Biomonitoring of metals in inhabitants of Northern Chile: implications of surveillance in areas with historical exposures

Abstract

Background: The presence of toxic metals in human populations is strongly associated with chronic diseases and should be monitored especially in communities with a history of chronic exposures as occurs in northern Chile.Objective: to establish concentrations and prevalence of exposure to metals in residents of the city of Antofagasta, Chile, and its main risk factors.Methods: a cross-sectional study in Antofagasta was made. The sample (1203 adults) had populational representability at the city level. Sociodemographic information, health status, and sources of exposure to metals were collected in the participants. Urinary Inorganic Arsenic (InAs), Cadmium (Cd), Chromium (Cr) and Mercury (Hg) levels, and Lead (Pb) in blood were measured using NIOSH methodology by Inductively coupled plasma atomic emission spectroscopy (ICP-AES).Results:The sample had an average age of 42.7 years, with an average residence time in the city of 30 years, predominantly women (54.5%), high smoking (51.5%), high occupation rate in mining activities (22.6%).Using cutoff used by the health authorities (35µg /L for urinary InAs, the prevalence was 8% in adults and 12.3% in children. However, 75% of the population has levels below 21.9 µg / L. The main factors associated with high levels of urinary inorganic arsenic in adults were sex (β= 3.12, IC 95% 0.2-6.05 for males) and low schooling (β= 7.1, IC 95% 0.4-14.6 in people having less 8 y of education). People residing more than 500 meters from fixed sources had higher InAs levels. Other metals are below risk levels defined by health authorities.Conclusions It is urgent that in this city all the sources related to InAs must be verified and develop social interventions and environmental health surveillance in order to reduce involuntarily exposure to this metalloid.