Abstract:

In this study, the potential ecological and health risks of the heavy metals cadmium (Cd), lead (Pb) and mercury
(Hg) in edible lily and its growing soil in Gansu province were analyzed by using the potential ecological risk index method
and target hazard quotient (THQ) method. The results showed that the contents of heavy metals in edible lily-growing
soil were significantly increased by 1.82, 0.27 and 1.71 times compared with the background values of soil heavy metals
in Gansu province in 1993, respectively, which were still in line with environmental quality standards for green foods.
According to the Environmental Quality for Green Food Producing Area (NY/T 391—2013), the average individual potential
ecological risk indices of Cd, Pb and Hg in edible lily-growing soil were 18.25, 2.78 and 5.19, respectively. All these risk
indices were less than 40, suggesting that the risk was at level A and the degree of ecological harm was relatively low.
Taking the background values of soil heavy metals in Gansu province in 1993 as reference, the order of degree of potential
ecological hazard in soil was Cd > Hg > Pb. Cadmium had a potential impact on the ecological environment of all producing
areas investigated. The comprehensive potential ecological hazard level was level B, which belonged to the medium level.
The biological enrichment coefficients of Cd, Pb and Hg in edible lily were 0.131, 0.003 and 0.022, respectively. The THQ
value of cadmium, lead and mercury was lower than 1. Heavy metal levels of lily did not exceed the maximum allowable
limit and thereby was not hazardous to human health.

Key words: soil-edible lily systems, heavy metal, assessment, potential ecological and health risks