Testing the waters fails to inform or help solve the problem
Richard H. Bennett Ph.D., President
Applied Life Sciences LLC
The recent article in WHT regarding the testing of beach water for microbes was useful as it raises awareness and helps us understand our influence on the ocean. Unwittingly, the paper walks right into a scientific conundrum that has plagued scientists and regulators for over 50 years. We do not have a valid measure of recreation water-borne disease risk.
A search of MEDLINE produced 6,971 research publications on microbial water safety. Most studies describe possible testing methods and others, their shortcomings. The overall message from the science is disappointing. We simply do not have the means to predict the disease risk precisely from recreating in ocean waters. At best, our current test system is a guesstimate and one entrenched in outdated methods and bureaucracy. Most of the microbe tests were developed long ago for assessing the safety of drinking water from municipal systems. Even here, the indicator bacteria fail to predict risk accurately. Similar indicator methods, however, are very imprecise when used for estimating disease risks from recreation on oceans, lakes, and streams.
There are two important considerations when we discuss the microbial safety of recreation waters.
(1) Using laboratory methods to test for the growth of a microbial surrogate indicator species to accurately predict the presence of pathogens (disease-causing microbes) in ocean water recreation, lacks scientific validation. Sure, some studies show weak associations in high-risk locations such as near urban rivers or waste treatment plants. Such modest statistical relationships are not evidence of cause, effect, and do not predict risk for all beaches. It is for this reason that we only see beach closures or warnings in Hawai‘i when there is an obvious sewage spill.
Twenty years ago, The American Academy of Microbiology (AAM) (Ford 1996) took the position that the use of bacterial indicator species, also known as Fecal Indicator Bacteria (FIB) fails to indicate the risk to people recreating in the water. The acronym FIB is ironically fitting. Recent studies (Gruber 2014) confirm the failings of the generic FIB, even for drinking water and affirms the 1995 position of the AAM.
(2) There is sufficient science to prove that fecal bacteria and virus in human wastes, disposed to the ground, move into the ground water (McRay 2010). It matters not if it is a cesspit or a new septic system. The massive quantity of human waste generated each day along the Kona slopes flows with the wastewater and downslope, sometimes very quickly, but ultimately to the sea.
The Kona side of our island has only a couple streams, but that does not mean water is not flowing. It just flows underground, out of sight and unfortunately out of mind. Researchers document hundreds of millions of gallons of ground water flowing into the sea along the Kona coastline daily (Prouty 2015). This water has many components of urban wastewater. (Hunt 2007, Parsons 2008)
During a day at the beach, we do not intentionally drink sea water. Getting splashed or even blasted by breaking waves is the fun many seek. As kids in the waves, we got ocean water forced into our nose, throat, mouth and eyes. Health studies on surfers (the canaries in the ocean coal mine) confirm that they often ingest a mouthful of seawater with each “wipeout”. Research confirms increased illness rates for surfers (Stone 2008). The disease rate was low and for a good reason. The ingestion of pathogenic bacteria is too few, and the water in the surf zone is well mixed. Most bacteria have to be ingested in large numbers and, in some cases, millions. This factor is called the 'Minimal Infective Dose' or MID. Unfortunately, even elevated FIB cannot determine an MID level for a particular bacterial pathogen in the water. For virus, this is especially relevant. As few as one pathogenic virus can be an infective dose (Teunis 2008). Virus can be present when the FIB are not.
The AAM did recommend that health agencies should measure for specific pathogens. So, why in 2016 are we still chasing FIBs? The answer is political and economic. Few, with a financial interest in tourism, would be thrilled with reports and headlines that revealed rates of dysentery or abscess forming bacteria at Hawaiian beaches. This type of testing is very expensive and agencies lack the funding. It takes teams of microbiologists and EPA certified labs to provide accurate and timely results.
The problem with "culture and grow" methods for detecting pathogens is that it takes days to get definitive results. Many ocean pathogens can be viable but not cultivable (McKay 1992). That is to say; the microbe is there, but we cannot grow it and thus can’t count it. We have no good data revealing how many false negatives are out there.
People are not happy when they learn that the beach water they played in a week ago had elevated FIB levels. Microbial testing is always an after-the-fact process. We face the same problem with food safety. The food is consumed long before the data was made public. Real-time diagnostic microbiology is needed, but remains an elusive technology.
The state of Hawaii uses Enterococci, as recommended by the EPA as the FIB for marine waters. Contemporary science further confounds our use of FIB. The FIB can survive and, in some cases, even grow in the environment. The often-repeated dogma that FIB comes only from the bowels of mammals is simply not true (Anderson 2005). In Hawaii, researchers revealed that the FIB, including the Enterococci, persist and grow in the environment and that this was unique to the islands. However, in research from all over the world--including much colder beaches--the standard FIB, such as the Enterococci, arise from and persist in the environment (Hardina 1991). The environment is the predominant source of most FIB (Desmarais 2002).
The other problem with using Enterococci is that it is a genus, with over 50 different species. A few are low-level human pathogens. Trying to control Enterococci is like counting all ant species as an indicator of the Fire Ant. Designing a control program base on vague data will yield vague results that have questionable public health value.
Adding confusion, Hawaii, the only state, measures another FIB, Clostridium perfringens. While this microbe is common in sewage, it is more common in stream and ocean sediments (Mueller-Spitz 2010). The Surfrider Foundation scientists report on locations in Kauai that have very high enterococci and C. perfringens counts. However, the waters have not been declared contaminated or posted. The Surfrider Foundation website states, “The Hawai'i DOH only posts warning signs of high bacteria levels at the beach when there is a known human source of the contamination, such as a sewage spill or a culpable cesspool. Otherwise, they do nothing”. We have to wonder....why do we measure FIB at all?
The other institutional problem with chasing Enterococci is testing the water near the surface. Bacteria can be found suspended in moving water. When water is calm, they will settle out. That also means that waves and people can stir things up. In general, bacteria attach to something so they can survive, grow and not be swept away.
Our work on Kona beaches, as well as research from Oahu, Seattle and San Diego beaches shows that these microbes are more common in the sand. In one study, beach sand was far more likely to contain several times more FIB than the water (Bonnilla 2007). Our sample protocol collected sand near the high wash of the waves. That sand had higher concentrations of Enterococci than the water many yards offshore (Bennett 2015). Since the mostly fresh ground water flows through the sand, these observations are congruent.
Moreover, other pathogens reside in the moist sand, only to be stirred up. If you paddle a canoe, surf or otherwise spend a lot of time in the sea, you have experienced or heard of Staphylococci aka “Staph” infections. More didactic dogma tells us staph is only spread person-to-person and is not common in salt waters. Staph is shed from showers and in feces. About one-third of us shed staph (Acton 2009). The proportion is higher in children.
Staph is found in wastewater treatment plants, and even storm water runoff. It is commonly isolated from the ocean. It uses salt to give it a competitive advantage. One UH researcher believed that all staph in the ocean simply washed off people. Researchers in Seattle were skeptical and tested the cold waters of the Puget Sound. They found Staph aureus in many locations and in particular after rains. Staph does wash off ocean users, and much greater numbers--over a 100-fold greater--come from the sand (Goodwin 2012).
It is said, and rightly so, that going into the ocean with an open wound is risky. This statement punctuates personal experience. A hand injury became infected from canoe paddling after a short healing hiatus. Fortunately, this strain of “Blistering Staph” was treatable. That season, at least ten fellow canoe club members acquired staph skin infections. One paddler required two bouts of hospitalization and IV therapy. Regrettably, these severe infections are not “Reportable Diseases”, so we do not have data on the prevalence.
The article in WHT suggested the numbers of the FIB are increasing over time. It may well be, and yet the data noise in the FIB test procedure is loud. This means that, when numbers are reported, they are not absolute. The MPN or Most Probable Number method represents a range of bacteria numbers, not an absolute number, as often inferred. Therefore, the report without a much larger sample size and some detailed statistics is the best guess, but one worthy of our close attention.
A trend we see in Hawaii is that of increasing turbidity of our waters. As divers and scientists, we have seen and measured this trend. Recently we studied turbidity in Keauhou Bay. We took over 200 samples in the span of 8 months. The inner bay is more turbid, compared to the open ocean near the entrance. Only about 40% of the variation in turbidity is attributed to turbulence from ocean swells. Along the Kona Coast, turbidly can be associated with green algae cells that freely live in the waters. At most times the numbers of algae are too few to cause a greening of the water. The algal greening of water near the shore is a very significant event. Natural tropical waters have very low nutrients and will not support visible greening.
This is where turbidity and microbes intersect. Our intense sunlight and its ultra-violet energy (UV) is an excellent disinfectant. The UV breaks the DNA in the microbes, and they perish. One reason why the pathogens are not exacting a greater toll is the control the UV provides. However, as the water becomes more turbid and the chlorophyll in the algae absorbs the UV energy, we can expect higher numbers of pathogens in the water near the shore. Perhaps the increased FIB data is suggesting this. However, without specific research, it’s only a matter of speculation. The algae, nourished by nutrients, thrive just as plants respond to fertilizer. The algae respond to nitrate and phosphate regardless of if they come from human waste or a golf course.
The second point for consideration: the Department of Health is finally coming around to recognize that the massive volumes of groundwater flowing into the sea each day contain wastes from human activity. UH hydrologists made this clear more than a decade ago. The commonly perpetrated myth that a septic system will solve the problem created by cesspits is devoid of any substantiating data. The myth even ignores some excellent science conducted in Hawai‘i (Tasato 1980). We are repeatedly told that "soil treatment” removes pathogens and nutrients. Soil, what soil? Dig down 12 inches in most places and what we find is lava rock, in its many forms. This broken rock has almost infinite permeability. “Toto, I don't think we are in Kansas anymore”. Even in Kansas, with 5 to 10 feet of soil, septic systems contaminate ground water. Many municipalities and states are moving toward eliminating septic systems. It begs the question. Why are we advocating them, when there is very little scientific justification for doing so?
Florida is grappling with the myriad of septic systems along its shores. They, too, have no soil, but mostly coral sand over a shallow water table. One study found that tracer virus, once “flushed”, could be found in the nearby sea in a matter of hours. In the Florida Keys, 95% of the ocean samples were positive for a pathogenic virus. Problematically, the FIB numbers were not elevated. Again, we see that FIB will not indicate for virus.
The viruses should concern us. They are minuscule and poorly filtered, even in mainland locations that have deep, high-quality soils. Unlike the bacteria, the MID can be as low as one virus. A person ill, or during recovery from viral enteritis, can excrete 100ʻs of trillions of virus particles each day. This virus is very persistent in ground water. However, once exposed to the sun and in clear water, most will be inactivated, but it takes time to get a 99.9999% kill. If only ten million are in beach water, at this kill rate, 10 remain alive. This is a numbers game not stacked in our favor and that is why this virus infects its way through cruise ship patrons like a hot knife through butter.
To continue our research, we will be using advanced bacterial RNA sequencing, as has been done in California, to demonstrate what common sense suggests. Human microbes flow with water downslope and to the sea. We plan a citizen-funded research project and seek supporters large and small. With real data, our arguments to prevent microbial pollution become very strong and convincing.
Many technologies can be applied to the issue. Advanced Treatment Units or ATUʻs show great promise for on-site waste treatment. ATU is a generic term, and not all ATUʻs are equal. The best ATUʻs remove over 50% of the nitrogen and disinfect as well. The reclaimed water can be safely used for landscape irrigation. Some advocates of the status quo greatly exaggerate the cost of Advanced Treatment Units to argue for the continued use of cesspits. Commercialization, economies of scale and gray water diversion, offer practical solutions to make these new systems cost effective.
While we wait for a leadership breakthrough, here are some simple things people can do to protect themselves, their families and our ocean.
- Avoid recreating in water with storm water runoff. It is almost as bad as sewage.
- Avoid floating scum. It can arise from cesspits located near the shore
- Open wounds do not heal in seawater. It harms the tissue and invites staph infection. Let them heal first.
- Vigorously clean and medicate wounds created in the sea. Watch for signs of infection, i.e., Red, Swollen, Hot, Painful, Draining
- Don't ignore a little pus-filled pimple that arises on the body or limbs. If it gets larger, seek medical attention.
- Wash off seawater and sand. Wash sand out of swim suits. Launder and dry!
- Gastrointestinal disease lasting more than a day or two, and those with fever, are reasons to seek medical attention
- Any serious sign, like significant bruising, fever, swelling with or without pain right after a swim requires medical attention ASAP
- Consider diverting washing machine water for landscape irrigation. Lowering the volume of water in the on-site system reduces the risk of microbial transport to ground water.
- Make your voice heard. We all can demand government to invest in productive human waste management systems. A good place to start would be to convert all public beach restroom cesspits and septic systems to the proven, advanced treatment units. Fix leaky sewer lines. Conventional sewer lines leak, including those near our beaches. Honolulu is fixing its broken system. Kona should also consider this important action. Preventing contamination is the solution.
While we scientists, bureaucrats, and politicians remain snarled in the debate, we inadvertently kick the can down the road, instead of choosing a course of action that best serves our children and grandchildren. The health and vitality of the people are closely tied to the health and vitality of our oceans. Hawaiian ‘ōlelo says it best. Mālama ʻoe i ke kai a mālama ke kai iā ʻoe, Care for the ocean and the ocean will care for you.
(Note: The complete article with full citations will be published later and can be found at http://www.h2okona.org
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