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What Happens When Environmentalists Ignore Data?
Rachel Carson effectively stopped the usage of DDT. This has led to disastrous consequences, writes Paul Offit in his new book, Pandora's Lab.
With environmental regulations being slashed daily, a resurgence in Rachel Carson’s Silent Spring has taken hold. Few books have impacted governmental policies like this 1962 juggernaut. Carson’s diatribe against DDT practically wiped the insecticide from the face of the planet. Looking back over a half-century later we have to ask: Is this a good idea?
Paul Offit doesn’t think so. In his new book, Pandora’s Lab: Seven Stories of Science Gone Wrong, the physician and co-inventor of a rotavirus vaccine investigates what happens when good (and sometimes bad) intentions fail to take the bigger picture into account. Rachel Carson, according to Offit, is one such example.
Having been warned by her mentors that a future in medicine was not in her cards, Carson took to writing in the thirties to stay involved in the sciences. She was a diligent worker and poetic author, never satisfied with her articles and books even as the press and public offered continual accolades. Silent Spring proved to be the culmination of decades of environmental research pointed at the ravages of DDT.
Our fear of chemistry makes sense. I rarely pass an older building in Los Angeles without a plaque warning of the carcinogenic materials embedded in the structure, my apartment complex included. Between 1947 and 1960, Offit writes, American chemical manufacturers increased their output from 124 million pounds to 638 million pounds. As a result the insects gorging on our vegetables fought back harder, which made us spray longer.
Carson took the lead in fighting against this unnatural assault on the environment. A month before the publication of Silent Spring, President Kennedy cited the book—a few chapters had been serialized in the New Yorker the previous summer. Two weeks after publication, 65,000 copies were sold; it remained #1 on the NY Times bestseller list for thirty-one weeks. Though Carson died the following year of metastatic breast cancer, the government’s “Pesticide Commission” turned into the EPA, one of the agencies the current administration appears bent on destroying.
The work of environmentalists are essential right now. Earlier today the president rolled back important regulations regarding the curbing of climate change. Carson might have been an early instigator, but her legacy is necessary today. By the time Nixon was in office the government was signing into law numerous environmental policies, a trend that we need to keep championing.
The problem, Offit writes, is that Carson got the science on DDT wrong. Because of that error, and despite the incredible progress America made in that short window of time, millions of people have died as a result.
While DDT, or dichlorodiphenyltrichloroethane, was created in a German lab in 1874, it sat on a shelf for sixty-five years. Its inventor, Othmar Zeidler, made a batch for his thesis, then found it useless. Paul Müller didn’t agree. In 1939 he found Zeidler’s formula when investigating how to destroy moths without damaging clothing. DDT took care of moths and just about every other insect imaginable.
Müller’s work didn’t catch on in the fashion world. It did, however, save millions of lives from typhus, a disease spread by body lice. He was awarded a Nobel prize in medicine and physiology for his discovery. An industry was born.
Typhus was a problem, but the world has seen worse, most notably malaria. Mosquito nets and quinine are important combatants, but Offit finds DDT to be more valuable:
Arguably, the best, cheapest, and most effective weapon in the fight against malaria was DDT. Following a spraying program in South Africa, the number of malaria cases decreased from 1,177 cases in 1945 to 61 cases in 1951; in Taiwan, from more than a million cases in the mid-1940s to 9 cases in 1969; and in Sardinia, from 75,000 cases in 1946 to 5 cases in 1951.
In 1970 the National Academy of Sciences declared that more than 500 million lives were saved thanks to DDT. It also worked on yellow fever and dengue by destroying disease-ridden mosquitos. While leading experts at the time were aware of its efficacy, within five years it was banned from numerous countries thanks to the legacy of Carson’s book.
In Silent Spring, Carson focused on bird populations decimated by DDT, including robins, meadowlarks, cardinals, and eagles. Yet she got her data wrong: the number of birds in each population actually increased during the periods of heaviest DDT usage; they too suffer from insect-borne diseases. As a member of the National Audubon Society, whose data showed the higher numbers, Carson should have known better. Offit speculates that she ignored the information because it didn’t fit in with her narrative, which led to tragic consequences.
For more than 30 years, countries where malaria epidemics were common had been denied the lifesaving chemical. Although there were alternatives, and some of those alternatives were used, no chemical was as cheap, long lasting, or effective as DDT. As a result, millions of people, mostly children, died needlessly.
Offit’s book highlights what happens when narrative overrides data. He looks at the legacies of eugenics, margarine, nitrogen, and lobotomies, among others. The distance between an idea and science is steep and often treacherous. Unfortunately we often assume that because someone has expressed an idea it must be true, an especially harrowing neurological glitch in the digital age. Even when we know better we persist in our follies. That’s a shame given what’s at stake for our own health and that of the planet.
Derek's next book, Whole Motion: Training Your Brain and Body For Optimal Health, will be published on 7/4/17 by Carrel/Skyhorse Publishing. He is based in Los Angeles. Stay in touch on Facebook and Twitter.
Certain water beetles can escape from frogs after being consumed.
- A Japanese scientist shows that some beetles can wiggle out of frog's butts after being eaten whole.
- The research suggests the beetle can get out in as little as 7 minutes.
- Most of the beetles swallowed in the experiment survived with no complications after being excreted.
In what is perhaps one of the weirdest experiments ever that comes from the category of "why did anyone need to know this?" scientists have proven that the Regimbartia attenuata beetle can climb out of a frog's butt after being eaten.
The research was carried out by Kobe University ecologist Shinji Sugiura. His team found that the majority of beetles swallowed by black-spotted pond frogs (Pelophylax nigromaculatus) used in their experiment managed to escape about 6 hours after and were perfectly fine.
"Here, I report active escape of the aquatic beetle R. attenuata from the vents of five frog species via the digestive tract," writes Sugiura in a new paper, adding "although adult beetles were easily eaten by frogs, 90 percent of swallowed beetles were excreted within six hours after being eaten and, surprisingly, were still alive."
One bug even got out in as little as 7 minutes.
Sugiura also tried putting wax on the legs of some of the beetles, preventing them from moving. These ones were not able to make it out alive, taking from 38 to 150 hours to be digested.
Naturally, as anyone would upon encountering such a story, you're wondering where's the video. Thankfully, the scientists recorded the proceedings:
The Regimbartia attenuata beetle can be found in the tropics, especially as pests in fish hatcheries. It's not the only kind of creature that can survive being swallowed. A recent study showed that snake eels are able to burrow out of the stomachs of fish using their sharp tails, only to become stuck, die, and be mummified in the gut cavity. Scientists are calling the beetle's ability the first documented "active prey escape." Usually, such travelers through the digestive tract have particular adaptations that make it possible for them to withstand extreme pH and lack of oxygen. The researchers think the beetle's trick is in inducing the frog to open a so-called "vent" controlled by the sphincter muscle.
"Individuals were always excreted head first from the frog vent, suggesting that R. attenuata stimulates the hind gut, urging the frog to defecate," explains Sugiura.
For more information, check out the study published in Current Biology.
Are "humanized" pigs the future of medical research?
The U.S. Food and Drug Administration requires all new medicines to be tested in animals before use in people. Pigs make better medical research subjects than mice, because they are closer to humans in size, physiology and genetic makeup.
In recent years, our team at Iowa State University has found a way to make pigs an even closer stand-in for humans. We have successfully transferred components of the human immune system into pigs that lack a functional immune system. This breakthrough has the potential to accelerate medical research in many areas, including virus and vaccine research, as well as cancer and stem cell therapeutics.
Existing biomedical models
Severe Combined Immunodeficiency, or SCID, is a genetic condition that causes impaired development of the immune system. People can develop SCID, as dramatized in the 1976 movie “The Boy in the Plastic Bubble." Other animals can develop SCID, too, including mice.
Researchers in the 1980s recognized that SCID mice could be implanted with human immune cells for further study. Such mice are called “humanized" mice and have been optimized over the past 30 years to study many questions relevant to human health.
Mice are the most commonly used animal in biomedical research, but results from mice often do not translate well to human responses, thanks to differences in metabolism, size and divergent cell functions compared with people.
Nonhuman primates are also used for medical research and are certainly closer stand-ins for humans. But using them for this purpose raises numerous ethical considerations. With these concerns in mind, the National Institutes of Health retired most of its chimpanzees from biomedical research in 2013.
Alternative animal models are in demand.
Swine are a viable option for medical research because of their similarities to humans. And with their widespread commercial use, pigs are met with fewer ethical dilemmas than primates. Upwards of 100 million hogs are slaughtered each year for food in the U.S.
In 2012, groups at Iowa State University and Kansas State University, including Jack Dekkers, an expert in animal breeding and genetics, and Raymond Rowland, a specialist in animal diseases, serendipitously discovered a naturally occurring genetic mutation in pigs that caused SCID. We wondered if we could develop these pigs to create a new biomedical model.
Our group has worked for nearly a decade developing and optimizing SCID pigs for applications in biomedical research. In 2018, we achieved a twofold milestone when working with animal physiologist Jason Ross and his lab. Together we developed a more immunocompromised pig than the original SCID pig – and successfully humanized it, by transferring cultured human immune stem cells into the livers of developing piglets.
During early fetal development, immune cells develop within the liver, providing an opportunity to introduce human cells. We inject human immune stem cells into fetal pig livers using ultrasound imaging as a guide. As the pig fetus develops, the injected human immune stem cells begin to differentiate – or change into other kinds of cells – and spread through the pig's body. Once SCID piglets are born, we can detect human immune cells in their blood, liver, spleen and thymus gland. This humanization is what makes them so valuable for testing new medical treatments.
We have found that human ovarian tumors survive and grow in SCID pigs, giving us an opportunity to study ovarian cancer in a new way. Similarly, because human skin survives on SCID pigs, scientists may be able to develop new treatments for skin burns. Other research possibilities are numerous.
The ultraclean SCID pig biocontainment facility in Ames, Iowa. Adeline Boettcher, CC BY-SA
Pigs in a bubble
Since our pigs lack essential components of their immune system, they are extremely susceptible to infection and require special housing to help reduce exposure to pathogens.
SCID pigs are raised in bubble biocontainment facilities. Positive pressure rooms, which maintain a higher air pressure than the surrounding environment to keep pathogens out, are coupled with highly filtered air and water. All personnel are required to wear full personal protective equipment. We typically have anywhere from two to 15 SCID pigs and breeding animals at a given time. (Our breeding animals do not have SCID, but they are genetic carriers of the mutation, so their offspring may have SCID.)
As with any animal research, ethical considerations are always front and center. All our protocols are approved by Iowa State University's Institutional Animal Care and Use Committee and are in accordance with The National Institutes of Health's Guide for the Care and Use of Laboratory Animals.
Every day, twice a day, our pigs are checked by expert caretakers who monitor their health status and provide engagement. We have veterinarians on call. If any pigs fall ill, and drug or antibiotic intervention does not improve their condition, the animals are humanely euthanized.
Our goal is to continue optimizing our humanized SCID pigs so they can be more readily available for stem cell therapy testing, as well as research in other areas, including cancer. We hope the development of the SCID pig model will pave the way for advancements in therapeutic testing, with the long-term goal of improving human patient outcomes.
Adeline Boettcher earned her research-based Ph.D. working on the SCID project in 2019.
Satellite imagery can help better predict volcanic eruptions by monitoring changes in surface temperature near volcanoes.
- A recent study used data collected by NASA satellites to conduct a statistical analysis of surface temperatures near volcanoes that erupted from 2002 to 2019.
- The results showed that surface temperatures near volcanoes gradually increased in the months and years prior to eruptions.
- The method was able to detect potential eruptions that were not anticipated by other volcano monitoring methods, such as eruptions in Japan in 2014 and Chile in 2015.
How can modern technology help warn us of impending volcanic eruptions?
One promising answer may lie in satellite imagery. In a recent study published in Nature Geoscience, researchers used infrared data collected by NASA satellites to study the conditions near volcanoes in the months and years before they erupted.
The results revealed a pattern: Prior to eruptions, an unusually large amount of heat had been escaping through soil near volcanoes. This diffusion of subterranean heat — which is a byproduct of "large-scale thermal unrest" — could potentially represent a warning sign of future eruptions.
Conceptual model of large-scale thermal unrestCredit: Girona et al.
For the study, the researchers conducted a statistical analysis of changes in surface temperature near volcanoes, using data collected over 16.5 years by NASA's Terra and Aqua satellites. The results showed that eruptions tended to occur around the time when surface temperatures near the volcanoes peaked.
Eruptions were preceded by "subtle but significant long-term (years), large-scale (tens of square kilometres) increases in their radiant heat flux (up to ~1 °C in median radiant temperature)," the researchers wrote. After eruptions, surface temperatures reliably decreased, though the cool-down period took longer for bigger eruptions.
"Volcanoes can experience thermal unrest for several years before eruption," the researchers wrote. "This thermal unrest is dominated by a large-scale phenomenon operating over extensive areas of volcanic edifices, can be an early indicator of volcanic reactivation, can increase prior to different types of eruption and can be tracked through a statistical analysis of little-processed (that is, radiance or radiant temperature) satellite-based remote sensing data with high temporal resolution."
Temporal variations of target volcanoesCredit: Girona et al.
Although using satellites to monitor thermal unrest wouldn't enable scientists to make hyper-specific eruption predictions (like predicting the exact day), it could significantly improve prediction efforts. Seismologists and volcanologists currently use a range of techniques to forecast eruptions, including monitoring for gas emissions, ground deformation, and changes to nearby water channels, to name a few.
Still, none of these techniques have proven completely reliable, both because of the science and the practical barriers (e.g. funding) standing in the way of large-scale monitoring. In 2014, for example, Japan's Mount Ontake suddenly erupted, killing 63 people. It was the nation's deadliest eruption in nearly a century.
In the study, the researchers found that surface temperatures near Mount Ontake had been increasing in the two years prior to the eruption. To date, no other monitoring method has detected "well-defined" warning signs for the 2014 disaster, the researchers noted.
The researchers hope satellite-based infrared monitoring techniques, combined with existing methods, can improve prediction efforts for volcanic eruptions. Volcanic eruptions have killed about 2,000 people since 2000.
"Our findings can open new horizons to better constrain magma–hydrothermal interaction processes, especially when integrated with other datasets, allowing us to explore the thermal budget of volcanoes and anticipate eruptions that are very difficult to forecast through other geophysical/geochemical methods."