QUESTION 1

Explain the two types of diseases :

a. CommunicableCommunicable diseases, also known as infectious diseases or transmissible diseases, are illnesses that result from the infection, presence and growth of pathogenic (capable of causing disease) biologic agents in an individual human or other animal host. Infections may range in severity from asymptomatic (without symptoms) to severe and fatal. The term infection does not have the same meaning as infectious disease because some infections do not cause illness in a host.

Disease causing biologic agents include viruses, bacteria, fungi, protozoa, multicellular parasites, and aberrant proteins known as prions. Transmission of these biologic agents can occur in a variety of ways, including direct physical contact with an infectious person, consuming contaminated foods or beverages, contact with contaminated body fluids, contact with contaminated inanimate objects, airborne (inhalation), or being bitten by an infected insect or tick. Some disease agents can be transmitted from animals to humans, and some of these agents can be transmitted in more than one way.

b. Non communicable

Non-communicable diseases (NCD) is a non-contagious disease process or transferred from one human to another. Random genetic abnormalities, heredity, lifestyle or environment can cause a patient to get diseases such as cancer, diabetes, asthma, hypertension, and osteoporosis. All these diseases cannot be transmitted. Autoimmune disease, trauma, fractures, mental disorders, malnutrition, toxicity and hormonal conditions in the category of non-communicable diseases.

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Question 2

Explain the types of communicable disease caused by pollution

a. Water Borne Disease

Waterborne diseases are caused by pathogenic microorganisms that most commonly are transmitted in contaminated fresh water. Infection commonly results during bathing, washing, drinking, in the preparation of food, or the consumption of food thus infected. Various forms of waterborne diarrheal disease probably are the most prominent examples, and affect mainly children in developing countries; according to the World Health Organization, such disease account for an estimated 4.1% of the total DALY global burden of disease, and cause about 1.8 million human deaths annually. The World Health Organization estimates that 88% of that burden is attributable to unsafe water supply, sanitation and hygiene. Some examples of communicable water borne disease are:

Cholera Bacillary Dysentery/Shigellosis Hepatitis A Typhoid fever

b. Food Borne Disease

Foodborne illness (also foodborne disease and colloquially referred to as food poisoning) is any illness resulting from the consumption of contaminated food, pathogenic bacteria, viruses, or parasites that contaminate food, as well as chemical or natural toxins such as poisonous mushrooms. Some examples of communicable food borne disease are:

E. Coli Infection Salmonellosis Shigellosis Norovirus Infection Botulism

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c. Insect Borne Diseases

Of the many diseases spread by insects, very few are actually caused by the insects themselves but rather, by other organisms passed on when they feed or bite. Insects are capable of spreading diseases caused by many different types of micro-organisms including bacteria, viruses, protozoans, etc. In these instances it is the micro-organism that is the pathogen (disease causer) and the insect involved is known as the vector.

Biting insects are active at all times of the day and night. However, some prefer different times of day eg. the mosquitoes that spread malaria are mainly active after dark but the mosquitoes that spread yellow fever and dengue fever are active during daylight hours. Some examples of communicable insect borne disease are:

Malaria Yellow Fever Dengue Fever West Nile Virus Tick Borne Encephalitis

d. Rodent Borne Disease

Rodentia is the order of mammals known as rodents, characterised by a single pair of continuously growing incisors in each of the upper and lower jaws which must be kept short by gnawing.

Forty percent of mammal species are rodents, and they are found in vast numbers on all continents other than Antarctica. Common rodents include mice, rats, squirrels, porcupines, beavers, guinea pigs, and hamsters. Rodents use their sharp incisors to gnaw wood, break into food, and bite predators. Most rodents eat seeds or plants, though some have more varied diets. Some species have historically been pests, eating seeds stored by people and spreading disease. Some examples of communicable rodent borne disease are:

Weil’s Syndrome Plague Bubonic Plague Rat-borne Disease. Bat-borne Disease.

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Question 3

Explain the types of non-communicable diseases caused by pollution:

a. Lead (plumbum)Acute or chronic poisoning by lead or any of its salts, with the acute form causing severe gastroenteritis and encephalopathy and the chronic form causing anemia and damage to the gastrointestinal tract and nervous system. Also called saturnism.

b. MercurySunburn and heat stroke are examples of some diseases caused by physical agents. Chemical agents which cause diseases are lead, mercury, potassium, cyanide, snake bite, poisoning from plants

c. InsecticidesTwo insecticides that cause health problems are lindane and methoxychlor. Excessive consumption of lindane is known to cause liver and kidney disorders. Excessive consumption of methoxycholor has been linked to reproductive disorders.

d. AsbestosAsbestos-related diseases are generally associated with exposure to high levels of asbestos over an extended period of time. Studies on workers in mines, factories and shipyards have shown that heavy exposures to asbestos can lead to three serious diseases:

asbestosis (scarring of lung tissue),

lung cancer , and

mesothelioma (a rare form of cancer affecting the lining of the lungs).

e. Cadmium

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Cadmium is first transported to the liver through the blood. There, it is bond to proteins to form complexes that are transported to the kidneys. Cadmium accumulates in kidneys, where it damages filtering mechanisms. This causes the excretion of essential proteins and sugars from the body and further kidney damage. It takes a very long time before cadmium that has accumulated in kidneys is excreted from a human body.

Other health effects that can be caused by cadmium are:

- Diarrhoea, stomach pains and severe vomiting- Bone fracture- Reproductive failure and possibly even infertility- Damage to the central nervous system- Damage to the immune system- Psychological disorders- Possibly DNA damage or cancer development

f. Nitrateparticulate

can be defined as the availability of gas, liquid or particles contained in the air until the change and affect the life or other materials.

Such materials suspended in the air and a negative impact on humans, plants and animals.

This is due to these materials will enter the human body through breathing and can block the flow of oxygen into the blood vessels.

This can cause a variety of diseases such as cramperd disease, cancer, asthma, cramps and anemia.

Dust, fumes, mists, vapors or other substances that can prevent eye sight is the various forms of air pollution.

g. Dioxin

Dioxins are toxins contained in the basic material for the manufacture of processed paper products, sanitary napkins, baby diapers and so on.

It is classified as a super toxic resulting from the reaction of the bleaching chlorine process.Dioxin 120 times strength than arsenic.

Use pads containing dioxins can cause hormonal imbalance Early signs of gynecological cancer Vagina Affect Fertility absorb anything and at

any time. When you insert the chemical into the vagina, the material will be in the blood

vessels and a half hours later.

Question 4

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Explain the sources ground water pollution :

a. Industrial wasteOne of the major causes of water pollution is the discharge of wastes from industries. It is a common observation that industries find rivers and the sea a comfortable place to dump their waste material into. These wastes contain toxic substances and also include elements like lead, mercury, nitrates and sulfates. They are quite harmful for humans as well as aquatic animals. A large amount of money is wasted on treating the water bodies that get contaminated and making them suitable to use for drinking purposes again. Moreover, there are still risks of various diseases after consuming the water containing such toxic materials. Often, hot or contaminated water is also released into the rivers from these industries, which increases the overall temperature of the rivers, thus making them unfavorable for the aquatic flora and fauna.

b. Domestic wasteAlso known as "municipal solid waste", domestic waste is waste that is generated as a result of the ordinary day-to-day use of a domestic premise and either :a. taken from the premises by or on behalf of the person who generated the wasteb. collected by or on behalf of a local government as part of a waste collection and

disposal system.

c. Municipal landfillWater pollution from landfills is a major problem in countries around the world. Chemicals from fertilizers, organic human waste, and metal are the leading causes of water contamination from landfills. The process of leaching, where water is filtered through layers of trash, can allow the contaminated water to enter local water sources easily. Household waste, including batteries and other common items, also contribute significantly.

d. Agriculture

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Agricultural production leaves considerable amounts of agricultural waste. Some of it is recycled into the agricultural production as fertilizer, while large amounts remain unused – and in many instances pose a disposal problem. Uncontrolled burning in the fields is not only a hazardous disposal solution - it is also wasting useful energy. With efficient collection systems, waste from agricultural production can be utilised as fuel for power and heat production. 

In some agricultural industries large amounts of biomass waste is already concentrated and readily available for utilisation. The palm oil industry, for instance, produces significant amounts of empty fruit bunches that can be incinerated. Liquid wastes may also be methanized and can secure a basis for own power and process heat production while delivering excess power to the grid. In the sugar industry, significant amounts of bagasse – the waste after extraction of sugar – is an equally excellent fuel. Rice production may also be industrialised to such an extent that rice husks are available in amounts sufficient for incineration in a boiler, thereby securing a basis for power and heat production. 

In the forest industry, large concentrations of biomass waste can be utilised for power and heat production, e.g. at sawmills. The forest industry also supplies raw material for briquettes production, where sawdust, charcoal dust, degradable waste paper and dust from agricultural production may constitute a final utilisation of waste materials from agriculture related production. The following sectors of agricultural waste utilisation are presented in this section: 

Waste in Forest Industry  Waste in Other Agricultural Industries  Waste in Palm Oil Industries  Waste in Rice Industry 

Question 5

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The phenomena of eutrophication:

1. Explain the eutrophication process occurred in a lake and its effects

During the rainy season, water influx with high organic content from the mainland is the main source of the element for phytoplankton growth. The process by which a body of water acquires a high concentration of nutrients, especially phosphates and nitrates. These typically promote excessive growth of algae. As the algae die and decompose, high levels of organic matter and the decomposing organisms deplete the water of available oxygen, causing the death of other organisms, such as fish. Eutrophication is a natural, slow-aging process for a water body, but human activity greatly speeds up the process.

2. Explain the causes of eutrophication

In the natural course of events, lakes and other bodies of freshwater receive nutrients like phosphorus and nitrogen. The gradual accumulation of these nutrients involves a process called eutrophication. As the lake ages, the nutrients build up with various effects. The process speeds up with cultural eutrophication, which involves the effects of man on the freshwater body.

lakes become cloudy This phenomenon will cause severe water quality and is not suitable for some

applications. life in the water disturbed by this phenomenon germs spread disease soil disturbance and quality soil erosion

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3. Identity the methods of eutrophication

The eutrophication of a lake can be controlled or its effects on water minimized by reducing the nutrient input to the lake; increasing nutrient output from the lake, immobilizing nutrients within the lake and controlling excessive growths of algae and macrophytes within the lake. Various methods that have been proposed in each of these areas are summarized under the following topics.

NUTRIENT REMOVAL FROM WASTE WATERS DIVERSION OF WASTE WATERS

DREDGING

FLUSHING

ZONING

CHEMICAL CONTROL OF NUISANCE PLANT GROWTHS

BIOLOGICAL CONTROL OF NUISANCE PLANT GROWTHS

HARVESTING

MIXING OF LAKES

CONTROL OF AGRICULTURAL SOURCES OF NUTRIENTS

URBAN DRAINAGE

HYPOLIMNETIC WITHDRAWAL

WATER-LEVEL MANAGEMENT

IMMOBILIZATION OF NUTRIENTS

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Question 6

Explain the sources of sea pollution:

Domestic and Industrial waste

The quantity of polluted water mass is increasing for lack of refining and proper management, and negligence, which is casting bad impact on the entire environment. Specialists expressed apprehension of terrible situation of water pollution if such waste disposal could not be stopped. Sources said houses have not specific management for keeping domestic garbage. Most of the people do not use safety tank and throw the wastes into drains, lakes and rivers. Some dump the wastes in low-laying places beside their houses which later get mixed with the river waters flowing down canals or drains after rain. None does follow the rule of dropping the wastewater into the river after refining and treatment in chemical method. As a result, the domestic wastes are polluting water and environment and fishes of different species are on the way of extinction. According to chemical analysis, domestic wastes contain poisonous Nitrate, Phosphate and BOD. The wastes need treatment in a specific level after throwing into the river or canal. Developed countries follow Sewerage Water Treatment Plant for waste treatment.Waste water from manufacturing or chemical processes in industries contributes to water pollution. Industrial waste water usually contains specific and readily identifiable chemical compounds. .

The most polluting of them are the city sewage and industrial waste discharged into the rivers. Industrial waste is defined as waste generated by manufacturing or industrial processes. The types of industrial waste generated include cafeteria garbage, dirt and gravel, masonry and concrete, scrap metals, trash, oil, solvents, chemicals, weed grass and trees, wood and scrap lumber, and similar wastes. Industrial solid waste - which may be solid, liquid or gases held in containers - is divided into hazardous and non-hazardous waste. Hazardous waste may result from manufacturing or other industrial processes

Sludge Disposal

The solids that result from wastewater treatment may contain concentrated levels of contaminants that were originally contained in the wastewater. A great deal of concern must be directed to the proper disposal of these solids to protect environmental considerations. Failure to do this may result in a mere shifting of the original pollutants in the waste stream to the final disposal site where they may again become free to contaminate the environment. A more reasonable approach to ultimate solids disposal is to view the sludge as a resource that can be recycled or reused.

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All the sewage sludge produced at a treatment plant must be disposed of ultimately. Treatment processes may reduce its volume or so change its character as to facilitate its disposal, but still leave a residue which in most cases must be removed from the plant site.

Oil Spill

 Effects of oil spills on marine life is endangered certain species of fish. Oil spill in large amounts will cause sea surface coated by oil. Layer of oil on the sea surface will also kill algae, seaweed and plankton which is the source of fish food. Extinction of a food source can also lead to the extinction of fish.  

Oil spill in the sea can also cause degradation of coral reefs. Coral reefs, especially in shallow areas are covered by a layer of dispersed oil causes coral to die. Layer of oil covering the sea surface also cause blocked sunlight and influence to the destruction of the ocean's coral.

The oil spill will destroy the natural habitat of marine life such as fish and other wildlife. Effects of oil spills at sea to humans, affecting tourism and leisure area. The natural beauty of the coast and the island will be affected because the spread of the oil spill. This resulted in tourism and leisure activities in coastal areas is not possible. In addition, the oil spill spread to the islands will affect water sports activities like diving on marine life has been destroyed in a shallow area of the island.

 Effects to the human is the lack of food supplies. When a lot of dead fish and possibly extinction of certain species of fish will cause a lack of supply at the same time will affect the supply of resources and food to the human protein. In addition, the effects of the spill spread far to the coast will cause aquatic life that makes the mangrove forests as habitats are destroyed. This will also cause disruption to the human food supply.

 

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