Research interests: From chemical oceanography and paleoceanography, my interests have increasingly turned to interactions between the environment and human health. The theme that runs through my on-going projects is that patterns of contamination, e.g. arsenic (As) in well water of across South Asia or lead (Pb) in soil contaminated with mine tailings in the Peruvian Andes, are spatially highly variable. This complicates prediction but also creates opportunities for mitigation. My students and I promote more widespread deployment of field kits for testing water and soil, developing new kits if necessary, in order to identify and avoid exposure to toxins of children in particular. I tend to focus on the vulnerability of (and access to) uncontaminated water or soil by working with earth scientists and engineers, as well as public health and social scientists.

Latest Highlight

Analysis of water samples from Newark, NJ collected by Jose Pagliery from Univision
September 23, 2019

To shed light on the performance of household filters distributed to Newark residents to remove lead from their tap water during summer 2019, we analyzed 76 pairs of input and output water samples that were returned by volunteer households. Here are the results from these analyses. [Download PDF]

Related: Newark says no more need for bottled water, but it's unclear why some homes fail tests, NJ.Com

Featured Video

Featured blog posts (arsenic and lead):

Study Identifies Better, Cheaper Ways to Stem Arsenic Poisoning in Bangladesh
Earth Institute blog linked to publication of review of almost two decades of arsenic mitigation in Bangladesh in Environmental Science and Technology in May 2019.

High School Students in Peru Discover Lead Contamination Hotspots
Earth Institute blog from March 2019 linked to first results from soil-lead survey in several Peruvian towns using a field kit developed at Columbia University's Earth Institute.

Arsenic Contamination is Common in Punjabi Wells, Study Finds
Earth Institute blog linked to publication of results from large-scale testing campaign of wells in Punjab plains of Pakistan and India in Science of the Total Environment in December 2018.

Q&A With Lex Van Geen on Arsenic Contamination
Q&A about well-water arsenic with Peter Debaere, Professor of Business Administration, Darden School of Business, on the occasion of an invited World Water Event talk at the University of Virginia in February 2018.

Report Charges 'Nepotism and Neglect' on Bangladesh Arsenic Poisoning
Earth Institute blog linked to publication of hard-hitting Human Rights Watch report about shortcoming of arsenic mitigation policy in Bangladesh in April 2016.

Citizen Science, Smartphone Apps and a $10,000 Prize
Announcement of Columbia University competition for funding to develop new smartphones app in April 2016.

Battling 'the Largest Mass Poisoning in History'
Earth Institute blog with two 9 min videos describing Columbia University's arsenic research in Bangladesh in July 2015.

Columbia University Scientists Propose Well-Switching as Key to Mitigating Bangladesh Arsenic Poisoning Tragedy
Earth Institute news release on first paper about well-switching in Bangladesh published in the Bulletin of the World Health Organization in June 2002.