Sludge Magic at the EPA
The Journal of Commerce; January 27, 1999
by David L. Lewis, Ph.D.
According to scientists working for the Environmental Protection Agency's Office of Research & Development, the
Sludge Rule on land application of municipal wastes (40 CFR Part 503) promulgated in 1993 may be the most
scientifically unsound action ever taken by the agency. Rather than being protective, the rule actually threatens public
health and the environment.
Testimony of David L. Lewis, Ph.D, The Impact of Science on Public Policy, Hearing by the Committee on
Resources, Subcommittee on Energy and Minerals, U.S. House of Representatives,
February 4, 2004
David L Lewis, et al., Interactions of pathogens and irritant chemicals in land-applied sewage sludges
(biosolids), US Environmental Protection Agency, National Exposure Research Laboratory, BMC Public
Health 2002 2:11,http://www.biomedcentral.com/1471-2458/2/11
A High-Level Disinfection Standard for Land-Applied
Sewage Sludges (Biosolids)
David K. Gattie1 and David L. Lewis 2
The potential for pathogen regrowth is the downside to sewage sludge being rich in
nutrients that promote the growth of bacteria and fungi.
Exotoxins—proteins and peptides secreted into the surrounding environment by growing
cells—are produced by both gram-negative and gram-positive bacteria. They are usually
the most toxic of the two general types of bacterial toxins. Because they can retain their toxicity at extremely
dilutions, some exotoxins, including staphylococcal enterotoxins
and shigatoxin, are used as biological warfare agents.
Interactions of pathogens and irritant chemicals in land-applied sewage sludges (biosolids).
Lewis DL, Gattie DK, Novak ME, Sanchez S, Pumphrey C.
US Environmental Protection Agency, National Exposure Research Laboratory, Athens, GA, USA.
A prevalence of Staphylococcus aureus infections of the skin and respiratory tract was found.
Approximately 1 in 4 of 54
individuals were infected, including 2 mortalities (septicaemia, pneumonia).