La Oroya is a town of 35,000 inhabitants located in the Peruvian Andes in an area rich in lead, copper, zinc, silver, and gold. The extraction and smelting of these metals has been La Oroya primary economic activity for decades. Several studies have documented the severe environmental contamination caused by the mining industry in La Oroya. For instance, in 1999 the Peruvian Ministry of Health found that 99.1% of children suffered from lead poisoning; 20% of these children needed urgent medical care due to the extremely high blood lead levels. Also, a 2002 report entitled “La Oroya Cannot Wait” described the very serious levels of ambient contamination of air, soil, and water in La Oroya. The findings in this report indicate that over 80% of blood lead levels in La Oroya children were two and three times greater than the level of concern of 10 µg/dl established by the CDC in the U.S. In addition, the report found that arsenic, cadmium, suspended particles, and sulfur dioxide (SO2) exceed international acceptable levels and pose serious health risks to the community.

Several grassroots and faith-based organizations in Peru have begun to raise awareness and educate residents of La Oroya about the harmful effects of ambient contamination to their health. Although there is now a better understanding of the extent of ambient contamination, members of these organizations feel that they also need to know the extent of the environmental contamination in their homes and its impact on their health. However, the information currently available on residential contamination in La Oroya is largely insufficient and thus they have concluded that an independent study is needed to address the question of residential contamination and its relationship with the health of home residents.

Unfortunately, these organizations do not have all the resources needed to design and implement such a study, especially the expertise required to ensure that the study meets the requirements for scientific and technical validity. Saint Louis University School of Public Health is conducting a community based participatory study of the contamination by lead, cadmium, and arsenic and its relationship with the health of residents. The study intends to address the following questions: