Joe Tobiason, a Young Adult Volunteer with the Joining Hands Network in Peru (or in Spanish Red Uniendo Manos Peru) wrote this post about La Oroya. On our eco-justice trip to Peru earlier this year we visited the town of La Oroya, and I was startled by the barren landscape that surrounded the town due to acid rain from the Doe Run smelter, and inspired by the Filomena workers who are fighting to protect La Oroya's children. Joe gives a good background on La Oroya and updates us on current Joining Hands efforts in La Oroya.
There is some information on La Oroya on the Kuzka podcast, in the Joining Hands news bulletins, and in the La Retama newsletter small bits about La Oroya. But here is my summary of what has led to it being listed as one of the most polluted cities in the world:
The La Oroya smelter was opened in 1922 and subsequently expanded. The smelter can deal with gold, sliver, lead, copper, and lots of other elements and minerals. What makes this smelter unique is the way that it can deal with all of these elements together and at a lower grade than many other plants. La Oroya is one of only such plants in the world and therefore materials from Peru and all over the world are brought there to deal be smelted. This also means that this plant is very difficult to "clean up" because of the complicated, unique nature of what it does.
There are also lots of companies around the world that are pretty keen on keeping it going because it is one of the only ways to get to whatever they need. From 1922 until 1974, the operation was owned by American Cerro de Pasco. Then it was nationalized and owned by the Peruvian state (referred to as Centromin) until it was sold to Doe Run (part of the Renco Group) in 1997. At this point, the output of the smelter went through the roof. Doe Run makes statements that their emissions perton (or whatever measurement they are using) is lower, which is true, but they were also producing at a much higher rate than the factory had ever operated at and therefore even more is added to the pollution. Their charts always start at 1997, when they purchased the company. It does not represent the overall changes in lead and other toxins over time. (wikipedia article on it, Doe Run web site, in spanish)