Piyal Bhattacharya

Human exposure to arsenic through foodstuffs cultivated using arsenic contaminated groundwater in areas of West Bengal, India

The widespread incidence of chronic arsenicosis in the Bengal Delta has led to intensive research on arsenic (As) enrichment in groundwater as well as accumulation in foodstuffs, as there are potential health risks associated with exposure to As from both sources. This study deals with human As exposure through the drinking of groundwater, consumption of locally grown foodstuffs (e.g., crops and vegetables) and cooked food in Nadia district, West Bengal. Groundwater and foodstuffs were collected and analyzed with FI-HG-AAS to estimate the total As content. Urine samples collected from human subjects were analyzed to assess the As exposure. Two major crops, boro and aman rice, showed a considerable amount of As, with mean values of 194 and 156 μg kg(-1), respectively. Significant levels of As were also found in other common crops and vegetables cultivated in this area (for example, the mean As in Arum and radish was 780 and 674 μg kg(-1), respectively). Total intake of As from foodstuffs by adults (560 μg day(-1)) and children (393 μg day(-1)) in the area was found to be at alarming levels. Arsenic exposure was demonstrated by the presence of As in urine (ranging between 154 and 276 μg L(-1)), with overall As retention of 50-60 %. The results of this study further indicate the potential risk of As exposure to local inhabitants through the food chain which is associated with continuous consumption of As-contaminated foodstuffs. Therefore, more action needs to be taken to control the contamination pathways (such as the water-soil-crop system) to protect humans from continuous ingestion of As through foodstuffs.

In vitro assessment on the impact of soil arsenic in the eight rice varieties of West Bengal, India.

Rice is an efficient accumulator of arsenic and thus irrigation with arsenic-contaminated groundwater and soil may induce human health hazard via water-soil-plant-human pathway. A greenhouse pot experiment was conducted on three high yielding, one hybrid and four local rice varieties to investigate the uptake, distribution and phytotoxicity of arsenic in rice plant. 5, 10, 20, 30 and 40 mg kg(-1) dry weights arsenic dosing was applied in pot soil and the results were compared with the control samples. All the studied high yielding and hybrid varieties (Ratna, IET 4094, IR 50 and Gangakaveri) were found to be higher accumulator of arsenic as compared to all but one local rice variety, Kerala Sundari. In these five rice varieties accumulation of arsenic in grain exceeded the WHO permissible limit (1.0 mg kg(-1)) at 20 mg kg(-1) arsenic dosing. Irrespective of variety, arsenic accumulation in different parts of rice plant was found to increase with increasing arsenic doses, but not at the same rate. A consistent negative correlation was established between soil arsenic and chlorophyll contents while carbohydrate accumulation depicted consistent positive correlation with increasing arsenic toxicity in rice plant.

Assessment of Potential Health Risk through Arsenic Flow in Food Chain—A Study in Gangetic Delta of West Bengal

West Bengal is one of the severely arsenic affected states in India. Over 500 million people are at risk through arsenic poisoning in the Ganga-Meghna-Brahmaputra plain (6 Chakraborti et al., 2004; 16 Pal et al., 2007). Nine out of eighteen districts of the state of West Bengal are reported to have groundwater arsenic contamination (5 Chakraborty et al., 2002). Among the affected districts, North 24-Parganas deserves special mention. More than 95% of the people here depend on the groundwater for drinking, cooking and other domestic uses and major amount of groundwater is also used for irrigation of crops specially during non-monsoon period. Thus there is a chance of land contamination and accumulation of arsenic through agricultural products grown in contaminated soil and water. The exposure to arsenic may involve a number of pathways through ecosystem. This indicates that water-soil-crop-food transfer as well as cooking and direct intake of drinking water may be the major pathway of arsenic entry in man and higher animal system. A number of people are thus suffering from arsenic induced skin lesions and other symptoms.

A Greenhouse Pot Experiment to Study Arsenic Accumulation in Rice Varieties Selected from Gangetic Bengal, India

It is predicted that around 100 million people living in the Ganga-Meghna- Brahmaputra plain are at the risk of serious arsenic toxicity through exposure of contaminated groundwater (Chakraborti D et al., Groundwater arsenic contamination in Ganga-Meghna-Brahmaputra plain, its health effects and an approach for mitigation. In: UNESCO UCI groundwater conference proceedings. http://www.groundwater-conference.uci.edu/proceedings.html#chapter1, 2008). Groundwater arsenic contamination in the Gangetic Bengal has been termed as the largest mass poisoning in the history of human kind (Smith et al., Bull WHO 78(9):1093–1103, 2000). Arsenic pollution has spread in fourteen out of total nineteen districts of Gangetic Bengal (Chakraborti et al., Mol Nutr Food Res 53(5):542–551, 2009). Application of arsenic-contaminated groundwater for irrigation in Gangetic Bengal has shown to influence accumulation of arsenic in rice, the major staple food in West Bengal (Meharg, Trends Plant Sci 9:415–417, 2004, 2009; Signes-Pastor et al., J Agric Food Chem 56(20):9469–9474, 2008; Bhattacharya et al., Paddy Water Environ 8(1):63–70, 2010a; Samal et al., J Environ Sci Health Part A: Environ Sci Eng 46:1259–1265, 2011; Banerjee et al., Sci Rep 3, Article number: 2195, 2013; Santra et al., Procedia Environ Sci 18:2–13, 2013). Rice is an efficient accumulator of arsenic than any other cereal crops (Su et al. Plant Soil 328:27–34, 2010) and consumption of rice has been termed as an important source of inorganic arsenic intake to human body (Meharg et al., Environ Sci Technol 43(5):1612–1617, 2009).