Monday, May 27, 2013

Rachel Carson: Is The World Heeding Silent Spring's Warning?

This Memorial Day is the anniversary of Rachel Carson's (1907-1964) birthday.
     by Kriss Perras Bland - Most known for her influential 1962 work, Silent Spring, Rachel Carson was a marine biologist, writer, and early environmental activist. This book has long been credited with setting into motion a massive environmental movement. The establishment in 1970 of the Environmental Protection Agency (EPA) too was a consequence of Silent Spring, in addition to its resulting public discourse. Her warnings on the use of pesticides, fertilizers and their ever-widening problem of polluting were in the beginning largely written-off as alarmist. The public and government then eventually took her work seriously. One of these people was the then newly elected President John F. Kennedy who later established a presidential commission to investigate environmental abuse based on Carson's allegations. Is the world today heeding her warnings?
     "Ironically, new research points strongly to a link between the disease Carson died from, breast cancer, and exposure to toxic chemicals. So in a sense, Carson was literally writing for her life when she wrote Silent Spring. She was also writing against the grain of an orthodoxy rooted in the earliest days of the scientific revolution: that man, and of course this meant the male of our species, was properly the center and the master of all things, and that scientific history was primarily the story of his domination -- ultimately, it was hoped, to a nearly absolute state," writes Vice President Al Gore in his introduction to the book. "When a woman dared to challenge this orthodoxy, one of its prominent defenders, Robert White Stevens, replied in terms that now sound not only arrogant but as quaint as the flat-earth theory: 'The crux, the fulcrum over which the argument chiefly rests, is that Miss Carson maintains that the balance of nature is a major force in the survival of man, whereas the modern chemist, the modern biologist and scientist, believes that man is steadily controlling nature.' The very absurdity of that world view from today's perspective indicates how revolutionary Rachel Carson was. Assaults from corporate interests were to be expected, but even the American Medical Association weighed in on the chemical companies' side. The man who discovered the insecticidal properties of DDT had, after all, been awarded the Nobel Prize. But Silent Spring could not be stifled. Solutions to the problems it raised weren't immediate, but the book itself achieved enormous popularity and broad public support."
     Carson writes eloquently on earth, environment, nature, fertilizers, pesticides and water, in fact the entire book is written so a layperson could easily understand.
     "Of all our natural resources water has become the most precious," writes Carson in the Silent Spring chapter Surface Waters And Underground Seas. "By far the greater part of the earth's surface is covered by its enveloping seas, yet in the midst of this plenty we are in want. By a strange paradox, most of the earth's abundant water is not useable for agriculture, industry or human consumption because of its heavy load of sea salts, and so most of the world's population is either experiencing or is threatened with critical shortages. In an age when man has forgotten his origins and is blind to even his most essential needs for survival, water along with other resources has become the victim of his indifference."
     Malibu Pier has recently received a beach bummer grade from Heal The Bay for its very poor water quality.
     "Los Angeles (L.A.) County leads Heal the Bay’s annual Beach Bummer List, with four locations in the ranking of the state’s 10 most polluted beaches," reports Heal The Bay. "Avalon Beach on Catalina Island, troubled by aging sewer infrastructure, holds the number one spot for the fourth time in five years."
     Heal The Bay's Top 10 Beach Bummers are:
     1.) Avalon Harbor Beach on Catalina Island (L.A. County)
     2.) Cowell Beach – at the wharf (Santa Cruz County)
     3.) Poche Beach (Orange County)
     4.) Cabrillo Beach harborside (Los Angeles County)
     5.) Malibu Pier (L.A. County)
     6.) Marina Lagoon (San Mateo County)
     7.) Doheny State Beach (Orange County)
     8.) Redondo Beach Pier (L.A. County)
     9.) Windsurfer Circle at Candlestick Point (San Francisco County)
     10.) Tijuana River Mouth (San Diego County)
     The Malibu Pier site is near the Malibu Pier on Carbon Beach, commonly known in popular culture as Billionaires Beach. It is monitored by the L.A. County Department of Public Health Environmental Health. The Malibu Pier site received an F for both dry and wet weather monitoring. The reason for the poor water quality was not immediately known to the organization, Heal The Bay, who states further monitoring and research is required to find out why.
     The world famous Surfrider Beach also received a poor grade for one of the monitoring seasons. It received a C in dry weather monitoring and an A+ in wet weather for the beach's breach location.
     "The entire Malibu Creek watershed drains into Malibu Lagoon. Beach water quality is often dramatically impacted when the Lagoon is breached," reports Heal The Bay.
     These grades are based on a 30-day period ending May 22, 2013. Yet this monitoring system is under threat.
     "In an alarming development, the U.S. EPA is once again recommending the complete elimination of its Beaches Grant Program, a key initiative for protecting public health at our nation’s beaches," reports Heal The Bay. "Nearly $10-million in beach water-quality monitoring money is on the chopping block in the Administration’s recently issued federal budget proposal for fiscal year 2014. Many counties in California rely solely on this money to conduct testing. "
     There are also endless published reports on plastic debris found in the world’s oceans, underlying the magnitude of this pollution problem. There are too an infinite number of types of plastic goods consumed by the public daily: plastic shopping bags, single-use plastic bags, such as sandwich and freezer bags, plastic bottles, cups and containers, a favorite of beachgoers, and the list goes on. The most long-lived of global macroscopic oceanic and beach pollutants is plastic.
     "The physical characteristics of polyethylene and polypropylene-based plastics, types of marine litter, show a high resistance to aging and minimal biological degradation. Marine litter is consistently between 60 and 80-percent plastic by mass," found a recent study by the  University of the Pacific in Stockton, and the Algalita Marine Research Foundation out of Long Beach.
     There are some bio-based plastics made from corn, wheat, tapioca and algae on the market and in development, reports the National Oceanic and Atmospheric Administration (NOAA) .
     "Bio-based plastics use a renewable carbon source instead of traditional plastics that source carbon from fossil fuels. Bio-based plastics are the same in terms of polymer behavior and do not degrade any faster in the environment," according to facts from NOAA. "Biodegradable plastics are designed to break down in a compost pile or landfill where there are high temperatures and suitable microbes to assist degradation. However, these are generally not designed to degrade in the ocean at appreciable rates."
     Malibu Pier was originally built in 1905, supported Frederick Hastings Rindge's Malibu Rancho, according to historical facts at the state's Parks And Recreation Department. It transported hides, grains, fruit and other agricultural products shipped from the pier. It is in addition to an economic and historical site, a sport fishing pier. It has been since 1934. Then most fishing gear was made of metal. Today, many fishing gear items are made of plastic, including nets, pots and traps, says NOAA.
     "Because of this, they last a long time when lost or discarded in the marine environment. Sitting at the bottom of the ocean or floating near the surface, these derelict fishing gear items pose an entanglement risk to marine species of all types, causing a problem termed ghostfishing," reports NOAA. "Entanglement can cause death due to drowning, starvation, physical damage and maiming; it presents issues of limited mobility, which can lead to laceration, infection and potential mortality; entangled animals can be seen as easy prey by predators."
     All of this plastic makes its way through ocean currents to places called gyres. The Great Pacific Garbage Patch (GPGP) is a layer of rubbish in the Pacific Ocean, in what is known as the Central North Pacific Gyre, which has been growing since the 1950s, according to the European Commission (EC).
     "A Gyre is a naturally occurring vortex of wind and currents that rotate in a clockwise direction in the northern hemisphere and counter-clockwise in the southern hemisphere. These create a whirlpool effect, whose vortex moves more slowly at the center, and that is where marine plastic debris collects," writes the gyre's clean-up site, gyrecleanup.org.
     Humankind produces 100-percent of the ocean's plastic pollution. It is an entirely preventable problem. Plastic is not biodegradable. It takes 450-years for a single plastic bottle to photodegrade, a process where the plastic breaks and splits into ever increasing smaller shards. These small plastics, less than 5-millimeters in length, are known as microplastics. These are subsequently consumed by marine animals. We humans in turn consume these polluted marine creatures in the world's great food chain. Thermo plastics in pellets are melted and formed into an enormous number of inexpensive consumer goods, many of which are discarded after a relatively short period of use and dropped haphazardly into watersheds. They then make their way to the ocean where some get ingested by marine life, found the  University of the Pacific and the Algalita Marine Research Foundation study.
     A separate study by the Scripps Environmental Accumulation of Plastic Expedition, or SEAPLEX, researchers found an estimated tens of thousands of tons of debris annually are ingested by fish in middle ocean depths of the North Pacific Ocean.
     "The first scientific results from an ambitious voyage led by a group of graduate students from Scripps Institution of Oceanography at UC San Diego offered a stark view of human pollution, and its infiltration of an area of the ocean that has been labeled as the Great Pacific Garbage Patch," writes Scripps. "The SEAPLEX team found evidence of plastic waste in more than nine-percent of the stomachs of fish collected during their voyage to the North Pacific Subtropical Gyre. Based on their evidence, authors Peter Davison and Rebecca Asch estimate fish in the intermediate ocean depths of the North Pacific ingest plastic at a rate of roughly 12,000 to 24,000 tons per year."
     Their results were published in the journal Marine Ecology Progress Series. (see: http://www.int-res.com/abstracts/meps/v432/p173-180/ )
     According to NOAA, there are five major Gyres in the oceans worldwide. They are the: North Atlantic Gyre; South Atlantic Gyre; Indian Ocean Gyre; North Pacific Gyre; South Pacific Gyre. Other Gyres worldwide are: The Tropical Gyres of the Atlantic Equatorial Current System, with two counter-rotating circulations, and the Pacific Equatorial Current System, where the Indian Monsoon Gyres reside, with two counter-rotating circulations in the northern Indian Ocean; The Subtropical gyres, which at its center is a high pressure zone; The Subpolar gyres, which form at high latitudes, at or around 60-degrees where circulation of surface wind and ocean water is anticlockwise in the Northern Hemisphere, around a low-pressure area, such as the persistent Aleutian Low and the Icelandic Low.
     Scientists believe all of these gyres contain plastic and persistent organic pollutants (POPs). These consist of carbon-containing chemical compounds that, to a varying degree, resist photochemical, biological and chemical degradation, writes gyrecleanup.org. The EPA describes POPs as toxic chemicals adversely affecting human health and the environment around the world.
     "Plastic debris accumulates POPs such as PCBs (polychlorinated biphenyls) up to 100,000 to 1-million times such levels found in seawater," according to NOAA. "Oceanic fragments have also tested positive for other POPs, such as DDT, PAHs (polycyclic aromatic hydrocarbons) and aliphatic hydrocarbons. Many of these pollutants, such as PCBs and DDTs, are known endocrine disruptors and developmental toxicants."
     According to Carey Friedman and Noelle Selin, of the MIT Center for Global Change Science, most POPs share similar chemistry, despite different sources such as:
     Industrial (PCBs, flame retardants)
     Pesticides (DDT, lindane)
Unintentional byproducts (PAHs, dioxins, furans)
     Of all the POP marine litter, the bottom line comes down to what is referred to as the Dirty Dozen, that is: aldrin ¹; chlordane ¹; dichlorodiphenyl trichloroethane (DDT)¹; dieldrin¹; endrin¹; heptachlor¹; hexachlorobenzene ¹, ²; mirex¹; toxaphene¹; polychlorinated biphenyls (PCBs) ¹,²; polychlorinated dibenzo-p-dioxins²(dioxins); polychlorinated dibenzofurans² (furans), according to the EPA.
     The refernce 1 means the pollutant is intentionally produced and 2 means it is unintentionally produced, or resultant from some industrial processes and combustion.(For more information, see the EPA table here: http://www.epa.gov/international/toxics/pop.html )
     Most of these are insecticides used on crops such as corn and cotton, or used to control malaria and typhus, or are other pest control substances used on such insects as fire ants, termites and mealybugs and the like.
     "Because they can be transported by wind and water, most POPs generated in one country can and do affect people and wildlife far from where they are used and released," says the EPA. "POPs persist for long periods of time in the environment. They can accumulate and pass from one species to the next through the food chain."
     The North Pacific Gyre, also known as the GPGP, is estimated to be twice the size of Texas, according to NOAA.
     "It swirls in the Pacific Ocean roughly between the coasts of California and Hawaii. Currently, an estimated 11-million tons and growing of floating plastic covers an area of nearly 5-million square miles in the Pacific Ocean, roughly 700-miles northeast of the Hawaiian Island chain and 1,000-miles off the coast of California," says gyrecleanup.org.
     It is the world's largest landfill: according to the EC's estimates, the GPGP spans an area roughly the size of Europe. The EU too has one at its frontdoor: it is called the Atlantic Garbage Patch (AGP).
     "While litter items can be found in this area, along with other debris such as derelict fishing nets, much of the debris mentioned in the media these days refers to small bits of floatable plastic debris. These plastic pieces are quite small and not immediately evident to the naked eye," according to NOAA.
     Another one is in the North Pacific in the Subtropical Convergence Zone (STCZ). This area, located north of the Hawaiian archipelago, has a high abundance of marine life, is a known area of marine debris concentration and is one of the mechanisms for accumulation of debris in the Hawaiian Islands, according to the gyre clean-up site. A third is called the Eastern Pacific Garbage Patch (EOGP).
     "Concentrations of marine debris have been noted in an area midway between Hawaii and California within the North Pacific Subtropical High, an area between Hawaii and California. Due to limited marine debris samples collected in the Pacific, it is still difficult to predict its exact content, size and location," reports NOAA.
     Because of the way plastic photodegrades, cleaning up these massive ocean landfills requires many resources and may cause more damage to the ocean area being cleaned.
     "This all adds up to a bigger challenge than even sifting beach sand to remove bits of marine debris," gyrecleanup.org tells us. "In some areas where marine debris concentrates, so does marine life, as in the STCZ. This makes simple skimming the debris risky—more harm than good may be caused. Remember that much of our ocean life is in the microscopic size range. For example, straining ocean waters for plastics, such as microplastics, would capture the plankton that are the base of the marine food chain and responsible for 50-percent of the photosynthesis on Earth. That's roughly equivalent to all land plants."
     The Pacific Ocean is the largest ocean in the world. Its long curling waves reach to the continents of the North and South Americas, the Antarctica, Asia and Australia.
     "While beachgoers may enjoy the pacific coastlines in cities such as San Diego and Malibu, California, the large expanse of the Pacific Ocean can be home to large amounts of pollution," National Geographic's Green Living tells us.
     The Pacific Ocean covers nearly 30-percent of Earth’s surface area, approximately 96-million square miles, or about 15-times the size of the continental US, reports gyrecleanup.org.
     "Surveying less than one-percent of the North Pacific Ocean, just a three-degree swath, requires covering approximately 1 x 106 km2. If you traveled at 11-knots, or 20 km/hour, and surveyed during daylight hours at approximately 10 hours per day, the area within 100m off of each side of your ship, it would take 68 ships one year to cover that area," calculates gyrecleanup.org.
     Now, add to that the fact that these areas of debris concentration have no distinct boundaries, move throughout the year and are affected by seasons, climate, El Niño and other such monumental obstacles, cleaning the patches becomes a more than difficult job.
     Other solutions are less massive in scope but just as effective. In California, 14-billion plastic bags are distributed annually and only 3-percent are recycled. Plastic bag ordinances currently cover 16-percent of the state’s population. The Malibu City Council voted unanimously in May 2008 to ban retailers from distributing single-use plastic shopping bags within city limits. They have joined numerous other green thinking cities that have recently adopted ordinances that curb the proliferation of plastic polluting bags. In 2011, a Supreme Court decision was handed down that the City of Manhattan Beach did not need an environmental impact report (EIR) to enact its 2008 plastic bag ordinance.
     "The door has been opened for other local jurisdictions to move forward with their own bans," said Californians Against Waste at that time.
     Big power brokers in the plastic bag industry though brought a legal challenge to the entire idea. They sought and failed against the Ban The Bag phenomenon.
     "This marked another big win as local governments continue to fight back against the Plastic’s Industry’s attempts to block local plastic bag ordinances through legal challenges," said Californians Against Waste. "A lawsuit filed by representatives for the Plastics Industry, claiming L.A. County’s ordinance banning single-use plastic violated Prop 26, was denied by the California’s State Supreme Court. L.A. County’s ordinance bans single use plastic bags in the unincorporated areas of the county, and requires stores that distribute paper bags to charge 10-cents per bag."
     In October 2011, Hilex Poly Co., LLC, based in Hartsville, South Carolina and the nation's largest plastic bag manufacturer and closed-loop recycling facility, announced they were filling a lawsuit against the County of Los Angeles in response to the County's decision to ban the use of plastic carry out bags and the imposition of the paper carry out bag charge. The LLC asked the court to declare the charge invalid and prohibit the County from enforcing the ordinance.
     In court documents, the plastic bag manufacturer stated they, "contend the ordinance violates article XIII C of the California Constitution, as amended by Proposition 26, because the 10-cent charge is a tax and was not approved by county voters."
     The March 23, 2012 decision states, "We conclude the paper carryout bag charge is not a tax for purposes of article XIII C because the charge is payable to and retained by the retail store and is not remitted to the county. We therefore will affirm the judgment in favor of the county and other respondents."
     Some of the other respondents included: The 5 Gyres Institute; California League of California Cities; State Association of Counties as Amici Curiae on behalf of Defendants and Respondents; Frank G. Wells Environmental Law Clinic, Sean B. Hecht and Xiao Y. Zhang for Surfrider Foundation; Heal the Bay; Environment California Research and Policy Center; Seventh Generation Advisors as Amici Curiae.
     "Single-use plastic bags clog landfills, foul our public spaces, waste energy and threaten marine life," says Heal The Bay. "California taxpayers spend more than $25-million per year to collect and dispose of the 19-billion one-use plastic shopping bags distributed annually."
     Jennie R. Romer, Esq.,, Founder and Director of the organization plasticbaglaws.org, a resource for cities and states considering laws limiting the use of plastic bags, says "Plastic bag manufacturers are engaged in a well funded battle to maintain an unregulated marketplace for their product."
     Romer was instrumental in San Francisco expanding its plastic bag ban. 
     "More than two dozen nations and metropolitan areas have recently enacted limited bans on plastic bags, including China, San Francisco and Paris," reports the  organization Californians Against Waste.
     Since L.A. County supervisors banned single-use plastic bags in July 2011 in unincorporated L.A. County, there has been a 95-percent reduction of single-use bag distribution, according to the L.A. County Department of Public Works.
     The most comprehensive list of California cities and counties with plastic bag ordinances at the Californians Against Waste.Website, cawrecycles.org.
     "American manufacturers admit to releasing 4-billion pounds of pollutants into our air and waterways annually," says gyrecleanup.org. "Collectively we humans make over 100,000 synthetic chemical compounds that take hundreds of years to break down. Many of these pollutants are known carcinogens and are harmful to both animals and humans when ingested. Studies have also shown that these ocean-borne plastic particles contain POP levels up to one-million times higher than in the surrounding sea water. For this reason, scientists refer to the Gyre as toxic soup.”
     Carson writes of this toxic soup in a global environmental perspective
     "The problem of water pollution by pesticides can be understood only in context, as part of the whole to which it belongs -- the pollution of the total environment of mankind," writes Carson, in Silent Spring in the chapter Surface Waters And Underground Seas. "The pollution entering our waterways comes from many sources: radioactive wastes from reactors, laboratories and hospitals; fallout from nuclear explosions; domestic wastes from cities and towns; chemical wastes from factories. To these is added a new kind of fallout -- the chemical sprays applied to croplands and gardens, forests and fields. Many of the agents in this alarming mélange imitate and augment the harmful effects of radiation, and within the groups of chemicals themselves there are sinister and little-understood interactions, transformations and summations of effect."
     According to a recent study where bed and suspended sediment samples were analyzed for 55 different pesticides, in the bed sediment samples, 17 pesticides were detected. This included pyrethroid and organophosphate (OP) insecticides -- DDT (dichloro-diphenyl-trichloroethane) and its degradates, in addition to several herbicides. The only pesticides detected more than half the time were dichlorodiphenyldichloroethane  (DDD),dichlorodiphenyldichloroethylene (DDE), a breakdown product of DDT and DDT itself.
     "The greatest number of pesticides were detected in samples collected from Lower Orcutt Creek, the major tributary to the Santa Maria estuary. In suspended sediment samples, 19 pesticides were detected. The most frequently detected pesticides were DDE, at 49-percent, DDT at 38-percent and chlorpyrifos at 32-percent," found the recent study, titled Occurrence of Pesticides In Surface Water And Sediments From Three Central California Coastal Watersheds, 2008–2009: U.S. Geololgical Survey (USGS) Data Series, conducted in 2011 by K.L. Smalling and J.L Orlando.
     DDE and DDD are chemicals similar to DDT that contaminate commercial DDT preparations, reports the United States Center For Disease Control (CDC). 
     "DDE has no commercial use, and DDD was also used to kill pests, but its use has also been banned. One form of DDD has been used medically to treat cancer of the adrenal gland," according to the CDC.
     Based on the Center's reports, exposure to DDT, DDE and DDD occurs mostly from eating foods containing small amounts of these compounds, particularly meat, fish and poultry.
     "High levels of DDT can affect the nervous system causing excitability, tremors and seizures," reports the Center.
     There is abundant evidence that some carnivores at the ends of longer food chains, such as ospreys, pelicans, falcons, and eagles, suffered serious declines in fecundity and hence in population size because of this phenomenon of biomagnification in the years before use of DDT was banned (1972) in the United States, says  Dr. John W. Kimball, a retired Harvard Professor.
     Biomagnification is "the sequence of processes in an ecosystem by which higher concentrations of a particular chemical, such as the pesticide DDT, are reached in organisms higher up the food chain, generally through a series of prey-predator relationships," according to Oxford University. This process transpires from plankton, the base of the food chain, or primary producers, all the way up to humans.
     "The concentration effect occurs because DDT is metabolized and excreted much more slowly than the nutrients that are passed from one trophic level to the next," according to Dr. Kimball. "So DDT accumulates in the body, especially in fat. Thus most of the DDT ingested as part of gross production is still present in the net production that remains at that trophic level. This is why the hazard of DDT to nontarget animals is particularly acute for those species living at the top of food chains. For example, spraying a marsh to control mosquitoes will cause trace amounts of DDT to accumulate in the cells of microscopic aquatic organisms, the plankton, which are primary producers, in the marsh. In feeding on the plankton, filter-feeders, like clams and some fish, harvest DDT as well as food. Concentrations of DDT 10-times greater than those in the plankton have been measured in clams. The process of concentration goes right on up the food chain from one trophic level to the next. Gulls, which feed on clams, may accumulate DDT to 40-time or more the concentration in their prey. This represents a 400-fold increase in concentration along the length of this short food chain. "
     Carson biographer Linda Lear, at rachelcarson.org and author of Rachel Carson: Witness for Nature (1997), writes, "Disturbed by the profligate use of synthetic chemical pesticides after World War II, Carson reluctantly changed her focus in order to warn the public about the long term effects of misusing pesticides. In Silent Spring she challenged the practices of agricultural scientists and the government, and called for a change in the way humankind viewed the natural world. Carson was attacked by the chemical industry and some in government as an alarmist, but courageously spoke out to remind us that we are a vulnerable part of the natural world subject to the same damage as the rest of the ecosystem. Testifying before Congress in 1963, Carson called for new policies to protect human health and the environment. Rachel Carson died in 1964 after a long battle against breast cancer. Her witness for the beauty and integrity of life continues to inspire new generations to protect the living world and all its creatures."
     Her book and the public discussion that followed led to a ban on DDT. Yet today DDT is still manufactured in the U.S. for sale outside this country.
     "Rachel Carson's book Silent Spring in 1962 stimulated widespread public concern over the dangers of improper pesticide use and the need for better pesticide controls," writes the EPA. "DDT was developed in the 1940s as the first of the modern synthetic insecticides. It is known to be very persistent in the environment, will accumulate in fatty tissues and can travel long distances in the upper atmosphere. Since the use of DDT was discontinued in the United States, its concentration in the environment and animals has decreased, but because of its persistence, residues of concern from historical use still remain."
     In 1972, the EPA issued a cancellation order for DDT based on adverse environmental effects of its use, such as those to wildlife, as well as DDT’s potential human health risks. Since then, studies have continued, and a causal relationship between DDT exposure and reproductive effects is suspected. Today, DDT is classified as a probable human carcinogen by the United States and international authorities. This classification is based on animal studies in which some animals developed liver tumors. 
     Today, atmospheric deposition is the current source of new DDT contamination in our Great Lakes. This occurs when pollutants travel from the air into the water through rain and snow, falling particles and absorption of the gas form of pollutants into the water. DDT, and its break-down products DDE and DDD, are persistent, bioacculumative and toxic (PBT) pollutants target by EPA.
     "These PBT substances can accumulate in wildlife, causing reproductive problems and other harmful effects," writes the EPA. "Many fish in the Great Lakes have high concentrations of these pollutants, thousands or even millions of times higher than levels in the water, making them unsafe for both people and wildlife to eat. In humans, PBTs have been linked to reduced birthweight, developmental problems in children, neurological problems and immune system disorders. Many are also suspected carcinogens."
     "DDT was initially used with great effect to combat malaria, typhus and the other insect-borne human diseases among both military and civilian populations, and for insect control in crop and livestock production, institutions, homes and gardens," writes the EPA. "DDT's quick success as a pesticide and broad use in the U.S. and other countries led to the development of resistance by many insect pest species."
     Rachel Carson Mini-Biography:
     Rachel Louise Carson was born May 27, 1907 in Springdale, Pennsylvania.
      "Carson, the youngest of three children, spent her childhood on 65-acres of woods and farm land about 14-miles outside of Pittsburgh," Chatham University, her alma mater, writes in their Rachel Carson Collection, College Archives.
     Her writing career began early on when St. Nicholas Magazine published in September 1918 her work A Battle in the Clouds, Chatham continues. The work is a short story about an aviator who fights a courageous arial battle against a German enemy plane. Later in life, Carson wrote with elegance on nature and anthropogenic causes of pollution.
     Due in part to biology professor Mary Skinker, she decided to switch her major from English to Science during the middle of her junior year, writes Chatham in their Carson Collection.
     "Carson graduated Magna Cum Laude with a degree in Science in 1929, and a scholarship to study for a Masters in Zoology at Johns Hopkins University. On May 26, 1952 Chatham, then named the Pennsylvania College for Women, presented Carson with an honorary Doctor of Literature," reports Chatham.
     Carson died after fighting breast cancer on April 14, 1964 in Silver Spring, Maryland.

Image Credits:

Rachel Carson, 1963, Paley Center For Media.

Deposition, U.S. EPA graphic

Dr. John W. Kimball: Biomagnification: The figure shows how DDT becomes concentrated in the tissues of organisms representing four successive trophic levels in a food chain.