Diana, There is quite a bit of animal research with a number of environmental contaminants interfering with mammary gland development and lactation. There is also a new human study I'm posting below that is one of the first studies to bridge the gap from the animal research to humans. I suspect it is the tip of the iceberg. I have corresponded with the author and encouraged her to follow these girls as they marry and have children-I'm dying to find out if what I suspect will happen really does. ~Lisa Environ Health Perspect. 2006 Mar;114(3):471-5. Links Altered breast development in young girls from an agricultural environment.Guillette EA, Conard C, Lares F, Aguilar MG, McLachlan J, Guillette LJ Jr. Department of Anthropology, University of Florida, Gainesville, Florida 02611, USA. [log in to unmask] In several human populations, the age at which female breast development begins is reported to have declined over the last five decades. Much debate has occurred over whether this reported decline has actually occurred and what factors contribute to it. However, geographical patterns reflecting earlier developmental onset in some human populations suggest environmental factors influence this phenomenon. These factors include interactions between genetic makeup, nutrition, and possible cumulative exposure to estrogens, both endogenous as well as environmental beginning during in utero development. We examined the onset of breast development in a group of peripubertal girls from the Yaqui Valley of Sonora, Mexico. We observed that girls from valley towns, areas using modern agricultural practices, exhibited larger breast fields than those of girls living in the foothills who exhibited similar stature [e.g., weight, height, body mass index (BMI)], and genetic background. Further, girls from valley towns displayed a poorly defined relationship between breast size and mammary gland development, whereas girls from the Yaqui foothills, where traditional ranching occurs, show a robust positive relationship between breast size and mammary size. The differences noted were obtained by a medically based exam involving morphometric analysis and palpation of tissues, in contrast to visual staging alone. In fact, use of the Tanner scale, involving visual staging of breast development for puberty, detected no differences between the study populations. Mammary tissue, determined by palpation, was absent in 18.5% of the girls living in agricultural areas, although palpable breast adipose tissue was present. No relationship was seen between mammary diameter and weight or BMI in either population. These data suggest that future in-depth studies examining mammary tissue growth and fat deposition in breast tissue are required if we are to understand environmental influences on these phenomena. *********************************************** Archives: http://community.lsoft.com/archives/LACTNET.html Mail all commands to [log in to unmask] To temporarily stop your subscription: set lactnet nomail To start it again: set lactnet mail (or [log in to unmask]) To unsubscribe: unsubscribe lactnet or ([log in to unmask]) To reach list owners: [log in to unmask]