应指标之一.

Effects of Arsenic Exposure through Drinking Water on Immune Function of Children

Objective To study the children immune function impacts caused by drinking water with high level arsenic.Methods one hundred and ninty-four pupils were selected as the study subjects,samples of the household drinking water were sampled and the samples of the fasting morning urine were collected,and the water and urinary arsenic concentrations were determined in 2006.The subjects were divided as control group(concentration of arsenic in water<0.05 mg/L)and exposure group (concentration of arsenic in water≥0.1mg/L)according to the water arsenic concentration and the T-lymphocyte subsets.immunoglobulin IgG,IgM,IgA and interleukin-2 (IL-2)were measured in the two groups'children aged over 9 years.The family general information,drinking water sources,parents'health and occupational exposure situations by questionnaire were investigated.Results In control and exposure group,the urinary arsenic medians were 0.02 mg/L and 0.12 mg/L respectively,urinary arsenic and water arsenic content correlated significantly.The mean percentages of T lymphocytes (CD3~+),CD4~+,CD8~+subsets and the mean of CD4~+/CD8~+ in exposure group were lower than those in control group.The mean percentages of CD4~+ subsets and CD4~+/CD8~+ in exposure groupwere significant lower than those in control group(P<0.05).The percentage of boys'T lymphocytes CD4~+ in exposure group was significant lower than that in control group(P<0.05),and the percentage of girls'T lymphocytes CD4~+ and the mean of CD4~+/CD8~+ in exposure group were lower than those in control group.The blood serum IgG content of the children in exposure group was higher,the IgM content was lower compared with the control group(P<0.05).Conclusion Drinking the water with high arsenic concentration over 0.1 mg/L can cause adverse impacts to children immune function.Children's peripheral blood T lymphocyte subset is one of the most sensitive health effective indicators to water arsenic exposure.