Category Science

WHAT IS WETLANDS?

An area of land that is either covered by water or saturated with water, wetlands are those areas where water covers the soil. While most scientists consider swamps, bogs, and marshes to be the three main kinds of wetlands, there are other types like peatlands, sloughs, and mires as well. Even though wetlands were seen as wastelands for most of history as they don’t support development, it has since been realised that these are among the most valuable ecosystems on Earth. Governments began recognising the value of wetlands from the 1970s and laws have been put in place in parts of the world to protect wetlands.

Categories of Wetlands

Wetlands vary widely because of regional and local differences in soils, topography, climate, hydrology, water chemistry, vegetation and other factors, including human disturbance. Indeed, wetlands are found from the tundra to the tropics and on every continent except Antarctica. Two general categories of wetlands are recognized: coastal or tidal wetlands and inland or non-tidal wetlands.

Coastal/Tidal Wetlands

Coastal/tidal wetlands in the United States, as their name suggests, are found along the Atlantic, Pacific, Alaskan and Gulf coasts. They are closely linked to our nation’s estuaries where sea water mixes with fresh water to form an environment of varying salinities. The salt water and the fluctuating water levels (due to tidal action) combine to create a rather difficult environment for most plants. Consequently, many shallow coastal areas are unvegetated mud flats or sand flats. Some plants, however, have successfully adapted to this environment. Certain grasses and grasslike plants that adapt to the saline conditions form the tidal salt marshes that are found along the Atlantic, Gulf, and Pacific coasts. Mangrove swamps, with salt-loving shrubs or trees, are common in tropical climates, such as in southern Florida and Puerto Rico. Some tidal freshwater wetlands form beyond the upper edges of tidal salt marshes where the influence of salt water ends.

Inland/Non-tidal Wetlands

Inland/non-tidal wetlands are most common on floodplains along rivers and streams (riparian wetlands), in isolated depressions surrounded by dry land (for example, playas, basins and “potholes”), along the margins of lakes and ponds, and in other low-lying areas where the groundwater intercepts the soil surface or where precipitation sufficiently saturates the soil (vernal pools and bogs). Inland wetlands include marshes and wet meadows dominated by herbaceous plants, swamps dominated by shrubs, and wooded swamps dominated by trees. Certain types of inland wetlands are common to particular regions of the country.

Many of these wetlands are seasonal (they are dry one or more seasons every year), and, particularly in the arid and semiarid West, may be wet only periodically. The quantity of water present and the timing of its presence in part determine the functions of a wetland and its role in the environment. Even wetlands that appear dry at times for significant parts of the year — such as vernal pools– often provide critical habitat for wildlife adapted to breeding exclusively in these areas.

Credit : EPA 

Picture Credit : Google 

WHAT IS CALLED WASTE MANAGEMENT?

Waste management corresponds to the process of managing unwanted waste items. This includes collection, transport, processing or waste treatment, recycling, and disposal. Mainly done for waste produced by human activities, it started off in an effort to reduce their effect on human health or local aesthetics, but now addresses their effect on the natural world and environment at large as well. Wastes can be generated domestically, industrially, agriculturally, and commercially, among others, and its management can involve solid, liquid, or gaseous substances with different methods for each.

The aim of waste management is to reduce the dangerous effects of such waste on the environment and human health. A big part of waste management deals with municipal solid waste, which is created by industrial, commercial, and household activity.

Waste management practices are not uniform among countries (developed and developing nations); regions (urban and rural areas), and residential and industrial sectors can all take different approaches.

Proper management of waste is important for building sustainable and liveable cities, but it remains a challenge for many developing countries and cities. A report found that effective waste management is relatively expensive, usually comprising 20%–50% of municipal budgets. Operating this essential municipal service requires integrated systems that are efficient, sustainable, and socially supported. A large portion of waste management practices deal with municipal solid waste (MSW) which is the bulk of the waste that is created by household, industrial, and commercial activity. According to the Intergovernmental Panel on Climate Change (IPCC), municipal solid waste is expected to reach approximately 3.4 Gt by 2050; however, policies and lawmaking can reduce the amount of waste produced in different areas and cities of the world.[8] Measures of waste management include measures for integrated techno-economic mechanisms of a circular economy, effective disposal facilities, export and import control and optimal sustainable design of products that are produced.

In the first systematic review of the scientific evidence around global waste, its management and its impact on human health and life, authors concluded that about a fourth of all the municipal solid terrestrial waste is not collected and an additional fourth is mismanaged after collection, often being burned in open and uncontrolled fires – or close to one billion tons per year when combined. They also found that broad priority areas each lack a “high-quality research base”, partly due to the absence of “substantial research funding”, which motivated scientists often require. Electronic waste (ewaste) includes discarded computer monitors, motherboards, mobile phones and chargers, compact discs (CDs), headphones, television sets, air conditioners and refrigerators. According to the Global E-waste Monitor 2017, India generates ~ 2 million tonnes (Mte) of e-waste annually and ranks fifth among the e-waste producing countries, after the US, P.R. China, Japan and Germany.

Credit :  Wikipedia 

Picture Credit : Google

WHAT IS UNIVERSAL WASTE?

Universal waste is one that is generated largely from consumer products containing mercury, lead, cadmium, etc that are harmful to human health. This include everything from batteries and pesticides to even lamps. Importantly, these are things that cannot be disposed of as domestic waste but still likely to be done so, Segregation at source and recycling help in universal waste management.

Why Do We Care About Universal Waste?
The primary environmental concern with universal waste is the heavy metal components that can easily contaminate the land and ground water (such as lead, mercury, and other elements that can be toxic to humans and the environment). In addition, all heavy metals are easily recyclable, so it makes no sense to throw metals into a landfill when they can be reclaimed and recycled. For this reason, you will usually hear universal waste disposal companies referred to as recyclers.

On the topic of electronic waste (e-waste) dumps in particular, PBS’s Frontline produced a documentary called Ghana: A Digital Dumping Ground about the export of e-waste from developed to developing countries, creating toxic living conditions. Since the documentary was released, there has been much greater scrutiny of e-waste disposal practices in the U.S. and around the world. If you are unfamiliar with this “hidden” world of e-waste dumping, it may be eye-opening to watch the 20-minute video, which will explain the problems associated with these wastes in more depth than we can provide on this webpage.

The U.S. Environmental Protection Agency (EPA) maintains statistics on the management of used and end-of-life electronics (see table below). As you can see, less than half of the electronics disposed of in 2009 were collected for recycling. Further, it is unclear how much was recycled in an environmentally and civically responsible manner. For more information on responsible e-waste recycling options, visit the environmental best practice for managing universal waste section at the bottom of this webpage.

Environmental Best Practice for Managing Universal Waste

Use an e-Steward or R2 certified e-waste recycler
There are two leading certifications for the responsible management of electronic waste, also known as e-waste. As described in the section why do we care about universal waste, if not managed properly, electronic waste can contaminate the environment and pose a danger to human health. E-Stewards is a certification system for electronic waste recyclers. It demands that these recyclers manage e-waste responsibly, such as not sending it overseas and ensuring that all hazards are controlled and managed. For a complete list of what an e-Stewards certified recycler commits to, visit the What is the e-Stewards Standard? page. The R2 Standard is another certification system for electronic waste recyclers and offers certification to recyclers and refurbishers who commit to environmental responsibility and worker safety. The U.S. EPA refrains from endorsing one certification system over the other; however, they do offer additional information about both e-Stewards and R2 on their webpage certification programs for electronics recyclers.
Purchase electronics equipment that is EPEAT-rated
EPEAT is a program that began with a grant from the EPA and is now managed by the Green Electronics Council. The EPEAT rating system applies to computers, imaging equipment, and televisions, and gives a rating (bronze, silver, or gold) based on a number of factors, including reduction of environmentally sensitive materials, end-of-life design, product longevity, energy conservation, corporate performance, and packaging choices. Manufacturers can choose to have their products evaluated for an EPEAT rating and can publish their EPEAT rating to consumers. Most of the large electronics manufacturers use EPEAT to some degree, so the next time you are in the market for office or electronic equipment, consider purchasing models that are EPEAT-rated. Visit the EPEAT Registry Search for available products. For more information on EPEAT in general, visit the EPA’s environmentally preferable purchasing section.
Recycle alkaline and button cell batteries
Though you are not required to do so, there are valuable metals in these types of batteries. Best environmental practice is to collect these batteries for recycling with your universal waste recycler. This is very simple to do; set up pails or boxes labeled “battery recycling” – you may be surprised by how many you collect. You can also encourage your staff to bring in used batteries from home. It is inexpensive to recycle batteries and should thus be encouraged at any opportunity.
Donate appliances and e-waste instead of throwing it away
That said, you should be particularly careful about HIPAA – which means it may not always make sense to donate computers or laptops (anything with a hard drive) from healthcare facilities. However, there are good opportunities to donate items like appliances, medical equipment, computer monitors, keyboards, and other accessories, as long as they still have a useful life, are in good working condition, are clean, and your intent is that someone can actually use the items (not just a free way to get rid of your junk). You can list items for reuse on the Minnesota Materials Exchange.
Switch inefficient lighting for efficient lighting
According to the U.S. Energy Information Administration, lighting accounts for approximately 21% of electricity consumption in the commercial sector (including hospitals, clinics, etc.). Increasing lighting efficiency with CFLs, LEDs, and other efficient lighting options will help you save money and reduce your electricity load.

Credit : MN TAPE 

Picture Credit : Google 

WHAT IS UV RADIATION?

Ultraviolet (UV) radiation is a form of electromagnetic radiation that comes from the sun. Humans have found use for this radiation in industry and dentistry. However, too much exposure to UV rays harms not just humans but can alter our environment because it can inhibit growth in green plants. The ozone layer that protects us from harmful UV rays has faced depletion, primarily due to certain types of chemicals we humans manufacture.

Our natural source of UV radiation:

The sun

Some artificial sources of UV radiation include:

  • Tanning beds
  • Mercury vapor lighting (often found in stadiums and school gyms)
  • Some halogen, fluorescent, and incandescent lights
  • Some types of lasers

UV radiation is classified into three primary types: ultraviolet A (UVA), ultraviolet B (UVB), and ultraviolet C (UVC), based on their wavelengths. Almost all of the UV radiation that reaches earth is UVA though some UVB radiation reaches earth. UVA and UVB radiation can both affect health but UVA penetrates deeper into the skin and is more constant throughout the year.

Benefits

The production of vitamin D, a vitamin essential to human health.

Vitamin D helps the body absorb calcium and phosphorus from food and assists bone development. The World Health Organization (WHO) recommends 5 to 15 minutes of sun exposure 2 to 3 times a week.

Risks

Sunburn is a sign of short-term overexposure, while premature aging and skin cancer are side effects of prolonged UV exposure.
UV exposure increases the risk of potentially blinding eye diseases, if eye protection is not used.
Overexposure to UV radiation can lead to serious health issues, including cancer.

Skin cancer is the most common cancer in the United States. The two most common types of skin cancer are basal cell cancer and squamous cell cancer. Typically, they form on the head, face, neck, hands, and arms because these body parts are the most exposed to UV radiation. Most cases of melanoma, the deadliest kind of skin cancer, are caused by exposure to UV radiation.

Anyone can have harmful health effects from UV radiation, but the risks increase in people who:

Spend a lot of time in the sun or have been sunburned.
Have light-color skin, hair, and eyes.
Take some types of oral and topical medicines, such as antibiotics, birth control pills, and benzoyl peroxide products, as well as some cosmetics, may increase skin and eye sensitivity to UV in all skin types.
Have a family member with skin cancer.
Are over age 50.

To protect yourself from UV radiation:

Stay in the shade, especially during midday hours.
Wear clothes that cover your arms and legs.
Consider options to protect your children.
Wear a wide brim hat to shade your face, head, ears, and neck.
Wear wraparound sunglasses that block both UVA and UVB rays.
Use sunscreen with sun protection factor (SPF) 15 or higher, for both UVA and UVB protection.
Avoid indoor tanning. Indoor tanning is particularly dangerous for younger users; people who begin indoor tanning during adolescence or early adulthood have a higher risk of developing melanoma.

Credt : National centre for Environment health   

Picture Credit : Google 

WHAT IS SOIL DEGRADATION ?

Soil degradation refers to the decline of soil quality due to its improper use, usually for agriculture, industry, and urban activity. Degraded soil can have lower amount of fertility and organic matter, and be high in salinity, acidity, and toxicity. Since soil is inevitable for all life forms on our planet, the continuous decline in soil quality can have disastrous results such as desertification, flooding, landslides, loss of wildlife, etc.

Various Causes of Soil Degradation

1. Physical Factors

There are several physical factors contributing to soil degradation distinguished by the manners in which they change the natural composition and structure of the soil. Rainfall, surface runoff, floods, wind erosion, tillage, and mass movements result in the loss of fertile top spoil thereby declining soil quality.

2. Biological Factors

Biological factors refer to the human and plant activities that tend to reduce the quality of the soil. Some bacteria and fungi overgrowth in an area can highly impact the microbial activity of the soil through biochemical reactions, which reduces crop yield and the suitability of soil productivity capacity.

Human activities such as poor farming practices may also deplete soil nutrients thus diminishing soil fertility. The biological factors affect mainly lessens the microbial activity of the soil.

3. Chemical Factors

The reduction of soil nutrients because of alkalinity or acidity or waterlogging are all categorized under the chemical components of soil degradation. In the broadest sense, it comprises alterations in the soil’s chemical property that determine nutrient availability.

4. Deforestation

Deforestation causes soil degradation on the account of exposing soil minerals by removing trees and crop cover, which support the availability of humus and litter layers on the surface of the soil.

5. Misuse or excess use of fertilizers

The excessive use and the misuse of pesticides and chemical fertilizers kill organisms that assist in binding the soil together. Most agricultural practices involving the use of fertilizers and pesticides often entail misuse or excessive application, thereby contributing to the killing of soil’s beneficial bacteria and other micro-organisms that help in soil formation.

6. Industrial and Mining activities

Soil is chiefly polluted by industrial and mining activities. As an example, mining destroys crop cover and releases a myriad of toxic chemicals such as mercury into the soil thereby poisoning it and rendering it unproductive for any other purpose.

7. Improper cultivation practices

There are certain agricultural practices that are environmentally unsustainable and at the same time, they are the single biggest contributor to the worldwide increase in soil quality decline. The tillage on agricultural lands is one of the main factors since it breaks up the soil into finer particles, which increase erosion rates.

8. Urbanization

Urbanization has major implications on the soil degradation process. Foremost of all, it denudates the soil’s vegetation cover, compacts soil during construction, and alters the drainage pattern.

9. Overgrazing

The rates of soil erosion and the loss of soil nutrients, as well as the topsoil, are highly contributed by overgrazing. Overgrazing destroys surface crop cover and breaks down soil particles, increasing the rates of soil erosion. As a result, soil quality and agricultural productivity are greatly affected.

Fatal Effects of Soil Degradation

1. Land degradation

Soil quality decline is one of the main causes of land degradation and is considered to be responsible for 84% of the ever-diminishing acreage. Year after year, huge acres of land lost due to soil erosion, contamination, and pollution.

2. Drought and aridity

Drought and aridity are problems highly influenced and amplified by soil degradation. As much as it’s a concern associated with natural environments in arid and semi-arid areas, the UN recognizes the fact that drought and aridity are anthropogenic induced factors especially as an outcome of soil degradation.

3. Loss of arable land

Because soil degradation contributes to land degradation, it also means that it creates a significant loss of arable land. As stated earlier, about 40% of the world’s agricultural land is lost on the account of soil quality depreciation caused by agrochemicals and soil erosion.

4. Increased flooding

The land is commonly altered from its natural landscape when it rids its physical composition from soil degradation. For this reason, the transformed land is unable to soak up water, making flooding more frequent.

5. Pollution and clogging of waterways

Most of the soil eroded from the land together with the chemical fertilizers and pesticides utilized in agricultural fields are discharged into waterways and streams. With time, the sedimentation process can clog waterways, resulting in water scarcity.

SOLUTIONS : There are many solutions to soil degradation, which include: practicing responsible farming techniques, active forestation, as well as preventing soil erosion and pollution. In addition, soil degradation can be avoided through responsible developments in urban and residential environments.

WHAT IS SEA LEVEL RISE AND WHY IS IT HAPPENING?

As our planet warms, oceans across the globe absorb a large portion of the heat generated. In the process, the water expands, resulting in universal sea-level rise. In addition, the rise is also caused by the melting of glaciers and icebergs. Usually such melting during warmer months and freezing during colder months is a natural phenomenon. However, with global warming, there’s more of the former than the latter, leading to alarming sea-level rise, threatening to submerge several cities within just a few decades.

Why does sea level change?

Causes sea level to rise because water expands as it warms up; melting of the world’s ice sheets. A large ice mass, which flows over hills and valleys and occupies a large portion of a continent. The world has only three major ice sheets today (Greenland, West Antarctica, and East Antarctica).

In Greenland and Antarctica;  melting of smaller around the world; and decrease in the amount of water held on land, for example, in groundwater beneath the land and in reservoirs above the land. Ocean warming accounts for around half of the observed change in sea level (this is often called “thermal expansion”), with the melting of thousands of small glaciers accounting for the other half of the increase in sea level. Since the 1800s, the melting ice sheets in Antarctica and Greenland have contributed relatively little to sea level change. But, these ice sheets are starting to melt faster due to global warming and may push sea level up much more in the future.

How much could sea level rise?

Because of global warming, the thermal expansion of the ocean and glacier melting will continue to play a role in the rise of sea level in the future . If all of the planet’s remaining as small glaciers were to melt, sea level would rise about 50 cm. The amount that thermal expansion can raise sea level in the future will depend on the continued warming of sea water. The largest possible contribution to sea level rise in the future comes from the world’s large ice sheets in Greenland, West Antarctica, and East Antarctica. If these ice sheets melted completely, the level of the oceans would rise about 7 m from the Greenland ice sheet, 5 m from the West Antarctic ice sheet, and 53 m from the East Antarctic ice sheet. This is why many glaciologists (scientists who study ice) focus on how Greenland and Antarctica are changing because of global warming.

How will sea level rise affect the countries of the world?

The effect of ice sheet melting on sea level is different across the world.

So, when the sea level rises, people will be affected in different ways, depending on where they live. The UK is used to occasionally dealing with rising sea level for short periods of time, particularly when there are storms at the same time as when the tides higher than usual. If the IPCC predictions are correct, we must consider the possible increase in sea level on top of natural tidal surges. This will cause dangerously high tides to occur more often in the coming decades, and these future tides might be more destructive than we are used to.

In farming regions near the coast, seawater flooding on land can contaminate the soils with salt, making them less able to support the growth of crops. The salty water may also get into underground stores of fresh water (known as groundwater), which is the source of important drinking water and also for farmers to grow crops.

In coastal cities, sea level rise will cause more flooding to houses, businesses, and while it may seem sensible to consider moving cities away from harmful floods, especially as we know it will likely happen in the future, our cities cost so much to develop that we are more likely to simply try to protect them from rising sea levels. A vision of our cities near the sea involves them with walls facing the ocean several meters high, with the street level of the cities themselves being below the level of the ever rising sea.

Credit : Frontiers for young mind 

Picture Credit : Google