title: Maternal exposure to neighborhood soil Pb and eclampsia risk in New Orleans, Louisiana (USA): evidence from a natural experiment in flooding.
abstract: BACKGROUND
  Previous studies link maternal blood lead (Pb) levels and pregnancy-related hypertensive disorders.
  
  
  OBJECTIVE
  Assess the relationship between neighborhood soil Pb and maternal eclampsia risk.
  
  
  METHODS
  Zip code summarized high density soil survey data of New Orleans collected before and after Hurricanes Katrina and Rita (HKR) were merged with pregnancy outcome data on 75,501 mothers from the Louisiana office of public health. Cross-sectional logistic regression analyses are performed testing the association between pre-HKR accumulation of Pb in soils in thirty-two neighborhoods and eclampsia risk. Then we examine whether measured declines in soil Pb following the flooding of the city resulted in corresponding reductions of eclampsia risk.
  
  
  RESULTS
  Cross-sectional analyses show that a one standard deviation increase in soil Pb increases the odds of eclampsia by a factor of 1.48 (95% CI: 1.31, 1.66). Mothers in zip code areas with soil Pb>333 mg/kg were 4.00 (95% CI: 3.00, 5.35) times more likely to experience eclampsia than mothers residing in neighborhoods with soil Pb<50mg/kg. Difference-in-differences analyses capturing the exogenous reduction in soil Pb following the 2005 flooding of New Orleans indicate that mothers residing in zip codes experiencing decrease in soil Pb (-387.9 to -33.6 mg/kg) experienced a significant decline in eclampsia risk (OR=0.619; 95% CI: 0.397, 0.963).
  
  
  CONCLUSIONS
  Mothers residing in neighborhoods with high accumulation of Pb in soils are at heightened risk of experiencing eclampsia.
authors: Department of Economics, C-312A Clark Building, Colorado State University, Fort Collins, CO, 80523-1771 USA; Robert Wood Johnson Health and Society Scholar, Columbia University, 722 W 168th St, New York, NY 10032, USA. Electronic address: szahran@colostate.edu.
authors: Sammy
authors: S
authors: Zahran
authors: Department of Environmental and Radiological and Health Sciences, 147 Environmental Health Building, Colorado State University, Fort Collins, CO, 80523-1681 USA. Electronic address: sheryl.magzamen@colostate.edu.
authors: Sheryl
authors: S
authors: Magzamen
authors: Pharmaceutical Health Services Research, University of Maryland School of Pharmacy, 220 Arch Street, 12th floor, Room 01-209, Baltimore, MD 21201, USA. Electronic address: ibreunig@rx.umaryland.edu.
authors: Ian M
authors: IM
authors: Breunig
authors: Department of Pharmacology, Tulane University School of Medicine, 1430 Tulane Avenue SL-83, New Orleans, LA, 70112-2699, USA. Electronic address: hmielke@tulane.edu.
authors: Howard W
authors: HW
authors: Mielke
mesh_terms: D003430:Cross-Sectional Studies; D004461:Eclampsia / Q000139:chemically induced* / Q000453:epidemiology; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D055868:Floods; D006801:Humans; D007854:Lead / Q000633:toxicity*; D018811:Maternal Exposure / Q000009:adverse effects*; D055820:New Orleans / Q000453:epidemiology; D011157:Population Dynamics; D011247:Pregnancy; D011256:Pregnancy Outcome; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D012989:Soil Pollutants; D007854:Lead
keywords: Eclampsia; Hurricanes Katrina/Rita; Pre-eclampsia; Pregnancy-related hypertensive disorders; Soil lead