Selenium levels in Lebanese environment

Very limited research has been conducted on selenium (Se) in Lebanese soils and forage crops but no work has been done on Se in water and locally produced vegetables and grains. This research was conducted in order to quantify Se levels and its availability in agricultural soils, vegetables and grains in Lebanon. Sixty-six (66) soil samples were collected from 33 selected sites in Lebanon: the Bekaa Valley, coastal and mountainous regions. Thirteen (13) different plant types (86 samples) were sampled from the same locations. Also, 13 spring water and 10 bottled water samples were collected. Soil samples were analyzed for their physical and chemical properties. Selenium was extracted from soils with: deionized-distilled water (Soluble-Se), KH2PO4-0.1M (MKP-Se) and concentrated (HNO3+HCl) mixture (acid-Se). Plant Se was extracted by acid digestion on a hotplate. Selenium concentrations were measured by the inductively coupled plasma-mass spectrophotometer (ICP-MS). The values of Soluble-Se, MKP-Se and acid-Se ranged between 47 and 142, 147 and 400, and 1749 and 4713μg-kg, respectively, with average values of 95, 306, and 3118μg-kg and at a ratio of 1:3:30. Thus, Se extracted with deionized-distilled water is a good indicator for Se availability in the studied soils. The average Se concentration in plants was in the following order: radishandgt;lettuceandgt;cucumberandgt;cabbageandgt;parsleyandgt;alfalfaandgt;onion (leaves)andgt;broccoliandgt;tomatoandgt;mintandgt;chickpeasandgt;wheatandgt;onion (bulbs). The Se levels in water samples were in the safe range (less than 50μg-L) and ranged between 2.14 and 17.6μg-L. The levels of Se in the three soil extractants were positively correlated with each other and with organic matter content, salinity and phosphorus (P). Selenium levels in plant samples were positively correlated at a 0.01 significance level with clay and P content. © 2010.

Al-Saleh Iman A., 1999, Journal of Environmental Pathology Toxicology and Oncology, V18, P37; Bashour I, 2007, METHODS ANAL SOILS A; BISBJERG B, 1969, PLANT SOIL, V31, P287, DOI 10.1007-BF01373572; CHAO TT, 1989, SOIL SCI SOC AM J, V53, P385; Dhillon KS, 2005, AUST J SOIL RES, V43, P639, DOI 10.1071-SR04166; ELRASHIDI MA, 1987, SOIL SCI, V144, P141, DOI 10.1097-00010694-198708000-00008; FAO, 1992, SOILS B, V65; Fordyce F. M., 2005, ESSENTIALS MED GEOLO, P373; GONDI F, 1992, BIOL TRACE ELEM RES, V35, P299, DOI 10.1007-BF02783773; Hawkesford MJ, 2007, J CEREAL SCI, V46, P282, DOI 10.1016-j.jcs.2007.02.006; JOHNSON CC, 2004, CR04016N BRIT GEOL S; Kabata Pendias A., 2001, TRACE ELEMENTS SOILS, P241; Lteif A, 2005, PLANT NUTR FOOD SECU, P716; McNeal J.M., 1989, SSSA SPECIAL PUBLICA, V23, P1; Mikkelsen R.L., 1989, SPEC PUB SOIL SCI SO, V23, P65; [NAS NRC], 1983, SEL NUTR; Oldfield JE, 1999, WORLD ATLAS SELENIUM; Selim HM, 2001, HEAVY METALS RELEASE, P191; Tan KH, 1989, SOIL SAMPLING PREPAR; Terry N, 2000, ANNU REV PLANT PHYS, V51, P401, DOI 10.1146-annurev.arplant.51.1.401; Wang MC, 2003, CHEMOSPHERE, V52, P585, DOI 10.1016-S0045-6535(03)00240-6

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