Response to the letter to the editor by Andrew Millard

Abstract This paper presents our reply to two questions posed by Dr. Millard concerning our paper Martinez-Garcia et al. [Martinez-Garcia MJ, Moreno JM, Moreno-Clavel JM, Vergara N, Garcia-Sanchez A, Guillamon A, Porti M, Moreno-Grau S. Heavy metals in human bones in different historical epochs. Sci Total Environ 2005;348:51–72], namely, whether diagenetic changes operating in human bones after burial and consideration of the physiological plausibility of the metal concentrations measured in such bones could invalidate the results presented in the aforementioned paper. In our reply, we show that diagenetic effects are not meaningful in our study and that the mathematical approach used by Millard to derive circulating blood concentration from bone levels is based on the incorrect manipulation of a statistical regression analysis and therefore is not valid. After exhaustively reviewing the two phenomena involved in Dr. Millard's questions as well as other concerns raised in his letter to the editor, we deem the three conclusions presented in Martinez-Garcia et al. [Martinez-Garcia MJ, Moreno JM, Moreno-Clavel J, Vergara N, Garcia-Sanchez A, Guillamon A, Porti M, Moreno-Grau S. Heavy metals in human bones in different historical epochs. Sci Total Environ 2005;348:51–72] to be entirely appropriate.

[1]  J. Handler,et al.  PATTERNING OF SKELETAL LEAD CONTENT IN BARBADOS SLAVES , 1987 .

[2]  E. González‐Reimers,et al.  Bone Cadmium and Lead in 18th Century Population Groups from the Canary Islands , 2003 .

[3]  A. Aufderheide,et al.  Lead in bone. IV. Distribution of lead in the human skeleton. , 1988, Archives of environmental health.

[4]  R. Boeckx.  Lead poisoning in children. , 1986, Analytical Chemistry.

[5]  C. Patterson,et al.  Comparative increases of lead and barium with age in human tooth enamel, rib and ulna. , 1991, The Science of the total environment.

[6]  T. Price,et al.  The use of barium and strontium abundances in human skeletal tissues to determine their geographic origins , 2003 .

[7]  C. Patterson,et al.  Lead in albacore: guide to lead pollution in Americans. , 1980, Science.

[8]  A. Millard.  Comment on Martínez-García et al. "Heavy metals in human bones in different historical epochs". , 2006, The Science of the total environment.

[9]  P. Grandjean.  Lead in danes. Historical and toxicological studies. , 1975, Environmental quality and safety. Supplement.

[10]  M. Rabinowitz,et al.  Toxicokinetics of bone lead. , 1991, Environmental health perspectives.

[11]  Stella Moreno-Grau,et al.  Particulate matter and heavy metals in the atmospheric aerosol from Cartagena, Spain , 2000 .

[12]  C. Patterson,et al.  Skeletal concentrations of lead in ancient Peruvians. , 1979, The New England journal of medicine.

[13]  F. Santolaria-Fernández,et al.  Paleonutritional analysis of the pre-Hispanic population from Fuerteventura (Canary Islands). , 2001, The Science of the total environment.

[14]  R. Garnier.  Toxicité du plomb et de ses dérivés , 2005 .

[15]  E. González‐Reimers,et al.  Bone cadmium and lead in prehistoric inhabitants and domestic animals from Gran Canaria. , 2003, The Science of the total environment.

[16]  Michael H. Kutner.  Applied Linear Statistical Models , 1974 .

[17]  Q. Jaradat,et al.  Chemical Composition of Urban Wet Deposition in Amman, Jordan , 1999 .

[18]  N. Gordon,et al.  Lead absorption in children. , 1967 .

[19]  C. Patterson,et al.  Natural skeletal levels of lead in Homo sapiens sapiens uncontaminated by technological lead. , 1991, The Science of the total environment.

[20]  C. Patterson,et al.  Lead in ancient human bones and its relevance to historical developments of social problems with lead. , 1987, The Science of the total environment.

[21]  J. Moreno-Clavel,et al.  Relationships between Levels of Lead, Cadmium, Zinc, and Copper in Soil and Settleable Particulate Matter in Cartagena (Spain) , 2002 .

[22]  J. Muñoz,et al.  Paleocontaminación: evidencias de contaminación atmosférica antrópica en Galicia durante los últimos 4000 años , 1997 .

[23]  A. Townshend,et al.  Lead concentrations in bones from Roman York , 1975 .

[24]  P. Bukovec,et al.  Determination of trace elements and calcium in bone of the human iliac crest by atomic absorption spectrometry. , 2000, Clinica chimica acta; international journal of clinical chemistry.

[25]  N. Ishinishi,et al.  Lead levels in ancient and contemporary Japanese bones , 1988, Biological Trace Element Research.

[26]  H. Waldron.  On the post-mortem accumulation of lead by skeletal tissues , 1983 .

[27]  T. Price,et al.  Correlation of Bone Ba/Ca and Sr/Ca due to Biological Purification of Calcium , 1999 .

[28]  E. Silbergeld.  Lead in bone: implications for toxicology during pregnancy and lactation. , 1991, Environmental health perspectives.

[29]  J. Ericson.  Ba/Ca as a Diagenetic Indicator for Evaluating Buried Bone Tissues: Advances in Tissue Selection, Reducing Contamination, and Data Evaluation , 1993 .

[30]  S. S. Srivastava,et al.  Rainwater Composition at a Regional Representative Site of a Semi-Arid Region of India , 2001 .

[31]  M. Porti,et al.  Heavy metals in human bones in different historical epochs. , 2005, The Science of the total environment.

[32]  N. Draper,et al.  Applied Regression Analysis , 1967 .