Exposición a nitratos en agua y su relación con disfunción de la glándula tiroides: revisión sistemática ¿Existen riesgos para la salud de la población?

Abstract

Exposure to nitrates in drinking water and its association with thyroid gland dysfunction Background: Nitrate exposure may be associated with thyroid gland dys-function. Aim: To review the available evidence about the relationship between nitrates in drinking water and thyroid gland dysfunction. Material and Methods: A wide search was performed using Medline, Cochrane, Lilacs, IBECS and Scielo databases using pertinent keywords, finding a total of 66 related studies. After filtering and in depth reviewing, a total of 12 studies were included in this review. Results: The main results reveal the importance of this ion for human health, finding evidence both in animals and human beings that suggest pathological changes in the gland as its relationship with the occurrence of subclinical hypothyroidism, and potentially cancer of the thyroid gland. In Chile, nitrate is not considered a critical contaminant so its regular measuring and control is not enforced. Conclusions: In light of the present review we believe that there is evidence to consider nitrate as a critical contaminant whose measurement, registration and correct implementation of valid policies would have a direct benefit for the population of this country. Without this information, it is not possible to quantify the damage to human health, especially in vulnerable groups residing in areas at greatest risk of exposure. (Rev Med Chile 2018; 146: 223-231)