Objective  To explore the distribution characteristics and accumulation rules of polycyclic aromatic hydrocarbons (PAHs) in cucurbitacae vegetables, and evaluate the health risks of each cucurbitacae vegetable to people in different age groups and genders in Nanning.

Method  The samples of Cucumis sativus, Momordica charantia, Luffa cylindrical and Benincasa hispida var. chieh-qua were collected. For each type of vegetable, we collected roots of 30 plants, 1 kg stems, 1 kg leaves, 1 kg petioles and 20 fruits. The vegetables were pretreated by ultrasonic extraction and solid phase extraction. The contents of 16 different PAHs in different parts of vegetables were detected by high performance liquid chromatography (HPLC).

Result  Sixteen types of PAHs were all detected in four kinds of cucurbitacae vegetables, the contents of total PAHs ranged from 88.44 to 1 229.85 μg.kg^–1. The order of detected PAHs amounts in cucurbitacae vegetables was 5-ring PAHs > 6-ring PAHs > 2-ring PAHs > 4-ring PAHs > 3-ring PAHs. The cancer risk levels of diverse population groups in Nanning by ingesting fruit from cucurbitacae vegetables were in the range of 1.48×10 ^–6 and 7.87×10^–5. The cancer risk levels caused by ingesting only edible portions were in the range of 2.23×10^–7 and 3.35×10^–6.

Conclusion  Comparing different organs of the same cucurbitacae vegetables, leaves had the highest PAH contents for all four vegetables, C. sativus pulp had the lowest PAHs content, M. charantia and L. cylindrical flesh had the lowest PAHs contents, B. hispida var. chieh-qua petious had the lowest PAHs content. Comparing leaves of different cucurbitacae vegetables, PAHs content was the highest in B. hispida var. chieh-qua while the lowest in M. charantia. Under the current consumption amount of vegetables, potential carcinogenic risks exist for Nanning residents by ingesting fruits of cucurbitacae vegetables.