The President’s Cancer Panel’s Report, referenced in my previous post, makes many important statements about cancer.  One summary statement stands out.  The PCP states:

“Single-gene inherited cancer syndromes are believed to account for less than 5 percent of malignancies in the United States.  An unknown percentage of cancers develop due to normal endogenous [internal] processes [such as aging]. . . . Other cancers develop as a result of exogenous [outside of the body] factors, some of which are controllable.”

Report, Sec. 1, at 1.  The PCP then goes on to point out that the existing studies of the relationship of environmental exposures to cancer are out of date, but that even newer studies cannot take into account the many synergistic effects of multiple exposures in the environment that could lead to cancer.

Part of this problem is due to the complex chain of exposures.  The PCP summarizes the chain as follows:

Use of chemicals or other substances in industry and agriculture:  exposure of workers

Dispersal of  contaminants through:




Consumer products

Entry of the contaminants into the human body through various routes, which may impact both somatic cells and germ cells (egg and sperm)

Occurrence of higher levels of toxic and hormone-disrupting substances in women, including maternal blood, placental tissue, and breast milk

Transference of the substances from the mother to the next generation can occur to the fetus in utero or to a breast-feeding infant

Because the substances may interfere with the genes of the parents, without directly causing disease in the parents, these genes may predispose future generations to cancer.  This transference of the propensity to cause cancer may go from the parents’ genes to the next generation and beyond.

 In one of only a few references to nanotechnology in the Report, the PCP said:  “Limited research to date on unintended health effects of nanomarterials, for example, suggests that unanticipated environmental hazards may emerge from the push for progress.”  Report, Exec. Summary, at iii.

Where does nanotechnology fit into the chain?  At least theoretically, at every stage.  But nanotechnology is a complicating factor in an already complex scientific task.  As a kind of facilitating system – or delivery system, for lack of a more accurate description – nanotechnology may change the characteristics of the substances the technology interfaces with.  This may occur at the earliest stages of developing a use for nanomaterials, but its ultimate impact may not be seen or even measurable for years or generations.  Very little is known about this process.  At the nanolevel, some substances may be absorbed into the human body in unanticipated ways.  Now place this into the exposure chain, and the problems of characterizing and measuring risk increase exponentially.

 I will continue to sort through the Report and its relevance to nanotechnology in future posts.