16
Trace Elements in Abiotic and Biotic Environments
from water is of a big concern, and several methods are proposed and used based on
mechanisms such as precipitation, adsorption, coagulation, and so on (Bang et al.
2011; Höll 2011). Nanotechnology may help alleviate water pollution, and as a result,
100 times more As can be captured using nanorust than with filtration systems using
larger particles. Nanoparticles of Fe-Mn oxide is used for the stabilization of As
in groundwater (An and Zhao 2012). Groundwater contains Fe-oxides that remove
arsenic as coprecipitates (Lee et al. 2011).
Median As concentration in bottled water of the EU countries is 0.21 μg/L,
which is a little bit higher than tap water (0.19 μg/L) (Birke et al. 2010). In Serbia,
drinking water contains up to about 6.5 μg/L, in both bottled and tap water (Ristić
et  al. 2011). Papić et  al. (2012) reported growing health hazard, especially cancer risk, with increased As contents in drinking water. The provisional guideline
value for As in drinking water is 10 μg/L (WHO 2011a). (The guideline value is
designated as provisional on the basis of treatment performance and analytical
achievability.)
3.4 AIR
As concentrations in air vary from 0.007 ng/m 3 in Antarctica to >50 ng/m 3 in urban
regions (Table 3.1). Its concentrations in remote areas should not exceed 1  ng/m 3
(Reimann and de Caritat 1998).
Natural As sources in air are volcanic eruption (20%–40% of the total natural
emission), sea salt aerosol (<10% of the total natural emission), soil-derived dusts,
and forest fires. The greatest As emission in the atmosphere are industrial sources,
mainly from coal combustion. Zevenhoven et  al. (2006) calculated that the total
anthropogenic As emission in EU-25 countries in 2000 as 260 t, whereas Pacyna and
Pacyna (2001) estimated its worldwide emission in the same year at 5011 t.
3.5 PLANTS
As concentration in plants is a function of both its total and soluble species contents in soils. This suggests that it is taken by plants passively, with the water flow.
However, various plants reveal different capability to As uptake, what is illustrated
by variable As contents among plants from the As-contaminated region; the highest
As content was in sarghina (Corrigiola telephiifolia), 1350 and 2110 mg/kg, and the
lowest in Spanish foxglove (Digitalis thapsi), 94 and 356 mg/kg, in roots and tops,
respectively (Garcia-Salgado et al. 2012).
Excessive As uptake, in all species (organic, As 3+ , and As 5+ ) is toxic to plants. In
general, As tolerance of various plants ranges from 2 to 8 mg/kg. However, the critical values for many plants are much higher, up to 100 mg/kg in tops and 1000 mg/kg
in roots. Arsenic reacts with several enzymes, disrupts energy flow in cells, and
inhibits root growth (Mukherjee and Bhattacharya 2001). As complexes with glutathione and phytochelatins, apparently to minimize the toxic effects, were identified
in plants from As-contaminated sites (Jedynak et al. 2012).
Plants reveal various capabilities to uptake As from the growth media. For
example, the average content of As in rice variety Boro is 0.29 mg/kg, whereas in