David Hersey spends most of his time propped up in bed in his living room these days. "I have one arm that still works," the former parachute rigger and skydiving enthusiast notes wryly as he extends his left hand to a visitor. It's been three years since he heard a neurologist say, in so many words, "You have ALS, there's no known treatment, and you're going to die." The doctor was only confirming what Hersey had already figured out from his own research after noticing that he kept stubbing his toe. Before that, the 58-year-old Deerfield, N.H., resident had never heard of amyotrophic lateral sclerosis, otherwise known as Lou Gehrig's disease.
Ever since, he's been watching it gradually creep upward, rendering his limbs useless while his sense of touch and mental abilities remain intact. "I will eventually die of respiratory failure," he says. Hersey, however, likes to point out that there is no typical ALS patient. He, for one, has little use for self-pity. "I don't have a list of things I didn't do," he explains. "I did them as I went along."
As his condition has progressed, his pursuits have taken an intellectual bent—learning Italian, exploring the Internet, and reading about ALS research, which, he's convinced, has made little progress since Yankees slugger Gehrig was diagnosed with the disease in 1939.
Elijah Stommel, a neurologist and researcher at Dartmouth-Hitchcock Medical Center, has been known to lie awake at night puzzling over possible causes of ALS. A few years ago, he started to notice clusters of ALS patients near lakes. At Mascoma Lake in Enfield, N.H., for example, he was seeing an occurrence of the disease roughly 25 times higher than expected. Around the same time, he read about a controversial theory linking ingestion of a toxin produced by blue-green algae to neurodegenerative diseases like ALS, Alzheimer's and Parkinson's. His search for a field biologist who could help him explore a possible connection between algae in lakes and ALS in lakeside residents led to Jim Haney, a UNH expert on aquatic organisms and the toxins they produce. Haney was also intrigued by the new theory.
One November day in 2007, Haney and graduate student Amanda Murby '06,'10G canoed out onto Mascoma Lake to get samples of the water and sediment. At the UNH Biotoxins Lab, the sediment revealed high levels of microcystin, a well-studied liver toxin produced by certain algae. Exposure through swimming can cause rashes and gastroenteritis, and ingestion of contaminated water has been blamed for animal and human deaths around the world. The neurotoxin suspected of causing ALS, the amino acid BMAA, has yet to be found in the lake. Although it is harder to identify and less well studied than microcystin, BMAA is produced by the same species of algae which was found in abundance in Mascoma. Later Murby mapped the algae in the lake, showing how currents could circulate the organisms toward the public beach in warm weather. Last summer, the N.H. Department of Environmental Services issued 17 advisories for harmful blue-green algae blooms at freshwater beaches, including Mascoma's.
Now Stommel asks all his new patients where they live and how long they have lived there. Using sophisticated geographical software, he and his colleague, neurologist Tracie Caller, have documented a significant statistical increase in the incidence of ALS cases near water bodies with a history of toxic algae blooms. They have also identified patients near these lakes who have developed some symptoms of ALS but not the full-blown disease.
In April, Haney and Stommel applied for a federal grant to study ALS clusters in northern New England and algae blooms in nearby lakes and waterways. If the research adds to the mounting evidence of a link between the disease and the algae, it could help light the way to a cure. But even if it doesn't, the researchers hope to raise awareness of a known health threat and to motivate the public to take better care of a beloved and valuable natural resource.
Jim Haney and his colleagues at the Biotoxins Lab, John Sasner and Mike Ikawa, were already experts on the deadly "red tide" algae when they got a call in 1997 from Silver Lake State Park in Hollis, N.H. Children who had been swimming in the lake were getting stomach ailments. Haney was surprised to find that water samples from the lake looked like a pure culture of the kind of algae that produces microcystin—in concentrations among the highest ever detected worldwide. He urged the state to keep children out of the water whenever the scum of an algae bloom formed. At the same time, he recognized "an unbelievable opportunity," and began to study blue-green algae.
Haney has a sort of scientific love-hate relationship with these microscopic organisms, which are actually bacteria and technically called cyanobacteria. They were here if not at the very dawn of life on Earth, then "only" about a billion years later. In fact, they were the first organisms to develop photosynthesis—producing the oxygen that enabled the rest of life as we know it to unfold.
Today blue-green algae can be found virtually anywhere on the globe—in the middle of the ocean, a handful of desert sand, the fur of a sloth, a dietary supplement, a glass of water, or a leaf of lettuce. Viewed through a microscope, they reveal a beautiful symmetry in delicate spirals or straight chains like opened bracelets. To the naked eye, however, an algae bloom can resemble pea soup, green latex paint, white flakes or brown scum.
In 2003, New Hampshire became one of the first states to test for blue-green algae in its freshwater beach inspection program, which is directed by biologist Sonya Carlson '06G, a former student of Haney's. The state issues an advisory when algae levels at a public beach exceed the World Health Organization standards for drinking water. The beach manager must then post a sign and decide whether to close the beach for the duration of the bloom.
With the support of a federal grant, Haney and his colleagues have tested levels of microcystin in 80 of New Hampshire's 959 lakes, using the highly sensitive ELISA (enzyme-linked immunosorbent assay) method. "It's misleading to talk about lakes having toxic cyanobacteria or not," he says. "It's a matter of how much they have." He's seen a thousandfold difference in levels from the lowest to highest concentrations.
Paul Cox, a world-renowned ethnobotanist, visited UNH recently to tell about his efforts to solve one of the great medical mysteries. Why has the native population of Chamorros on Guam had an incidence of a fatal ALS-like disease up to 100 times higher than normal? At its peak in the 1950s, 25 to 30 percent of the population succumbed to the ailment, in the largest cluster of the disease ever documented. The culprit, Cox concluded, was the Chamorros' predilection for a local delicacy, the giant fruit bat—which they devoured fur, head, and all.
When analysis of the preserved brains of victims of the disease revealed high levels of BMAA, Cox saw a classic case of biomagnification. In a "House That Jack Built" sort of chain of causality, the Chamorro are the people who ate the bats, who ate the cycad seeds, which contain the BMAA, which is produced by the blue-green algae, which live symbiotically in cycad roots.
The surprising discovery of BMAA in the brains of some of Cox's controls—who were victims of Alzheimer's disease—strengthened his hypothesis that blue-green algae toxins may cause neurodegenerative disease in susceptible people.
When Cox published his findings in Neurology in 2002, some neurologists welcomed his scientific crossover, but others were skeptical, particularly scientists who had promoted other theories about the Chamorro mystery. Some of his results have been confirmed independently, however, and scientists at the University of Miami have just published a study in which high levels of BMAA were detected in 49 out of 50 brain samples from North American ALS and Alzheimer's victims.
If BMAA does somehow cause neurodegenerative diseases—by damaging glutamate receptors in the brain, perhaps, or replacing normal amino acids in brain proteins—scientists believe the process would only occur in people who have a genetic predisposition to accumulate the toxin.
Haney and Stommel plan to explore the possible correlation between ALS and algae through patient interviews, tests of water and fish, and sophisticated mapping and statistical analysis. Cox's lab will assist with analysis of hair and brain samples from victims. Lake-bottom cores can give clues to past levels of contamination. Haney found, for example, that a sudden jump in toxin levels revealed the point when a state fish hatchery came online 70 years ago and started polluting a Berlin, N.H., lake with nutrients. In the seemingly upside-down world of lake management, "nutrients" and "feeding" are not nice words.
On a Thursday night in May, several pairs of UNH students presented the results of a semester-long study of the water quality in local lakes before a small audience. It was the culmination of Haney's lake management course, which provides a service to the state while training students from a variety of majors.
Although each lake was different, the recommendation for maintaining or improving water quality was invariably the same: reduce or prevent the flow of nutrients into the lake. Nutrients such as phosphate from fertilizers, animal wastes and detergents can lead to overgrowth of aquatic organisms. The solution is to maintain a buffer of vegetation along the shore, reduce or eliminate use of fertilizer adjacent to the lake, keep septic systems well maintained and resist the pressure to pave over swaths of land in the lake's watershed.
An important goal of the algae and ALS project is to raise public awareness. The N.H. Department of Environmental Services and UNH Cooperative Extension will play key roles in this part of the project. New Hampshire already has 900 citizen volunteers monitoring the water quality of lakes across the state under the guidance of UNH and Cooperative Extension, and 500 more, under N.H. Department of Environmental Services' supervision, are watching for invasive weeds. Members of both monitoring programs have already started to learn about signs of algae problems in lakes. Other efforts will be aimed at informing veterinarians and medical doctors so that they can be on the lookout for algae-related illness.
In the meantime, the experts recommend several ways to avoid getting sick from algae toxins. The most obvious caveat is to avoid drinking contaminated water, which can happen inadvertently while swimming during a bloom. Haney cautions that the toxins in blue-green algae are not destroyed, and may even be intensified, by boiling. They can also concentrate in shellfish or finfish in contaminated lakes, bays, rivers or oceans. "Aerosolization," a documented means of transmission of toxins such as red tide, could theoretically spread contaminants through wind, or the spray created by waterskiing. And perhaps it goes without saying that you won't find blue-green algae supplements on the kitchen shelves of any of these researchers.
The scientists want to convey concern, but not alarm, about the algae in New Hampshire lakes. In general, the lakes have tested below the WHO drinking-level standards, except during active blooms. "I'd be thrilled to own a cottage on a New Hampshire lake," says Cox, whose Institute for Ethnomedicine is based in Wyoming. In fact, northern New England has less of a problem with blue-green algae blooms than many states with more development, more farming or a warmer climate.
David Hersey has his own, rather metaphysical, theory as to why he may have contracted ALS. In the year 2000, virtually everyone he had ever been close to died, one after another, of unrelated diseases, mostly cancer. Can it be a coincidence, he muses, that someone could suffer such a devastating series of losses, and then contract a disease where "everything is gradually disappearing"?
Hersey isn't part of an ALS cluster, although he did spend many a summer afternoon swimming in a local lake as a boy and also lived for more than 20 years near (and often rollerbladed along) the Charles River in Boston, which has also had algae blooms. "I do feel like the neurotoxic effect of these algae blooms is a piece of the puzzle," he says.
Even if they don't receive the National Institute of Environmental Health grant, says Haney, the researchers will find the money to continue working on this puzzle. "We think we live in this Garden of Eden world and assume everything out there is there for us to use, that lakes are free of problems," he warns. "But there are problems out there that we don't know about."
And whether the result of algae toxins is just an upset stomach or one of mankind's most dread diseases, this is one of those times when what we don't know can hurt us. ~
Return to UNH Magazine Spring '09 "Dangerous Waters"