Background and aims: Contaminants are a disturbing factor for ecosystems, among which “heavy metals” are considered as significant due to their physiological effects at low concentrations on organisms. This contamination is concentrated several times more in the products that are available in markets as oil than in natural plant, and in each consumption time, a considerable amount, higher than authorized amount of heavy metals may enter into consumer’s body. This study was designed and conducted for this aim to investigate the contamination rate with lead and cadmium in canola (Brassica napus) and safflower (Carthamus tinctorius L.) in the farms around Isfahan Steel factory and to compare this contamination with oil extracted from them.

Methods: The present study was conducted in 2012. The samples were randomly selected from oil seeds of B. napus and C. tinctorius L. in the farms within a 20 to 50 km distance from Isfahan Steel factory. Samples were assigned to two groups and only group 1 underwent washing operation with deionized water. The amount of lead and cadmium in seeds and their oil was measured by atomic absorption. Data were analyzed by SPSS.

Results: The results indicated that the lowest lead concentration was 0.00 µg.g in washed B. napus samples and the highest lead concentration was 24.74 µg.g in C. tinctorius L. oil extracted by traditional method. The amount of lead was less in washed seeds than unwashed seeds, with a significant difference for B. napus seeds (P<0.05). No cadmium contamination was observed in B. napus and C. tinctorius L. plants and the oils extracted from them.

Conclusion: A rate of contamination with lead was seen in the plants cultivated near Isfahan Steel factory, but no contamination with cadmium was seen. In view of the lead amount being less in the group washed with deionized water than the unwashed group, it is recommended to do washing steps of oil seeds in the factory at low volume, with clean water, and carefully prior to oil tapping.