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Are bacteria blooms in NH lakes linked to Lou Gehrig’s Disease? New report casts doubt on that idea

  • Dartmouth ALS doctor and researcher Elijah Stommel sits in his office at Dartmouth–Hitchcock Medical Center in Lebanon, on April 7, 2016. (ELIZABETH FRANTZ / Monitor staff) Elizabeth Frantz

  • Dr. Elijah Stommel, right, and his colleagues Dr. Tracie Caller and Nicholas Field, fourth-year medical student at the University of Vermont, are studying the link between blue-green algae and Lou Gehrig's disease. October 2011. (courtesy photo by Jon Gilbert Fox)

  • Dartmouth ALS doctor and researcher Elijah Stommel sits in his office at Dartmouth–Hitchcock Medical Center in Lebanon, on April 7, 2016. (ELIZABETH FRANTZ / Monitor staff) Elizabeth Frantz


Monday, November 20, 2017

Science is so successful partly because its results are always being questioned. All scientists know this, but that doesn’t make it any easier when your results are the ones being questioned.

Consider a report issued earlier this month by the United States Geological Survey. It casts doubt on assertions made by researchers, including Elijah Stommel at Dartmouth College, that blooms of cyanobacteria, often misleadingly called blue-green algae, are connected to certain neurological diseases, including ALS – also known as Lou Gehrig’s Disease – and possibly Alzheimer’s.

“I agree with them that there is still some healthy skepticism in making correlations between cyanobacterial blooms and the potential for neuro-degeneration, but there’s a fair amount of evidence that there is an association,” said Stommel. You may have heard of him in relation to studies about pockets of ALS around Lake Mascoma near Lebanon, which has drawn considerable attention in New Hampshire.

“It’s well-written and inclusive of most of the literature … but I think that some of the people on that paper may have other agendas than just the science,” he said of the paper. “And it does affect funding. … It’s hard enough to get funding as it is, without having somebody kick you in the pants.”

Aside from the public health question, which is non-trivial, there’s another reason this area of research draws attention: Property values.

Algae blooms seem to be happening more often in our water bodies due to warming weather and changes in land use. If it turns out that they can cause an insidious horrible disease, then all those wonderful lakeside homes might be worth a lot less, and a good chunk of New Hampshire’s recreation-linked economy might wobble.

Actually, it’s worse than that. Stommel says that research at Dartmouth and other sources indicate that aerosolization of cyanobacteria – that is, getting carried through the air on tiny droplets of moisture from the surface of the lake and then inhaled – “may be an important route for the exposure.”

In other words, if these blooms contribute to ALS then even avoiding the water during the blooms may not entirely protect you: Even on shore you might breath it in.

“If so, I’d say don’t jog along a waterway when there’s a bloom and you’re breathing hard,” said Stommel.

Sheesh! No wonder some people want to shut down scientific research: It has a nasty habit of reaching conclusions that we don’t want to hear.

Anyway, back to that report released by USGS. Published in the Journal of Toxicology and Environmental Health, it has 12 authors from a variety of places, including a couple of universities, with the bulk of them associated with the Environmental Protection Agency.

It is a review, meaning that it examines past research publications rather than doing new research, and doesn’t specifically respond to research by Stommel and colleagues. Instead, it focuses on a variety of research done on animals and epidemiological studies in Guam and parts of Japan and New Guinea, where ALS and related neuro-degenerative diseases are relatively common.

All that work is basic to the field of possible connections between ALS and cyanobacteria, so even if it doesn’t discuss Lake Mascoma directly, it does cast doubt on conclusions being reached about links.

And what are the paper’s doubts? There are many, but unfortunately they’re the sort of concerns that don’t translate well to laymen like me.

For example, the paper expresses concern that the effects of subcutaneous exposure of BMAA, the amino acid produced by cyanobacteria that seems to be the culprit (if there is one), are being improperly extrapolated to reach conclusions about what happens when we breathe in BMAA.

Is that a legitimate concern that kicks the legs out from under conclusions about health effects, or is it a red herring to distract us from the problem?

Darned if I know, and darned if I’ll ever know without learning a lot more about certain aspects of basic biology, which I’m realistically not going to do. I’m dependent on experts to reach a decision.

In the meantime, I agree with Stommel that we shouldn’t let this debate distract us from tackling the problem of cyanobacteria blooms.

“Even if you take neuro-degeneration out of the equation completely, we still have to worry about health issues,” he said. “There’s no question that it can cause liver disease, that’s well established … There’s a lot of dogs that die every year and cattle (from drinking affected water), and you certainly don’t want to be swimming in that stuff if there’s an active bloom.”

Reducing the blooms, alas, also collides with questions of property values, land ownership and development. The most important step in reducing them is to reduce the flow of nutrients into the water, which means limiting septic systems and construction near lakes or ponds, plus maintaining natural buffers that often block the view of water that leads people to want to live near lakes in the first place.

Those are good ideas, although hard to implement. We should pursue them even as the scientific process churns through this more complicated question.

“I don’t want to overstate our hypothesis either. I don’t intend to say we’ve proven it by any means. But science is a process and requires time and repeated testing, repeated experiments … More work needs to be done.” said Stommel.

(David Brooks can be reached at 369-3313 or dbrooks@cmonitor.com or on Twitter @GraniteGeek)