Sweeney Anne M, Symanski Elaine
Department of Epidemology and Biostatistics, School of Rural Public Health, Texas A&M University System Health Science Center, TAMU Mail Stop 1266, College Station, TX 77843-1266, USA.
Environ Res. 2007 Nov;105(3):370-9. doi: 10.1016/j.envres.2007.03.006. Epub 2007 May 7.
The determination of critical windows of susceptibility to environmental chemical exposures and health has become a major public health focus. This study examined the association between early age at exposure to polybrominated biphenyls (PBBs) and subsequent birth weight and gestational length in offspring among females. The study population consisted of 1111 births that occurred among 560 women enrolled in the Michigan PBB Cohort from 1975 to 1994. Maternal age at exposure was categorized into three groups:<10 years (n = 64), 11-16 years (n = 149), and 17-42 years (n = 347). Overall serum PBB levels ranged from 0 to 1490 ppb, with a median of 2, 3, and 2 ppb in the three age groups, respectively. Separate mixed-effects linear regression models were used to evaluate the effect of age at exposure (years) and initial PBB level (ppb) on birth weight (grams) and gestational age (weeks), controlling for gestational age (weeks) (in the model examining effects on birth weight), BMI (kg/m(2)) and serum PCB level at enrollment (ppb), maternal age and paternal education at delivery, parity, infant gender, interval between the initial serum test and date of delivery (years), and the trimester in which prenatal care was initiated. Relative to the oldest age group, age<10 years at exposure was the most important predictor of increased birth weight (estimated regression coefficient = 225 g, P = 0.012). Infant birth weight increased approximately 16 g for every 10 ppb increase in serum PBBs (P=0.004). There was no association between initial PBB levels and gestational age, nor were initial serum PCB levels associated with either infant birth weight or gestational length. These results provide support for the hypothesis that early age at exposure may be an important determinant in subsequent health effects due to environmental chemical exposures.
确定对环境化学物质暴露及健康的易感性关键窗口期已成为公共卫生的一大重点。本研究调查了女性在幼年时期接触多溴联苯（PBBs）与后代出生体重及妊娠期长度之间的关联。研究人群包括1975年至1994年在密歇根州PBB队列中登记的560名女性所生育的1111例婴儿。接触时的母亲年龄分为三组：<10岁（n = 64）、11 - 16岁（n = 149）和17 - 42岁（n = 347）。总体血清PBB水平范围为0至1490 ppb，三个年龄组的中位数分别为2、3和2 ppb。分别采用混合效应线性回归模型来评估接触时的年龄（岁）和初始PBB水平（ppb）对出生体重（克）和胎龄（周）的影响，同时控制胎龄（周）（在考察对出生体重影响的模型中）、BMI（kg/m²）、入组时的血清多氯联苯（PCB）水平（ppb）、分娩时的母亲年龄和父亲教育程度、产次、婴儿性别、初始血清检测与分娩日期之间的间隔（年）以及开始产前护理的孕期。相对于年龄最大的组，接触时年龄<10岁是出生体重增加的最重要预测因素（估计回归系数 = 225克，P = 0.012）。血清PBBs每增加10 ppb，婴儿出生体重约增加16克（P = 0.004）。初始PBB水平与胎龄之间无关联，初始血清PCB水平与婴儿出生体重或妊娠期长度也无关联。这些结果为以下假设提供了支持：幼年时期接触可能是环境化学物质暴露对后续健康产生影响的一个重要决定因素。
