Journal of Hazardous Materials 262 (2013) 1072–1079 Contents lists available at ScienceDirect Journal of Hazardous Materials j o ur nal homep age: www.elsevier.com/locate/jhazmat Arsenic in groundwater and its influence on exposure risks through traditionally cooked rice in Prey Vêng Province, Cambodia A. O’Neill a , D.H. Phillips a , S. Kok b , E. Chea b , B. Seng b , B. Sen Gupta a,∗ a Environmental Engineering Research Centre, School of Planning, Architecture and Civil Engineering, Queen’s University of Belfast, Belfast, BT9 5AG, Northern Ireland, UK b Department of Environmental Science, Royal University of Phnom Penh, Russian Federation Blvd., Phnom Penh, Cambodia h i g h l i g h t s • We examine the extent of As-contaminated groundwater in Prey Vêng, Cambodia. • High As risk zones are centralised along the Mekong River plain. • We determine risk associated with consuming rice cooked in As-contaminated water. • Households are consuming up to 24 times more inorganic As daily than recommended by the WHO. • Rice cooked in rainwater significantly reduces As dietary exposure. a r t i c l e i n f o Article history: Received 3 October 2012 Received in revised form 20 March 2013 Accepted 29 March 2013 Available online 8 April 2013 Keywords: Arsenic Groundwater Traditionally cooked rice Dietary intake Rainwater harvesting Cambodia a b s t r a c t Arsenic (As) contamination of communal tubewells in Prey Vêng, Cambodia, has been observed since 2000. Many of these wells exceed the WHO As in drinking water standard of 10 g/L by a factor of 100. The aim of this study was to assess how cooking water source impacts dietary As intake in a rural community in Prey Vêng. This aim was fulfilled by (1) using geostatistical analysis techniques to examine the extent of As contaminated groundwater in Prey Vêng and identify a suitable study site, (2) conducting an on-site study in two villages to measure As content in cooked rice prepared with water collected from tubewells and locally harvested rainwater, and (3) determining the dietary intake of As from consuming this rice. Geostatistical analysis indicated that high risk tubewells (>50 g As/L) are concentrated along the Mekong River’s east bank. Participants using high risk tubewells are consuming up to 24 times more inorganic As daily than recommended by the previous FAO/WHO provisional tolerable daily intake value (2.1 g/kgBW/day). However, As content in rice cooked in rainwater was significantly reduced, therefore, it is considered to be a safer and more sustainable option for this region. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved. 1. Introduction Since the 1990s, groundwater collected from tubewells has become the primary source of water for rural Cambodians, due to the high mortality rates associated with consuming pathogen contaminated surface water and an ease of accessibility [1,2]. This water source is mainly used for human consumption, bathing and agricultural purposes (irrigating crops etc.) [3]. However, dur- ing the past decade groundwater sources were discovered to be naturally contaminated with arsenic (As). In some locations, As contamination was as high as 100 times the World Health Organi- sation’s (WHO) permissible standard of 10 g/L [4]. Studies have indicated that the greatest As concentrations are present in the ∗ Corresponding author. Tel.: +44 28 9097 4554; fax: +44 28 90974278. E-mail address: B.Sengupta@qub.ac.uk (B. Sen Gupta). expansive shallow groundwater chambers underlying Asia’s major delta regions [5]. Over sixty million people in South and Southeast Asia are impacted by As concentrations exceeding the WHO per- missible standard [5–7]. This endemic has been classified as the ‘largest mass poisoning in history’ [5,8], which was first discovered over thirty years ago in the Bengal Delta Region. According to cen- sus data, 2.25 million Cambodians are living within As risk zones, primarily within the Mekong Delta [9]. The United States Environmental Protection Agency (US EPA) classifies As as a human carcinogen (class A) [10], indicating that there is a significant risk of contracting cancer following chronic exposure. Arsenicosis refers collectively to the health effects associ- ated with As exposure [5], which typically occur through ingestion of As contaminated water and food. There are various stages of As exposure. Acute exposure undermines the body’s essential enzyme functions, which can result in a series of non-cancerous ailments [11], such as vomiting, abdominal pain, weakness and diarrhoea 0304-3894/$ – see front matter. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jhazmat.2013.03.063