PAH TRANSFER FROM SOIL TO SELECTED VEGETABLES GROWN ON INDUSTRIALLY CONTAMINATED SOIL

摘要

Polycyclic aromatic compounds (PAH) represent a large group of organic compounds whose molecular structure contains two or more fused aromatic rings. PAH class of substances could include over 10 000 compounds. PAH present serious concern because of their adverse health effects such as cancer or reproductive disorders. They occur mainly in oil or coal deposit and are resulted as by-products of incomplete burning of materials such as fuel, wood or garbage. The risks associated with soils contaminated by polycyclic aromatic hydrocarbons (PAHs) are generally assessed by measuring individual PAHs in the soil and correlating the obtained amounts to known adverse biological effects of the PAHs. Once deposited on or released in soil, a compound ability to be transported in different media of the environment (e.g. air, water, sediments, etc.) is controlled by its availability. High availability indicates that the compound may spread and potentially pose a threat to other parts of the environment such as vegetation. The amount of a compound that is taken up by organisms in the soil (thereby potentially being able to cause an adverse effect in the organism or facilitating its transport to other parts of the food web) is governed by the compounds bioavailability. Hence, both the availability and bioavailability of a compound are important to determine when assessing the potential risk of contaminated soil. Several soil samples and vegetables samples - potato, corn samples as root, leaf and fruit - were collected from the Cluj district region. The soil and vegetable samples were analysed for PAHs by gas chromatography (GC) with a flame ionisation detector (FID) and PAHs were extracted using the Soxhlet extraction procedure. The common PAH compounds that were identified in environmental soil samples were anthracene (2.1-35.8 μg/kg), naphthalene (10.5-28.6 μg/kg), phenanthrene (7-21 μg/kg), benzo[a]pyrene (3.8-15.6 μg/kg), naphthacene (6.3-27.4 μg/kg), pentacene (1.5-7.5 μg/kg) and pyrene (1.1-32.4 μg/kg). Polycyclic aromatic hydrocarbons were detected in all plants grown in the contaminated soils. However, their concentration was low compared with the initial soil concentration.