Abstract
The purpose of this study was to investigate current blood lead (PbB) and zinc protoporphyrin (ZPP) levels in adults presently living in environmentally Pb-contaminated Andean communities, and to compare the findings with the PbB and ZPP levels of Pb-exposed adult cohorts from the same study area tested between 1996 and 2007. Blood samples from 39 adults were measured for PbB and ZPP concentrations. The current mean PbB level (22.7 μg/dl) was significantly lower than the mean (37.9 μg/dl) of the initial 1996 cohort. PbB levels for the 1997, 1998, 2003, and 2006 cohorts were also significantly lower than the levels for the 1996 group. Elevated ZPP/heme ratios of 103.3, 128.4, and 134.2 μmol/mol were not significantly different for the 2006, 2007, and 2012 groups, indicating chronic Pb exposure. While ZPP levels of Andean Ecuadorian Pb-glazing workers have remained elevated, PbB levels declined. Lead exposure of the workers needs to be continually monitored.
Acknowledgments
The authors thank Universidad San Francisco de Quito Colegio Ciencias de la Salud, Escuela de Medicina in Quito, Ecuador, for continued support of this project. We thank Dr. Gonzalo Mantilla, Dean of the College of Health Sciences, Universidad San Francisco de Quito Medical School, for ongoing support and excellent advice. We thank Gladys Pacheco, nurse at the Subcentro de Salud, La Victoria, Ecuador, for assistance. The Minister of Public Health of Ecuador, Carina Vance Mafla, is thanked for her consultation and Ministry of Public Health staff support. The authors are grateful to Dr. Merilee Grindle and Monica Tesoriero of the David Rockefeller Center for Latin American Studies at Harvard University for support of this project. We thank Dr. Jeremy Bloxham, Dean of Science at Harvard University; Harvard Biological Laboratories; Harvard University Health Services; and the Eunice Kennedy Shriver Center/University of Massachusetts Medical School for support. LHB is supported in part by National Institutes of Health (NIH) grant P30 HD04147.