6.1.2: Waste Disposal - Biology

6.1.2: Waste Disposal - Biology

We are searching data for your request:

Forums and discussions:
Manuals and reference books:
Data from registers:
Wait the end of the search in all databases.
Upon completion, a link will appear to access the found materials.

There are three primary methods for waste disposal: open dumps, sanitary landfills, and incineration. Sanitary landfills and incineration prevent reuse, recycling, and proper decomposition. While open dumps promote decomposition better than other methods of waste disposal and allow discarded materials to be salvaged or recycled, they promote disease spread and cause water pollution. They are thus illegal in many countries.

Open Dumps

Open dumps involve simply piling up trash in a designated area and is thus the easiest method of waste disposal (figure (PageIndex{a})). Open dumps can support populations of organisms that house and transmit disease (reservoirs and vectors, respectively). Additionally, contaminants from the trash mix with rain water forming leachate, which infiltrates into the ground or runs off. This liquid leachate may contain toxic chemicals such as dioxin (a persistent organic pollutant), mercury, and pesticides.

Figure (PageIndex{a}): An open dump in Vietnam. Image by Julien Belli (CC-BY).

Sanitary Landfills

After recycling, composting, and incineration, the remaining 50% of municipal solid waste (MSW) in the U.S. was discarded in sanitary landfills (figure (PageIndex{b})). Trash is sealed from the top and the bottom to reduce contamination of surroundings (figure (PageIndex{c})). Rainwater that percolates through a sanitary landfill is collected in the bottom liner, and this bottom layer thus prevents contamination of groundwater. The groundwater near the landfill is closely monitored for signs of contamination from the leachate. Layers of soil on top prevent disease spread. Each day after garbage is dumped in the landfill, it is covered with clay or plastic to prevent redistribution by animals or the wind.

Figure (PageIndex{b}): A sanitary landfill in 1972. Image by Bill Shrout/EPA (public domain).

Figure (PageIndex{c}): A sanitary landfill. Trash is compacted and stored underground. A landfill liner prevents leachate from draining into the aquifer and contaminating groundwater, which is monitored using a well. Additionally, leachate is collected and treated. A clay cap prevents animals or wind from accessing the trash. A methane gas recovery system captures the potent greenhouse gas, which can be used as a biofuel. Image by EPA/National Energy Education Development Project (public domain).

Several practices can reduce the environmental impact of sanitary landfills. Compacting in landfills reduces water and oxygen levels, slowing decomposition and promoting methane release. In the U.S., the Clear Air Act requires that landfills of a certain size collect landfill gas (biogas), which can be used as a biofuel for heating or electricity generation. Other gases such as ammonia and hydrogen sulfide may also be released by the landfill, contributing to air pollution. These gases are also monitored and, if necessary, collected for disposal. To address the often dry condition of wastes within landfills, the concept of bioreactor landfills has emerged. These recirculate leachate and/or inject other liquids to increase moisture and promote decomposition (and therefore increasing the rate of biogas production). Upon closure, many landfills undergo "land recycling" and can be redeveloped as golf courses, recreational parks, and other beneficial uses.

With respect to waste mitigation options, landfilling is quickly evolving into a less desirable or feasible option. Landfill capacity in the United States has been declining for several reasons. Older existing landfills are increasingly reaching their authorized capacity. Additionally, stricter environmental regulations have made establishing new landfills increasingly difficult. Finally, public opposition delays or, in many cases, prevents the approval of new landfills or expansion of existing facilities.


Incineration is simply burning trash. This has several advantages: it reduces volume and can be used to generate electricity (waste-to-energy). In fact, the sheer volume of the waste is reduced by about 85%. Incineration is costly, however, and it pollutes air and water. Air pollutants released by incineration include particulates, sulfur dioxide, nitrogen oxides, methane, heavy metals (such as lead and mercury), and dioxins. The byproduct of incineration, ash, is often toxic. Depending on its composition, ash might require special disposal; other types of ash can be repurposed.

An incinerator processes trash and burns it in a combustion chamber (figure (PageIndex{d-e})). The heat boils water, and the resultant steam is used to generate electricity. The smoke (called flue gases) goes through a pollution-removal before it is released, but it still contains some pollutants. The U.S. incinerated 11.8% of MSW in 2018.

Figure (PageIndex{d}): Wheelabrator Technologies' Waste-to-Energy plant in Saugus, Massachusetts has been in service since 1975. Image and caption (modified) from Fletcher6 (CC-BY).

Figure (PageIndex{e}): A waste incinerator (waste-to energy system). A grabber collects the waste and transfers it into the incinerator. Heat from combusting the trash is used to produce steam and generate electricity. Emissions (flue gases) pass through a scrubber and particulate removal system to limit pollution before the gases are released through a chimney. Ash remains after incineration. Image by Kaza, Silpa; Bhada-Tata, Perinaz. 2018. Decision Maker’s Guides for Solid Waste Management Technologies. Urban Development Series Knowledge Papers;. World Bank, Washington, DC. © World Bank. (CC-BY)

You can watch the video below to take a virtual tour of an incinerator.

There are two kinds of waste-to-energy systems: mass burn incinerators and refuse-derived incinerators. In mass burn incinerators all of the solid waste is incinerated. The heat from the incineration process is used to produce steam. This steam is used to drive electric power generators. Acid gases from the burning are removed by chemical scrubbers. Any particulates (small particles that remain suspended in the air) in the combustion gases are removed by electrostatic precipitators, which charge particulates and remove them with electrodes. The cleaned gases are then released into the atmosphere through a tall stack. The ashes from the combustion are sent to a landfill for disposal.

It is best if only combustible items (paper, wood products, and plastics) are burned. In a refuse-derived incinerator, non-combustible materials are separated from the waste. Items such as glass and metals may be recycled. The combustible wastes are then formed into fuel pellets which can be burned in standard steam boilers. This system has the advantage of removing potentially harmful materials from waste before it is burned. It also provides for some recycling of materials.

In the past, communities around the world used the ocean for waste disposal, including the disposal of chemical and industrial wastes, radioactive wastes, trash, munitions, sewage sludge, and contaminated dredged material. Little attention was given to the negative impacts of waste disposal on the marine environment. Even less attention was focused on opportunities to recycle or reuse such materials. Wastes were frequently dumped in coastal and ocean waters based on the assumption that marine waters had an unlimited capacity to mix and disperse wastes.

Although no complete records exist of the volumes and types of materials disposed in ocean waters in the United States prior to 1972, several reports indicate a vast magnitude of historic ocean dumping:

  • In 1968, the National Academy of Sciences estimated annual volumes of ocean dumping by vessel or pipes:
    • 100 million tons of petroleum products
    • two to four million tons of acid chemical wastes from pulp mills
    • more than one million tons of heavy metals in industrial wastes and
    • more than 100,000 tons of organic chemical wastes.
    • 38 million tons of dredged material (34 percent of which was polluted),
    • 4.5 million tons of industrial wastes,
    • 4.5 million tons of sewage sludge (significantly contaminated with heavy metals), and
    • 0.5 million tons of construction and demolition debris.

    Following decades of uncontrolled dumping, some areas of the ocean became demonstrably contaminated with high concentrations of harmful pollutants including heavy metals, inorganic nutrients, and chlorinated petrochemicals. The uncontrolled ocean dumping caused severe depletion of oxygen levels in some ocean waters. In the New York Bight (ocean waters off the mouth of the Hudson River), where New York City dumped sewage sludge and other materials, oxygen concentrations in waters near the seafloor declined significantly between 1949 and 1969.

    6.1.2: Waste Disposal - Biology

    The Mississippi environmental regulations were renumbered and reformatted in 2013 pursuant to the amended Administrative Procedures Act passed by the state legislature which mandated that all state agencies have uniform numbering to conform to a statewide administrative code. The regulations, were effective August 26, 2013, and thereafter. Although the changes are not substantive, they affected the numbering and citation of all of the Mississippi Commission on Environmental Quality and the Mississippi Environmental Quality Permit Board regulations. While the numbering and citation of the regulations changed, the numbering, formatting and citation of the state environmental statutes remain the same. Beginning August 26, 2013, the regulations shall be referenced and cited consistent with standard form required by the Secretary of State.

    The regulations may also be viewed in the Administrative Code located on the Mississippi Secretary of State website.
    Use the drop down for “Agency Search” and select “Title 11 – Mississippi Department of Environmental Quality”, then click “Search.”

    The use of fly larvae for organic waste treatment

    The idea of using fly larvae for processing of organic waste was proposed almost 100 years ago. Since then, numerous laboratory studies have shown that several fly species are well suited for biodegradation of organic waste, with the house fly (Musca domestica L.) and the black soldier fly (Hermetia illucens L.) being the most extensively studied insects for this purpose. House fly larvae develop well in manure of animals fed a mixed diet, while black soldier fly larvae accept a greater variety of decaying organic matter. Blow fly and flesh fly maggots are better suited for biodegradation of meat processing waste. The larvae of these insects have been successfully used to reduce mass of animal manure, fecal sludge, municipal waste, food scrapes, restaurant and market waste, as well as plant residues left after oil extraction. Higher yields of larvae are produced on nutrient-rich wastes (meat processing waste, food waste) than on manure or plant residues. Larvae may be used as animal feed or for production of secondary products (biodiesel, biologically active substances). Waste residue becomes valuable fertilizer. During biodegradation the temperature of the substrate rises, pH changes from neutral to alkaline, ammonia release increases, and moisture decreases. Microbial load of some pathogens can be substantially reduced. Both larvae and digested residue may require further treatment to eliminate pathogens. Facilities utilizing natural fly populations, as well as pilot and full-scale plants with laboratory-reared fly populations have been shown to be effective and economically feasible. The major obstacles associated with the production of fly larvae from organic waste on an industrial scale seem to be technological aspects of scaling-up the production capacity, insufficient knowledge of fly biology necessary to produce large amounts of eggs, and current legislation. Technological innovations could greatly improve performance of the biodegradation facilities and decrease production costs.

    Keywords: Agricultural waste Bioconversion Food waste Maggot Manure.

    What do environmental engineers do?

    Environmental engineers use the principles of engineering, soil science, biology and chemistry to develop solutions to environmental problems, according to the BLS. Some projects involving environmental engineers include:

    • Roman Stocker of MIT studied the interactions between tiny marine organisms, their environment and their food sources, which led to a better understanding of how algae blooms occur. (Stocker also was the scientist behind recent research &mdash and popular high-speed video &mdash into how cats lap milk.)
    • Michael Nassry, who, as a Ph.D. student in biological systems engineering at Virginia Tech, studied how nutrients flow through glaciers in Alaska.
    • Glenn Morrison, an associate professor of environmental engineering at Missouri University of Science and Technology, is studying how methamphetamine accumulates in building materials, furniture and common household items during production.

    One of the most important responsibilities of environmental engineering is to prevent the release of harmful chemical and biological contaminants into the air, water and soil, the BLS says. This requires extensive knowledge of the chemistry and biology of the potential contaminants as well as the industrial or agricultural processes that might lead to their release. With this knowledge, new processes can be designed, or existing processes can be modified, to reduce or eliminate the release of pollutants.

    Another important function performed by environmental engineers is detecting the presence of pollutants and tracking them back to their source, the BLS says. In some cases, this can present a significant challenge. For instance, the source of contamination in a lake could be anywhere within several thousands of acres of land surrounding the lake and its tributaries. Contamination of oceans can present even greater challenges in identifying the source.

    Once the environmental engineer identifies a source of contamination, it must be stopped or significantly reduced. Simply shutting down a business is not always a viable option, because of the potential for severe economic consequences. Environmental engineers often work with businesses to determine ways to avoid or reduce the production of pollutants or to separate them so they can be disposed of in a safe manner.

    Critical skills needed by environmental engineers include a working knowledge of chemical engineering, fluid dynamics, geography, geology and hydrology. Also, because of the numerous legal issues involved and the prevalence of litigation in environmental issues, environmental engineers must be familiar with applicable laws, and many of them are also practicing attorneys.

    History of pollution

    Although environmental pollution can be caused by natural events such as forest fires and active volcanoes, use of the word pollution generally implies that the contaminants have an anthropogenic source—that is, a source created by human activities. Pollution has accompanied humankind ever since groups of people first congregated and remained for a long time in any one place. Indeed, ancient human settlements are frequently recognized by their wastes—shell mounds and rubble heaps, for instance. Pollution was not a serious problem as long as there was enough space available for each individual or group. However, with the establishment of permanent settlements by great numbers of people, pollution became a problem, and it has remained one ever since.

    Cities of ancient times were often noxious places, fouled by human wastes and debris. Beginning about 1000 ce , the use of coal for fuel caused considerable air pollution, and the conversion of coal to coke for iron smelting beginning in the 17th century exacerbated the problem. In Europe, from the Middle Ages well into the early modern era, unsanitary urban conditions favoured the outbreak of population-decimating epidemics of disease, from plague to cholera and typhoid fever. Through the 19th century, water and air pollution and the accumulation of solid wastes were largely problems of congested urban areas. But, with the rapid spread of industrialization and the growth of the human population to unprecedented levels, pollution became a universal problem.

    By the middle of the 20th century, an awareness of the need to protect air, water, and land environments from pollution had developed among the general public. In particular, the publication in 1962 of Rachel Carson’s book Silent Spring focused attention on environmental damage caused by improper use of pesticides such as DDT and other persistent chemicals that accumulate in the food chain and disrupt the natural balance of ecosystems on a wide scale. In response, major pieces of environmental legislation, such as the Clean Air Act (1970) and the Clean Water Act (1972 United States), were passed in many countries to control and mitigate environmental pollution.

    6.1.2: Waste Disposal - Biology

    by Jen Fong and Paula Hewitt

    Worm composting is using worms to recycle food scraps and other organic material into a valuable soil amendment called vermicompost, or worm compost. Worms eat food scraps, which become compost as they pass through the worm's body. Compost exits the worm through its' tail end. This compost can then be used to grow plants. To understand why vermicompost is good for plants, remember that the worms are eating nutrient-rich fruit and vegetable scraps, and turning them into nutrient-rich compost.

    Materials to use (and avoid) in a classroom worm bin

    For millions of years, worms have been hard at work breaking down organic materials and returning nutrients to the soil. By bringing a worm bin into the classroom, you are simulating the worm's role in nature. Though worms could eat any organic material, certain foods are better for the classroom worm bin.

    We recommend using only raw fruit and vegetable scraps. Stay away from meats, oils and dairy products, which are more complex materials than fruits and vegetables. Thus, they take longer to break down and can attract pests. Cooked foods are often oily or buttery, which can also attract pests.

    Avoid orange rinds and other citrus fruits, which are too acidic, and can attract fruit flies. Try to use a variety of materials. We have found the more vegetable matter, the better the worm bin. Stay away from onions and broccoli which tend to have a strong odor.

    Setting up a worm bin is easy. All you need is a box, moist newspaper strips, and worms. To figure out how to set up a worm bin, first consider what worms need to live. If your bin provides what worms need, then it will be successful. Worms need moisture, air, food, darkness, and warm (but not hot) temperatures. Bedding, made of newspaper strips or leaves, will hold moisture and contain air spaces essential to worms.

    You should use red worms or red wigglers in the worm bin, which can be ordered from a worm farm and mailed to your school. The scientific name for the two commonly used red worms are Eisenia foetida and Lumbricus rubellus.

    When choosing a container in which to compost with worms, you should keep in mind the amount of food scraps you wish to compost, and where the bin will be located. A good size bin for the classroom is a 5- to 10- gallon box or approximately 24" X 18" X 8". The box should be shallow rather than deep, as red wigglers are surface-dwellers and prefer to live in the top 6" of the soil..

    Whether you choose a plastic, wooden or glass container to use as a worm bin is a matter of personal preference based primarily on what is available. Some teachers have extra aquariums available. Some have wooden boxes which they would like to reuse. Others may prefer to buy or reuse a plastic container, such as commercially manufactured storage bin (e.g. "Rubbermaid," "Tucker," "Sterilite").

    No matter what material you choose, make sure to rinse out the container before using. For wooden bins, line the bottom with plastic (e.g. from a plastic bag or old shower curtain). Cover the bin with a loose fitting lid. This lid should allow air into the bin.

    If you take care of your worms and create a favorable environment for them, they will work tirelessly to eat your "garbage" and produce compost. As time progresses, you will notice less and less bedding and more and more compost in your bin. After 3-5 months, when your bin is filled with compost (and very little bedding), it is time to harvest the bin. Harvesting means removing the finished compost from the bin. After several months, worms need to be separated from their castings which, at high concentrations, create an unhealthy environment for them.

    To prepare for harvesting, do not add new food to the bin for two weeks. Then try one of two methods for harvesting:

    Push all of the worm bin contents to one half of the bin, removing any large pieces of undecomposed food or newspaper. Put fresh bedding and food scraps in empty side of bin. Continue burying food scraps only in freshly bedded half.

    Over the next 2-3 weeks, the worms will move over to the new side (where the food is), conveniently leaving their compost behind in one section. When this has happened, remove the compost and replace it with fresh bedding. To facilitate worm migration, cover only the new side of the bin, causing the old side to dry out and encouraging the worms to leave the old side.

    Dump the entire contents of the worm bin onto a sheet of plastic or paper. Make several individual cone-shaped piles. Each pile will contain worms, compost and undecomposed food and bedding. As the piles are exposed to light,, the worms will migrate towards the bottom of the pile. Remove the top layer of compost from the pile, separating out pieces of undecomposed food and newspaper. After removing the top layer, let pile sit under light for 2-3 minutes as the worms migrate down. Then remove the next layer of compost. Repeat this process until all of the worms are left at the bottom of the pile. Collect the worms, weigh them (for your record keeping) and put them back in their bin with fresh bedding.

    Regardless of which method you choose, the compost you harvest will most likely contain a worm or two, along with old food scraps and bedding. If you are using the compost outdoors, there is no need to worry--the worms will find a happy home and the food scraps and bedding will eventually decompose. If you are using the compost indoors, you may want to remove old bedding and food scraps for aesthetic purposes and ensure that there are no worms in the compost. Though the worms will not harm your plants, the worms may not like living in a small pot.

    For both methods, you may continue to compost your food scraps after harvesting. Just add fresh bedding and food scraps. If, for some reason, you do not want to continue composting, please offer the setup to another teacher or to someone who will take the worm bin home. Anyone with a garden will find the worm compost extremely valuable. As a last resort, if you cannot find anyone who wants good worm compost, you may add the worms to a garden bed.

    You can use your compost immediately, or you can store it and use it during the gardening season, or whenever. The compost can be directly mixed with your potting soil or garden soil as a soil amendment, which helps make nutrients available to plants. Or, the compost can be used as a top dressing for your indoor or outdoor plants.

    You can also make "compost tea" with your compost. Simply add 1-2" of compost to your water can or rain barrel. Allow compost and water to "steep" for a day, mixing occasionally. Then water plants as you normally would. The resulting "tea" helps make nutrients already in the soil available to plants.

    Worms can live for about one year in the worm bin. If a worm dies in your bin, you probably will not notice it. Since the worm's body is about 90% water, it will shrivel up and become part of the compost rather quickly. New worms are born and others die all the time.

    Worms are hermaphrodites, which means they are both male and female at the same time. In order to mate, they still require two worms. The worms line up in opposite directions near their band (or clitellum), which contains some of the sexual organs. The worms are attached for about 15 minutes while they exchange sperm cells. Several days later, eggs come in contact with the sperm cells and form a cocoon, or egg case. The cocoon separates from the worm, then fertilization takes place. Inside the cocoon, 2-5 baby worms may be found.

    The baby worms live in the egg case for at least 3 weeks, sometimes longer depending on the surrounding conditions. For example, in the winter time, baby worms may stay in the cocoon for many weeks until the temperature warms up again. When the baby worms eventually crawl out, they are the thickness of a piece of thread and possibly 1 cm 1/4" long. Usually the worms appear white, as they have not yet developed pigmentation, or do not have enough pigmentation (or blood) to be seen.

    Successful vermicompost projects

    Many schools have been successfully composting with worms over the past few years. Some elementary school classes keep worm bins as part of an environmental unit, others for science. In most cases, teachers find a variety of multidisciplinary ways to use a worm bin. For example, one class called their room the "Worm World." Writing assignments, math lessons and art work focused on worms as a theme.

    AQA GCSE Grade 9-1 Biology Foundation Tier

    I will add the past paper links as soon as they become available from the examination board website

    AQA GCSE 9-1 Biology May June Summer foundation and higher Examination Papers 2018

    AQA GCSE 9-1 Biology 8461 8461/2F Biology Foundation Tier Paper 2 June 2018

    AQA GCSE 9-1 Biology 8461 8461/2H biology Higher Pier Paper 2 June 2018

    AQA GCSE 9-1 Biology May June Summer foundation and higher Examination Papers June 2019

    AQA GCSE 9-1 Biology 8461 8461/2F foundation biology Paper 2 June 2019

    AQA GCSE 9-1 Biology 8461 8461/2H higher biology Paper 2 June 2019

    button for past paper download links

    AQA GCSE 9-1 Biology May June Summer foundation and higher Examination Papers June-November 2020

    AQA GCSE 9-1 Biology 8461 8461/2F biology foundation Paper 2 June-November 2020

    AQA GCSE 9-1 Biology 8461 8461/2H biology higher Paper 2 June-November 2020

    AQA GCSE 9-1 Biology May June Summer foundation and higher Examination Papers June 2021

    AQA GCSE 9-1 Biology 8461 8461/2F biology foundation Paper 2 June 2021

    AQA GCSE 9-1 Biology 8461 8461/2H biology higher Paper 2 June 2021

    ALL AQA GCSE (Grade 9-1) Level 1/Level 2 SCIENCES specifications and syllabus revision summary links

    Biohazardous lab glass and plastic

    Identify biohazardous lab glass and plastic

    Biohazardous lab glass and plastic includes items contaminated with biohazards (including recombinant or synthetic DNA/RNA) that could puncture a plastic bag. These items are not considered sharps but are capable of puncturing bags:

    • Micropipette tips
    • Serological pipettes
    • Syringes without needles
    • Test tubes, swabs and sticks
    • Any contaminated item that is not a regulated sharp but could puncture a biohazard bag

    Package biohazardous lab glass and plastic

    These items are not considered sharps but do need to be packaged to prevent punctures. Place contaminated plastic pipettes and tips in a container that cannot be punctured and can be easily autoclaved, such as a pipette box/keeper. Or package contaminated items in a sturdy cardboard box lined with a biohazard bag. Label the box with the biohazard symbol and PI name and room number. Seal with “Laboratory Glass” tape. Never use cardboard boxes for sharps waste.

    Decontaminate biohazardous lab glass and plastic

    Refer to the information on the Biohazardous Waste page for decontamination of biohazardous waste.

    Pictograms and Descriptions

    Health Hazard: A cancer-causing agent (carcinogen) or substance with respiratory, reproductive or organ toxicity that causes damage over time (a chronic, or long-term, health hazard).

    Flame: Flammable materials or substances liable to self ignite when exposed to water or air (pyrophoric), or which emit flammable gas.

    Exclamation Mark: An immediate skin, eye or respiratory tract irritant, or narcotic.

    Gas Cylinder: Gases stored under pressure, such as ammonia or liquid nitrogen.

    Corrosion: Materials causing skin corrosion/burns or eye damage on contact, or that are corrosive to metals.

    Exploding Bomb: Explosives, including organic peroxides and highly unstable material at risk of exploding even without exposure to air (self-reactives).

    Flame Over Circle: Identifies oxidizers. Oxidizers are chemicals that facilitate burning or make fires burn hotter and longer.

    Skull and Crossbones: Substances, such as poisons and highly concentrated acids, which have an immediate and severe toxic effect (acute toxicity).

    Environmental Hazard: Chemicals toxic to aquatic wildlife. (Non-Mandatory)

    Plastic Pollution Affects Sea Life Throughout the Ocean

    Our ocean and the array of species that call it home are succumbing to the poison of plastic. Examples abound, from the gray whale that died after stranding near Seattle in 2010 with more than 20 plastic bags, a golf ball, and other rubbish in its stomach to the harbor seal pup found dead on the Scottish island of Skye, its intestines fouled by a small piece of plastic wrapper.

    According to the United Nations, at least 800 species worldwide are affected by marine debris, and as much as 80 percent of that litter is plastic. It is estimated that up to 13 million metric tons of plastic ends up in the ocean each year&mdashthe equivalent of a rubbish or garbage truck load&rsquos worth every minute. Fish, seabirds, sea turtles, and marine mammals can become entangled in or ingest plastic debris, causing suffocation, starvation, and drowning. Humans are not immune to this threat: While plastics are estimated to take up to hundreds of years to fully decompose, some of them break down much quicker into tiny particles, which in turn end up in the seafood we eat.

    The following photos help illustrate the extent of the ocean plastics problem.

    Research indicates that half of sea turtles worldwide have ingested plastic. Some starve after doing so, mistakenly believing they have eaten enough because their stomachs are full. On many beaches, plastic pollution is so pervasive that it&rsquos affecting turtles&rsquo reproduction rates by altering the temperatures of the sand where incubation occurs.

    A recent study found that sea turtles that ingest just 14 pieces of plastic have an increased risk of death. The young are especially at risk because they are not as selective as their elders about what they eat and tend to drift with currents, just as plastic does.

    Plastic waste kills up to a million seabirds a year. As with sea turtles, when seabirds ingest plastic, it takes up room in their stomachs, sometimes causing starvation. Many seabirds are found dead with their stomachs full of this waste. Scientists estimate that 60 percent of all seabird species have eaten pieces of plastic, a figure they predict will rise to 99 percent by 2050.

    While dolphins are highly intelligent and thus unlikely to eat plastic, they are susceptible to contamination through prey that have ingested synthetic compounds.

    Plastic in our oceans affects creatures large and small. From seabirds, whales, and dolphins, to tiny seahorses that live in coral reefs&hellip &hellip

    . and schools of fish that reside on those same reefs and nearby mangroves.

    Plastic waste can encourage the growth of pathogens in the ocean. According to a recent study, scientists concluded that corals that come into contact with plastic have an 89 percent chance of contracting disease, compared with a 4 percent likelihood for corals that do not.

    Unless action is taken soon to address this urgent problem, scientists predict that the weight of ocean plastics will exceed the combined weight of all of the fish in the seas by 2050.

    Simon Reddy directs The Pew Charitable Trusts&rsquo efforts to prevent ocean plastics.

    Watch the video: Proper Biohazardous Waste Management. Esco Scientific (February 2023).