Table 1.

Environmentally safe limits for thallium

	Thallium limits	Sources
Drinking water	2 μg L−1	USEPA (2015), Xiao et al. (2004)
Arable soils	1 mg kg−1	CCME (2003), Xiao et al. (2004)
World land plants	0.008–1.0 mg kg−1	Kabata Pendias and Pendias (1992)
World edible plants	0.03–0.3 mg kg−1
World average daily intake	2 μg day−1	Sabbioni et al. (1984), Xiao et al. (2004)
Oral reference dose	0.056 mg day−1	RAIS (2003), Xiao et al. (2004)