Presentation on theme: "Arsenic as a Global Pollutant Arsenic in Rice Presented by Tiffany Berg 1."— Presentation transcript:
Arsenic as a Global Pollutant Arsenic in Rice Presented by Tiffany Berg 1
Arsenic pollution Industrial waste waters 1 and mining 2, fertilizing with poultry litter 3, prior pesticide use in orchards, potato fields, and blueberry fields 4 1. Z. Wang, B. He, X. Pan, K. Zhang, C. Wang, J. Sun, Z. Yun and G. Jiang; Sci. China Ser. B., 2010, 53, 1809-1817. 2. O. Gunduz, C. Simsek and A. Hasozbek; Water Air Soil Pollut., 2010, 205, 43-62. 3. C. W. Liu, C. C. Lin, C. S. Jang, G. R. Sheu and L. Tsui; J. Plant Nutr. Soil Sc.; 2009, 172, 550-556. 4. S. Quazi, D. Sarkar, and R. Datta.; Appl. Geochem.; 2010, 25, 1422-1430. http://mossnutritionblog.wordpress.com/2010/06/24/chicken- litter-to-fertilize-or-not-to-fertilize/ http://www.flickr.com/photos/19779889@N00/4058241089/ http://www.coxcolvin.com/Arsenical_Pesticides.php 2
Irrigation water http://scripts.mit.edu/~brehm/beccablog/ 3 Soil Plant uptake Rice Grain + How does arsenic get into the food supply?
A study* completed in West Bengal, India found: Agricultural soil contained 5700-9710 ppb Irrigation water contained 318-643 ppb Boro rice grain contained 190-780 ppb Aman rice grain contained 60-600 ppb *Bhattacharya, P.; Samal, A. C.; Majumdar, J. and Santra, S. C.; Water Air Soil Pollut. (2010) 213, 3-13. 4
How much arsenic is in rice? An international study* analyzing 900 polished white rice grain samples collected from 10 countries reported a range from 10 to 820 µg kg -1 with an average concentration of 150 µg kg -1 5 http://www.thenakedscientists.com/HTML/conte nt/news/news/1797/ *Meharg, A.A.; Williams, P.N.; Scheckel, K.G.; Feldmann, J.; Raab, A.; Zhu, Y. and Islam, R., Environ. Sci Technol. 2008, 27, 810-816.
How much arsenic can we tolerate? Table 1. Regulations for arsenic in drinking water and food. 6 Regulating BodySample As concentration threshold limit World Health Organization (WHO)drinking water 10 µg L -1 Food and Agriculture Organization of the United Nations (FAO)/WHO in 2010 provisional tolerable weekly intake (PTWI) 3.0 µg/ kg body weight per day European Food Safety Authority (EFSA) in 2009 benchmark dose lower confidence limit (BMDL 01 ) 0.3 µg/ kg body weight per day
7 Assuming: a person weighs 70 kg the person eats 200 g rice containing 150 µg kg -1 of arsenic (1) How many µg of arsenic per kg body weight per day has this person consumed? (2) Is this above the JEFCA PTWI for arsenic (3.0 µg/ kg body weight per day)? 200 g rice x 1 kg x 150 µg arsenic = 30 µg arsenic per day 1 day 1000 g 1 kg rice 30 µg arsenic per day = 0.43 µg arsenic per kg body weight per day 70 kg body weight