vacuolar myelinopathy is a neurological disease most commonly seen in bird species such as eagles and coots. the brains of the infected organisms develop lesions in the white matter of the nervous system, causing a loss of motor function. mortuary circles call this “swiss cheese brain.”

from its first recorded instance near degray lake in arkansas during the winter of 1994-1995, researchers, including aquatic scientist susan wilde, conducted field and laboratory studies to determine how species contract this disease. through laboratory and field experimentation, wilde and her team have recently concluded that a toxin produced by cyanobacteria is growing on invasive plant species within water bodies in the southeastern united states.

wilde, an associate professor at the university of georgia, worked with an international team from various scientific backgrounds. their findings, published in science, discovered the epiphytic cyanobacteria (aetokthonos hydrillicola) grow on hydrilla verticillata, a non-native plant species found in bodies of water. wildlife, such as fish, birds, and amphibians, eat these plants and consume the neurotoxin that leads to vacuolar myelinopathy.

vacuolar myelinopathy is not limited to the waterfowl that feed on these plants, explained anton j. reiner, a professor of anatomy and neurobiology at the university of tennessee health science center.

“it’s not a uniquely avian brain disease. it winds up looking like a uniquely avian brain disease because you have to consume a lot of it,” said reiner.

vacuolar myelinopathy also affects fish and amphibians that end up eating these cyanobacteria-infected invasive plants. fish, amphibians and waterfowl that feed on hydrilla become infected with vacuolar myelinopathy. higher-level predators such as coots and eagles consume the smaller animals, thus continuing the spread of the disease throughout the entire food web.

“so-called ‘apex predators’ like eagles, for example, wind up being especially susceptible to [vacuolar myelinopathy] because of their diet,”reiner said.

the disease manifests approximately five days after exposure when clinical signs of loss of motor control function become visible in avian species like eagles and coots. infected coots will float on the surface of the water on their backs and spin in circles, making them easy prey for eagles and other large avian predators. infected eagles will sit on tree branches with their wings drooping downward. according to reiner, there are instances of eagles flying into the sides of mountains while infected with vacuolar myelinopathy.

“every eagle i’ve ever seen with symptoms [of vacuolar myelinopathy] has died,” said william bowerman, professor and chair of the department of environmental science & technology at the university of maryland.

bowerman is a long-time collaborator of wilde’s on vacuolar myelinopathy, and his current research revolves around eagles as indicators of climate change and contaminants around the great lakes. he explained that birds are quality gauges of how the environment responds to various stressors, so the conservation of avian species from vacuolar myelinopathy impacts everyone.

“[vacuolar myelinopathy] killed tens of thousands of waterfowl and over 100 bald eagles. so, it’s a new, emerging disease, and it could be linked to pollution and also may be somewhat of an indicator of climate change,” said bowerman.

wilde and her team discuss spreading awareness and advocacy as a means to combat vacuolar myelinopathy in their recently published research. early in the paper, they state that the shift from the previous name of the neurological disease, “avian vacuolar myelinopathy,” to its current title “vacuolar myelinopathy” is necessary as it is not only limited to avian species. wilde and her team state that they are not yet sure of the potential impact vacuolar myelinopathy has on humans and recommend that further research be conducted.

“we want people to know the lakes where this disease has been documented and to use caution in consuming birds and fish from these lakes,” wilde told the american association for the advancement of science.

while there is still plenty of research to be done on vacuolar myelinopathy, wilde and her team’s discovery of the link between the cyanobacterial toxins and the lethal neurological disorder helps lie to rest the source of the perplexing avian deaths. bowerman hopes that wilde’s work will serve as a reminder of the importance of conserving a clean environment.

“it’s just important to understand that our organisms in the environment tell us what’s going on,” bowerman said. “if the birds and the mammals are healthy, then people are healthy.”

global warming may make infectious diseases such as covid-19 more widespread, warn health and climate experts. they say increasing temperatures are changing disease progression and interaction among people in ways that make it hard to predict and prepare for future public health crises.

with 2020 tied with 2016 for the warmest year on record and covid-19 topping 400,000 deaths in the u.s., climate change and public health are both at crisis points and inextricably linked. nasa scientists report that rising temperatures are part of the long-term trend of global warming, resulting in more droughts and heat waves, more intense and frequent hurricanes, and increased flooding and infrastructure damage.

“all of those things are being affected by the changes in climate, so the net effect of those is quite hard to predict ahead of time,” said gavin schmidt, director of nasa’s goddard institute for space studies, in a press webinar on 2020 temperature rise.

the warming climate is also affecting disease progression. schmidt said diseases carried by hosts that are sensitive to temperature — mosquitoes, parasites or other organisms such as bats — will shift, making people more vulnerable to unknown diseases in the future.

these diseases may be spread more rapidly as people congregate in warmer weather. but colder weather is posing challenges as well. in the case of covid-19, the winter season has made it likelier that people congregate indoors, where the virus is more easily transmitted to others.

“coronaviruses are spread person to person, so the way that climate change is going to affect the spread of infectious diseases such as the covid-19 virus is really how it changes the way people interact,” said dr. robert horsburgh, professor of epidemiology at boston university and founding steering committee chairman of the cdc’s tuberculosis epidemiologic studies 2022年世界杯亚洲预选赛结果 .

horsburgh said deforestation and habitat destruction, accelerated by climate change, may expose more people to zoonotic diseases (those that pass from animals or insects to humans). human expansion into natural areas increases interaction between people and pathogen-carrying animals.

at the same time, biodiversity loss poses challenges for antibiotic development to protect against new diseases. the world wildlife fund’s 2020 living planet report found a nearly 70% decline in the population sizes of mammals, birds, amphibians, reptiles, and fish between 1970 and 2016. one in five plants are now threatened with extinction.

“we don’t know what we’ve missed,” he said. “many of our effective biologicals come from plant sources … so there’s certainly a theoretical possibility that by changing the environment, we will lose some possible antibiotics in the future.”

responding quickly is key. in his first few hours in office wednesday, president joe biden signed a series of executive orders, including rejoining the paris agreement for international cooperation to curtail climate change and mandating mask-wearing on federal property. the day one directives promise more aggressive action by the biden administration to combat the covid-19 pandemic and climate change.

but there is a lag in the effect human corrective activity will have on environmental recovery. the rollback of protective measures under former president donald trump, together with the delay of international negotiations due to covid-19, will continue to have serious public health consequences.

“i’ve been saying for years that we’re not spending enough time to try to prevent the spread of infectious diseases, and perhaps the covid epidemic has been a wake-up call,” horsburgh said. “we need to be vigilant about looking out for the next epidemic — and it won’t be a coronavirus. it’ll be something that we never expected. that’s what’s hardest to prevent: something that you don’t expect.”

covid-19 is just one example of a zoonosis, a disease that was transmitted from animals to humans. other examples of zoonoses include hiv, ebola, sars, and rabies.

according to the center for disease control 3 out of 4 emerging infectious diseases in humans have animal origins. additionally, a recent report released by the united nations environment programme states that zoonoses are becoming increasingly common.

this is mainly because zoonoses “spillover” into human populations due to increased human-wildlife contact.

human-wildlife contact is increasing for a few reasons, according to dr. kurt sladky, a professor of zoological medicine at the university of wisconsin-madison and expert in ecosystem health. 

first, urbanization has caused human populations to spread into what was once wild, pristine habitat. this means that humans are coming into contact with wild animal populations that we have never encountered before.

human consumption of wild animals for protein is another way in which zoonotic diseases can spread.

according to sladky, bushmeat consumption is a key pathway in which zoonotic diseases spread to humans. because of humans’ “voracious appetite” for hunting and eating wildlife, exposure to wild animals has been increasing.

of course, some human populations, especially in the developing world, rely on consumption of bushmeat as their main source of protein. this makes these populations more vulnerable to contracting zoonotic diseases, sladky said.

deforestation is another way humans come into contact with wildlife harboring zoonotic diseases. the ebola virus is a prime example of the ways in which deforestation allows zoonoses to escape their natural habitats and spread to human populations.

the ebola virus existed in african rainforests, and cycled there between human populations, for centuries. however, since deforestation has become more widespread, the ebola virus has expanded outside of these forests, and has caused 25 major outbreaks in countries across africa, killing several thousand individuals. 

unfortunately, experts say unless something is done to mend the damage inflicted on the planet and its natural ecosystems, future pandemics are expected to become more frequent.

“i only see these potential pandemics getting worse and worse because of what we as humans are doing to the environment,” sladky said.

additionally, sladky noted how global travel via airplanes facilitates the global spread of disease. this has been documented during the covid-19 pandemic, as well as other zoonotic disease pandemics and outbreaks. 

the covid-19 pandemic should be a wake-up call to all of us that our actions are not just hurting the environment, but are actually hurting humans as well. 

scientists call this the “one health paradigm,” the idea that animal health, human health, and environmental health are all intrinsically connected.

although each pandemic or disease outbreak has been previously treated as an isolated incident, it is crucial to remember that human actions are driving many of these events. 

in order to prepare ourselves for the future, understanding the connections between humans and our environment is critical in order to prevent future pandemics.

my home state of wisconsin is a hotbed for tick-borne illnesses such as lyme disease. the disease affects on average 3 thousand wisconsinites per year. in 2017, there were more than 4,000 cases! black-legged ticks, also referred to as deer ticks, can be found in every county in the state.

​the bad news doesn’t end there. our climate is changing because the earth is warming. as a result, we’ll start seeing ticks in new areas. and in areas where the disease already exists, fewer disease-carrying ticks will die off during winter. essentially, the risk of contracting lyme disease will increase.

but back to the tick app. although researchers know where ticks are, they don’t always know how people get exposed to ticks. the tick app was created to understand more about how people’s daily lives impact their exposure to ticks. 

image from www.flickr.com/photos/fairfaxcounty/7209178448​

background music, “i am a man who will fight for your honor” by chris zabriskie
source: chriszabriskie.com/honor/
artist: chriszabriskie.com/

planet forward: you’re a teacher here at george washington university?

susan anenberg: yes, i just started as an associate professor here about a month ago. i’m currently developing a new course on global air pollution, climate change, health impacts, and public policy. that will be taught this summer for the first time.

pf: what made you want to pursue a career in health and environmental science?

anenberg: i was an undergrad at northwestern university, and i was pre-med and working nights at an emergency room. i realized that i was seeing the same patients over and over again at the hospital. it occurred to me that if we can take care of some of the more underlying factors that affect people’s health, on a population basis, rather than an individual basis, we would do more than just treating the symptoms and actually prevent the health impacts from occurring in the first place. so that’s what led me to want to be involved with public health. i was also personally interested in climate change and global air pollution, which were both rising in prominence at the time. i realized i could kind of marry the two together and work toward improving public health by tackling climate change and air pollution.

pf: i myself live in buffalo, ny, which has a high rate of cancer within the area, as well as a high rate of air pollution. do you think that air pollution rates have a strong correlation to the cancer rates within a community?

anenberg: i do. air pollution has been studied, and studied, and studied over the last say, 40 years or more throughout this country and the world. i always joke that fine particles in the air and ground level ozone, two very ubiquitous and common pollutants, are probably the most studied pollutants in environmental health because they go back to the 1970s in terms of linking pollutants with health. time and time again we see results coming out of these studies from individual cities, multiple cities, and even multiple countries showing that these pollutants are associated with higher rates of lung cancer, cardiovascular disease, and respiratory disease. we are even seeing some novel health outcomes that are now being associated with air pollution exposure, including diabetes and neurological disorders.

pf: so what particles or chemicals would you consider to be the largest contributors to health implications in mass populations?

anenberg: it appears that particles in the atmosphere caused by incomplete combustion of fuel — those that are released during incomplete combustion of fuels, which could be anything from vehicles burning gasoline or diesel, to a coal-fired power plant, to the fireplace that you use to heat your home — are the most strongly associated with health impacts and really dominate the burden of disease caused by these environmental pollutants. 

pf: in regards to your research with the epa, what did you work on and how extensive is the regulatory process? it seems that there is a public misconception that the epa simply pushes out environmental regulations on whatever it feels like, with discussion going no further than a lunch conversation. 

anenberg: actually, it is incredibly complicated. in fact, when i started at the epa i was a graduate student doing my ph.d., and i was realizing during this time how hard it was to do research and to get published in academic literature, you have to go through a peer-review process, and it’s not an easy thing. i thought when i joined the epa, it was just going to be easy to construct policy, and it was not going to be as hard as conducting scientific research. boy was i wrong! it is really hard to develop new policy in this country. i think that there is good reason for that. these are very costly regulations that the epa handles, but they have massive public health benefits, so they are very essential to have in place. the process is extremely complicated, it starts with a very, very thorough review of the scientific literature including toxicology, epidemiology, and an entire body of literature that has examined the influence of pollutants on public health. this is called an integrated science assessment, which typically runs about a 1,000 pages for each individual pollutant. based on the results of the assessment, the epa then produces a risk and exposure assessment, which is on the order of about 500 pages, where they very thoroughly assess the influence of current levels of air pollution in the atmosphere on public health, so how much are populations around the country experiencing risk from air pollution. and then following that 500 page document, there is a regulatory-impact analysis.

pf: which would be a cost-benefit analysis, correct?

anenberg: yes, that is a cost-benefit analysis where they try to estimate the full cost and health benefits resulting from lowering an air-quality standard. in total, the process takes years to complete and produces thousands of pages of analysis. and at every step along the way there are multiple levels of public review and public comment periods where people from all walks of life come to meet with the epa to bring their research and perspective into it. in total, it’s just a very comprehensive and thorough process that the epa does not take lightly.

pf: and you obviously think these emission regulations are important?

anenberg: absolutely. air pollution is currently considered to be the worst environmental health risk factor on a global scale. it is a massive public health problem that affects developing countries and developed countries alike and is essential to manage, which can ensure that people are living healthy lives.

pf: when we talk about the effects of climate change, we often talk about the economic implications. however, how do you think climate change will affect our health on a global scale?

anenberg: that’s a great question. health has not been a key element around the discussions of climate change over the last 20 to 30 years. i think that’s a shame because there are a lot of different pathways by which climate will affect health. the situation is changing now. the u.s. government, under the obama administration, started addressing the health impacts of climate change and has written several very high profile, comprehensive reports about the health effects of climate change. but more can be done. one way to do that would be to build health into cost-benefit analyses that relate to regulating greenhouse gases, rather than just the ecosystem and economic impacts. some of the ways climate change will affect health is very varied. it can influence heat related stress, vector-borne diseases, air quality. [climate change could] make it harder to achieve the low levels of air pollution necessary to ensure people are living healthy lives. it could lead to more dust in the atmosphere, more wildfires — there are just a lot of different ways climate change might influence health. we know very little about it at this point but it is growing in momentum.

pf: it seems that for a long time the environment has been viewed as this sort of waste sink. do you think this attitude over the past couple of decades is changing? why or why not?

anenberg: i do think so. i think there is now recognition that to lead healthy lives we have to take care of our planet. this is the only planet we live on. there is this new frame of thinking that has evolved over just the past few years that some call “one health” or “planetary health” that taking care of our environment is really essential to safeguarding public health. this can be through making sure we are growing the right crops and making sure these crops are able to grow so we can sustain nutrition for people around the world. it could be ensuring that our glaciers aren’t melting so quickly that people are losing their access to clean water used for drinking water and irrigation. so, our public health is very intertwined with the state of the environment and i do think that is entering the conscience of the public as well.

pf: thank you. my final question here is for citizens concerned about the health and climate effects in their own communities. what is the best way to address these grievances?

anenberg: one of my favorite aspects of working on the issue of climate change, is that it is so multi-faceted. there are so many different way you can approach it. you can take the legal angle, you can come from a scientific standpoint — looking at climate science and how climate change will affect ecosystems and public health in your community. you can be a community organizer, you can run for public office. you can bring an economic skill set [to the issue]. there are just so many different angles to address this problem, and we need so many different [experts] to address it, because it is such a large problem. i think the opportunities for engagement are just endless.

this summer alone i must have been bitten nearly 30 times by a mosquito; each time, though annoyed, i wasn’t afraid for my life—but there are millions of people who fear that every day and their vulnerability is growing because of climate change.

i’m from connecticut; my house sits 100 yards from the mianus river park—an incredibly serene place to walk dogs, take hikes, and go fishing on the weekends. on any given hot summer day, this tranquil park transforms into a doggy playground, buzzing with the sounds of panting, overly excited neighborhood dogs and mosquitos breeding at the edge of the river. lurking in the dense forest are the ticks that silently attack, spreading lyme disease, another vector borne disease making its way across the northeast region of the united states.

eleven years ago, my mom was bitten by a tick infected with lyme disease, and that’s when her battle began. she suffered with an array of disparate symptoms for 8 years until her doctors diagnosed her 3 years ago, when she was finally able to begin immediate and aggressive treatment. luckily my mom has not been burdened with some of the worst symptoms, which can include nerve damage and heart problems, but she is not symptom free by any means; many people do experience these unimaginable symptoms.

richelle jones of old greenwich walks her dog “oliver” at mianus river park in stamford, conn. on monday august 27, 2012. photo: dru nadler via stamford advocate

it’s in our backyards, and it’s spreading…

according to the 2014 national climate assessment, several studies in the northeast have linked tick activity and lyme disease incidence to climate, specifically abundant late spring and early summer moisture. lyme disease will be more prevalent in the mianus river park in years to come, leaving many more people, like my mom, vulnerable to ticks bites that could transmit the disease.

lyme disease is a costly illness that takes its toll on the mind and body, and requires extensive treatment, especially when it goes undetected. my mom went eight years untreated – eight years. late diagnoses happen way too often, and many symptoms are simply not visible or consistent across patients.

according to the lyme disease association, in 1996 a “disseminated lyme case could cost over $61,000 to treat”, which today would be around $92,000. that’s 55% more than an american’s median yearly income of $51,000. we can’t afford to waste another penny fighting lyme disease, be we continue to do so because it’s our parents’ health and our neighbors dog, these are their battles that they can’t do it alone.

the costs are clearly high, but the stakes are even higher. this threat is imminent and global; it’s not just malaria in africa, or lyme disease in connecticut. more people are susceptible; these vectors are growing; by 2080, the projected expansion of tick habitat, according to the nca, includes much of the eastern half of the country. for a deeper understanding, interact with the map found in the 2014 nca and see how changes to our climate will affect the transmission cycle of lyme disease in the northeast region of the united states.

the maps show the current and projected probability of establishment of tick populations (ixodes scapularis) that transmit lyme disease. projections are shown for 2020, 2050, and 2080. source: brownstein et al. 2005 via the 2014 national climate assessment

lyme disease is spreading; everyone should be prepared and protected outdoors. right now, we can take preventative measures to reduce many of the future costs associated with climate change. while climate change will not reverse itself overnight, if we act soon and responsibly we may be able to reduce the likelihood that any more people will suffer from this exhausting, costly, and preventable disease.

if we don’t act now even our best adaptive efforts later may fall short. many more people like my mom could become vulnerable to the bites of infected ticks and mosquitoes. the ball is in our court; let’s make sure we make the right play—our futures and health are at stake.

lauren pollack is a junior at the george washington university majoring in political communication.