This paper provides the first quantitative information on accumulation of cadmium, lead, and arsenic in the soil, leaf, and root of wheat (Triticum aestivum L.), corn (Zea Maize), and tomato (Solanum lycopersicum) in the downstream agricultural lands of an industrial area and agricultural lands of a rural area, Razavi Khorasan province, Iran. The results showed that there is a significant difference among the cadmium concentrations in the soil, root and leaf/seed in various plants (p = 0.00 for wheat and corn and p = 0.0004 for tomato). There was no significant difference between the lead concentrations in the soil, root and leaf/seed in the case of wheat (p > 0.05), but there was a significant difference for other plants. Furthermore, statistical analysis was done on arsenic concentrations of soil, root and leaf/seed in the wheat, tomato, and corn. In the case of rural area, the results showed significant difference between the cadmium and lead concentrations of soil, root and leaf/seed in the wheat and tomato. In this area, statistical analysis was done on the arsenic concentrations of soil, root and leaf/seed in wheat, tomato, and corn (p = 0.00 for wheat, p = 0.00 for tomato, and p > 0.05 for corn). The heavy metals concentrations in some parts of the plants in the industrial area were above the standards. The concentrations of cadmium, lead, and arsenic for soil were below the limits proposed by WHO, EPA, and EU. In this study, the Total Hazard Quotient (THQ) through consumption of wheat was less than 1, indicating no significant potential health risk associated with the consumption of wheat from the areas. The cancer risk of arsenic from wheat consumption was as 255 × 10-6 and 0.00 in the industrial and rural areas, respectively. •Atomic absorption spectrophotometer (AAS) equipped with graphite furnace was used for heavy metal analysis.•The general results revealed that the levels of Cd, Pb, and As in the industrial area were higher than the rural area.•The cancer risk of arsenic in wheat for the industrial area is greater than 1 × 10-6, which is unacceptable.