Germination of Lepidium sativum as a method to evaluate polycyclic aromatic hydrocarbons (PAHs) removal from contaminated soil

The sensitivity of Lepidium sativum germination to polycyclic aromatic hydrocarbons (PAHs) was investigated in soil(s) artificially and historically contaminated with mixtures of PAH. The level of germination of L. sativum decreased with increasing concentration of the PAH in the artificially contaminated soil, while no germination occurred in the historically polluted soil. At a concentration of 1000 and 50 ppm, the germination levels were <16% and >75%, respectively. The same germination levels, as a function of PAH concentration, were observed when a non-ionic surfactant was present in the soil(s). When used during phytoremediation of PAH, the germination level of L. sativum was inhibited during the first weeks, after which germination increased, possibly due to PAH dissipation from the soil. The data suggest that the germination of L. sativum can be used to monitor the removal of PAH pollutants from soil.