Assessment of the variation of heavy metals and pesticide residues in native and modern potato (Solanum tuberosum L.) cultivars grown at different altitudes in a typical mining region in Peru

This research paper presents the preliminary outcomes of an investigation conducted on the levels of heavy metals (such as As, Cd, Pb, Al, Mn, Cu, Ba, Cr, and Ni) and pesticide residues found in both traditional and modern potato cultivars grown in Moquegua, one of the principal copper-producing departments of Peru. A total of 160 samples of potatoes and soil were collected at altitudes between 58 and 3934 m above sea level (m.a.s.l.), and measured by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES), respectively. Determinations of pesticide residues were conducted by using the QuEChERS method. Metal concentrations in potato samples varied from 0.006 to 0.215 mg/kg for Pb; 0.01–0.25 mg/kg for As; 0.001–0.048 mg/kg for Cd; 0.4–47.9 mg/kg for Al; 0.008–0.802 mg/kg for Cr; 0.505–2.729 mg/kg for Cu; 0.022–29.894 mg/kg for Mn; 0.03–2.76 mg/kg for Ba; to 0.006–0.419 mg/kg for Ni. Among the principal findings of the study were that (i) potatoes grown at lower altitude (Chala and Yunga regions) accumulated more As, Cr, Ni and Al than those grown at higher altitudes (Suni region); (ii) modern potatoes in most cases show a higher concentration of metals than native ones; (iii) the principal positive correlation found between soil and potatoes was for As; (iv) 90% of the samples analyzed were free from pesticide residues.