Blood-lead levels.

Lead-poisoning has been at the center of attention in La Oroya for years—so much so that the children of La Oroya are commonly referred to as “Children of Lead”. And so, the annual results of blood-lead level (BLL) studies could theoretically be used as a measure of progress (or lack thereof) in La Oroya. Unfortunately, however, some such studies have proven inconsistent and even unreliable.

From 2004 to 2008, Doe Run Peru, the Regional Government of Junín, and the Ministry of Health have collaborated on a series of BLL studies in La Oroya. Specifically, they averaged blood-lead levels for children under six years of age in La Oroya. At first glance, the results of these surveys are encouraging—they show a reduction of almost 35% in blood-lead levels from 2004 to 2008. Further investigation, however, shows the results to be questionable.

In 2004, 100% of the blood samples used in the study were taken in La Oroya Antigua, the town closest to the smelting complex, where lead exposure is known to be by far the highest. In each of the following years, however, the study began to include other parts of La Oroya. By 2008, the study included samples from children in La Oroya Nueva, Paccha, Huari, and Santa Rosa de Sacco—all of which are located further away from the complex than La Oroya Antigua and therefore more likely to have lower blood-lead averages than La Oroya Antigua. The fact that there was no geographic consistency in sampling from year to year means that the data is not reliable for determining trends in blood-lead levels.

Blood-lead levels are significantly higher in La Oroya Antigua than they are in surrounding parts of La Oroya. According to a 2005 study, for example, the average blood-lead levels for children six years and younger was 36.1 in La Oroya Antigua, and 23.2 in the rest of La Oroya. This is a significant difference—certainly significant enough to bring down the overall averages.

The results of the 2008 studies cannot be reliably compared to those of 2004. DRP, the Junín government, and the Ministry of Health should release a direct comparison for the 2004/2008 numbers in for each part of town, separately. I was able to make such a comparison, but only for years 2004-2006. In those years, blood-lead levels in La Oroya Antigua increased by 3%, to 33.47 micrograms per deciliter. That is more than three times the maximum limit set by the WHO, the CDC, and other international organizations.