Healthy soils

scientists in Canada after analysing soils eaten by people in China, Zimbabwe and the us have concluded that eating soils have their own advantages. Susan Aufreiter of the University of Toronto and William Mahaney of York University, also in Toronto, used a technique called instrumental neutron activation analysis to get a precise chemical breakdown of the soil samples.

The first sample, a fine, light yellowish soil from China's Hunan province, was used as "famine food" in the 1950s. This soil is rich in iron, calcium, magnesium, manganese and potassium -- all of which would be in short supply in times of a famine. The second, a soft clay from Stokes County in North Carolina, was rich in iron and iodine, important for the health of both children and women of childbearing age, and often missing from the diets of the poor. The third sample, a red soil from termite mounds in Zimbabwe were eaten by people to soothe upset stomachs. This soil has the principal ingredient which is used in commercial diarrhoea treatment.