EHP：孕妇接触有机磷农药可导致婴儿体重偏低

近日，加拿大研究人员一项最新调查发现，孕妇接触有机磷农药，可能会导致孕期缩短、婴儿出生体重偏轻。相关研究发表在新一期《环境卫生展望》（Environment Health Perspectives）杂志网络版上。

在此次调查中，研究人员选取了美国俄亥俄州辛辛那提的306名孕妇作为样本。结果显示，暴露在有机磷农药水平较高环境下的孕妇所产下的婴儿出生体重平均偏轻三分之一磅（约合150克），孕期平均缩短3至4天。

进行调查的加拿大不列颠哥伦比亚省儿童医院的研究人员认为，上述数据看起来似乎对孕妇和新生儿的影响并不大，但如果放到数量足够多的孕妇群中，婴儿出生体重降低150克就可能使得早产率明显升高。

另外，对于一名孕妇来说，其婴儿出生体重降低150克或许不会带来严重后果，但这只是孕妇生产过程中需要面对的诸多风险之一。如果这名孕妇面临4至5个危险因素，累加起来的后果就会相当严重。

研究表明，孕妇接触有机磷农药后导致孕期缩短以及婴儿出生体重偏低，与吸烟孕妇产下婴儿体重偏轻的情况类似。虽然这一研究结论还需被进一步证实，但它却再次引发了人们对环境污染危害的担忧。

此前曾有研究发现，孕妇暴露在有机磷农药较高水平的环境下，可能会导致将来婴儿智商稍低，而且婴儿日后出现一些行为障碍的风险更大。研究人员表示，这些研究结果如果被进一步证实，将有助于把有机磷农药界定为导致早产儿和低出生体重婴儿的风险因素。

doi:10.1289/ehp.1104615
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Associations of Prenatal Exposure to Organophosphate Pesticide Metabolites with Gestational Age and Birthweight

Stephen A. Rauch, Joe M. Braun, Dana Boyd. Barr, Antonia M. Calafat, Jane Khoury, M. Angela Montesano, Kimberly Yolton, Bruce P. Lanphear

Background: Prenatal exposure to organophosphate (OP) insecticides, a widely-used class of pesticides, may be associated with decreased gestational age and lower birthweight. Single nucleotide polymorphisms in paroxanase (PON1) enzyme genotypes may modify the relationships between OP exposure and perinatal outcomes. Objectives: To examine the relationship of prenatal OP insecticide exposure, measured using urinary dialkyl phosphate (DAP) metabolite concentrations, with gestational age and birthweight. Methods: We measured the concentrations of six nonspecific DAP metabolites of OP insecticides in two maternal spot urine samples collected in a prospective birth cohort. We performed multivariable regression to examine associations between the sum of six DAP concentrations (ΣDAP) with gestational age and birthweight. We also examined whether these associations differed according to infant PON1192 and PON1108 genotypes. Results: Among 306 mother/infant dyads, a 10-fold increase in ΣDAP concentrations was associated with a decrease in covariate-adjusted gestational age (-0.5 weeks; 95% confidence interval [CI]:-0.8, -0.1), and birthweight (-151g; CI:-287, -16); the decrements in birthweight were attenuated after adjusting for gestational age. The relationship between ΣDAP concentrations and gestational age was stronger for white (-0.7 weeks, CI:-1.1, -0.3) than black (-0.1 weeks, 95% CI:-0.9, 0.6) newborns. In contrast, there was a greater decrease in birthweight with increasing urinary ΣDAP concentrations for black (-188g, CI:-395, 19) than white (-118g, CI:-296, 60) newborns. Decrements in birthweight and gestational age associated with ΣDAP concentrations were greatest among infants with PON192QR and PON108CT genotypes. Conclusions: Prenatal urinary ΣDAP concentrations were associated with shortened gestation and reduced birthweight in this cohort, but the effects differed by race/ethnicity and PON1192/108 genotypes.