Clinical parameters and biomarkers of oxidative stress in agricultural workers who applied copper-based pesticides

Copper based-pesticides are widely used in agricultural practice throughout the world. We studied the (i) concentration of Cu and proteins involved in Cu homeostasis, (ii) plasma redox status, and (iii) biomarkers of exposure in Cu-based pesticide applicators in order to compare them with clinical biochemical tests. Thirty-one professional applicators and 32 control subjects were recruited. Oxidative stress biomarkers, ceruloplasmin (CRP), metallothioneins (MTs), copper, hematological parameters, and biochemical markers for pancreatic, hepatic and renal function were measured in plasma. Copper was increased in the exposed group compared to the control group concomitantly with TBARS, protein carbonyls, and nitrate+nitrite levels. In the exposed group, α-tocopherol and the FRAP assay were lower and LDH, transaminases, GGT, ALP, urea, creatinine, CRP and MTs were higher than in the control group. The relative leukocyte subclasses were also different between the two groups. Clinical chemistry tests did not surpass the upper reference limit. Our results suggest that the incorporation of oxidative stress biomarkers to biochemical/clinical tests should be considered for validation and included in the human health surveillance protocols.