舟山海岛地区孕妇及新生儿内环境汞暴露现状调查研究

目的调查研究舟山地区孕妇及新生儿汞暴露现状,为相关防治措施的制定提供科学依据。方法选择2006年3月～2007年7月在舟山市妇幼保健医院分娩的舟山本地户籍孕妇及其新生儿作为本次研究对象,对孕妇尿、血、头发及其新生儿脐带血进行汞含量测定,并进行书面问卷调查。结果本研究共测定孕妇尿汞样2 190份,算术平均值为2.58μg/L;发汞3 109份,算术平均值为1.27 mg/kg;血汞3 337份,算术平均值为5.40μg/L;新生儿脐带血汞样本2 998份,算术平均值为7.71μg/L;获得孕妇尿汞、发汞、血汞及新生儿脐带血汞相对应样本及问卷1 554份,研究显示孕妇的尿汞值、发汞值、血汞值、新生儿脐血汞值存在关联性,其中孕妇血汞值与脐血汞值关联性最强（r=0.600,P〈0.01）,其他的相关系数均小于0.20。孕妇吃鱼次数与尿汞、血汞和新生儿脐带血汞水平相关。结论舟山地区孕妇尿、血和脐带血汞量与孕妇吃鱼次数有关,有很大比例的孕妇和新生儿有潜在的汞危害,需要进一步采取措施进行干预。     

胎儿期汞暴露对新生儿神经行为发育影响

目的 了解浙江省舟山市胎儿期汞暴露对新生儿神经行为发育影响,为采取干预措施提供参考依据.方法 采用自行设计调查表,对2006年3月-2007年7月在舟山市妇幼保健院整群随机抽取的418名新生儿母亲进行问卷调查,并检测新生儿脐带血汞及其母亲尿汞、血汞和发汞值,评定新生儿的神经行为发育情况.结果 新生儿脐带血汞平均汞含量为(7.9±4.7)μg/ L;母亲尿汞、血汞和发汞平均汞含量为(2.8±3.2)μg/L、(5.7±4.0)μg/L和(1.2±0.7)mg/kg;Spearman相关分析结果表明,新生儿脐带血汞与母亲尿汞、发汞和血汞,母亲尿汞与发汞、血汞,母亲发汞与血汞均呈正相关关系(P<0.01);除母亲发汞外,新生儿脐带血汞、母亲尿汞和血汞均随母亲怀孕期间吃鱼次数增多而增加(P<0.01);418名新生儿神经行为发育评分平均为(38.41±1.30)分,一般评估、原始反射、被动肌张力、主动肌张力和行为能力5个维度满分率分别为96.89%、94.98%、74.64%、65.55%和49.04%;多因素非条件Lo-gistic回归分析结果表明,新生儿脐带血汞含量≥18μg/L是新生儿NBNA得分的危险因素.结论 舟山市孕妇和新生儿汞暴露与食鱼有关;新生儿脐带血汞含量较高能影响新生儿神经行为发育.     

舟山群岛新生儿脐带血汞暴露水平及影响因素研究

目的了解舟山群岛新生儿脐带血汞暴露水平及影响因素。方法选择2012年6月—2013年7月进行围产保健并住院分娩的舟山户籍孕产妇及其新生儿为研究对象,对孕产妇全血和新生儿脐带血进行汞含量检测,问卷调查新生儿家庭社会环境与健康状况。结果共检测3 052名孕妇全血及其新生儿脐带血汞水平,孕妇血汞平均为(5.33±3.69)μg/kg,中位数为4.63μg/kg,P25~P75为2.8~8.2μg/kg。新生儿脐带血汞含量平均为(7.72±4.87)μg/kg,中位数为7.31μg/kg,P25~P75为4.7~11.2μg/kg。单因素分析提示新生儿脐血汞与母亲孕期吃马鲛鱼有关联(OR=1.79,P0.01),而与新生儿性别,母亲孕期补维生素、补钙、补铁、修补牙齿个数,母亲经常使用皮肤增白化妆品,孕期每月吃鱼及海产品次数及父亲每天吸烟、家庭月平均收入、在本地居住时间等均无关联。经多因素Logistic回归分析显示,脐血汞值与母亲孕期吃马鲛鱼存在关联(OR=1.96,P0.01)。结论舟山地区新生儿脐带血汞量水平较高,孕妇血汞值与脐血汞值相关,孕妇进食马鲛鱼是新生儿脐带血暴露水平的影响因素,有待进一步研究证实。     

胎儿期低水平汞暴露对婴儿神经行为发育影响的前瞻性研究

[目的] 探讨胎儿期低水平汞暴露对婴儿神经行为发育的影响. [方法] 采用整群法选取舟山市定海区第三人民医院产科出生的384名足月新生儿及其母亲,按脐带血汞水平把婴儿分为相对高汞组及相对低汞组,进行3月龄、12月龄发育随访. [结果] 高汞组和低汞组发汞值在出生后均显著下降(t=5.58和2.23,P均<0.05).婴儿发汞和脐带血汞有明显的相关性(r=0.684和0.460,P均<0.01).分别以3、12月龄发汞为协变量,比较3、12月龄时两组智力发育指数(mental development index,MDI)、神经运动发育指数(psychomotor development index,PDI)的修正均数,差异均无显著性(F值分别为0.376、1.225;0.526、1.010,P均>0.05);协变量对MDI、PDI均数的差异亦无显著性(F值分别为=0.001、0.058;0.430、0.104,P均>0.05). [结论] 尚未发现舟山地区现有胎儿期低水平汞暴露对婴儿神经行为发育有负面影响.     

松原地区居民汞暴露途径的初步研究

研究分析了松原地区居民发汞含量水平,及市售鱼类、罐装鱼类、肉类、鸡蛋等食品中的汞含量。结果表明,27.26%的受检居民发汞含量超过美国EPA最新制定的标准,表明该调查地区居民具有潜在的汞暴露风险;常食鱼人群的发汞含量显著高于不常食鱼人群的发汞含量,存在显著差异(P<0.01),头发中的汞含量与食鱼量有显著的正相关关系(r=0.243,P<0.05),这说明头发中的汞含量随着食鱼量的增加而增加;不同的饮水来源、食肉的频率、饮用牛奶的习惯对发汞含量没有显著影响;常吃鸡蛋人群的发汞含量显著低于不常吃鸡蛋人群的发汞含量;食鱼是该地区人群汞暴露风险的最主要途径。     

孕妇及新生儿汞暴露水平及影响因素分析

目的调查大连、上海市孕妇及其新生儿汞暴露水平及其影响因素。方法整群抽取上海和大连市三甲医院妇产科病房待产的孕妇,对孕妇周围血及与其对应的新生儿脐带血进行血汞检测,并分析其影响因素。结果上海市孕妇血汞和新生儿脐带血汞中位数分别为1.35和2.29μg/L,大连市孕妇血汞和新生儿脐带血汞中位数分别为1.99和3.57μg/L,2地新生儿脐带血汞均明显高于母亲血汞(P0.01);大连市孕妇血汞中有3例(1.7%)、脐带血汞中有9例(8.4%)超过美国国家环保局推荐的国际标准(5.8μg/L);应用多重线性回归分析发现,上海市父亲吸烟、孕妇家中使用杀虫剂、大连市孕妇有被动吸烟史对2地孕妇血汞及新生儿脐带血汞的影响差异有统计学意义。结论对于非职业暴露人群相对工业环境污染、不良生活方式和居住环境因素等对血汞暴露水平的影响更为明显和直接。     

吴江地区胎儿宫内汞暴露现状及高危因素

目的:研究吴江地区胎儿宫内汞暴露的现状以及影响脐带血汞值的各种高危因素。方法:采取整群法对入院产妇进行健康因素问卷调查,所分娩的新生儿(除多胎、出生缺陷外)做脐带血汞测定。结果:2 496例新生儿脐血汞均值为(2.02±1.97)μg/kg,其中男婴(1 287例)为(2.01±1.99)μg/kg,女婴(1 209例)为(2.04±1.94)μg/kg,性别间差异无统计学意义(P>0.05)。4～6月、10～12月分娩新生儿的脐带血汞均值明显高于1～3月、7～9月(P<0.01)。经多因素回归分析,居住环境、工种、较多食用海鱼或河鱼、镶牙、生活燃煤、化妆品使用、丈夫抽烟等与脐血汞值呈显著正相关。结论:除治理工业排放污染、加强涉汞工种劳动保护外,孕期避免生活中各种汞接触高危因素同样重要。     

松原市区居民发汞水平及影响因素分析

为了弄清第二松花江流域的环境现状,在第二松花江下游的松原市区搜集了113名居民的头发样品,用冷蒸气原子吸收法测定头发样品中的总汞含量。头发样品中总汞含量为0.07~39.6 mg/kg,平均为1.081mg/kg。在113份样品中,有17人头发中总汞含量超过了美国环保局制定的1 mg/kg的限值,占总人数的15%,说明在松原市地区仍有人群汞中毒的风险。在影响发汞含量的因素中,经常吃鱼人群的发汞含量大于不常吃鱼人群的发汞含量;吸烟、饮酒、染发人群的发汞含量分别高于不吸烟、不饮酒、未染发人群的发汞含量,居民的年龄和性别对发汞水平没有显著影响。     

婴幼儿汞暴露相关影响因素分析

目的 调查福建省厦门市婴幼儿汞暴露现状,并分析其相关因素,为采取干预措施提供依据.方法 采用整群分层法选取10个社区的1 041名婴幼儿,对其日常家庭社会环境进行问卷调查,同时采集其发样进行发汞含量测定.结果 婴幼儿发汞均值为0.985μg/g,几何均数为0.724 μg/g,＞1μg/g者占31.70％;海岛社区婴幼儿的发汞均值最高,为1.559 μg/g,超标率为53.26％,偏僻农村最低,为0.684 μg/g,超标率为14.42％;鱼类与贝类辅食摄入频率与婴幼儿发汞含量呈正相关,差异均有统计学意义(F=12.68,P＜0.01;F=6.867,P=0.009);家中有人使用染发剂时婴幼儿发汞含量较高(t=3.165,P=0.002);婴幼儿的月龄与婴幼儿发汞含量呈正相关(β =6.186,t=2.220,P=0.027),婴幼儿性别、睡眠等因素与发汞含量无关.结论 厦门市婴幼儿发汞水平接近临界值,居住在海岛的儿童发汞值高于偏僻乡村,随着年龄的增长,婴幼儿的发汞值逐渐增高;鱼类、贝类辅食的摄入及家庭环境中染发剂等的使用是婴幼儿汞暴露的主要来源.     

西班牙首都马德里居民的发汞研究

1983年上半年,Gonzalez等人检测了106名受试者的发汞(男50名、女56名),其中20份,18份、8份样品分别来自人乳哺养的婴儿与其母亲、职业性接触的工人及二个家庭。调查发现:马德里人群(随机抽样)发汞含量范围为1.29～129.47μg/g(几何均数为7.96μg/g),高于马德里人群曾经报道的均值4.08μg/g,该人群每周食用一至三次鱼。此均值也高于日本的     

Prenatal exposure to mercury and neurobehavioral development of neonates in Zhoushan City, China

Exposure to hazardous Hg can adversely affect children's neurodevelopment. However, few data are available on either Hg levels in neonates and their mothers or the impact of prenatal exposure to Hg on neonates' neurobehavioral development in the Chinese population. Therefore, this study examined Hg levels in neonates and their mothers and the relationship between prenatal exposure to Hg and neonates' neurobehavioral development in Zhoushan City, Zhejiang Province, China. Between August and October 2004, 417 women who delivered their babies at Zhoushan Women's and Children's Health Hospital, an island city in east China were invited to take part in this study. A total of 408 complete questionnaires, 405 maternal hair samples, and 406 umbilical cord samples were collected. Neonatal behavioral neurological assessments (NBNA) were conducted for 384 neonates. The geometric mean (GM) of Hg level in cord blood was 5.58 microg/L (interquartile range: 3.96-7.82 microg/L), and the GM of maternal hair Hg level was 1246.56 microg/kg (interquartile range: 927.34-1684.67 microg/kg), a level much lower than other reported fish-eating populations, indicating Hg exposure in Zhoushan city is generally below those considered hazardous. However, according to the reference dose of Hg levels (RfD 5.8 microg/L) derived by EPA, 69.9% of newborns had levels at or above the RfD, an estimated level assumed to be without appreciable harm. There was a strong correlation between maternal hair and cord blood Hg levels (r = 0.82, P < 0.01). Frequency of fish consumption was associated with hair Hg (r = 0.48, P < 0.01) and cord blood Hg levels (r = 0.54, P < 0.01). Increased prenatal Hg exposure was associated with decreased behavioral ability for males (OR = 1.235, 95%CI of OR = 1.078-1.414, P < 0.001), but not for females. Our results provide some support for the hypothesis that there is neurodevelopmental risk for males from prenatal MeHg exposure resulting from fish consumption. But the findings of this study may be due to chance, and long-term follow-up research is needed to evaluate cumulative effects of exposure to mercury.     

Hair mercury levels versus freshwater fish consumption in household members of Swedish angling societies

Hair mercury levels were determined in 143 individuals from households of members in angling societies in an area of Sweden with many lakes that have freshwater fish with relatively high mercury levels. Thus, the individuals had a potentially high intake of methyl mercury. The mean mercury concentration of pike and perch was approximately 0.7 microg/g. One-third of the subjects consumed these freshwater fish at least once a week. As could be expected, there was a clear increase in hair Hg with reported freshwater fish consumption (P < 0.001). The median mercury level in hair was 0.9 microg Hg/g for the whole group, and for those who reported consumption of freshwater fish at least once a week it was 1.8 microg/g. The highest hair mercury level was 18.5 microg/g, in a man who consumed pike and perch several times per week. Men had higher hair Hg than women, also when stratified for fish consumption. This was verified in 32 couples, of which the man and woman consumed the same fish and reported the same consumption. The median hair mercury level in these 32 couples was 1.3 microg/g for men and 0.8 microg/g for women (P = 0.002). About half of the subjects had hair mercury exceeding 1 microg/g, corresponding to the reference dose (RfD) of 0.1 microg of mercury per kilogram body weight set by the US Environmental Protection Agency. Although the RfD applies to all populations, the most at-risk group at these levels is pregnant women. There were only 2 women (of 12) of fertile age with hair mercury above 1 microg/g. In Sweden pregnant women are advised not to eat perch and pike at all during pregnancy. Since fish is rich in many important nutrients, it is unsatisfactory that fish consumption must be restricted, and thus there is a need to reduce mercury levels in fish.     

Hair mercury levels in U.S. children and women of childbearing age: reference range data from NHANES 1999-2000

Exposure to methyl mercury, a risk factor for neurodevelopmental toxicity, was assessed in U.S. children 1-5 years of age (n = 838) and women 16-49 years of age (n = 1,726) using hair mercury analysis during the 1999-2000 National Health and Nutrition Examination Survey (NHANES). The data are nationally representative and are based on analysis of cross-sectional data for the noninstitutionalized, U.S. household population. The survey consisted of interviews conducted in participants' homes and standardized health examinations conducted in mobile examination centers. Distributions of total hair mercury levels expressed as micrograms per gram hair Hg and the association of hair Hg levels with sociodemographic characteristics and fish consumption are reported. Geometric mean (standard error of the geometric mean) hair mercury was 0.12 microg/g (0.01 microg/g) in children, and 0.20 microg/g (0.02 microg/g) in women. Among frequent fish consumers, geometric mean hair mercury levels were 3-fold higher for women (0.38 vs. 0.11 micro g/g) and 2-fold higher for children (0.16 vs. 0.08 microg/g) compared with nonconsumers. The NHANES 1999-2000 data provide population-based data on hair mercury concentrations for women and children in the United States. Hair mercury levels were associated with age and fish consumption frequency.     

Methyl mercury and inorganic mercury in Swedish pregnant women and in cord blood: influence of fish consumption

We studied exposure to methyl mercury (MeHg) in Swedish pregnant women (total mercury [T-Hg] in hair) and their fetuses (MeHg in cord blood) in relation to fish intake. The women were recruited at antenatal care clinics in late pregnancy to participate in an exposure study of environmental pollutants. Fish consumption was evaluated using food frequency questionnaires including detailed questions on fish consumption. In addition, we determined inorganic mercury (I-Hg) and selenium (Se) in cord blood. On average, the women consumed fish (all types) 6.7 times/month (range 0-25 times/month) during the year they became pregnant. They reported less consumption of freshwater fish--species that might contain high concentrations of MeHg--during than before pregnancy. T-Hg in maternal hair (median 0.35 mg/kg; range 0.07-1.5 mg/kg) was significantly associated (R2 = 0.53; p < 0.001) with MeHg in cord blood (median 1.3 microg/L; range 0.10-5.7 microg/L). Both hair T-Hg and cord blood MeHg increased with increasing consumption of seafood (r = 0.41; p < 0.001 and r = 0.46; p < 0.001, respectively). Segmental hair analysis revealed that T-Hg closer to the scalp was lower and more closely correlated with MeHg in cord blood than T-Hg levels in segments corresponding to earlier in pregnancy. We found a weak association between Se (median 86 microg/L; range 43-233 microg/L) and MeHg in cord blood (r = 0.26; p = 0.003), but no association with fish consumption. I-Hg in cord blood (median 0.15 microg/L; range 0.03-0.53 microg/L) increased significantly with increasing number of maternal dental amalgam fillings.     

Mercury levels in high-end consumers of fish

Consumption of food containing mercury has been identified as a health risk. The U.S. Environmental Protection Agency (U.S. EPA) and the National Academy of Sciences recommend keeping the whole blood mercury level < 5.0 microg/L or the hair level < 1.0 microg/g. This corresponds to a reference dose (RfD) of 0.1 microg/kg body weight per day. All patients in a 1-year period (n = 720) who came for an office visit in a private internal medicine practice in San Francisco, California, were evaluated for mercury excess using the current RfD. One hundred twenty-three patients were tested (93 females, 30 males). Of these, data were statistically analyzed for 89 subjects. Mercury levels ranged from 2.0 to 89.5 microg/L for the 89 subjects. The mean for 66 women was 15 microg/L [standard deviation (SD) = 15], and for 23 men was 13 microg/L (SD = 5); 89% had levels exceeding the RfD. Subjects consumed 30 different forms or types of fish. Swordfish had the highest correlation with mercury level. Sixty-seven patients with serial blood levels over time after stopping fish showed a decline in mercury levels; reduction was significant (p < 0.0001). A substantial fraction of patients had diets high in fish consumption; of these, a high proportion had blood mercury levels exceeding the maximum level recommended by the U.S. EPA and National Academy of Sciences. The mean level for women in this survey was 10 times that of mercury levels found in a recent population survey by the U.S. Centers for Disease Control and Prevention. Some children were > 40 times the national mean.     

Mercury levels in urine and hair of children in an Andean gold-mining settlement

This field study investigated mercury (Hg) levels in urine and hair of Andean children of indigenous Saraguro and Metizo gold miners in the Nambija, Ecuador gold mining settlement. Spot samples of urine and hair samples were collected concurrently from 80 children each. Urine samples were used to determine the inorganic Hg burden, while hair samples were used as an index of methylmercury (MeHg) exposure from consumption of Hg contaminated fish. The mean level of Hg in urine (HgU) was 10.9 microg/L, and the mean level in hair (HgH) was 6.0 microg/g. Regression analysis showed a significant association (r = 0.404, p = 0.0007) between matched HgU and HgH samples. Mean HgU and HgU levels tended to be higher for children aged 6-14 years than for a younger group. The wide range of Hg levels in the urine and hair of Andean children of gold miners may place them at risk for neurodevelopmental and learning disorders.     

Mercury exposure in two coastal communities of the Bay of Fundy, Canada

There is a rising global concern with regard to mercury (Hg) exposure among coastal populations. Two communities on the Bay of Fundy (New Brunswick, Canada) were assessed by hair monitoring and dietary methods. Average concentration of total Hg in hair was 0.70+/-0.55 mg/kg (N=91) at Grand Manan and 0.42+/-0.15 mg/kg (N=52) at St. Andrews/St. Stephen. Average daily consumption of fresh fish and shellfish was 50+/-40 g/day for Grand Manan and 19+/-19 g/day for St. Andrews/St. Stephen. Average daily total Hg intake estimated from the food frequency and 24-h recall questionnaires was 0.05+/-0.04 microg Hg/kg bw/day at Grand Manan and 0.03+/-0.04 microg Hg/kg bw/day at St. Andrews/St. Stephen. A significant correlation (r=0.47, P=0.002) between Hg intake and hair was observed for Grand Manan. Low Hg intakes and body burden can be attributed to the low Hg levels found in the species commonly consumed: haddock, canned tuna, lobster, and pollock (all below 0.2 microg/g wet weight). The results showed that Hg exposure in these Canadian coastal communities is low; fish with higher levels of Hg (shark, tuna, swordfish, pickerel, and bass) are not consumed locally.     

Total mercury levels in hair, toenail, and urine among women free from occupational exposure and their relations to renal tubular function

To investigate the relations among total mercury levels in hair, toenail, and urine, together with potential effects of methylmercury intake on renal tubular function, we determined their levels, and urinary N-acetyl-beta-D-glucosaminidase activity (NAG) and alpha1-microglobulin (AMG) in 59 women free from occupational exposures, and estimated daily mercury intakes from fish and other seafood using a food frequency questionnaire. Mercury levels (mean+/-SD) in the women were 1.51+/-0.91 microg/g in hair, 0.59+/-0.32 microg/g in toenail, and 0.86+/-0.66 microg/g creatinine in urine; and, there were positive correlations among them (P<0.001). The daily mercury intake of 9.15+/-7.84 microg/day was significantly correlated with total mercury levels in hair, toenail, and urine (r=0.551, 0.537, and 0.604, P<0.001). Among the women, the NAG and AMG were positively correlated with both the daily mercury intake and mercury levels in hair, toenail, and urine (P<0.01); and, these relations were almost similar when using multiple regression analysis to adjust for possible confounders such as urinary cadmium (0.47+/-0.28 microg/g creatinine) and smoking status. In conclusion, mercury resulting from fish consumption can explain total mercury levels in hair, toenail, and urine to some degree (about 30%), partly through the degradation into the inorganic form, and it may confound the renal tubular effect of other nephrotoxic agents. Also, the following equation may be applicable to the population neither with dental amalgam fillings nor with occupational exposures: [hair mercury (microg/g)]=2.44x[toenail mercury (microg/g)].     

Gold-mining activities and mercury contamination of native amerindian communities in French Guiana: key role of fish in dietary uptake

In 1994, the French National Public Health Network reported significant mercury exposure of native Amerindians in French Guiana. In 1997, a study was conducted in the Wayana community to quantify the dietary intake and to identify the fish species contributing the most to the contamination. The study was completed by an impregnation analysis based on Hg determination in hair samples. The methodology used was a detailed familial dietary study associated with Hg measurements in fish and some game. The study was conducted over 7 days in two different seasons in the four most populated Wayana villages on the upper part of the Maroni River (521 people; 70% of the Wayana population in French Guiana). Analysis was based on data on consumption obtained from 165 people in a 1-14 day period (i.e., 940 persons [times] days) and involved 270 fish samples from 48 species. Total Hg and monomethylmercury (MMHg) were also determined in hair samples (235 samples for total Hg). The results confirm mercury exposure of the Wayana population related to a diet rich in fish, which are relatively highly contaminated for certain species (up to 1.62 mg/kg fresh weight or 8.1 mg/kg dry weight in skeletal muscle). Results from hair samples showed that 57% of the Amerindians had Hg levels above the World Health Organization (WHO) safety limit (10 microg/g); all those over 1 year of age had a Hg intake greater than the WHO safety limit (200 microg MMHg/week for a 60-kg male). Hg concentrations in fish muscle were closely linked to the feeding regime and position of fish in the food webs. Overall, 14.5% of the fish collected exceeded the 0.5 mg/kg (fresh weight) safety limit. Four carnivorous species accounted for no less than 72% of the metal ingested by the Wayana families, although these represented only 28% of the consumed fish biomass. In conclusion, this study revealed excessive exposure to mercury in the Wayana population in French Guiana related to the consumption of contaminated fish.     

Maternal fish consumption, mercury levels, and risk of preterm delivery

BACKGROUND: Pregnant women receive mixed messages about fish consumption in pregnancy because unsaturated fatty acids and protein in fish are thought to be beneficial, but contaminants such as methylmercury may pose a hazard. METHODS: In the Pregnancy Outcomes and Community Health (POUCH) study, women were enrolled in the 15th to 27th week of pregnancy from 52 prenatal clinics in five Michigan communities. At enrollment, information was gathered on amount and category of fish consumed during the current pregnancy, and a hair sample was obtained. A segment of hair closest to the scalp, approximating exposure during pregnancy, was assessed for total mercury levels (70-90% methylmercury) in 1,024 POUCH cohort women. RESULTS: Mercury levels ranged from 0.01 to 2.50 pg/g (mean = 0.29 microg/g; median = 0.23 microg/g). Total fish consumption and consumption of canned fish, bought fish, and sport-caught fish were positively associated with mercury levels in hair. The greatest fish source for mercury exposure appeared to be canned fish. Compared with women delivering at term, women who delivered before 35 weeks' gestation were more likely to have hair mercury levels at or above the 90th percentile (> or = 0.55 microg/g), even after adjusting for maternal characteristics and fish consumption (adjusted odds ratio = 3.0; 95% confidence interval, 1.3-6.7). CONCLUSION: This is the first large, community-based study to examine risk of very preterm birth in relation to mercury levels among women with low to moderate exposure. Additional studies are needed to see whether these findings will be replicated in other settings.