When Research Turns to Sludge
It’s not just corporate funding that creates conflicts of interest. Even government and nonprofit funding can have
strings attached.

By Steve Wing

Environmental epidemiologists sometimes hear from people dealing with pollutants and sickness. So I wasn’t
surprised when Nancy Holt contacted me about the millions of gallons of municipal sewage sludge being spread
on fields near her home in Orange County, North Carolina. Sometimes, she said, the stench was so awful that she
and her husband had to cover their faces when they went outside. They had trouble breathing. Sores broke out
on her grandchildren’s bodies after they played in a nearby creek. She had her well tested. It was contaminated
with bacteria and chemicals. Droplets of wet sludge covered her mailbox.

By the time she called me at my office at the University of North Carolina at Chapel Hill, Nancy was fed up with the
runaround from local, state, and federal agencies. Government employees had tried to reassure her that sewage
sludge is safe, that existing rules protect public health, and that there is no evidence sludge ever harmed anyone.
When she learned that our research group had been studying the effects of industrial hog operations on
neighbors’ health and quality of life, she thought we might be able to evaluate the impacts of sewage sludge.

1/9/2011  Prions David W. Colby1 and Stanley B. Prusiner1,2 Downloaded from on
January 4, 2011 - Published by Cold Spring Harbor Laboratory Press  

The discovery of infectious proteins, denoted prions, was unexpected. After much debate over the chemical basis
of heredity, resolution of this issue began with the discovery that DNA, not protein, from pneumococcus was
capable of genetically transforming bacteria (Avery et al. 1944). Four decades later, the discovery that a protein
could mimic viral and bacterial pathogens with respect to the transmission of some nervous system diseases
(Prusiner 1982) met with great resistance. Overwhelming evidence nowshows that Creutzfeldt–Jakob disease
(CJD) and related disorders are caused by prions. The prion diseases are characterized by neurodegeneration
and lethality. In mammals, prions reproduce by recruiting the normal, cellular isoform of the prion protein (PrPC)
and stimulating its conversion into the disease-causing isoform (PrPSc). PrPC and PrPSc have distinct
conformations: PrPC is rich in a-helical content and has little b-sheet structure, whereas PrPSc has less a-helical
content and is rich in b-sheet structure (Pan et al. 1993). The conformational conversion of PrPC to PrPSc is the
fundamental event underlying prion diseases. In this article, we provide an introduction to prions and the diseases
they cause.