Archived Publication Announcements

April 1 2014

Water Arsenic >= 5 mug/L pose possible threat to children

Environmental Health has published in its April 2014 edition the Columbia SRP paper,  "A cross-sectional study of well water arsenic and child IQ in Maine schoolchildren." CU SRP Project 2 scientist Gail Wasserman is the lead author. Her Columbia collaborators include Xinhua Liu, Nancy J LoIacono, Jennie Kline, Pam Factor-Litvak, Alexander van Geen, Jacob L Mey, Diane Levy, and Joseph H Graziano. Richard Abramson formerly with Readfield ME Public Schools and Amy Schwartz at the University of New Hampshire also contributed to this paper.

The authors start with a description of past studies. Earlier research by the CU SRP team focused on dose-dependent adverse associations between consumption of arsenic (As)- contaminated water from household wells and intellectual function in young Bangladeshi children. Their  initial work with 6- and 10-year olds, after adjustment for social factors related to intellectual function, indicated that water arsenic concentration (WAs) was significantly negatively related to WPPSI-III and WISC-III Performance (nonverbal ability) scores, but, in most instances, not to other components of intelligence, such as Verbal scores.  A more recent study of Bangladeshi 9-10 year olds, resulted in marginally significant associations between WAs and both Verbal Comprehension and Working Memory scores from the WISC-IV, after adjustments for socio-demographic features and for co-occurring exposure to manganese in drinking wate.  Water Arsenic was unrelated to other aspects of intellectual functioning. These and other studies in different populations have suggested that As exposure may affect early development. However, there has been little consistency in the specific components of child intelligence most affected.

The CU SRP study described in this paper included 272 childrent in grades 3-5 in 3 Maine public school districts. It examined associations between drinking water Arsenic and intelligence as measured by the WISC-IV test. The findings suggest that levels of Water Arsenic equal or greater than 5 mug/L, levels, which are below EPA national standards and occur frequently in some US regions, could pose a threat to child development.


Wasserman Gail A, Liu  Xinhua, LoIacono Nancy J, Kline Jennie, Factor-Litvak  Pam, van Geen  Alexander, Mey Jacob L, Levy  Diane, Abramson  Richard, Schwartz Amy, Graziano Joseph H. A cross-sectional study of well water arsenic and child IQ in Maine schoolchildren. Environmental Health 2014, 13:23 (1 April 2014). DOI: 10.1186/1476-069X-13-23

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March 5 2014

Additional evidence that nutritional status may explain differences in susceptibility to arsenic toxicity

Caitlin Howe, Columbia SRP student with Project 3, is the lead author of the upcoming paper, "Folate and Cobalamin Modify Associations between S-adenosylmethionine and Methylated Arsenic Metabolites in Arsenic-Exposed Bangladeshi Adults" that will appear in the May 2014 publication of the Journal of Nutrition. Co-authors include Columbia SRP student alumnae and scientists as well as collaborators from Columbia University Arsenic Project in Bangladesh. The key findings provide additional evidence that nutritional status may explain some differences among individuals in arsenic metabolism and, thus, susceptibility to arsenic toxicity. The paper is currently available online. Please see the link below.

Suggested citation:

Howe CG, Niedzwiecki MM, Hall MN, Liu X, Ilievski V, Slavkovich V, Alam S, Siddique AB, Graziano JH,4 and Gamble MV. Folate and Cobalamin Modify Associations between S-adenosylmethionine and Methylated Arsenic Metabolites in Arsenic-Exposed Bangladeshi Adults J. Nutr. May 2014 jn.113.188789; first published online March 5, 2014. doi:10.3945/jn.113.188789.

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September 11 2013

Nature publication: Retardation of arsenic transport through a Pleistocene aquifer


Nature published on September 11, 2013 a paper by CU SRP scientists Alexander van Geen, Benjamin Bostik, Kathleen Radloff, Zahid Aziz, Jacob L. Mey along with several of their collaborators on "Retardation of arsenic transport through a Pleistocene aquifer". Here they present findings from their study on the contamination of a Pleistocene aquifer near Hanoi, Vietnam. Their study reveals that "changes in groundwater flow conditions and the redox state of the aquifer sands induced by groundwater pumping caused the lateral intrusion of arsenic contamination more than 120 metres from a Holocene aquifer into a previously uncontaminated Pleistocene aquifer.We also find that arsenic adsorbs onto the aquifer sands and that there is a 16–20-fold retardation in the extent of the contamination relative to the reconstructed lateral movement of groundwater over the same period. Our findings suggest that arsenic contamination of Pleistocene aquifers in south and southeast Asia as a consequence of increasing levels of groundwater pumping may have been delayed by the retardation of arsenic transport."

The research presented here was fund by the US National Science Foundation and the NIEHS Superfund Research Program.

Additional authors include Vi Mai Lan, Nguyen-Ngoc Mai, Phu Dao Manh and Pham Hung Viet, of the Hanoi University of Science, Mason Stahl and Charles Harvey from MIT, Beth Weinman from Vanderbilt University along with researchers from Anchor QEA, Eawag Swiss Federal Institute of Aquatic Science and Technology,Institute of Geochemistry and Petrology, Swiss Federal Institute of Technology.

Suggested citation:
van Geen, A., Bostick, B., Thi Kim Trang, P., et al. 2013. Retardation of arsenic transport through a Pleistocene aquifer. Nature 501, 204–207 doi:10.1038/nature12444 (onine 12 September 2013).

Sponsored by: NIEHS Superfund Research Program and National Science Foundation
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July 1 2013

Blood glutathione redox status and global methylation of peripheral blood mononuclear cell DNA in Bangladeshi adults

The July issue of Epigenetics will include a paper by Mailman graduate student Megan Niedzwiecki and her Columbia SRP colleagues entitled “Blood glutathione redox status and global methylation of peripheral blood mononuclear cell DNA in Bangladeshi adults”. In this article, the researchers investigated the relationship between oxidative stress and DNA methylation in humans.   Oxidative stress and DNA methylation are metabolically linked:  depletion of glutathione (GSH), the body’s primary antioxidant, might lead to depletion of S-adenosylmethionine (SAM), the universal methyl donor for methylation reactions.  Additionally, many enzymes involved in DNA methylation show altered activity under oxidized cellular conditions., The Columbia SRP scientists tested the hypothesis that a more oxidized blood GSH redox status is associated with decreased global peripheral blood mononuclear cell (PBMC) DNA methylation in a sample of Bangladeshi adults. They found that a more oxidized blood GSH redox state was associated with decreased global DNA methylation, but blood SAM was not a mediator of this association. Future research should explore mechanisms through which cellular redox status might influence global DNA methylation as this may represent an important pathway leading towards both carcinogenic and non-carcinogenic mechanisms of action of arsenic. Given that redox status and DNA methylation are both potentially modifiable through nutritional and other interventions, a greater mechanistic understanding of these observations could ultimately have therapeutic implications.

Suggested citation:

Niedzwiecki M, Hall MN, Liu X, Oka J, Harper KN, Slavkovich V, Ilievski V, Levy D, van Geen A, Mey JL, Alam S, Siddique AB, Parvez F, Graziano JH, and Gamble MV. Blood glutathione redox status and global methylation of peripheral blood mononuclear cell DNA in Bangladeshi adults. Epigenetics 2013:8(7):730-738. Published Online: May 17, 2013.

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June 21 2013

EHP Publication: Chronic Arsenic Exposure and Blood Glutathione and Glutathione Disulfide Concentrations in Bangladeshi Adults

Exposure to arsenic (As) has been shown to deplete glutathione (GSH), the primary intracellular antioxidant, and induce oxidative stress in In vitro and rodent studies. Glutathione disulfide (GSSG) is produced after GSH donates an electron to reactive oxygen species.  The primary objective of this study was to test whether As exposure was associated with decreases in GSH and increases in GSSG, i.e., a more oxidized intracellular environment. Lead author Dr. Hall and her colleagues also investigated whether As exposure was associated with reductions in cysteine (Cys) and increases in cystine (CySS); Cys and CySS are the predominant thiol/disulfide redox couple found in human plasma.  The authors observed inverse associations of As exposure with GSH and Cyss, but no associations with GSSG and Cys and concluded that “The observed associations are consistent with the hypothesis that As may influence concentrations of GSH and other non-protein sulfhydryls through binding and irreversible loss in bile and/or possibly in urine.”

Hall MN, Niedzwiecki M, Liu X, Harper KN, Alam S, Slavkovich V, Ilievski V, Levy D, Siddique S, Parvez F, Mey JL, van Geen A, Graziano J, and Gamble MV. Chronic Arsenic Exposure and Blood Glutathione and Glutathione Disulfide Concentrations in Bangladeshi Adults. Environmental Health Perspectives Advance Publication: 21 June 2013.

June 10 2013

Two Potential Perils in Cancer Studies Involving DNA Methylation Array Analysis

The June publication of Cancer Epidemiology Biomarkers & Prevention features a paper by Kristin Harper, Bradilyn Peters, and Mary Gamble on “Batch Effects and pathway analysis: Two potential perils in cancer studies involving DNA methylation array analysis”. It includes some recent findings from their research under the Columbia Superfund Research Program’s Project 3, Impact of Nutrition on Arsenic-Induced Epigenetic Dysregulation.

DNA methylation microarrays have become an increasingly popular means of studying the role of epigenetics in cancer, although the methods used to analyze these arrays are still being developed and existing methods are not always widely disseminated among microarray users.

Harper, Peters, and Gamble investigated two problems likely to confront DNA methylation microarray users: (i) batch effects and (ii) the use of widely available pathway analysis software to analyze results. First, DNA taken from individuals exposed to low and high levels of drinking water arsenic were plated twice on Illumina's Infinium 450 K HumanMethylation Array, once in order of exposure and again following randomization. Second, they conducted simulations in which random CpG sites were drawn from the 450 K array and subjected to pathway analysis using Ingenuity's IPA software.

They concluded that the analyses illustrated the pitfalls of not properly controlling for chip-specific batch effects as well as using pathway analysis software created for gene expression arrays to analyze DNA methylation array data. The in silico pathway analysis experiment yielded spurious but significant findings due to over-representation of CpGs on the 450K array chip that were associated with genes involved in pathways linked to cancer, developmental disorders, cellular development, cell morphology, embryological development, and more.

Suggested citation

Harper KN, Peters BA, Gamble MV. Batch Effects and pathway analysis: Two potential perils in cancer studies involving DNA methylation array analysis. Cancer Epidemiol Biomarkers Prev 2013; 22(6); 1–9. Published OnlineFirst April 29, 2013; doi:10.1158/1055-9965.EPI-13-0114.

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May 10 2013

Arsenic, Methylation, and Cardiovascular Risk-- Online Publication in EHP

On May 10th Environmental Health Perspectives provided an advance publication of the paper, "A Prospective Study of Arsenic Exposure, Arsenic Methylation Capacity, and Risk of Cardiovascular Disease in Bangladesh" by Dr. Yu Chen, Associate Professor at NYU Langone Medical Center and her Columbia SRP colleagues. They carried out "a case-cohort study of 369 incident fatal and non-fatal cases of CVD, including 148 stroke cases and 211 cases of heart disease, and a subcohort of 1,109 subjects randomly selected from the 11,224 participants in the Health Effects of Arsenic Longitudinal Study." Their overall conclusion is that exposure to arsenic in drinking water together with reduced arsenic methylation capacity is associated with increased heart disease risk.

Suggested citation:

Chen Y, Wu F, Liu M, Parvez F, Slavkovich V, Eunus M, Ahmed A, Segers S, Argos M, Islam T, Rakibuz-Zaman M, Hasan R, Sarwar G, Levy D, Graziano J, Ahsan H. A Prospective Study of Arsenic Exposure, Arsenic Methylation Capacity, and Risk of Cardiovascular Disease in Bangladesh. Environmental Health Perspectives (tba). doi:10.1289/ehp.1205797 Online publication: May 10, 2013.


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March 1 2013

Broad Scope of Health Effects from Chronic Arsenic Exposure: Update on a Worldwide Public Health Problem

CU SRP Director Joseph Graziano and PI Habibul Ahsan collaborated with NIEHS staff, Marisa Naujokas, Beth Anderson, Claudia Thompson, and SRP Director Bill Suk along with UA SRP scientist H. Vasken Aposhian to synthesize the large body of current research pertaining to arsenic exposure and health outcomes worldwide. Following their review, the authors conclude that the data indicate “arsenic-related pathologies exist in broader contexts than previously perceived”. Pregnant women and children are particularly susceptible, leading to potentially life-long developmental impacts from arsenic exposure: “Most remarkably, early-life exposure may be related to increased risks for several types of cancer and other diseases during adulthood.” The authors such as a top priority foods and drinking water for arsenic, including individual private wells, must be tested in order to reduce exposure and improve health for those populations most at risk.

Suggested Citation:

Naujokas MF, B Anderson, H Ahsan,, HV Aposhian, JH Graziano, C Thompson, and WA Suk. (2013) The Broad Scope of Health Effects from Chronic Arsenic Exposure: Update on a Worldwide Public Health Problem. Environ Health Perspect 121:295–302 (2013). [Online 3 January 2013]

PDF icon Full paper1.06 MB

January 9 2013

USGS Report on Arsenic in NH Groundwater from Bedrock Aquifers


Estimated Probability of Arsenic in Groundwater from Bedrock Aquifers in New Hampshire, 2011

By Joseph D. Ayotte, Matthew Cahillane, Laura Hayes, and Keith W. Robinson


Probabilities of arsenic occurrence in groundwater from bedrock aquifers at concentrations of 1, 5, and 10 micrograms per liter (µg/L) were estimated during 2011 using multivariate logistic regression. These estimates were developed for use by the New Hampshire Environmental Public Health Tracking Program. About 39 percent of New Hampshire bedrock groundwater was identified as having at least a 50 percent chance of containing an arsenic concentration greater than or equal to 1 µg/L. This compares to about 7 percent of New Hampshire bedrock groundwater having at least a 50 percent chance of containing an arsenic concentration equaling or exceeding 5 µg/L and about 5 percent of the State having at least a 50 percent chance for its bedrock groundwater to contain concentrations at or above 10 µg/L. The southeastern counties of Merrimack, Strafford, Hillsborough, and Rockingham have the greatest potential for having arsenic concentrations above 5 and 10 µg/L in bedrock groundwater.

Significant predictors of arsenic in groundwater from bedrock aquifers for all three thresholds analyzed included geologic, geochemical, land use, hydrologic, topographic, and demographic factors. Among the three thresholds evaluated, there were some differences in explanatory variables, but many variables were the same. More than 250 individual predictor variables were assembled for this study and tested as potential predictor variables for the models. More than 1,700 individual measurements of arsenic concentration from a combination of public and private water-supply wells served as the dependent (or predicted) variable in the models.

The statewide maps generated by the probability models are not designed to predict arsenic concentration in any single well, but they are expected to provide useful information in areas of the State that currently contain little to no data on arsenic concentration. They also may aid in resource decision making, in determining potential risk for private wells, and in ecological-level analysis of disease outcomes. The approach for modeling arsenic in groundwater could also be applied to other environmental contaminants that have potential implications for human health, such as uranium, radon, fluoride, manganese, volatile organic compounds, nitrate, and bacteria.

Suggested citation:

Ayotte, J.D., Cahillane, Matthew, Hayes, Laura, and Robinson, K.W., 2012, Estimated probability of arsenic in groundwater from bedrock aquifers in New Hampshire, 2011: U.S. Geological Survey Scientific Investigations Report 2012–5156, 25 p., available only at

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November 1 2012

Study suggests large investment in Bangladesh water supply infrastructure would be justified

Two of Columbia's SRP Community Engagement Core scientists Sara Flanagan and Yan Zheng along with their colleague Richard Johnston published a paper in the November 2012 WHO Bulletin examining the health and economic impacts and implications for the mitigation of arsenic in tube well water in Bangladesh. A recent survey in Bangladesh estimates that 35 to 77 million people have been chronically exposed to arsenic in their drinking water. The health implications of chronic arsenic exposure in such a large population are substantial. Interventions in areas with the highest proportion of unsafe wells are likely to reach the population exposed to the highest arsenic concentrations and therefore at highest risk of experiencing adverse health outcomes. This paper provides evidence that large investments in the water supply infrastructure to reduce levels of arsenic in drinking water is economically justified when the health and economic burdens of unabated arsenic exposure are considered.


Flanagan, S.V., R.B. Johnston,and Y. Zheng. 2012. Arsenic in tube well water in Bangladesh: health and economic impacts and implications for arsenic mitigation.Bulletin of the World Health Organization 2012;90:839-846. doi: 10.2471/BLT.11.101253

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