27-7 Influence of Environmental Controls on Rice Grain Arsenic Concentrations in Cambodia: Insights from Soil Spectroscopy

Session: Environmental Geochemistry and Health (Posters)

Poster Booth No.: 80

Presenting Author:

Amelia Casassa

Authors:

Casassa, Amelia¹, Chambial, Sienna², Stahl, Mason Odell³, Lawless, Keith⁴, Snyder, Devin⁵, Hoeng, Sophanith⁶, Phin, Samnang⁷, Phan, Kongkea⁸, Phan, Samrach⁹, Coleman, Eva¹⁰, Tran, My Thu¹¹, Thompson, Emma¹², Sousa, Daniel¹³, McGarry, Tavehon¹⁴, Halpert, Eden¹⁵

(1) Department of Geosciences, Union College, Schenectady, NY, USA, Union College, Schenectady, NY, USA, (2) Department of Geosciences, Union College, Schenectady, NY, USA, (3) Department of Geosciences, Union College, Schenectady, NY, USA, (4) Department of Geosciences, Union College, Schenectady, NY, USA, (5) Department of Geosciences, Union College, Schenectady, NY, USA, (6) International University, Phnom Penh, Cambodia, (7) Water Innovation Lab, Kampong Siem, Cambodia, (8) International University, Phnom Penh, Cambodia, (9) Water Innovation Lab, Kampong Siem, Cambodia, (10) San Diego State University, San Diego, CA, USA, San Diego State University, San Diego, CA, USA, (11) San Diego State University, San Diego, CA, USA, (12) San Diego State University, San Diego, CA, USA, (13) San Diego State University, San Diego, CA, USA, (14) Lamont Doherty Earth Observatory, Columbia University, Palisades, NY, USA, (15) Lamont Doherty Earth Observatory, Columbia University, Palisades, NY, USA, (16) Lamont-Doherty Earth Observatory, Geochemistry Division, Columbia University, Palisades, NY, USA,

Abstract:

Rice is an important cereal grain crop, providing 20% of the calories consumed worldwide. The crop’s unique physiology and the environments it is grown in make it susceptible to arsenic uptake and accumulation within its grain. Arsenic is a naturally occurring metalloid in most soils, and is toxic to both the rice crop as well as the humans that consume it. 

To understand the environmental factors that govern the accumulation of arsenic in rice grains, we have sampled rice grains, rice leaves, soil, and water from over 150 rice paddies across a varied geographical range within Cambodia, a country which relies on rice for over 60% of its annual caloric intake. The traditional farming practices prevalent in the region allow us to isolate and inspect various environmental factors efficiently. Arsenic concentrations within the rice grains and soil were measured using ICP-MS, XRF and soil visible reflectance measurements were made using a visible reflectance spectrophotometer. Here, we present the results on visible reflectance spectroscopy of soil and link it to soil and grain arsenic levels. Our research suggests that while soil arsenic concentration is poorly predictive of rice grain arsenic concentration, spectroscopy of soil within the visible spectrum is potentially a useful tool in forecasting rice grain quality prior to planting the crop, and can have prospective implications on increased food security in Cambodia and other regions where rice is a staple.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-9054

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