From the book list: co-authored volume

travel button

Front cover

Discharge to the Environment of Viruses in Wastewater, Sludges and Aerosols

by John S. Slade and Brian J. Ford
chapter in: Viral Pollution of the Environment, pp 3-15
ISBN: 0-8493-6245-8, Boca Raton: CRC Press, 1983


The study of viruses in water and wastewater is one of the newest branches of the natural sciences. Viruses in water are also a topic of urgency, which the increasing demands of a rapidly developing global human community will continue to emphasize. In a climate of understanding that tends to take virus investigations for granted, it is easy to forget the essential novelty of the discipline. Yet a mere 20 years ago, there were no data showing that there were any viruses present in London's river water, whereas it is now known that every surface water in the Thames Water Authority region which has been examined for viruses has provided a positive result in routine tests. To move from a state of total ignorance of contamination to the acceptance of a virtually 100% incidence in less than two decades can have few precedents, and we are faced with a growing list of problems in consequence. When we realize that parallel situations exist in the rest of the developed nations and in many of those that are still essentially primitive, it is apparent that the international magnitude of the task facing the virologist and those who are responsible for the future of water management is considerable.

Although viruses had not been demonstrated in surface waters, their presence there had clearly been anticipated. The existence of fecal contamination in river water, for instance, implies that any intestinal pathogen is likely to be present. The upsurge of scientific interest in this field mirrors the development of laboratory techniques to detect viruses, rather than a sudden rise in their occurrence. Indeed, it is important to distinguish between an apparent increase revealed by novel technology and a "new" problem. When we consider the transmission of viruses via fecal and airborne routes we are misled if we conclude that these are societal phenomena, resulting from human artifice alone. Though it is undeniable that civilization has altered the way in which viruses interact with the environment, and hence with the human host, in many ways we may more clearly perceive the rationale of virus transmission when we emphasize the evolutionary significance of the process. It may be said (with the exception of such minority routes as venereal contact or direct contagion) that viruses are usually ingested, injected, or inhaled. In this context we can see how important in the natural history of a virus disease may be the fecal and aerosol modes of dissemination. This will also teach us something of the ability of a virus to survive en route. Viruses have a lineage far longer than that of mankind, without doubt, and we may assume that they are well-equipped to endure their seemingly arduous travels. Knowing the sensitivity of viruses to changes in temperature, pH, etc, we may better devise means of tackling the virus problem.

The vast communities of microorganisms that occur in natural water courses are in many ways responsible for their wholesomeness, and it is helpful to envisage the purification process not as the imposition of high-technology on wastewater, but rather the optimization of natural, ecological mechanisms.Through this "evolutionary" approach we can appreciate how an unsophisticated society is likely to suffer a burden of virus diseases when these diseases are not controlled by the natural process of water purification.