WASTE MANAGEMENT

Waste management: All activities, administrative and operational (including transportation activities), involved in the handling, treatment, conditioning, storage and disposal of waste.

Waste management has different purposes which may include:

· protect people who handle waste items from accidental injury,

· prevent the spread of infection to healthcare workers who handle the waste,

· prevent the spread of infection to the local community, and

· safely dispose of hazardous materials (toxic chemicals and radioactive compounds).

Waste can be classified into different groups such as combustible waste and non combustible waste, contaminated waste and non contaminated waste.

Combustible (burnable) wastes include paper, cardboard and contaminated wastes such as used dressings and gauze. Noncombustible (nonburnable) wastes include glass and metals. Wastes from hospitals and healthcare facilities may be contaminated (potentially infectious) or noncontaminated. Approximately 85% of the general waste produced by hospitals and clinics is noncontaminated waste and poses no infectious risk to persons who handle it. Examples of noncontaminated waste include paper, trash, boxes, bottles, plastic containers and food. They can be disposed of by the usual methods or sent to the local landfill or dumpsite (CDC 1985; Rutala 1993).

Some waste from healthcare facilities, however, is contaminated. If not disposed of properly, contaminated wastes may carry microorganisms that can infect the people who come in contact with the waste as well as the community at large. Contaminated wastes include blood, pus, urine, stool and other body fluids, as well as items that come in contact with them, such as used dressings. Wastes from operating rooms (human tissue, blood or blood soaked sponges, gauze or cotton) and laboratories (blood, feces, sputum, urine specimens and microbiological cultures) should be considered contaminated. Soiled medical devices or items that can inflict injury (e.g., used needles and scalpel blades) are capable of spreading bloodborne diseases such as hepatitis B, hepatitis C and AIDS, and are also considered contaminated waste.

Other types of waste that do not contain infectious agents, but are considered hazardous because of the potential harm they can cause to the environment include:

Ø chemical and pharmaceutical residues (e.g., cans, bottles or boxes containing expired drugs and vaccines, laboratory reagents and disinfectants such as formaldehyde and glutaraldehydes, and organic solvents such as acetone and chloroform);

Ø cytotoxic waste (e.g., drugs typically used in cancer chemotherapy);

Ø waste with a high content of heavy metals (e.g., mercury from broken thermometers, blood pressure gauges or dentistry materials, and cadmium from discarded batteries); and

Ø nonrecyclable and discarded pressurized containers (spray cans), that are hazardous if burned because they can explode.

Because of the risk that waste posed on the environment, different ways of disposals have been developed to enable a sustainable environment for all. Few among the many disposal methods are:

Encapsulation: is recommended as the easiest way to safely dispose of sharps. Sharps are collected in puncture-resistant and leakproof containers. When the container is three-quarters full, a material such as cement (mortar), plastic foam or clay is poured into the container until completely filled. After the material has hardened, the container is sealed and may be landfilled, stored or buried. It is also possible to encapsulate chemical or pharmaceutical waste together with sharps (WHO 1999).

Sanitary landfill: Engineered method of disposing of solid waste on land in a manner that protects the environment (e.g., by spreading the waste in thin layers, compacting it to the smallest practical volume and then covering it with soil at the end of each working day).

Incineration: is a high-temperature process that reduces the volume and weight of waste. This process is usually selected to treat waste that can not be recycled, reused or disposed of in a sanitary landfill or dumpsite.

Types of Incinerator can range from extremely sophisticated, high-temperature ones to very basic units that operate at much lower temperatures. All types of incinerators, if operated properly, eliminate microorganisms from waste and reduce the waste to ashes.

Four basic types of incinerators are used for treating waste:

1. Double-chamber, high-temperature incinerators are designed to burn infectious waste.

2. Single-chamber, high-temperature incinerators are less expensive and are used when double-chamber incinerators are not affordable.

3. Rotary kilns operate at high temperatures and are used for destroying cytotoxic substances and heat-resistant chemicals.

4. Drum or brick (clay) incinerators operate at lower temperatures and are less effective, but can be made locally using readily available materials.

Types of Waste That Should Not Be Incinerated

· Pressurized gas containers (aerosol cans)

· Large amounts of reactive chemical waste

· Silver salts and photographic or radiographic wastes

· Plastic containing polyvinyl chloride (blood bags, IV tubing or disposable syringes)

· Waste with high mercury or cadmium content, such as broken thermometers, used batteries and lead-lined wooden panels.

Adapted from: WHO 1999

Open piles of waste should be avoided because they:

· are a risk to those who scavenge and unknowingly reuse contaminated items,

· allow persons to accidentally step on sharp items and injure themselves,

· produce foul odors, and

· attract insects and animals.

In summary, we should be environmentally conscious and avoid buying or using chemical products or other products that can create impossible or very expensive disposal problems wherever possible.

References:

ü Centers for Disease Control (CDC). 1985. Recommendations for preventing transmission of infection with human T-lymphotropic virus type III/lymphadenopathy-associated virus in the workplace. MMWR34(45): 681–686; 691–695.

ü World Health Organization (WHO). 1999. Safe Management of Wastes from Healthcare Activities. WHO: Geneva.

ACID RAIN

ACID RAIN

The term "acid rain" is commonly used to mean the deposition of acidic components in rain, snow, fog, dew, or dry particles. It can also be referred to as precipitation such as rain or snow which contains a higher level of acid than normal. The more accurate term is "acid precipitation." Distilled water, which contains no carbon dioxide, has a neutral pH of 7. Liquids with a pH less than 7 are acid, and those with a pH greater than 7 are alkaline (or basic). "Clean" or unpolluted rain has a slightly acidic pH of 5.6, because carbon dioxide and water in the air react together to form carbonic acid, a weak acid. Around Washington, D.C., however, the average rain pH is between 4.2 and 4.4.

The extra acidity in rain comes from the reaction of air pollutants, primarily sulfur oxides and nitrogen oxides, with water in the air to form strong acids (like sulfuric and nitric acid). The main sources of these pollutants are vehicles and industrial and power-generating plants. Therefore, acid rain is mainly caused by sulfur dioxide, nitrogen oxide and other pollutants being released into the atmosphere when fossil fuels such as oil or coal containing sulfur are burnt. Carbon combines with sulfur trioxide from sulfur-rich fuel to form particles of an acid substance. The effects of acid rain are primarily felt by wildlife. The water in lakes becomes very clear as fish and microscopic animal life are killed. It is believed that it is acid rain that kills trees, especially conifers, making them gradually lose their leaves and die. Acid rain can damage surfaces such as stone buildings when it falls on them. Acidity in rain is measured by collecting samples of rain and measuring its pH. To find the distribution of rain acidity, weather conditions are monitored and rain samples are collected at sites all over the country.

 

BIOREMEDIATION

What Is Bioremediation?
Bioremediation is the use of organisms to break down and thereby detoxify dangerous chemicals in the environment. Plants and microorganisms are used as bioremediators. The technology can take advantage of a natural metabolic pathway or genetically modify an organism to have a particular toxic "appetite."

Bioremediation can be defined as any process that uses microorganisms or their enzymes to return the environment altered by contaminants to its original condition. Bioremediation may be employed in order to attack specific contaminants, such as chlorinated pesticides that are degraded by bacteria, or a more general approach may be taken, such as oil spills that are broken down using multiple techniques including the addition of fertilizer to facilitate the decomposition of crude oil by bacteria.

Not all contaminants are readily treated through the use of bioremediation; for example, heavy metals such as cadmium and lead are not readily absorbed or captured by organisms. The integration of metals such as mercury into the food chain may make things worse as organisms’ bioaccumulate these metals.

However, there are a number of advantages to bioremediation, which may be employed in areas which cannot be reached easily without excavation. For example, hydrocarbon spills (or more specific: gasoline) may contaminate groundwater well below the surface of the ground; injecting the right organisms, in conjunction with oxygen-forming compounds, may significantly reduce concentrations after a period of time. This is much less expensive than excavation followed by burial elsewhere or incineration, and reduces or eliminates the need for pumping and treatment, which is a common practice at sites where hydrocarbons have contaminated groundwater.
Generally, bioremediation technologies can be classified as in situ or ex situ. In situ bioremediation involves treating the contaminated material at the site while ex situ involves the removal of the contaminated material to be treated elsewhere. Some examples of bioremediation technologies are bioventing, land farming, bioreactor, composting, bioaugmentation and biostimulation.

Compost is the decomposed remnants of organic materials (those with plant and animal origins). Compost is used in gardening and agriculture, mixed in with the soil. It improves soil structure, increases the amount of organic matter, and provides nutrients.
Compost is a common name for humus, which is the result of the decomposition of organic matter. Decomposition is performed primarily by microbes, although larger creatures such as worms and ants contribute to the process. Decomposition occurs naturally in all but the most hostile environments, such as buried in landfills or in extremely arid deserts, which prevent the microbes and other decomposers from thriving.
Composting is the controlled decomposition of organic matter. Rather than allowing nature to take its slow course, a composter provides an optimal environment in which decomposers can thrive. To encourage the most active microbes, the compost pile needs the proper mix of the following ingredients:

Carbon Nitrogen Oxygen (air) Water Decomposition happens even in the absence of some of these ingredients, but not nearly as quickly and not nearly as pleasantly (for example, the plastic bag of vegetables in your refrigerator is decomposed by microbes, but the absence of air encourages anaerobic microbes that produce disagreeable odors).

References:
Bolin, Frederick. "Leveling Land Mines with Biotechnology." Nature Biotechnology 17 (1999): 732.
Eccles, Harry. Bioremediation. New York: Taylor and Francis, 2001.
Hooker, Brian S., and Rodney S. Skeen. "Transgenic Phytoremediation Blasts onto the Scene." Nature Biotechnology 17 (1999): 428.
Lewis, Ricki. "PCB Dilemma." The Scientist 15 (2001): 1.


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Be Eco-friendly

Sunkanmi Rufai

Desertification: A Natural Disaster (...cont'd)

...continued from last post

PROBLEM
Desertification became well known in the 1930’s, when parts of the Great Plains turns into the “Dust Bowl” as a result of drought and poor practices in farming, although the term itself was not used until almost 1950.
“Dust Bowl” as result of drought
During the dust bowl period, millions of people were forced to abandon their farms and livelihoods. Greatly improved methods of agriculture and land and water management in the Great Plains Have prevented that disaster from recurring, but desertification presently affects millions of people in almost every continent. Increased population and livestock pressure on marginal lands has accelerated desertification. In some areas, nomads moving to less arid areas disrupt the local ecosystem and increase the rate of erosion of the land. Nomads are trying to escape the desert, but because of their land-use practices, they are bringing the desert with them. It is a misconception that drought cause desertification. Droughts are common in arid and semiarid lands. Well-managed lands can recover from drought when the rains return. Continued land abuse during droughts, however, increases land degradation. By 1973, the drought that began in 1968 in the Sahel of West Africa and the land-use practices there had caused the deaths of more than 100,000 people and 12 million cattle, as well as the disruption of social organizations from villages to the national levels.

CONTROL
Desertification can be controlled through effective management and policy approaches that promote sustainable resource use. Major policy intervention and changes in management approaches, both local and global levels, are needed in other to prevent, control, stop or reversing desertification. The creation of preventive measures that promotes alternative livelihood and conservation strategies can go a long way towards protecting drylands both when desertification is just beginning and when it is ongoing. It requires change in government and people’s attitude. Populations can prevent desertification by improving agricultural practices such as afforestation, shifting cultivation, crop rotation etc. and grazing practices in a sustainable way. Even once land has been degraded, rehabilitation and restoration measures such as controlling burning, alternative fuel source, fire traces etc., terracing prevents further gully erosion, pegging, ridges along slopes also check any further erosion and good irrigation system can help restore lost ecosystem services. The success of rehabilitation practices depends on the availability of policies and technologies and the close involvement of local communities. With all the causes and effects, desertification has poses one of the greatest environmental challenges today and constitutes a major barrier to meeting basic human needs. Effectively fighting desertification will help reduce global poverty and will contribute to meeting the Millennium Development Goals (MDGs).

REFERENCE
“Ecosystems and human well-being: Desertification Synthesis”, a report published in 2005 by the Millennium Ecosystem Assessment (MA)

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© Rufai Sunkanmi

Desertification: A Natural Disaster

The world’s greatest deserts were formed by natural processes interacting over long intervals off time. During most of these times, desert have grown and shrunk independent of human activities. In some regions, deserts are separated sharply from surrounding. In other areas, desert fringes form a gradual transition from a dry to a more humid environment making it more difficult to define the desert border. These transition zones have very fragile delicately balanced ecosystems. In these marginal arrears, human activity may stress the ecosystem beyond its tolerance limit, resulting in degradation of the land. This degradation of formerly productive land to barren land or a persistence degradation of dry land ecosystem by variation in climate and human activities is called DESERTIFICATION.

CAUSES
Desertification is a complex process which involves multiple causes as a result of “drought and poor practices in farming”. Also, an increase in population and livestock pressure on marginal land has accelerated desertification. In dryland, water scarcity limit the production of crops, forage, wood, and other services ecosystem provide to humans, still the increase in human pressures on the exploitation of plants both in dry lands and humid areas thereby leading to desertification is the major cause of desertification. It is also caused by a combination of social, political, economic and natural factors which varies from region to region. Water erosion and reduced soil conservation negatively affect ecosystem services. Policies that can lead to an unsustainable use of resources and lack of infrastructure are major contributor to land degradation. Agriculture can play either a positive or negative role, depending on how it is managed. Policies favouring” sedentary farming” (the act of staying in a particular area/land) over “nomadic herding” (the act of feeding animals) in regions more suited to grazing can contribute to desertification. The process of globalization both contribute to desertification and prevent it, for instance, in some cases, trade liberalization, economic reforms, and export oriented production in dry land can promote desertification. In other cases, enlarged markets outside of the drylands also contribute to successful agricultural improvement. Livelihoods have been based on a mixture of hunting, gathering, farming and herding. This mixture varied with time, place, and culture, since the harsh conditions forced people to be flexible in land use. Population growth has led to the extension of cultivated lands and the irrigation of these lands is brought about by desertification, as well as other environmental problems. Other causes include burning which also can turn vegetation to an exposed soil thereby leading to desertification. So also overtillage and erosion can have tremendous implication on the environment leading to loss of soil conservation, loss of nutrient and soil exposure.

DISASTER
Desertification has various disastrous effects on the environment because of its wide spread. It was reported that desertification affects the livelihood of millions of people, as it occurs in all continents (except Antarctica).Desertification takes place in drylands all over the world. Some 10 to 20% of all drylands may already be degraded, but the precise extent of desertification is difficult to estimate, because few comprehensive assessments have been made so far.

A large majority of dryland population lives in developing countries as population growth and increased food demands are expected to drive the expansion and intensification of land cultivation in drylands. If no counter measures are taken, desertification in drylands will threaten future improvement in human well-being and possibly reverse gains in some regions compared to the rest of the world; these populations lag far behind in terms of human well being, per capita income and infant mortality. The situation is worst in the drylands of Asia and Africa. Desertification has environmental impacts that go beyond the areas directly affected. For instance, loss of vegetation can increase the formation of large dust clouds that can cause health problems in the more densely populated areas, thousands of kilometer away. Desertification is also disastrous such that it diminishes biological diversity, a diversity which contributes to many of the services provided to humans by drylands ecosystems. Vegetation and its diversity are key for soil conservation and for the regulation of surface water and local climate. Desertification, however contributes to global climate change by releasing to the atmospheric carbon stored in dryland vegetation and soil. The effect of global climate change on desertification is complex and not yet sufficiently understood. On the one hand, higher temperatures resulting from increased carbon dioxide levels can have a negative impact through increased loss of water from soil and reduced rainfall in drylands. Desertification also affect products such as food and water, natural processes such as climate regulation, but also non-material services such as recreation and supporting services such as soil conservation. These can lead to unsustainable agricultural practice, further land degradation, exacerbated urban sprawl, and socio-political problems. Moreover, the social and political impacts of desertification also reach non-drylands areas. For example, human migration from drylands to cities and other countries can harm political and economic stability.

Next Post shall be addressing; Problem and Control.

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Be Environment Friendly

Sunkanmi Rufai