[Urinary heavy metals and blood lead levels among residents of Antofagasta, Chile].

BACKGROUND

The presence of toxic metals in human populations is strongly associated with chronic diseases.

AIM

To determine levels of lead, chromium, cadmium, mercury and inorganic arsenic (AsIn) in the general population aged over 5 years in Antofagasta, Chile.

MATERIAL AND METHODS

People living in Urban Antofagasta for at least five years were considered eligible. Biological samples were obtained to measure heavy metals.

RESULTS

One thousand two hundred three participants with a median age of 43 years (656 women) were studied. Their mean time of residence in the city was 30 years, and 52% smoked. Eight percent of the adult population and 12% of children had AsIn values above 35 µg/L, while 75% of the population had levels below 21.9 µg/L. The other metals were below the risk levels defined by the health authority (10 µg/L for chromium, 10 µg/L for mercury, 2 µg/L for cadmium, 5 and 10 μg/dL for blood lead for children and adults, respectively). The factors associated with high levels of AsIn in adults were male sex, living more than 200 meters from monitoring points, and low schooling. In children, the associated variables were high intake of seafood products and having a caregiver with less than 8 years of schooling. Contrary to expectations, the greatest risk of presenting altered levels of the metals occurred in the population living more than 500 meters from the identified risk sources (90% of the population).

CONCLUSIONS

The findings of this study suggest that all potential sources of exposure to AsIn should be evaluated, and surveillance actions should be established to reduce involuntary exposure to this metalloid.