Research Article Open Access Open Access Research Article Funk et al., J Environ Anal Toxicol 2015, S7 DOI: 10.4172/2161-0525.S7-002 J Environ Anal Toxicol Toxicology & Environmental Safety ISSN: 2161-0525 JEAT an open access journal *Corresponding author: William E Funk, Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, 680 N Lake Shore Drive, Suite 1400, Chicago, IL 60611, USA, Tel: 312 503 4092; E-mail: w-funk@northwestern.edu Received July 02, 2015; Accepted July 16, 2015; Published July 24, 2015 Citation: Funk WE, Pleil JD, Sauter DJ, McDade TW, Holl JL (2015) Use of Dried Blood Spots for Estimating Children’s Exposures to Heavy Metals in Epidemiological Research. J Environ Anal Toxicol S7: 002. doi:10.4172/2161-0525.S7-002 Copyright: © 2015 Funk WE, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Use of Dried Blood Spots for Estimating Children’s Exposures to Heavy Metals in Epidemiological Research William E Funk 1* , Joachim D Pleil 2 , Dana J Sauter 3 , Thomas W McDade 4 and Jane L Holl 1 1 Department of Preventive Medicine, Northwestern University, Chicago, IL, USA 2 United States Environmental Protection Agency, National Exposure Research Laboratory/ORD, Research Triangle Park, NC, USA 3 Cabot Microelectronics, Aurora, IL USA 4 Department of Anthropology and Institute for Policy Research, Northwestern University, Evanston, IL, USA Keywords: Dried blood spots; Heavy metals; Children Introduction Te discipline of environmental exposure science is intricately linked with epidemiological investigations for protecting public health [1,2]. Historically, methods were focused on measurements of environmental media used to estimate potential human exposure through various uptake pathways. More recently, there has been a shif towards incorporating biomarker data as a more direct link to exogenous exposures through measurements from human biological media such as blood, breath, and urine for exploring the concept of the human exposome-representing all chemical exposures from conception throughout life [3-5]. Te combined use of biomarkers of exposure and biomarkers of efect has also become a central theme for linking the external environment to potential adverse health outcomes [6-8]. Tere are now large databases such as the U.S. National Health and Nutrition Examination Survey (NHANES), the German Environmental Survey (Ger ES), Te Korea National Health and Nutrition Examination Survey (KNHANES), and the Canadian Health Measures Study (CHMS) that are making such data mining readily available to the research community [9-12]. Tese are based on detailed analyses of thousands of “snapshot” measures from stratifed random selections of subjects from the general populations of the respective countries. Supplementing such information with repeat measures and many more subjects will provide an ever-improving statistical understanding of environmental exposures, onboard dose, environmental metabolomics, and ultimately public health sustainability [13-16]. Currently, a major issue is the exposure of children to heavy metals, which are of particular concern early in development. In fact, As, Pb, Hg, and Cd are listed as the 1 st , 2 nd , 3 rd , and 7 th most important hazardous substances on the Agency for Toxic Substances and Disease Registry’s 2013 CERCLA priority list of 275 substances, respectively. Exposure to heavy metals can occur through a variety of exposure routes, including inhalation as dust and fumes [17,18], and ingestion from food and water [19-21], and can cause a wide spectrum of health problems including convulsions, coma, renal failure, injuries to the lungs and neurologic system, memory loss, delirium, diabetes, kidney damage, and a variety of cancers [22]. In addition, heavy metals can cross the placental barrier during pregnancy resulting in toxic exposures during highly susceptible periods of fetal development [23-25]. Yet, the health impacts of exposures to toxic metals during all stages of early development are not well understood due to the paucity of in vivo human data. Tus, additional studies are critically needed using emerging exposure assessment tools. Abstract Background: Children’s exposures to arsenic (As), lead (Pb), mercury (Hg), and cadmium (Cd) are of particular concern in early-life. Exposures to heavy metals are traditionally measured in whole venous blood, which is costly and invasive. As an alternative we describe a method for quantifying As, Pb, Hg, and Cd in dried blood spot (DBS) samples. Objectives: To validate a method for quantifying levels of As, Pb, Hg, and Cd in fnger-stick DBS samples. Background metal contamination in blood collection cards poses a challenge for quantifying heavy metals in DBS samples. Here we report a method to remove background contamination from the flter paper prior to blood collection to improve assay precision. Methods: Matched samples of venous blood and fnger-stick DBS samples were collected from 82 children ages 1-21. Whole venous blood samples were also applied to pre-cleaned and untreated blood collection cards. All samples were analyzed for As, Pb, Hg, and Cd using inductively coupled plasma mass spectrometry (ICP-MS). Results: Matched venous blood and fnger-stick DBS samples from untreated cards were signifcantly correlated, but with relatively weak R 2 values of 0.083, 0.186, 0.498, and 0.022 for As, Cd, Hg, and Pb, respectively. When blood collection cards were decontaminated prior to blood collection the correlations between venous blood and DBS samples were highly signifcant, with R 2 values of 0.66, 0.99, 0.98, and 0.94 for As, Pb, Hg, and Cd, respectively. Conclusions: Standard blood collection cards contain signifcant and highly variable background levels of heavy metals. Once blood collection cards are treated to remove residual contamination, DBS sampling can be used as a minimally-invasive alternative to venipuncture to estimate exposures to toxic metals. Journal of Environmental & Analytical Toxicology J o u r n a l o f E n v i r o n m e n t a l & A n a l y t i c a l T o x i c o l o g y ISSN: 2161-0525