Current methods using indicator bacteria for testing recreation waters for microbial safety are antiquated and replete with false positives and false negatives. We have the technology but not the will to adopt new science-based water safety testing.
The recent commentary by state Health Department Director Bruce Anderson makes some assurances the monitoring of recreation water bacteria is all good (“Ocean-water quality monitoring improves,” Island Voices, Aug. 7).
Unfortunately, all is not good. The methods used are grossly obsolete, and there is ample scientific evidence to the fact. The mandate for these 1970s methods is the U.S. Beach Act (2000).
To qualify for federal funds, the state must use the method and guidelines. Once again, politics usurps science.
The indicator bacteria measured is the genus Enterococci. In recreation waters where there is no discharge of wastewater, the test is less than 50/50 for predicting disease risk. The microbes of concern are not bacteria, but human virus.
In the genus Enterococci, there are 10-plus species detected by the official test. Only two species are common in feces of most animals, and humans. What makes this test very imprecise is the fact that these two species of Enterococci, as well as many others, grow readily in the environment. Just about any place there is moisture and organic debris, these microbes can be found.
The health director implied that this soil growth issue is unique to tropical Hawaii. But these indicator species are common in the environment with human activities, even in cold places like Alaska and the lakes of Michigan.
In coastal waters, the major source of Enterococci is the beach sand itself. Entero persists there very well. Waves and tides that stir the sand, resuspend the bacteria into the water. If beach water is tested soon after such an event, high indicator numbers can be found. The health risk is negligible in most cases.
To be clear, we cannot project the disease risk from any bacterial indicator measurement. There are far too many false positives and false negatives. If a medical blood test was correct only half the time, it would be a useless diagnostic. Environmental Protection Agency scientists would like to solve this problem, but there is no political will at the top.
Amid all this uncertainty, some may fear recreating in our ocean. There is reassurance. The sun is the greatest disinfector ever known. The UV light penetrates deeply in clear water and will reduce bacterial and viral counts in a matter of a few hours of midday sun. We need to assure the waters remain clear, but we are not doing well in this regard.
The human waste nutrients flowing into the sea cause marine phytoplankton to grow and waters become turbid. As this happens, the UV of the sun penetrates less. Disease risk increases with turbidity. We must begin to limit the massive flow of human waste nutrients into the sea.
Science-based techniques for measuring fecal contamination are coming. Phylochip is an exact tool that can monitor the entire fecal microbiome and identify its source. Once the technology is commercialized for public health labs, the costs become competitive.
Another indicator of human waste is Sucralose, known as Splenda, the artificial sweetener. Tests in Florida waters show fecal Sucralose in wastewater is detectable in fresh and marine waters. The test method is straightforward and can be commercialized.
What’s needed now is the initiative and funding from private and public partnerships to implement technology to help protect Hawaii’s most precious resource, the sea.
OFF TODAY
New York Times columnist Maureen Dowd is off.
