Environmental exposure and fingernail analysis of arsenic and mercury in children and adults in a Nicaraguan gold mining community

Gold mining can release contaminants, including mercury, into the environment, and may increase exposure to naturally occurring elements such as arsenic. The authors investigated environmental and human tissue concentrations of arsenic and mercury in the gold mining town of Siuna, Nicaragua. The study involved 49 randomly selected households in Siuna, from whom a questionnaire along with environmental and fingernail samples were collected. Environmental samples indicated that mercury concentrations in drinking water, although generally low, were higher near the mine site. Arsenic concentrations were elevated in water and soil samples, but their distribution was unrelated to the mining site. Mercury concentrations in fingernail samples were correlated with residential proximity to the mine, drinking water concentrations, occupation, and, among children, with soil concentrations. Fingernail arsenic concentrations correlated with drinking water concentrations among adults who consumed higher levels, and with soil concentrations among children. Fingernail analysis helped to identify differential exposure pathways in children and adults. Mercury and arsenic uptake via soil exposure in children warrants further consideration.     

Water Consumption as Source of Arsenic,Chromium, and Mercury in Children Living in Rural Yucatan,Mexico: Blood and Urine Levels

Studies investigating the correlation between metal content in water and metal levels in children are scarce worldwide, but especially in developing nations. Therefore, this study investigates the correlation between arsenic, chromium, and mercury concentrations in drinking and cooking water and in blood and urine samples collected from healthy and supposedly non-exposed children from a rural area in Yucatan, Mexico. Mercury in water shows concentrations above the recommended World Health Organization (WHO) value for drinking and cooking water. Also, 25% of the children show mercury in urine above the WHO recommended value. Multivariate analyses show a significant role for drinking and cooking water as a vector of exposure in children. Also, the factor analysis shows chronic exposure in the case of arsenic, as well as an ongoing detoxification process through urine in the case of mercury. Further studies should be done in order to determine other potential metal exposure pathways among children.     

Hair and toenail arsenic concentrations of residents living in areas with high environmental arsenic concentrations

Surface soil and groundwater in Australia have been found to contain high concentrations of arsenic. The relative importance of long-term human exposure to these sources has not been established. Several studies have investigated long-term exposure to environmental arsenic concentrations using hair and toenails as the measure of exposure. Few have compared the difference in these measures of environmental sources of exposure. In this study we aimed to investigate risk factors for elevated hair and toenail arsenic concentrations in populations exposed to a range of environmental arsenic concentrations in both drinking water and soil as well as in a control population with low arsenic concentrations in both drinking water and soil. In this study, we recruited 153 participants from areas with elevated arsenic concentrations in drinking water and residential soil, as well as a control population with no anticipated arsenic exposures. The median drinking water arsenic concentrations in the exposed population were 43.8 micro g/L (range, 16.0-73 micro g/L) and median soil arsenic concentrations were 92.0 mg/kg (range, 9.1-9,900 mg/kg). In the control group, the median drinking water arsenic concentration was below the limit of detection, and the median soil arsenic concentration was 3.3 mg/kg. Participants were categorized based on household drinking water and residential soil arsenic concentrations. The geometric mean hair arsenic concentrations were 5.52 mg/kg for the drinking water exposure group and 3.31 mg/kg for the soil exposure group. The geometric mean toenail arsenic concentrations were 21.7 mg/kg for the drinking water exposure group and 32.1 mg/kg for the high-soil exposure group. Toenail arsenic concentrations were more strongly correlated with both drinking water and soil arsenic concentrations; however, there is a strong likelihood of significant external contamination. Measures of residential exposure were better predictors of hair and toenail arsenic concentrations than were local environmental concentrations.     

Environmental Exposure of Children to Toxic Trace Elements (Hg,Cr, As) in an Urban Area of Yucatan,Mexico: Water,Blood, and Urine Levels

Merida is the largest urban center in the Mexican State of Yucatan. Here domestic sewage is deposited in poorly built septic tanks and is not adequately treated. Because of contamination from such waste, water from the top 20 m of the aquifer is unsuitable for human consumption. Given this situation and because children are highly vulnerable to environmental pollution, including exposure to toxic trace elements, this study focused on evaluating the exposure of children to arsenic (As), chromium (Cr), and mercury (Hg) in water. It also evaluated the relationship between the levels of these elements in water and their concentrations in urine and blood. Among the 33 children monitored in the study, arsenic surpassed WHO limits for blood in 37% of the cases, which could result from the ingestion of poultry contaminated with organoarsenic compounds. In the case of WHO limits for Mercury, 65% of the water samples analyzed, 28% of urine samples, and 12% of blood samples exceeded them. Mercury exposure was correlated with biological sex, some lifestyle factors, and the zone in Merida in which children live. These data suggest that the levels of some toxic metals in children may be affected by water source, socioeconomic factors, and individual behavior.     

Metal sources and exposures in the homes of young children living near a mining-impacted Superfund site

Children living near hazardous waste sites may be exposed to environmental contaminants, yet few studies have conducted multi-media exposure assessments, including residential environments where children spend most of their time. We sampled yard soil, house dust, and particulate matter with aerodynamic diameter <2.5 in 59 homes of young children near an abandoned mining area and analyzed samples for lead (Pb), zinc (Zn), cadmium (Cd), arsenic (As), and manganese (Mn). In over half of the homes, dust concentrations of Pb, Zn, Cd, and As were higher than those in soil. Proximity to mine waste (chat) piles and the presence of chat in the driveway significantly predicted dust metals levels. Homes with both chat sources had Pb, Zn, Cd, and As dust levels two to three times higher than homes with no known chat sources after controlling for other sources. In contrast, Mn concentrations in dust were consistently lower than in soil and were not associated with chat sources. Mn dust concentrations were predicted by soil concentrations and occupant density. These findings suggest that nearby outdoor sources of metal contaminants from mine waste may migrate indoors. Populations farther away from the mining site may also be exposed if secondary uses of chat are in close proximity to the home.     

Pathways of human exposure to arsenic in a community surrounding a copper smelter

Several studies have found elevated levels of urinary arsenic among residents living near a copper smelter in Tacoma, Washington. To assess pathways of exposure to arsenic from the smelter, biological and environmental samples were collected longitudinally from 121 households up to 8 miles from the smelter. The concentration of inorganic and methylated arsenic compounds in spot urine samples was used as the primary measure of exposure to environmental arsenic. Urinary concentration of arsenic dropped off to a constant background level within one-half mile of the smelter in contrast to environmental concentrations, which decreased more steadily with increasing distance. Among all age-sex-specific groups in all areas, only children ages 0-6 living within one-half mile of the smelter had elevated levels of arsenic in urine. A separate analysis of data for these children suggests that hand-to-mouth activity was the primary source of exposure. Inhalation of ambient air and resuspension of contaminated soil were not important sources of exposure for children or adults.     

基于地理信息系统的泰国某锡矿区人群慢性砷中毒的空间特征分析

目的探讨泰国某锡矿区环境砷污染的空间分布特点以及与人群慢性砷中毒的关系。方法创建该锡矿区的基础地理信息系统(GIS),整合砷污染的环境监测和慢性砷中毒病人的发生地资料,在此基础上分析砷污染状况以及慢性砷中毒病人的空间分布特征。用空间内插法(IDW)形成该地地下水、耕作层土壤的砷污染趋势面,并结合缓冲地带划定及查询功能,等级相关分析等对慢性砷中毒病人出现及未出现区域的环境特点进行了分析。结果按照当地环境卫生标准,将地下水、耕作层土壤的污染程度进行了空间分级,找出了相对危险区域。慢性砷中毒病人的出现区域与未出现区域的地下水中砷的含量及土壤类型明显不同(P<0.05),但与土壤中水溶性砷含量关系不明显(P>0.05)。结论饮水砷浓度是该地慢性砷中毒的决定因素,而土壤类型影响慢性砷中毒的发生;GIS的空间趋势面分析对了解砷污染的状况和人群病情监控提供了重要工具。     

Biomarkers of mercury exposure in two eastern Ukraine cities

This study evaluates biomarkers of mercury exposure among residents of Horlivka, a city in eastern Ukraine located in an area with geologic and industrial sources of environmental mercury, and residents of Artemivsk, a nearby comparison city outside the mercury-enriched area. Samples of urine, blood, hair, and nails were collected from study participants, and a questionnaire was administered to obtain data on age, gender, occupational history, smoking, alcohol consumption, fish consumption, tattoos, dental amalgams, home heating system, education, source of drinking water, and family employment in mines. Median biomarker mercury concentrations in Artemivsk were 0.26 μg/g-Cr (urine), 0.92 μg/L (blood), 0.42 μg/g (hair), 0.11 μg/g (toenails), and 0.09 μg/g (fingernails); median concentrations in Horlivka were 0.15 μg/g-Cr (urine), 1.01 μg/L (blood), 0.14 μg/g (hair), 0.31 μg/g (toenails), and 0.31 μg/g (fingernails). Biomarkers of mercury exposure for study participants from Horlivka and Artemivsk are low in comparison with occupationally exposed workers at a mercury recycling facility in Horlivka and in comparison with exposures known to be associated with clinical effects. Blood and urinary mercury did not suggest a higher mercury exposure among Horlivka residents as compared with Artemivsk; however, three individuals living in the immediate vicinity of the mercury mines had elevated blood and urinary mercury, relative to overall results for either city. For a limited number of residents from Horlivka (N = 7) and Artemivsk (N = 4), environmental samples (vacuum cleaner dust, dust wipes, soil) were collected from their residences. Mercury concentrations in vacuum cleaner dust and soil were good predictors of blood and urinary mercury.     

Arsenic geochemistry and human health in South East Asia

Arsenic occurs naturally in many environmental components and enters the human body through several exposure pathways. Natural enrichment of arsenic may result in considerable contamination of soil, water, and air. Arsenic in groundwater can exceed values hundreds of time higher than the concentration recommended for drinking water. Such exposure levels indicate a serious potential health risk to individuals consuming raw groundwater. Human activities that have an impact on the environment may increase the distribution of inorganic arsenic. Abandoned mines are of great concern due to the extremely high arsenic concentrations detected in mine drainage and tailings. Diet, drinking water, air, soil, and occupational exposures are all sources of inorganic arsenic for humans. Interdisciplinary efforts to better characterize the transport of arsenic and reactants that facilitate their release to the environment are important for human health studies. Multi-disciplinary efforts are needed to study diet, infectious disease, genetics, and cultural practices unique to each region to better understand human health risk and to design public health interventions.     

Mercury occurrence in prothonotary warblers (Protonotaria citrea) inhabiting a National Priorities List site and reference areas in southern Alabama

Mercury occurrence in prothonotary warblers (Protonotaria citrea) was evaluated over two years in southern Alabama. Mercury was found in warbler nestlings and adults inhabiting National Priority List (NPL) sites in McIntosh, Alabama. Food items that were collected from nestlings also contained elevated mercury. When mercury concentrations in soil, food, and nestling were plotted at each nest box location, the distribution of mercury in the three matrices yielded information that direct bioaccumulation factors could not. There were site differences in mercury accumulation in nestlings inhabiting the NPL sites. Nestling mercury accumulation correlated with solid mercury concentrations near the nest box where the nestling was raised. Trophic transport of mercury was poorly defined by mercury in food; however, closer examination of prey items shows that food source influences accumulation. Mercury distributions in matrices provide useful information of uptake that can be integrated with risk assessment endpoints.     

Analysis and reduction of the uncertainty of the assessment of children's lead exposure around an old mine

Exposure to lead is a special problem in children, because they are more highly exposed than adults and because this pollutant, which accumulates in the body, induces neurobehavioral and cognitive effects. The objective of this study was to determine the probability density of the lead exposure dose of a 2-year-old child around an old mine site and to analyze its uncertainties, especially those associated with the bioavailability of lead in soil. Children's exposure was estimated indirectly from environmental samples (soils, domestic dust, water, air) and parameters (volume inhaled, body weight, soil intake rate, water intake, dietary intake) from the literature. Uncertainty and variability were analyzed separately in a two-dimensional Monte Carlo simulation with Crystal Ball software. Exposure doses were simulated with different methods for accessing the bioavailability of lead in soil. The exposure dose per kilogram of body weight varied from 2 microg/kgday at the 5th percentile to 5.5 microg/kgday at the 95th percentile (and from 2 to 10 microg/kgday, respectively, when ignoring bioavailability). The principal factors of variation were dietary intake, soil concentrations, and soil ingestion. The principal uncertainties were associated with the level of soil ingestion and the bioavailability of lead. Reducing uncertainty about the bioavailability of lead in soil by taking into account information about the type of mineral made it possible to increase our degree of confidence (from 25% to more than 95%) that the median exposure dose does not exceed the Tolerable Daily Intake. Knowledge of the mineral very substantially increases the degree of confidence in estimates of children's lead exposure around an old mining site by reducing the uncertainty associated with lead's bioavailability.     

不同浓度饮水型砷暴露人群尿砷代谢产物的研究

目的 结合WHO推荐的饮水砷卫生标准(0.01 mg/L)和我国农村分散式供水采用的饮水砷卫生标准(0.05 mg/L),初步探讨不同浓度饮水砷暴露人群的砷代谢状况和甲基化水平.方法 于2008年10月选择山西高砷地区不同饮水砷浓度暴露的部分成年人为研究对象,高暴露组124人,饮水砷浓度≥0.05 mg/L;低暴露组154人,0.01 mg/L≤饮水砷浓度<0.05 mg/L;对照组70人,饮水砷浓度<0.01 mg/L.采用氢化物发生原子吸收分光光度法检测其尿中不同形态的砷代谢产物.结果 随着饮水砷暴露浓度的升高,尿中各种形态砷代谢产物以及总砷含量也逐渐增高(P<0.05) .在同一水砷浓度暴露水平下,高暴露组中女性DMA,TAs含量以及SMR水平显著高于男性(P<0.05);低暴露组和对照组iAs、MMA、DMA、TAs含量、FMR和SMR水平在不同性别间差异均无统计学意义(P>0.05).高暴露组中60岁～人群FMR水平显著高于18～39岁人群和40～49岁人群(P<0.05).而低暴露组与对照组内不同年龄段人群FMR和SMR水平均无显著差异(P>0.05).结论 成人在较高饮水砷暴露水平下,女性二甲基化能力高于男性,高年龄组显示甲基化能力增强.在低饮水砷暴露条件下,性别、年龄对机体甲基化能力未见明显影响.     

DNA damage in blood cells from children exposed to arsenic and lead in a mining area

In this work, we studied the frequency of DNA damage in children living in Villa de la Paz, Mexico, a mining site contaminated with arsenic and lead. DNA damage in blood cells was assessed using the Comet assay, and the results were compared to those found in children living in a less exposed town (Matehuala). In Villa de la Paz, high concentrations of arsenic and lead in surface soil and household dust were found. All of the soil samples had concentrations above 100 mg/kg of arsenic, and 58% of the samples were higher than 400 mg/kg of lead (these concentrations are used as intervention guidelines by the United States Environmental Protection Agency). In agreement with the environmental results, urinary arsenic in children living in Villa de la Paz (geometric mean 136 microg/g creatinine) was significantly higher than that found in children living in Matehuala (34 microg/g creatinine). Blood lead levels were also significantly higher in children from Villa de la Paz (11.6 microg/dL) than in children from Matehuala (8.3 microg/dL). The results of the Comet assay showed that the tail length and the tail moment in children living in Villa de la Paz were higher than those observed for children in Matehuala (P<0.05). Taking all the data into account, our study has shown increased DNA damage in children exposed to arsenic and lead in the mining site of Villa de la Paz.     

Spatial distributions of arsenic exposure and mining communities from NHEXAS Arizona. National Human Exposure Assessment Survey.

Within the context of the National Human Exposure Assessment Survey (NHEXAS), metals were evaluated in the air, soil, dust, water, food, beverages, and urine of a single respondent. Potential doses were calculated for five metals including arsenic. In this paper, we seek to validate the potential dose calculations through spatial analysis of the data. Others report elevated arsenic concentrations in biological and environmental samples from residents of mining towns, particularly Ajo, Arizona. These reports led us to expect potential arsenic doses above the 90th percentile of the NHEXAS exposure distribution to be from residents of mining communities. Arsenic dose was calculated using media concentrations, time activity patterns, and published exposure factors. Of the 179 homes evaluated, 54 were in mining communities; 11 of these were considered separately for reasons of population bias. Of the 17 homes with the greatest potential arsenic doses, almost half (47%) were in mining communities. We evaluated the potential doses by media from nonmining and mining areas using the nonparametric Mann-Whitney U test. Statistically significant (p = 0.05) differences were found between mining (n = 43) and nonmining sites (n = 122) for total exposure and for each of the following media: house dust, yard soil, outdoor air, beverage consumed, and water consumed. No differences were found in either food or indoor air of mining and nonmining areas. We eliminated outliers and repeated the test for all media; significance increased. Dietary, organic arsenic from fish consumption contributed to elevated arsenic exposure among people from nonmining communities and acted as an initial confounder. When controlling for fish consumption, we were able to validate our potential dose model using arsenic, particularly in Ajo. Further, we identified three mining communities lacking elevated arsenic exposure. Additional work is needed speciating the arsenic and evaluating health risks. The utilization of Geographic Information System facilitated spatial this project and paves the way for more sophisticated future spatial analyses.     

Mercury Occurrence in Prothonotary Warblers (<Emphasis Type="Italic">Protonotaria citrea</Emphasis>) Inhabiting a National Priorities List Site and Reference Areas in Southern Alabama

Mercury occurrence in prothonotary warblers (Protonotaria citrea) was evaluated over two years in southern Alabama. Mercury was found in warbler nestlings and adults inhabiting National Priority List (NPL) sites in McIntosh, Alabama. Food items that were collected from nestlings also contained elevated mercury. When mercury concentrations in soil, food, and nestling were plotted at each nest box location, the distribution of mercury in the three matrices yielded information that direct bioaccumulation factors could not. There were site differences in mercury accumulation in nestlings inhabiting the NPL sites. Nestling mercury accumulation correlated with solid mercury concentrations near the nest box where the nestling was raised. Trophic transport of mercury was poorly defined by mercury in food; however, closer examination of prey items shows that food source influences accumulation. Mercury distributions in matrices provide useful information of uptake that can be integrated with risk assessment endpoints. Received: 20 February 2002/Accepted: 29 July 2002     

Cancer incidence and high environmental arsenic concentrations in rural populations: Results of an ecological study

A number of ecological studies have suggested associations between arsenic in drinking water and increased rates of some cancers. To investigate associations in areas with high environmental arsenic concentrations, geographical areas with surface soil inorganic arsenic concentrations of >100 mg/kg and/ or drinking water arsenic concentrations >0.01 mg/l were selected and the relationship with cancer incidence explored. Standardised incidence rates (SIRs) for cancer were generated for 22 areas between 1982 and 1991 using Victorian Cancer Registry data and Victorian cancer rates as a baseline. SIRs were also generated for combined areas according to environmental exposure type, i.e. whether an area had high soil and/or high water arsenic concentrations. The SIRs for both males and females for the combined 22 areas were increased for all cancers 1.06 (95% confidence interval, CI; 1.03-1.09), prostate cancer 1.14 (1.05-1.23), kidney cancer 1.16 (0.98-1.37), melanoma 1.36 (1.24-1.48), chronic myeloid leukemia 1.54 (1.13-2.10) and breast cancer in females 1.10 (1.03-1.18). When stratifying into exposure categories, the SIR for prostate cancer was significant at 1.20 (1.06-1.36) for the high soil/high water category only. No significant dose- response relationship between drinking water and individual cancers was observed. Of the a priori cancers associated with environmental arsenic exposure, only prostate cancer incidence was significantly elevated in this study. This result was likely confounded by a number of factors and was limited by low power and exposure misclassification.     

Mercury as a serious health hazard for children in gold mining areas

In many developing countries, mercury is used to extract gold from ore in small-scale mining areas. Exposure through mercury in these small-scale mining communities is a serious health hazard, especially to the children living and working there. Many children begin working with immediate contact to mercury from the very early age of seven. In Indonesia and Zimbabwe, 166 children were clinically examined for mercury. The mercury concentration in the blood, urine, and hair was analyzed. Compared to the control groups, the exposed children showed typical symptoms of mercury intoxication, such as ataxia. The children working with mercury had high levels of this substance in the various biomonitors. The exposure derives mainly from the liquid mercury used to bind gold, forming an amalgam. The amalgam is heated and the smelting amalgam releases mercury vapor plus the wanted gold. Mercury vapor in contrast to liquid mercury is highly toxic. This elemental, vaporized mercury is the main form of exposure. Since in over 50 countries children live in small-scale gold mining areas and are exposed in a similar way to mercury, immediate action is needed to reduce this severe chemical health hazard for children. Child labor with hazardous substances such as mercury must be stopped.     

Mercury in Wing and Tail Feathers of Hatch-Year and Adult Tidal Marsh Sparrows

We estimated mercury exposure and bioaccumulation in sparrow feathers to determine variation among age groups, between sparrow species, and between feather types. Results of feather mercury studies in piscivorous birds indicate that mercury concentrations tend to increase with age and differ between feather types; however, data for insectivorous birds are lacking. We estimated mercury exposure of two insectivorous and sympatric tidal marsh sparrows: coastal plain swamp sparrow (Melospiza georgiana nigrescens), and seaside sparrow (Ammodramous maritimus). Tidal marshes have favorable conditions for mercury methlyation, thus it is likely that tidal marsh sparrows are exposed to methylmercury. We found no difference in mercury concentrations between males and female birds of both species. Adult swamp sparrow feather mercury concentrations did not differ among adult age groups; therefore, mercury was not found to increase with age in sparrows at the site. Hatch-year birds had significantly greater feather mercury concentrations compared with adult birds for both species. Mercury concentrations in adult seaside sparrows were twice as high as those in adult swamp sparrows suggesting species-specific variation, although concentrations in hatch-year sparrow species did not differ. Mercury concentrations differed between feather types in adults of both species. The first primary feather of both species had at least three times greater mercury concentrations than the outer tail feather possibly reflecting varying depuration rates with feather type.     

东平湖湖水汞砷形态赋存特征及健康风险评价

了解东平湖湖水中汞(Hg)和砷(As)的形态赋存特征及健康风险。方法于2016年5月,在东平湖采集30个表层水样,采用原子荧光光度法对Hg和As的总浓度及其不同形态浓度进行测定,并采用美国国家环保署(US EPA)推荐的健康风险评价模型对其通过饮水途径产生的健康风险进行了评价。结果东平湖湖水中总As浓度为(7.289±0.832)μg/L,总Hg浓度的中位数为0.929(0.063~3.230)μg/L;总As浓度均符合国家Ⅲ类水标准,而总Hg的超标率为96.7%。溶解态Hg浓度占总Hg的平均比例为63.4%,高于颗粒态Hg浓度占总Hg的比例(36.6%)。各采样点溶解态As和颗粒态As占总As比例的平均值分别为53.4%和46.6%,湖区北部采样点溶解态As所占比重较大;溶解态As中致毒性较大的As(Ⅲ)比例较小。As和Hg通过饮水途径产生的健康风险值分别为5.46×10~(-5)/a和1.56×10~(-9)/a,As的健康风险值远高于Hg,且超过最大可接受水平(5×10~(-5)/a)。结论东平湖湖水中Hg浓度超标,As通过饮水途径产生的健康风险值超过最大可接受风险水平,Hg和As应作为东平湖的重点监控因子。     

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.