Word Count: 3546
The very earliest civilizations have shown significant importance placed on public health in regards to public hygiene and subsequent sewage management. In the Indus Valley in Northern India, excavations show an early culture that had impressive paved streets and most of the homes had bathroom facilities, and the streets had sunken sewers. The sewers were two feet below the surface of the streets and consistent of molded bricks with mortars of mud. Drainpipes were made of pottery. In a similar time frame, the Cretan-Mycenean culture demonstrated control of water supply with drinking water conduits and had flush toilets identified in the diggings from their buildings. Many of the houses had actual water pipes present as well. Certainly in early cultures, cleanliness and godliness were interrelated and in fact the presence of disease in the community could often be related to divine judgments. In Egypt, Sekhmet, goddess of pestilence, produced epidemics when aroused. The idea of epidemics as a judgment certainly carries over into a similar time frame for Old Testament biblical stories. This represents the theurgical theory of disease. This approach included that religious higher authority was responsible for epidemics and disease often precipitated by human failings. This perception of epidemics and disease lasted several millennia and cross multiple cultures.
The Greeks applied medical thought at a rational scientific theory of disease, and many of their approaches have carried through equating that health and disease resulted from natural processes. In the Hippocratic book on “Airs, Waters, and Places”, we find some of the first examples attempting to define the causal relations between the environment and disease. The central factors included basic elements such as climate, soil, and water, as well as the mode of life and nutrition of individuals. A disturbance in the equilibrium would therefore result in disease states. The Greeks were the first to describe the comparison of endemic disorders – those always present versus epidemic diseases – disorders with an episodic event. The fundamental perception of disease as a disturbance of equilibrium had no major change in the ensuing 2000 years – actually to the advent of bacteriology in the late 1800’s.
Certainly the Romans approached public health with a new vigor, applying engineering to many of the ideas that the Greeks had passed over. Rome itself, as well as its peripheral cities, was well known for sewers, baths, and as providers of very high quality water supplies. The Roman Aqueducts often are in textbooks leading as examples for social engineering. It is difficult to estimate the actual supply of fresh water via theseaqueducts, but estimates include as many as 222,000,000 gallons per day at a time in which the population of Rome numbered 1,000,000. This represents 40 gallons per head per day and in fact is fairly comparable to modern conditions in numerous countries today. American cities often have 45-400 gallons and an average of about 150 is quite common. These aqueducts had settling basins and flowed into a large reservoir just outside Rome and subsequently were piped for further use. The water was felt to be quite pure and consumption was limited to drinking. Some parts of Rome, particularly on the right bank, required wells and water carriers were utilized to fetch water. In the time of Emperor Claudius, a position of “procurator aquarum” ran 700 slaves to maintain the waterways and the reservoirs. They also were responsible for the great sewer system of Rome – Cloaca Maxima. This ran down to the Tiber River, being as large as 10 ft. x 12 ft. in height. The same group ran public latrines. One wonders what the ECUA could do if they had slaves. Interestingly, in the time of Roman expansion, they often applied some of the Greek ideas looking for an environmental balance in climate, soil, and health when choosing areas for new towns. They had an interesting process of liver inspection in which animals grazing on proposed land were slaughtered and the livers were examined. Those who had a greenish-yellow liver apparently were felt to be unhealthy for man and the site would often be passed. Certainly that left an opportunity for hepatologists, and interesting back up in this day of managed care.
It took many years to re-establish the level of public works lost with the fall of Rome. Small-walled cities did not lend themselves to great strides in public health; since sewage and water access systems were often in close proximity and even paving of streets was not an initial option, leading to much refuse in the street. Middle Ages were well known for times of great epidemics, probably partly based on these limited public health improvements.
This time period represents a very important step in the transition to more exacting science associated with infectious diseases. There was tremendous controversy in the early 1830’s and carrying for several decades regarding the actual origin of communicable diseases. The Miasmatic theory suggested that communicable diseases arose from “effluvia”, which is a process produced by decaying organic matter. These emanations brought forth with certain meteorologic conditions thus resulting in epidemics. The initial solution was felt to be that of cleaning up communities rather than quarantine measures. Social fabric at the time supported the Miasmatic theory,particularly since quarantines would have significant economic impact on free trade, goods transferred and have a negative impact on commerce. This was also a period of time in which travel became incredibly different – in past years travel caravans probably lost many of the participants infected with diseases long before they ever reached Europe. In the age of more rapid travel with trains and ships, epidemics became possible – often jumping from an endemic area such as India. These waves of epidemics affecting Europe led to increasing need to define public health and boards of health were established, looking into various meteorologic conditions, which were supporting the presence of epidemics.
The story of John Snow, M.D., in London as he documented the 1848 cholera epidemic finally established the first sound epidemiologic basis for development of the “theory of contagion”. This theory of contagion was subsequently applied to multiple disorders including diphtheria, scarlet fever, yellow fever, and measles. John Snow was a practitioner of the lifespan 1813-1858. He was actually best known in his time frame as an anesthetist, having delivered chloroform to Queen Victoria in 1853 and 1857. Today, however, he is remembered as a landmark epidemiologist – a science that wasn’t even defined at the time of his observations of the 1848 cholera epidemic. In that time frame, he studied case reports showing contaminated water was the source of problem – not the evil humors felt by the Miasmatics. He went on to determine that infected sewage was affecting water sources, specifically the Broad street pump. At a time in which death rates had risen in London to 200-300 per week, he was able to tabulate the actual cases, looking at their water supply and other factors, and determined that this represented a point source and therefore was likely a contagious outbreak. He also noted that the problems crossed economic social strata, if the victims had been exposed to the water, thus making public health as a less likely process suggested by the Miasmatic Theory. Interestingly, the London General Board of Health was called together in the same time frame but was heavily weighted towards chemists and meteorologists, and in fact many of their solutions had to do with meteorologic weather and chemical aspects of the problem rather than anything to do with a point source of infection. In fact, they also had observed comma-like organisms in the rice water of cholera victims but felt it was a secondary process rather than primary. The defective sewage treatment from cholera patients led to further spread of the disease, since isolation and fecal oral contamination routes were not approached. However, with the observations of John Snow, subsequent control through sewage management, hand washing and cleaning food, as well as water sources, led to a tremendous public health breakthrough. The final agent was not completely described until 1883, when Koch isolated vibrio cholera confirming Snow’s observations back in the 1850’s. This finally settled the controversy of Miasma versus contagion aspects of disease. Interestingly, the public health issues of that time frame included that many of the Miasmatic followers also were considered very liberal, perceived as fighting for individual freedoms against the presumed reactionary time frame of contagionism (since contagious problems would require government control and quarantine and loss of personal freedoms). It is interesting to also juxtapose the role of the industrialists and the merchants who supported this idea of Miasmatic disorders, possibly promulgated because of the negative economic impact to themselves on free trade if contagious problems were identified as the actual source. There is much suggestion in my reading that the Miasmatic theories were often promulgated not as much on science, but also on social perception. It took the advent of the bacteriology wave of the 1880’s to completely change the perception of public health and communicable diseases. Once this became clearer, interestingly, the approach was often to reach into third world countries such as around the Suez Canal and trying control travel and good movement in those countries, rather than deal with the issues of sewage and clean water in the European cities themselves.
1870-1900 – Chicago
I think an interesting historic sidelight is that of Chicago, representing problems of typhoid outbreaks in the city in this burgeoning midwestern metropolis. With city growth, sewers and water supply became an increasing issue and interestingly, the Chicago River was often the source of the sewer effluent and Lake Michigan was the source of water supply. As the population grew, additional new intake pipes were needed in the Chicago River and in fact, in the epidemic of 1871-1872, there were approximately 100,000 cases with tens of thousands of deaths associated with typhoid in Chicago. The death toll in the 1870’s from typhoid in Chicago on a yearly basis was in the neighborhood of 7% – it was only 2-3% in New York and Boston. It was a leap of important insight when the infectious components of this problem became apparent – the water intake and sewage effluent were within one mile of each other, resulting in a great deal of impure water consumption. In 1882 the Illinois State Board of Health administrator noted that “water is one of the commonest mediums through which cholera spreads, but aside from this typhoid and other malarial fevers, diarrhea, dysentery and other diseases are caused by impure and polluted water”. A novel solution was developed in Chicago in 1887, when it became apparent that Lake Michigan was not a very good source of sewer management and drinking water. In that time frame, a 28-mile sanitary ship canal was proposed and subsequently built at a cost of $45,000,000 – to reverse the flow of the Chicago River. This is an interesting solution since it moved the effluent out towards the Mississippi. There were subsequently extensive conflicts including landmark cases in the legal arena as downstream cities such as St. Louis contested this decision. Many of the bacteriologic standards set at that time have been handed down, including the fecal coliform count as well as chemical analysis for various phosphates and nitrogens, all promulgated during the time of that case. The St. Louis dispatch decried the opening of the sanitary canal in January 1900 with a revision of an old song.
“An old song revised”
Oh, a wonderful tale of bacilli,
All reeking with slathers of slime,
We’d hear if the waters were vocal,
And to listen we’d plenty of time;
And the blood in our veins would be frozen,
If the innermost truths we should know,
For a terrible tale they would tell us,
If the waters could speak as they flow!
Of deaths at the dawn and the twilight,
Of sickness at the morning and noon,
We’d learn, if the current could whisper
Of germs that will poison us soon!
Of danger and death and destruction,
Of weariness, worry and woe,
We’d hear, like the damning of demons,
If the waters could speak as they flow! St. Louis Post Dispatch, January 1900
Once bacteriologic etiology was recognized, as a very important component, including water management, sewer plants were developed and water sources were further refined. The change over from mixing storm water drainage with sewer drainage occurred earlier in this century but was not completely accomplished for a number of decades after the turn of the century. We still have in our own community issues on water management, which actually help precipitate the indication for my discussion today. Water sources represent increasing coverage in our local newspapers, since we have actually a crisis in evolution given the growth and urbanization of our own microcosm community. Water resources in the world represent only a fixed amount available, and only 0.2% of all water is in fact fresh water. The hydrologic cycle is critical in the restoration of these water resources. The appeals of 1900, as exampled by the Chicago case, have left the concept that “self-purification” can be a solution to be in much doubt. No longer is the solution to pollution dilution. As noted, we will use between 50-150 gallons per day of water in the United States, with seasonal increases in the summer months increasing up to 50%. In third world countries such as Asia and Africa, consumption is certainly much less with 10-15 gallons a day not uncommon. At this point 80% of the United States is on combination water and sewer systems, where 20% is involved with well and septic systems. Certainly the sources of water need be studied and examined. As one looks at potential public health issues, water has a number of sources but they mainly include rainwater, surface water, ground water, ocean or brackish water, and water reclaimed or reused. In our own city, the water effluent from the ECUA downtown station is 15,000,000 gallons per day, with an additional 3,000,000 contributed from other outlying facilities. This gives a rough estimate of 75-125 gallons per consumer per day- right in mind with the national consumption. What I am concerned about is the handling of the fluid as well as the solid wastes. We have used various means looking at indicators for contaminated water. Again, many of the original descriptions from the Chicago case carryover with coliform counts per 100 cc. However, these coliforms can be found from other sources including birds and animals. We have significant impact on coliform counts on the basis of agricultural runoff, domestic sewage, and recreational uses ( such as boats and little Sabin ). Certainly industrial effluent can have an impact as well as the mixing of storm water and surface water. There is a great deal of seasonal variability, and this is probably interrelated to water flow rates and various weather effects. The summer coliform counts in Bayou Texar have reached remarkable levels the last few summers. It was with relief that I noted that ECUA suggested that the ducks might be the source of the coliform count. Further scrutiny suggests that ducks ( nor pelicans and blue herons) are the likely source of this coliform count, and the indictment is more likely human source and confirmation will require significant advancement and techniques to monitor fecal contamination. The concept of a conflict box is an interesting example. All of the sewer lines leading from the bayou are basically with gravity drainage. The sewer lines are actually many years old in the older community surrounding the bayou. Juxtaposed on these sewer lines are storm water lines, again older in character, and often made of terracotta rather than new construction concrete. Anytime a sewer line crosses a storm line we have a “conflict box”. The summer spill of 200+ gallons of sewage in the bayou was at a conflict box, where the sewer line has to physically pass through the storm line to move by gravity to its destination. A small break in that area resulted in the 200 gallons publicized this summer. The problem is that the ECUA and city departments have no idea how many conflict boxes exist, and maps of the conflict boxes have never been obtained, though I understand that the ECUA is now beginning to study the situation as a potential alternative to the duck issue.
Technology to monitor sources of coliforms need be re-examined. Attempts have been made by using other bacterial measures such as Streptococcus or Enterococcus – the latter being more suggestive of human source. I have seen interesting papers on using the ratios of coliforms to Enterococcus, which to me seems still remarkable primitive. Interestingly, the advent of gene typing has led to newer approaches that may offer some hope of better identification and thus tracking the sources of contamination. Bacteriodes Fragilis is a bacteria, very common in the human alimentary tract. Measurement of bacteriophage activity represents a potential good indicator for human sewage contamination, since birds and slaughterhouse effluent will not contain this species type. Once will need a very rapid technique, since the weather patterns change as does mixing. The bayou is an interesting measurement area, since actual coliform propagation in the saline of the bayou is not likely (unless it involves a number of dead floating fish). I think it is very important to begin to address and apply other potential tracking mechanisms, since the ECUA studies were done at times of no rain – and I would postulate that the conflict boxes are utilizing a Venturi effect at times of high rain, utilizing small micro cracks in the terracotta piping and sucking sewer straight into the bayou – giving us our summer bloom, so to speak. We need additional techniques, and in fact the application of PCR – polymerase chain reaction – to identify specific DNA probes from bacteria would be most important. I think the advent of further scrutiny could also entail at least two other issues. It would be fairly simple using radionuclide probes to test for comixing of storm water and sewers, and many radiopharmaceuticals could easily be applied to that approach – an interesting science project, at least for our high school seniors.
The last feature that need be reconsidered is the still to be defined aspects of potential public health ramification for environmental virology. By environmental virology, one would consider the potential effects of viruses in water and soil deposits. There is good reason for concern for this issue since viruses have been well documented to have relative resistance to killing mechanisms including chlorination and thermal challenge. Episodes of major epidemics have occurred in which viral epidemics occur even when the coliform counts of the water in question met all standards applicable. Part of this issue is the difficulty in quantifying viruses since many viruses are difficult to cell culture and some cannot even be cultured to date. The application of PCR techniques offers new hope for quantification. Again, the presence of viral DNA will no necessarily define infectivity, however. This is a particularly relevant in trying to monitor new ultraviolet light systems for purification of wastewater. Such deposition in ocean water can demonstrate enteric viruses still salvaged from the sediment after seventeen months. Poliovirus can be documented to be present in soil at least ninety-six days after sediment deposition and ground water can demonstrate viral particles even after percolation through 6 – 12 feet of sand and application of chlorination/sunlight/spray/percolation and subsequently demonstrate the virus in ground water. Virus resistance to standard killing agents such as chlorine must be considered very carefully. It is also apparent that enteroviruses may cause unapparent or silent infections that are not recognized until secondary person to person spread finally leads to overt disease. There are even reports that various enteroviruses may be associated with latent disease. For instance, one month ago, new scientists reported that there is an increased frequency of echovirus in patients having ALS ( Lou Gehrig’s Disease). It would be most challenging if in fact viral activity and disease were subsequently documented to be related to exposures years later. Certainly, influenza can cause effects with Parkinson’s, etc. – why not neurologic disorders. There are at least 120 virus types know to be excreted in human feces – whether or not illness is manifested. Multiple groups of viruses are expressed in this group as previously discussed. One need look a bit further at the potential application of ultraviolet light for purification at our own downtown sewer plant. The system that is soon to be applied does not describe in its literature documentation for viral killing and I think that this documentation may be remarkable difficult since PCR techniques would probably be excluded. The potential for mechanical failure also can lead to great question since no chemicals will be used for the final processing prior to discharge into the bay. The possibility exists that federal regulations for virologic discharge haven’t been established simply because the newer techniques for virus detection such as PCR have only recently become wide spread. Previous standards could not even be considered if cell culture were the means of monitoring. One might speculate that standards not applied today will be applied in coming years once latent medical effects of massive viral discharge occur and more poignant documentation for regulation needs regarding viral discharge be made.