Concentrations and characteristics of selenium in soil samples from Dashan Region, a selenium-enriched area in China

Figures & data

Figure 1 Study site (located in Chizhou, Anhui Province).

Table 1 Number of soil samples for each soil type and land use

Soil type^†	Relevant soil type^‡	Land use	Number of samples
Yellow soil	Alisols, Acrisols, Cambisols	Woodland	16
		Tea garden	11
Yellow brown soil	Cambisols, Alisols	Woodland	10
		Tea garden	18
Red soil	Cambisols	Woodland	2
Paddy soil	Anthrosols	Farmland	12

†By classification of soil in China (Gong 1994).

‡By classification of soil from FAO–UNESCO (FAO-UNESCO 1990).

Table 2 Operating parameters of the hydride generation atomic fluorescence spectrometry (HG-AFS) instrument

Parameters	Settings
Negative high voltage of the photomultiplier (V)	300
Lamp current (mA)	100
Atomization temperature (°C)	800
Atomizer height (mm)	8
Flow rate of carrier gas (mL min^−1)	500
Flow rate of shield gas (mL min^−1)	1000
Read mode	Peak area
Measurement method	Standard curve
Delay time (S)	1
Read time (S)	15
Injection volume (mL)	2

Table 3 Soil properties and concentration of total selenium (Se) in Dashan region.

	Total Se (mg kg^−1)		Clay (%)		pH (H2O)		OM (mg kg^−1)
	Mean	Range	Mean	Range	Mean	Range	Mean	Range
Dashan Region (n = 69)	1.50	0.31–7.65	19	12.9–29.8	5.02	4.09–7.18	7.24	0.73–24.1
Farmland (n = 12)	0.97	0.31–1.87	17.50	14.2–20.4	5.61	4.62–7.18	4.79	2.27–6.49
Woodland (n = 28)	1.63	0.32–7.65	18.96	12.9–29.8	4.92	4.09–5.71	8.30	0.73–24.13
Tea garden (n = 29)	1.58	0.36–5.54	19.58	15.4–29.2	4.88	4.13–6.48	7.26	2.62–14.73

OM, organic matter.

Table 4 Comparison of concentrations of selenium (Se) in soils of Dashan Region with previous data

Country	Regions	Mean (mg kg^−1)	Range (mg kg^−1)	Reference
China	Dashan Region (n = 69)	1.50	0.31–7.65	This study
	Farmland (n = 12)	0.97	0.31–1.87	This study
	Woodland (n = 28)	1.63	0.32–7.65	This study
	Tea garden (n = 29)	1.58	0.36–5.54	This study
	Enshi	6.33	–	(Zhang and Ma 2008)
	Hong Kong Special Administration Region	0.76	0.07–2.26	(Zhang et al. 2005)
	Guizhou Province	0.37	0.06–1.33	(He 1996)
	Ziyang	0.32	–	(Zhao et al. 1993)
	Mainland China	0.29	0.05–0.99	(Liu 1996)
New Zealand	Whole country	0.5	–	(Oldfield 1999)
Yugoslavia	Whole country	0.2	–	(Maksimovic et al. 1992)
Japan	Paddy	0.43	–	(Yamada et al. 2009)
	Upland	0.51	–
Sri Lanka	Low goiter incidence(<10%) village group	0.23	–	(Fordyce et al. 2000)
	Moderate goiter incidence(10–25%) village group	0.88
	High goiter incidence(>25%) village group	1.12
India	Punjab	1.19	–	(Dhillon and Dhillon 1999)
	Himachal Pradesh	0.4
	Andhra Pradesh	0.13
	Karnataka	0.16
Worldwide		0.40	0.10–2.00	(Zhang et al. 2005)

Table 5 Content and proportion of selenium (Se) species in soils in Dashan region compared with previous data

Country	Regions	Se speciation	Content (μg kg^−1)	Proportion (%)	Reference
China	Dashan Region (n = 24)	W-Se	7.71–26.8	0.28–1.45	This study
		E-Se	24.7–93.3	0.54–4.50	This study
		A-Se	112–1430	5.45–24.4	This study
		O-Se	26–765	1.01–14.6	This study
		R-Se	1300–5330	62.6–88.8	This study
		B-Se	32.41–120.1	0.82–5.95	This study
	Ziyang	B-Se	2.21–56.38	0.1–0.9	(Zhao et al. 1993)
	Enshi	B-Se	960–22260	< 5	(Yuan et al. 2012)
	Farmland in China	B-Se	–	1.1–6.7	(Tan et al. 2002)
England	Rothamsted	B-Se	–	1.4	(Tolu et al. 2011)
	Whole country	B-Se	245–590	1.1–3.4	(Stroud et al. 2010)
USA	Benton lake	B-Se	–	2.6–7.3	(Zhang and Moore 1996)
	Fresno County	B-Se	–	3.3	(Martens and Suarez 1997)
Japan	Kyoto prefecture	B-Se	5.5–40.2	5.12	(Yamada et al. 2012)
India	Punjab	B-Se	–	50	(Bajaj et al. 2011)

Se, Selenium; W-Se, water-soluble Se; E-Se, exchangeable Se; A-Se, acid-soluble Se; O-Se, organic-bound Se; R-Se, residue Se, B-Se, bioavailable S.

Table 6 Correlation among total selenium (Se), different species of Se, pH value, organic matter (OM) and clay content in soils

	Total Se	W-Se	E-Se	A-Se	O-Se	R-Se	B-Se	pH	OM	Clay
Total Se	1
W-Se	0.198	1
E-Se	0.292	0.845**	1.
A-Se	0.852**	0.339	0.477*	1
O-Se	0.783**	0.481*	0.633**	0.901**	1
R-Se	0.978**	0.092	0.158	0.729**	0.650**	1
B-Se	0.280	0.901**	0.993**	0.460*	0.618**	0.148	1
pH	−0.512**	0.566**	0.707**	0.147	0.280	−0.196	0.695**	1
OM	0.615**	−0.621**	−0.552*	−0.162	−0.253	0.260	−0.583**	−0.623**	1
Clay	0.539**	0.220	0.135	0.611**	0.573**	0.587**	0.160	−0.222	0.068	1

*Significant at the 0.05 level. **significant at the 0.01 level.

W-Se, water-soluble Se; E-Se, exchangeable Se; A-Se, acid-soluble Se; O-Se, organic-bound Se; R-Se, residue Se, B-Se, bioavailable S.

Gong ZT 1994: Chinese Soil Taxonomic Classification, pp. 35–109. Science press, Beijing. (in Chinese).

 Google Scholar

FAO-UNESCO 1990: Soil Map of the World. Revised Legend. World soil Resources Report 60. FAO, Rome.

 Google Scholar

Zhang ZH, Ma YP 2008: Study on the relationship between total selenium content and water- soluble selenium content in soil of Enshi prefecture. J. Hubei Univ., 26, 287–290. (in Chinese).

 Google Scholar

Zhang HB, Luo YM, Wu LH, Zhang GL, Zhao QG, Wong MH 2005: Hong Kong Soilresearches distribution and content of selenium in soils. Acta Pedol. Sin., 4, 404–410. (in Chinese).

 Google Scholar

He YL 1996: Se content and distribution in soils of Guizhou Province. Acta Pedol. Sin., 33, 391–397. (in Chinese).

 Google Scholar

Zhao CY, Ren JH, Xue CZ 1993: Selenium in soils of selenium-rich areas in Ziyang county. Acta Pedol. Sin., 3, 254–259. (in Chinese).

 Google Scholar

Liu Z 1996: Trace Element in Chinese Soil, pp. 108–116. Jiangsu Science and Technology Press, Nanjing. (in Chinese).

 Google Scholar

Oldfield JE 1999: Selenium World Atlas, pp. 83. Selenium–Tellurium Development Association, Grimbergen, Belgium.

 Google Scholar

Maksimovic ZJ, Djujic I, Jovic V, Rsumovic M 1992: Selenium deficiency in Yugoslavia. Biol. Trace. Elem. Res., 33, 187–196. doi:10.1007/BF02784022

 PubMed Web of Science ®Google Scholar

Yamada H, Kamada A, Usuki M, Yanai J 2009: Total selenium content of agricultural soils in Japan. Soil Sci. Plant Nutr., 55, 616–622. doi:10.1111/j.1747-0765.2009.00397.x

 Web of Science ®Google Scholar

Fordyce FM, Johnson CC, Navaratna URB, Appleton JD, Dissanayake CB 2000: Selenium and iodine in soil, rice and drinking water in relation to endemic goitre in Sri Lanka. Sci. Total Environ., 263, 127–141. doi:10.1016/S0048-9697(00)00684-7

 PubMed Web of Science ®Google Scholar

Dhillon KS, Dhillon SK 1999: Adsorption–desorption reactions of selenium in some soils of India. Geoderma, 93, 19–31. doi:10.1016/S0016-7061(99)00040-3

 Web of Science ®Google Scholar

Yuan LX, Yin XB, Zhu YY 2012: Selenium in plants and soils, and selenosis in Enshi China: implications for selenium biofortification. Phytorem. Biofor., 2, 7–31.

 Google Scholar

Tan JA, Zhu WY, Wang WY 2002: Selenium in soil and endemic diseases in China. Sci. Total Environ., 284, 227–235. doi:10.1016/S0048-9697(01)00889-0

 PubMed Web of Science ®Google Scholar

Tolu J, Le Hecho I, Bueno M, Thiry Y, Potin-Gautier M 2011: Selenium speciation analysis at trace level in soils. Anal. Chim. Acta, 684, 126–133. doi:10.1016/j.aca.2010.10.044

 PubMed Web of Science ®Google Scholar

Stroud JL, Broadley MR, Foot I 2010: Soil factors affecting selenium concentration in wheat grain and the fate and speciation of Se fertilisers applied to soil. Plant Soil, 332, 19–30. doi:10.1007/s11104-009-0229-1

 Web of Science ®Google Scholar

Zhang YQ, Moore JN 1996: Selenium fractionation and speciation in a wetland system. Environ. Sci. Technol., 30, 2613–2619. doi:10.1021/es960046l

 Web of Science ®Google Scholar

Martens DA, Suarez DL 1997: Selenium speciation of soil/sediment determined with sequential extractions and hydride generation atomic absorption spectrophotometry. Environ. Sci. Technol., 31, 133–139.

 Web of Science ®Google Scholar

Yamada H, Kang A, Aso T, Uesugi H, Fujimura T, Yonebayashi K 2012: Chemical forms and stability of selenium in soil. Soil Sci. Plant Nutr., 43(3), 385–391.

 Web of Science ®Google Scholar

Bajaj M, Eiche E, Neumann T, Winter J, Gallert C 2011: Hazardous concentrations of selenium in soil and groundwater in North-West India. J. Hazard. Mater., 189, 640–646. doi:10.1016/j.jhazmat.2011.01.086

 PubMed Web of Science ®Google Scholar