Oxidative Stress Index Is Increased in Children of Riverside Towns Affected by Industrial Discharges in Central Mexico and Is Inversely Correlated with Metabolite Excretion of VOC

摘要

INTRO The Atoyac River located into Tlaxcala and Puebla states in Mexico, has been classified as highly polluted by environmental authorities, several communities are settled on its banks, affecting around 1.5 million persons, as well as farmland. The river receives waste from industrial discharges, mainly in liquid form, containing a large amount of volatile organic compounds (VOCs), thus giving rise to an environmental distribution of toxics in the area. METHODS To demonstrate that this environment affects important physiological processes that have an impact in health, we conducted a study of schoolchildren from small communities on the banks of the river and in another similar town located far from it. 91 and 93 students (age range: 8-12, no diagnosed chronic disease), were studied from each site for oxidative stress index (OSI) in blood plasma samples, calculated from the total antioxidant capacity and the total oxidative status, BTEX metabolite excretion in urine samples, and relevant metabolic polymorphisms participating in the bioactivation-detoxification of most VOC: CYP2E1 Rsal, NQO1 C609T, and null polymorphisms of GSTT1 and GSTM1. RESULTS OSI was significantly higher in children living by the river (5.23 ± 3.4 vs 2.59 ± 1.46, 95% C.I.). At this site, OSI was correlated with diminishing metabolite excretion and a diminished antioxidant capacity; an association with allelic variants of the metabolic polymorphisms of CYP2E1 c2c2, GSTT1 present and NQO1 CC was also observed. CONCLUTIONS The expected health problems for these children as they grow older involves a wide array of disorders, including cancer and fertility risks for them and their children. Protection programs must be designed that include a constant monitoring of early biological effects, at the same time that environmental protection measures are applied to halt the deterioration of fundamental resources for a healthy life.