Wednesday, April 16, 2014

Chytrid in Amphibians: A Worldwide Problem

A victim of chytrid: Southern Corroboree frog.
 One of Australia's most endangered and colorful frogs.
Only about 50 remain in the wild.

             Amphibian populations are decreasing all over the world.  Chytrid is a deadly disease that only    affects amphibians.  Chytrid is a skin fungus, called Batrachochytrium dendrobatidis, or B.d. and was discovered in 1999 as the causative agent for rapid amphibian die-offs.  This fungus causes amphibians’ skin to thicken and leads to cardiac arrest.  At least 350 species of amphibians have been infected with chytrid, and 200 of those species have suffered massive population reductions or extinctions.  Chytrid fungus is the leading cause of amphibian extinction worldwide and has been documented in North America, South America, Africa, Australia, Asia, and Europe.  This disease is devastating amphibian populations all over the world.

The global distribution of chytrid., Batrachochytrium dendrobatidis (Bd) assessed in 2013.
Image credit: Olson et al. (2013)

North America
            Despite the fact that chytrid spreads easily and is deadly, frogs are still being imported and exported from country to country.  One example of importation is the American Bullfrog.  American Bullfrogs are native to the U.S., but they are raised all over the world in factory farms, and every year millions are imported as food and pets.  A study testing for the presence of chytrid was done on 493 fresh bought frogs from markets in San Francisco, Los Angeles, and New York.  The results showed that 62 percent of the frogs were infected with chytrid.  Although it’s not known if bullfrogs introduced chytrid to the U.S., they are still a constant source of infection.
            Amphibian populations in the United States are declining so quickly that they could actually disappear from half of their habitats within the next 20 years. Endangered amphibians in the U.S. could disappear from half of their habitats in 6 years.  A study discovered that on average, 3.7% of the amphibian population is lost every year in the U.S, and species that are threatened or endangered are declining at an average rate of 11.6% every year.  The specific cause of these amphibian deaths was not determined, although chytrid almost certainly played its role in the massive die-offs, because even in areas where the habitat is protected die-offs still occur.
South America
            Manu National Park in Peru has the most diverse amphibian population in the world and has approximately 155 species of amphibians.  This park ranges from lowland Amazonian rainforests to high-altitude cloud forests along the eastern slope of the Andes.  Frogs in this park are being affected by chytrid.  The chytrid fungus is threatening the biodiversity present in this park and threatens amphibian populations all over the world. 
            In Chile the Darwin’s frog has been hit hard by chytrid.  One species of this frog has been pushed to probable extinction, while the other species has suffered a severe decline in population.  The decline of the Darwin’s frog is one of the first instances in which the fungus has been directly implicated in its disappearance.  The spread of chytrid to Chile may be from the introduction of the African clawed frog to the region in the mid-20th century.   
            A new chytrid species has been identified, Batrachochytrium salamandrivorans, “the salamander-eating fungus.”  Fire salamanders in Europe have been greatly affected by chytrid, and one of the last surviving populations is found in Bunderbos in the southern Netherlands.  In some cases, and in the case of the fire salamander, preemptive testing was done on rare and endangered amphibians, and early detection of chytrid allowed for the establishment of captive breeding populations.  In addition to the Netherlands, chytrid has also been discovered in the United Kingdom.  Not much is known about its distribution in the U.K, and studies are being done to map the presence of disease in order to understand how it spreads so that a plan of action can be made.
            American bullfrogs farmed in Southeast Asia, used in commercial trade, were found to test positive for chytrid in Singapore.  The American bullfrog is tolerant of chytrid infections, so it may just act as a carrier for spreading chytrid to a region when it is imported for commercial trade.  A co-author of the study investigating the presence of chytrid in Singapore, Assistant Professor David Bickford, from the Department of Biological Sciences at the NUS Facility of Science,  says “In light of the fact that this emerging infectious disease is now known to be spread by commercial trade, it is in everyone's best interest to eliminate it from the trade in live animals before both the native amphibian populations of Southeast Asia are affected and before it completely decimates the commercial trade and people are unable to make a living. This is not just about the frogs.”
Grim Future
            Amphibian populations continue to suffer massive population reductions all over the world due to chytrid.  The international trade of amphibians allows for the continuous spread of this disease.  Unless a treatment is developed or the international trade is stopped, amphibian populations all over the world will continue to decline and eventually face the threat of extinction. 

Tuesday, April 15, 2014

         Many environmentalists have heard about the Great Pacific Garbage Patch but not many have heard about the garbage patches in other oceans. There are five other garbage patches including one that sits just hundreds of miles off the coast on The United States; this is the Atlantic Garbage Patch. The main part of the Atlantic garbage patch reaches from 22°N to 38°N. This is equivalent to the distance between Virginia and Cuba. There is no knowledge of how tall the patch reaches because no one has yet to venture the whole length.

The average plastic concentration in the North Atlantic
Garbage Patch.
         The Atlantic Garbage Patch is invisible from space and it can sometimes not been seen from the deck of a boat. Contrary to popular belief, the patch is not a large floating island of plastic waste. The plastic has been broken down by the sun drying it out. There are 520,000 fragments per square mile in the Atlantic patch.  90% of which are plastic. Eighty percent of the garbage in the Atlantic had comes from land sources. Either it has been dumped a lot the beach or has been blown from open waste disposals. The ocean currents concentrate the garbage in a gyre. It took 22 years to map out the concentrations of the garbage in the Atlantic. The concentrations in the Atlantic have not increased by a notable amount compared to the other garbage patches that on average have increased by 5x.
         One of the major issues with the patch is its impact on aquatic life. As many as 100,000 marine animal die from trash-related deaths each year. Birds eat the plastic and cannot break it down and it causes them to not receive nutrients that it needs to survive. Aquatic life can get plastic rings stuck around their necks and choke because of it. Bottle caps, balloons, and plastic wrap can be a choking hazard. Filter feeders can mistake the fractions of the plastic for fish eggs. Barnacles can drift to non-native areas by being stuck to the plastic. Also the plastic degrades in the water due to the sunlight and it releases toxins into the water that can bioaccumulate.

       Because of the damage to marine life a clean-up strategy needs to come very soon. It is said that this issue is caused by population growth and having more waste. The other issue is that only 7% of plastic in the United States is recycled. Clean-up would be difficult because the particles are small and hard to see until you take a net and collect them. Some of the particles drift down to 300 ft. below the surface. One idea to make the plastic marketable by turning it into fuel but the patch is too far away from the shore that it would take too long to gather the resources. It would also take up massive amounts of time. Taking nets to the water could endanger the marine life. The most realistic option is to stop the spread on beaches and have better waste disposal by the coasts. 

Monday, April 14, 2014

Meat and Antibiotic Combo, Please

Antibiotics are well-known products that help treat bacterial infections in animals and humans.  They have been considered live savers for a long period of time and have helped to cure many diseases that were once considered fatal.  However, many doctors advise that individuals do not overuse this type of medication because bacteria can easily become resistant.

Even though the above information is available, it has been estimated that approximately 70% of the antibiotics produced in the United States are used for livestock.  The animals are forced to ingest the excessive medication because it is believed to enhance growth, promote feed efficiency and prevent diseases and infections.  This is becoming an issue because the extensive use is causing mutations of many bacteria.  These microbes are antibiotic-resistant “superbugs.”  Once the microbes leave the bodies of the affected cows, pigs, chickens, etc., they enter groundwater, compost and fertilizers.  The result is the contamination of meat, water and other non-meat foods.  Many human infections and diseases are occurring.  The most common disease is Salmonella, associated with poultry, which can result in hospitalizations and very low treatment success.  The bacterium that causes the infection is resistant to animal and human antibiotics.
The misuse of antibiotics is common not only in America, but also around the world.  For example, China also uses these products as a way to increase the size of livestock.  The issue here is that many of the superbugs are present in groundwater and compost, and are being linked to high rates of human infections.  Furthermore, antibiotic-resistance is more of a problem here because China uses four times as much as the United States for livestock alone.  Another example is the outbreak of poultry-related human infections in Germany.  At one point, 96% of the meat birds were being fed antibiotics, even if they were healthy, to prevent future diseases.  This has caused the formation of resistant bacteria in many regions, specifically extended-spectrum beta-lactamase.  ESBL is considered a superbug, which is introduced to humans via drinking water or contaminated vegetables.  Many of the farmers around the world intend to continue using the antibiotics, but only because they fear losing a large number to illness that may be easily prevented.  But what they do not understand is that they are only causing more possible infections by continuing the use of unnecessary medications.

There has to be something to look forward to, right?  Well, if you have ever eaten at Chipotle, I am sure you have heard or read the slogan “Food with Integrity.”  What this means is that their animal products are free of antibiotics and growth hormones.  The chain made the switch nearly a decade ago when they realized pork sales had dropped.  Not only customers noticed this change, but so did other food providers; Hyatt Hotels, Bon Appetit Management Co. and even Wal-Mart are offering the option of antibiotic-free meats.  This is good news because consumers have an opportunity to choose safer, healthier products.  It has also increased the demand for farmers who refrain from feeding their animals unnecessary medications.

Many individuals are hopeful of this current movement away from antibiotic use in livestock.  The Food and Drug Administration is currently working on a voluntary relabeling program for drug companies.  Some of the current and most previous antibiotic labels indicated that these products promote growth and feed efficiency.  This is a problem because most of the animals are not sick but are still being fed these medications.  One company has already changed the description to “"only for therapeutic purposes of treating, controlling and preventing diseases…”  The FDA requests that antibiotics are only used for sick animals, under the care and supervision of a veterinarian, and by prescription only.  With the decreased abuse of medications, superbugs and other resistant bacteria will correspondingly decline.  If we follow this path, the future should offer healthier animals and humans.

Saturday, April 12, 2014

Chemical Contaminants and our Drinking Water

On January 10th, 2014 in Charleston, West Virginia, residents surrounding the Elk River were advised not to drink, bathe in, or cook with tap water.  A total of 5000 gallons of MCHM (4-methylcyclohexane methanol) was accidentally released, affecting 300,000 people.
A similar situation occurred on February 2nd 2014, with 82,000 tons of toxic coal ash spilled into the Dan River, near the border of North Carolina and Virginia.  Coal ash contains arsenic, mercury, lead, thallium, among other contaminants.  Like the West Virginia spill, state health officials warned people not to swim or eat fish from the river.

These examples illustrate a growing problem of contamination of United States water.  Typically, chemicals in the United States are introduced into the market without rigorous testing, unless they pose a serious health hazard to aquatic, terrestrial or human life.  This saves money and time on testing, but it may come at a price to human and environmental health.

The above figure represents data from 2004-2009 for tap water that American’s received with all chemicals found and unregulated chemicals, including those over health guidelines.  (, Environmental Working Group)
In 2009, only 91 contaminants were regulated by the Safe Drinking Water Act, yet more than 60,000 chemicals were used within the United States.  The number of chemicals in use has risen to 80,000 at the end of 2013, which most have unknown health risks.  William K. Reilly, the E.P.A. administrator under President George H. W. Bush said, “For years, people said that America has the cleanest drinking water in the world, which was true 20 years ago.  But people don’t realize how many new chemicals have emerged and how much more pollution has occurred. If they did, we would see very different attitudes.” 
There has been opposition to testing chemicals for their potentially hazardous effects.  Opponents say that drinking water that does not meet a federal health guideline will not necessarily make someone ill.  Many contaminants are hazardous only if consumed for years, and some researchers argue that even toxic chemicals, when consumed at extremely low doses over long periods, pose few risks.
Others argue that the cost of removing minute concentrations of chemicals from drinking water does not equal the benefits.
Some say testing chemicals is a waste of time, as chemicals not tested yet probably aren’t a serious threat. And since science is complicated, often based on extrapolations from animal studies, and sometimes hard to apply nationwide, it is not worth the effort.     
Not only do chemical spills compromise the quality of our drinking water, but droughts, floods and chronic pollution from personal care products and pharmaceuticals (PPCP) do as well.  Flooding from Hurricane Floyd in 1999 flushed hog waste into waterways which caused widespread fecal contamination.  A report found that 254,000 people in the Tulare Lake Basin and Salinas Valley are at risk for nitrate contamination of their drinking water with the current drought in California.  PPCP’s like antibiotics, steroids, soaps, shampoos, and lotions are washed down the drain and sewage treatment plants are not equipped to remove them.
Industry and poor environmental regulations in China have also seriously affected the water quality.  Measured by the government’s standards, more than half of the country’s largest lakes and reservoirs were so contaminated in 2011 that they were unsuitable for human consumption.  Nearly three-fifths of all water supplies are “relatively bad” or worse.  Water quality degradation is the result of quick progress and the failure to keep up with the country’s quick industrialization. 
Hopefully in the future, development of chemical knowledge and more efficient technologies will help make water safer to use in the US and around the world.  Chemical contamination like the West Virginia spill demonstrates how quickly the trust that most people place in their drinking water can be destroyed.  Steve Fleischli, director and senior attorney for the Natural Resources Defense Council Water Program in Los Angeles says, “We often don't think about where our water comes from… if your water source is not protected, people face a real risk”.

Wednesday, April 9, 2014

Global Air Pollution

          Green technologies cannot develop fast enough as major cities around the world are dealing with the negative effects of pollution. High economic activity in many major cities is leading to increased air pollution. It has even gotten so bad that in the city of Shanghai, public transit drivers are getting lost on their daily routes due to smog coverage. What is the point of continuing economic growth in these areas if the health of the local environment deems the area unlivable? As the human population continues to grow and become more urbanized, personal as well as environmental health will become more of an issue.
            China seems to get the heat for being one of the worlds worst contributors to air pollution. Although some major cities in China (Beijing and Shanghai) do show aggressively high levels of particulate matter in the air, New Delhi ( in India) takes the cake. A recent measurement of this particulate matter in the air put New Delhi’s average daily peak reading at more than twice as much as Beijing’s. The focus may be stuck on China for now, but other major cities throughout the world are experiencing the same air quality issues. India has even been reported to have the world’s highest death rate due to chronic respiratory diseases. This particulate matter can make its way into lungs and degrade human health. Asthma is only one example of the many diseases caused by air pollution. A sad truth lies in the fact that both China and India were very resistant on setting lowered pollution limits in global climate talks. These countries are showing their reluctance on taking proactive and reactive steps to better the quality of life in these areas.
            Another issue that causes a decrease in air quality is trans-pacific and intercontinental air pollution. These types of air pollution will effect neighboring cities/states/countries of highly polluted areas as typical wind patterns carry bad air downstream. An example of trans-pacific air pollution can be found as the westerlies (northern hemisphere wind pattern) carry dangerous pollutants from a polluted China to the west coast of the United States. The United States, however, cannot act completely innocent as we outsource a lot of our products from China. The east coast of the United States can also serve as a victim to downstream air pollution as the Midwest continues to burn coal mercilessly. Some states in the Midwest seem to have more lenient emission regulations as compared to eastern states such as Connecticut and New Jersey who are experiencing these down-wind pollution effects. Current petitions are going out in an effort to halt some of these negative externalities faced by eastern states. Wind borne air pollution may be a global wake up call to curb carbon emissions.

            Resistance to cutting back on carbon emissions is beginning to meet its match. In Paris, France, police began pulling over vehicle’s with even number license plates and fined them an equivalence of 31 U.S dollars. Police will continue the enforcement of this new law in an effort to show citizens their effect on the environment. There are some exceptions to this law, which include individuals using hybrid vehicles, vehicles with three or more people, and motorcycles. These efforts need to be implemented throughout the world in cities facing dangerous levels of particulate matter in the air. As human population growth shows its devastating effects on all aspects of the environment, air pollution seems to be one of the most evident problems. Without action to combat our environmentally unsafe practices, human health on a global scale will take a hit.

Wednesday, March 19, 2014

The Fight Against Cancer and Associated Environmental Triggers

The fight against cancer is ever going, from the time we go to sleep, to the time we wake, being seen for thousands of years and throughout the world.  In today’s age the word itself is known by just about everyone, yet most people have no idea what exactly it is, what causes it, and how the environment we live in is contributing to it.
                As defined by the National Cancer Institute, cancer is a class of diseases in which abnormal cells divide without control and show the ability to spread (metastasize) throughout the body.  There are more than 100 types of cancers, in which are named for where they originate i.e. colon cancer originated in the colon.  In order to understand what cancer is it is helpful to understand that all cells divide in a controlled fashion, it is only when the genetic makeup of these cells is changed or damaged allows dangerous mutations to occur.  Researchers have estimated that as many as two-thirds of cases of cancer are linked in one way or another to an environmental factor
These environmental factors could be anything from the air we breathe, to the water and food we consume, to even exposure to radiation and infectious agents.  Certain types of exposures are linked to specific cancers.  For example, Benzidine (chemical found in various dyes) is linked to bladder cancer, exposure of asbestos is linked to lung cancer and certain carcinogens from tobacco use are linked to several types of cancer, including cancers of the mouth, lung, and esophagus.  
Globally people in Europe and North America and other more developed countries throughout the world are at the highest risk to be diagnosed with the disease compared to undeveloped countries.  On the other hand developed countries have a much higher rate of surviving the disease than that of undeveloped countries, due to better healthcare services and screening.  Pollution at all levels and various agents in more populated and industrial developed environments display a direct role in rates of cancer diagnosis.  Eradicating the disease is not as simple as just removing the carcinogens but rather changing the lifestyle and way of life of millions.  Denmark is known as the “Cancer Capital of the World” due to its high air carcinogen pollution and unhealthy life styles.  With 326 of 100,000 people each year developing the new disease each year, the country is a place most would put towards the bottom of their vacation destinations.

From the time we are born to the time we die, we as mankind are exposed to carcinogens regularly.  Chemicals found is our gasoline such as benzene, radon in the basements of our homes, to even traces of arsenic in our drinking water are known carcinogens that are found in our everyday lives.  On October of 2013, the World Health Organization of all things added air pollution to the list of carcinogens, citing that the air we breathe killed over two-hundred thousand people with the only solution of  to “clean up the air”.  There are numerous regulations and restrictions already in place in American and numerous other countries to prevent carcinogens from entering our lives, yet they are everywhere.   Exercise and dieting is at the top of the list in prevention of the disease especially in the more prevalent overweight developed countries, supporting a direct “push” away from our unhealthy life styles.

It is estimated that one in every two men and one and every three women will be diagnosed with cancer in their lifetimes.  With such a high statistical rate in diagnosis linked to environmental causes this issue should be at the top of the list for environmental concern.