ASSESING TRACE METALS EXPOSURE IN WHOLE BLOOD DURING DIFFERENT WINDOWS OF SUSCEPTIBILITY IN PREGNANCY IN PUERTO RICO

Abstract

Background and Aims Trace metal exposure has been previously associated with adverse pregnancy outcomes. Puerto Rico, which has a high preterm birth rate (~19%) and density of superfund sites, is the setting for a recently developed epidemiological cohort. The aim of this exploratory study was to evaluate exposure to different metals of interest among pregnant women participating in the Puerto Rico Testsite for Contamination Threats (PRoTECT) study. Methods: In a pilot sample of N=53 pregnant women, venous whole blood samples were collected at two time points during pregnancy (16-20th and 28-32nd week of gestation). Analysis of total trace metals was performed using an Inductively Coupled Plasma Mass Spectrometer (ICP-MS). Results: The geometric mean concentrations and ranges (?g/L, except Pb (?g/dL)) of the measured elements during the first clinic visit were: As 1.35 (0.48-6.80), Cd, 0.47 (0.25-1.03), Cr 0.56 (0.32-1.38), Pb 0.42 (0.19 -1.00), Se 191.4 (141.6-256.0), An 4.19 (2.51 -8.04), Co 0.82 (<LOD -1.84), Mo 1.99 (0.84 – 13.26), Ta 0.04 (<LOD – 0.14), W 0.59 (0.34 – 1.20), Zn 4135 (2481.2 – 5543.2), Mn 9.84 (4.47-21.33). Al, V, Ni, Ti, and U levels were under their respective detection limits. Trace metal geometric mean levels were similar between visits. However, only weak to moderate correlations between visits were observed within women for most metals (coefficients ranged from -0.01 to 0.78), which could have important implications for exposure assessment in epidemiology studies estimating exposure during pregnancy. Conclusions: This is the first study to include a panel of both micronutrients and toxic metals in a Puerto Rican population throughout pregnancy. Future analysis will focus on using questionnaire data to assess predictors of exposure, analyzing other biological media, exploring relationships with adverse pregnancy outcomes, and examining possible metal interactions.