Thacker, S B Five longitudinal studies designed to measure the effect of low-level body burdens of lead. [electronic resource] - Archives of environmental health - 204-5 p. digital Publication Type: Letter; Comment ISSN: 0003-9896 Standard No.: 10.1080/00039896.1994.9940384 doi Subjects--Topical Terms: BiasChildChild Development--drug effectsConfounding Factors, EpidemiologicEnvironmental Exposure--adverse effectsHumansIntelligence--drug effectsLead--adverse effectsLongitudinal StudiesMeta-Analysis as Topic