Health impact of air pollution

Since the onset of the industrial revolution, there has been a steady change in the composition of the atmosphere mainly due to the combustion of fossil fuels used for the generation of energy and transportation.

Air pollution is a major environmental health problem affecting the developing and the developed countries alike. The effects of air pollution on health०২੨੩৩ are very complex as there are many different sources and their individual effects vary from one to the other. It is not only the ambient air quality in the cities but also the indoor air quality in the rural and the urban areas that are causing concern. In fact in the developing world the highest air pollution exposures occur in the indoor environment. Air pollutants that are inhaled have serious impact on human health affecting the lungs and the respiratory system; they are also taken up by the blood and pumped all round the body. These pollutants are also deposited on soil, plants, and in the water, further contributing to human exposure. As you read on you can learn about health impacts of specific air pollutant.Sources of air pollution

Air pollutants consist of gaseous pollutants, odours, and SPM, (suspended particulate matter) such as dust, fumes, mist, and smoke. The concentration of these in and near the urban areas causes severe pollution to the surroundings. The largest sources of human-created air pollution are energy generation, transportation, and industries that use a great deal of energy sources. Depending on their source and interactions with other components of the air, they can have different chemical compositions and health impacts. Since these pollutants are generally concentrated in and around urban areas, the outdoor urban pollution levels are far higher than in the rural areas.

Fires are another major source of air pollution and can lead to severe problems if the smoke is inhaled for a period of time. These fires can either be forest fires, oil well fires, burning of leaves in the backyard or as in the case of rural areas, large-scale burning of agricultural waste. Other sources include industries and power plants located in these areas.Impact of air pollution on health

The magnitude of the London fog of 1952, which affected such a large number of people, was the first incident that made people aware of the damage done to the atmosphere due to industrialization. The SPM levels increased manifold and resulted in over 4000 deaths.

Indoor air pollution can be particularly hazardous to health as it is released in close proximity to people. It is stated that a pollutant released indoors is many times more likely to reach the lung than that released outdoors. In the developing countries a fairly large portion of the population is dependent on biomass for their energy requirements. These include wood, charcoal, agricultural residue, and animal waste. Open fires used for cooking and heating are commonly found in the household both in the rural and the urban areas. The stove is often at floor level, adding to the risk of accident and the hygiene factor. In addition, they are often not fitted with a chimney to remove the pollutants. In such households the children and women are most likely to be affected, as they are the group that spends more time indoors. The main pollutant in this environment is the SPM. In fact, death due to indoor air pollution, mainly particulate matters, in the rural areas of India are one of the highest in the world. Many of the deaths are due to acute respiratory infections in children; others are due to cardiovascular diseases, lung cancer, and chronic respiratory diseases in adults. If emissions are high and ventilation is poor, household use of coal and biomass can severely affect the indoor air quality.

Pollutant emissions per meal are also very high compared to those of other fuels. Household use of fossil fuel is also fairly common in the developing countries, particularly coal—both bituminous and lignite. These are particularly damaging as they burn inefficiently and emit considerable quantities of air pollutants. If emissions are high and ventilation poor, then the exposure levels to the gases emitted are far higher. The most harmful of the gases and agents that are emitted are particulate matter, carbon dioxide, polycyclic organic matter, and formaldehyde. The indoor concentrations of these are far higher than the acceptable levels and is cause for concern in rural areas.

Health impact of specific air pollutants

Some of these gases can seriously and adversely affect the health of the population and should be given due attention by the concerned authority. The gases mentioned below are mainly outdoor air pollutants but some of them can and do occur indoor depending on the source and the circumstances.

Tobacco smoke. Tobacco smoke generates a wide range of harmful chemicals and is a major cause of ill health, as it is known to cause cancer, not only to the smoker but affecting passive smokers too. It is well-known that smoking affects the passive smoker (the person who is in the vicinity of a smoker and is not himself/herself a smoker) ranging from burning sensation in the eyes or nose, and throat irritation, to cancer, bronchitis, severe asthma, and a decrease in lung function.Biological pollutants. These are mostly allergens that can cause asthma, hay fever, and other allergic diseases. Volatile organic compounds. Volatile compounds can cause irritation of the eye, nose and throat. In severe cases there may be headaches, nausea, and loss of coordination. In the longer run, some of them are suspected to cause damage to the liver and other parts of the body.Formaldehyde. Exposure causes irritation to the eyes, nose and may cause allergies in some people.Lead. Prolonged exposure can cause damage to the nervous system, digestive problems, and in some cases cause cancer. It is especially hazardous to small children.Radon. A radioactive gas that can accumulate inside the house, it originates from the rocks and soil under the house and its level is dominated by the outdoor air and also to some extent the other gases being emitted indoors. Exposure to this gas increases the risk of lung cancer.Ozone. Exposure to this gas makes our eyes itch, burn, and water and it has also been associated with increase in respiratory disorders such as asthma. It lowers our resistance to colds and pneumonia.Oxides of nitrogen. This gas can make children susceptible to respiratory diseases in the winters.Carbon monoxide. CO (carbon monoxide) combines with haemoglobin to lessen the amount of oxygen that enters our blood through our lungs. The binding with other haeme proteins causes changes in the function of the aff
ected organs such as the brain and the cardiovascular system, and also the developing foetus. It can impair our concentration, slow our reflexes, and make us confused and sleepy.Sulphur dioxide. SO₂ (sulphur dioxide) in the air is caused due to the rise in combustion of fossil fuels. It can oxidize and form sulphuric acid mist. SO₂ in the air leads to diseases of the lung and other lung disorders such as wheezing and shortness of breath. Long-term effects are more difficult to ascertain as SO2 exposure isoften combined with that of SPM.SPM (suspended particulate matter). Suspended matter consists of dust, fumes, mist and smoke. The main chemical component of SPM that is of major concern is lead, others being nickel, arsenic, and those present in diesel exhaust. These particles when breathed in, lodge in our lung tissues and cause lung damage and respiratory problems. The importance of SPM as a major pollutant needs special emphasis as a) it affects more people globally than any other pollutant on a continuing basis; b) there is more monitoring data available on this than any other pollutant; and c) more epidemiological evidence has been collected on the exposure to this than to any other pollutant.

How do you get sick?

The human body is extremely vulnerable to germs from bacteria and viruses in the air. Sneezing, sniffling, and incessant coughing are external tell-tale signs the body is fighting to eliminate infection, but what exactly happens internally when foreign invaders attack the immune system? In Life Noggin’s video “What Happens When We Get Sick?” host Patrick Graziosi explains although the immune system combats thousands of bacteria and viruses inhaled from the air, the occasional germ or two sneaks into the body and spreads infection.

Infections with viruses and bacteria can easily be transmitted from person to person, especially in the workplace. A recent survey from Staples found 60 percent of people still show up to work sick, putting their co-workers at risk with their symptoms. A person with a cold can spread infection by coughing and/or sneezing; bacteria or viruses can be passed on by touching or shaking hands with another person.

These foreign bodies have the ability to sneak into the body and get you sick. This leads the mucus membrane to become infected and inflamed, which causes the body to respond by sending more blood to these areas. The increase in blood flow lets loose a greater amount of antibodies and white blood cells that attack anything unusual, according to Life Noggin. As a result, the blood vessels begin to swell to allow this influx of blood.

For example, when you get a sore throat, they press up against nerve endings, which cause soreness. This is a sign that the body is healing itself. The same can be seen when you have a stuffy nose. Before you blow your nose, the mucus membrane secretes mucus to protect the body. This helps trap the bacteria and viruses and provides a good way for them to exit the body through your nose.

Lastly, when we’re sick we're susceptible to fevers caused by pyrogens. Although they can come from outside the body, they are more often than not triggered inside as part of the immune system’s response to invading germs. They cause the hypothalamus to raise the body’s overall temperature, which helps inhibit many viruses and bacteria.  

Remember, the next time you get infection symptoms, they are just your immune system’s way of fighting off foreign invaders. 

Tips for whitening teeth

- Routine. Set up a routine using these remedies and stick to it, at all costs, to get the most out of them.

- While not “natural” per say, using 3% (I repeat, 3%) hydrogen peroxide as a mouth rinse can whiten your teeth through the process of oxidation. It is an active indigent in many OTC whitening kits, but is often times found in much higher (and expensive) combinations in them.

- It’s fairly common knowledge, and difficult in today’s world, but try to avoid dark drinks, such as coke and coffee that stain your teeth.

Why do teeth get yellow?

To figure out how to whiten our teeth, we have to know why they get yellow in the first place. There are several factors that play a part, including genetics, what kind of food and drink you consume, and how well you practice oral hygiene. A tooth is made up of 4 tissues-enamel, which is the strong white covering that protects the tooth, dentin, which supports the enamel and is a hard yellow material that carries nerves, pulp, which is at the center of the tooth and contains blood and lymph vessels, and cementum, which covers the root of the tooth.The enamel and dentin is what play the biggest role in color. Certain food and drinks will directly stain the enamel, yes, but over time the two biggest culprits are the nasty food and drink that actually break down the enamel, and weakening enamel as we age. As the enamel breaks down, it reveals the yellow dentin underneath. These remedies will focus on whitening teeth that have already lost some white enamel, but it’s also good to keep in mind that doing things to strengthen enamel is just as important so you can keep it from breaking down further. An ounce of prevention is worth a pound of cure (or whitening!)

1. Baking Soda and Lemon Juice Paste

Baking Soda isn’t a shocker here. Sodium bicarbonate (its official name) is mildly abrasive; gently scrubbing away surface stains to return teeth to a whiter shade. It’s also very alkaline (the opposite of acidic) so I would think if you have a very acidic mouth or eat a lot of acidic food, it could help balance out the Ph, which would be useful as acid breaks down enamel-this is strictly speculation on my part. It will also reduce the acidity of the lemon juice, which acts as a natural bleach of sorts. I use a mixture of baking soda and water on some days, and use the lemon juice on others, as I don’t want to overdo it.

You will need…
-Several teaspoons of baking soda
-Enough lemon juice or water to form a paste
-A toothbrush

Directions
Mix several teaspoons of baking soda with enough fresh lemon juice (or water) to make a paste. Wipe your teeth and any extra saliva off of them with a paper towel. Put a good amount of paste onto your toothbrush and apply.Leave the paste on for 1 minute, then rinse, so as to avoid the acid effecting enamel. If you are using just water you can leave it on for up to 3 minutes.         

2. Strawberry, Salt and Baking Soda Scrub

Strawberries are high in Vitamin C, which can help break-down plaque that is causing your teeth to look yellow. It also has an enzyme called malic acid, which may help to remove surface stains. The salt acts as an abrasive portion of the paste, physically scrubbing away stain-causing gunk, and the baking soda is an extra touch that you can choose to leave out if you’d prefer (I just like to add it to anything involving my teeth.)

You will need…
-1-3 large strawberries
-A pinch of seat salt
-1/2 teaspoon of baking soda (optional)

Directions
Mash the berries into a pulp, and add a pinch of sea salt and ½ teaspoon of baking soda, if you’re using it. Wipe any extra saliva off your teeth with a paper towel, and then apply a generous portion of the mixture to a toothbrush and apply. Let the mixture sit for 5 minutes, then rinse. Do this nightly.

3. Coconut Oil Rinse

I know this sounds absolutely mad (I thought it was crazy too when I first read about it) but rinsing your mouth with coconut oil (called ‘oil pulling’) is a unique, old, remedy that people swear by to help whiten teeth. It doesn’t sound like the most pleasant thing in the world, but I actually don’t mind the taste, and I think it does make a difference in the color of your teeth. It won’t make a difference by “bleaching” per say, but lauric acid in coconut oil can rid your teeth of bacteria found in plaque that can make them yellow. It is also supposed to promote gum health, and help keep your breath fresh.

You will need…
-About a tablespoon of coconut oil

Directions

In the morning, before you brush your teeth, scoop out a tablespoon or a little less (depending on the size of your mouth) of coconut oil. You can either soften it, or just put it in your mouth (I usually do the latter, and just let it soften.) Push, swish, and “pull” the oil through and around your teeth for 10-15 minutes, then spit it out, rinse with water, and brush your teeth.

3. Coconut Oil Rinse

I know this sounds absolutely mad (I thought it was crazy too when I first read about it) but rinsing your mouth with coconut oil (called ‘oil pulling’) is a unique, old, remedy that people swear by to help whiten teeth. It doesn’t sound like the most pleasant thing in the world, but I actually don’t mind the taste, and I think it does make a difference in the color of your teeth. It won’t make a difference by “bleaching” per say, but lauric acid in coconut oil can rid your teeth of bacteria found in plaque that can make them yellow. It is also supposed to promote gum health, and help keep your breath fresh.

You will need…
-About a tablespoon of coconut oil

Directions

In the morning, before you brush your teeth, scoop out a tablespoon or a little less (depending on the size of your mouth) of coconut oil. You can either soften it, or just put it in your mouth (I usually do the latter, and just let it soften.) Push, swish, and “pull” the oil through and around your teeth for 10-15 minutes, then spit it out, rinse with water, and brush your teeth.

3 Natural ways to Whiten teeth at home

Whiter teeth, like is something that many people in our cosmetically driven world desire today. In fact, Americans spend over $1.4 billion dollars in over-the-counter teeth whitening products every year-that’s a good chunk of money just to achieve a different shade of teeth. I’ll be the first to admit that I’ve tried OTC teeth whitener-I even paid to have my dentist do it once. It worked for a bit, but my teeth got so sensitive I couldn’t stand it. I also felt I really didn’t need to be so obsessed with the color of my teeth that I paid a bunch of money for a bunch of who-knows-what that made my teeth hurt, so I started looking into more natural alternatives. With a bit of patience, I think you can naturally restore whiteness to your teeth. They may not get to be scary sear-out-somebodies-corneas –when-you –smile white, but they’ll appear more like you took good care of your pretty pearly whites rather than just bleaching them like crazy.

3 ways to keep strong Teeth

In addition to brushing and flossing, a healthful diet (with natural or added fluoride) protects teeth from decay and keeps the gums healthy. Read on to discover how to keep your smile safe and strong.

Tooth decay (cavities and dental caries) and gum disease are caused by colonies of bacteria that constantly coat the teeth with a sticky film called plaque. If plaque is not brushed away, these bacteria break down the sugars and starches in foods to produce acids that wear away the tooth enamel. The plaque also hardens into tartar, which can lead to gum inflammation, or gingivitis.

A well-balanced diet provides the minerals, vitamins, and other nutrients essential for healthy teeth and gums. Fluoride, occurring naturally in foods and water, or added to the water supply, can be a powerful tool in fighting decay. It can reduce the rate of cavities by as much as 60 percent.                                                                                          Dental Health Guidelines

Start right by eating right during pregnancy. Make sure that your children’s teeth get off to a good start by eating sensibly during pregnancy. Particularly important is calcium, which helps to form strong teeth and bones, and vitamin D, which the body needs to absorb calcium.

You need lots of calcium for healthy teeth and gums. Low-fat dairy products, fortified soy and rice beverages, canned salmon or sardines (with bones), almonds, and dark green leafy vegetables are excellent sources of calcium.

You need vitamin D to help absorb the calcium. Vitamin D is obtained from fluid milk, fortified soy and rice beverages, margarine, fatty fish such as salmon, and moderate exposure to the sun.

Fluoride is key. To a large extent, cavities can be prevented by giving children fluoride in the first few years of life. Fluoride is supplied through fluoridated water (not all municipalities fluoridate their water supply, however), beverages made with fluoridated water, tea, and some fish, as well as many brands of toothpaste and some mouthwash. Fluoride supplements are available for children who don’t have access to fluoridated drinking water. It is wise to check to see if the water supply in your area is fluoridated. Excess consumption of fluoride can cause mottling of the teeth.

Also needed are phosphorus, magnesium, vitamin A, and beta carotene. In addition to calcium and fluoride, minerals needed for the formation of tooth enamel include phosphorus (richly supplied in meat, fish, and eggs) and magnesium (found in whole grains, spinach, and bananas). Vitamin A also helps build strong bones and teeth. Good sources of beta carotene, which the body turns into vitamin A, include orange-colored fruits and vegetables and the dark green leafy vegetables.

Children are particularly vulnerable to tooth decay; parents should:
1. Provide a good diet throughout childhood

2. Brush children’s teeth until they’re mature enough to do a thorough job by themselves (usually by 6 or 7 years old)

3. Supervise twice-daily brushing and flossing thereafter

4. Never put babies or toddlers to bed accompanied by a bottle of milk (which contains the natural sugar lactose), juice, or other sweet drink5. Never dip pacifiers in honey or syrup

1. The sugar factor. Sucrose, most familiar to us as granulated sugar, is the leading cause of tooth decay, but it is far from the only culprit. Although sugary foods, including cookies, candies, and sodas, are major offenders, starchy foods (such as breads and cereals) also play an important part in tooth decay. When starches mix with amylase, an enzyme in saliva, the result is an acid bath that erodes the enamel and makes teeth more susceptible to decay. If starchy foods linger in the mouth, the acid bath is prolonged, and the potential for damage is all the greater.

Be careful when eating dried fruits. Dried fruits can have an adverse effect on teeth, because they are high in sugar and cling to the teeth. Even unsweetened fruit juices can contribute to tooth decay — they are acidic and contain relatively high levels of simple sugars.

Fresh fruits, especially apples, are better choices. Fresh fruit, although both sweet and acidic, is much less likely to cause a problem, because chewing stimulates the saliva flow. Saliva decreases mouth acidity and washes away food particles. Apples, for example, have been called nature’s toothbrush because they stimulate the gums, increase saliva flow and reduce the build-up of cavity-causing bacteria. A chronically dry mouth also contributes to decay. Saliva flow slows during sleep; going to bed without brushing the teeth is especially harmful. Certain drugs, including those used for high blood pressure, also cut down saliva flow.

2. Gum disease. More teeth are lost through gum disease than through tooth decay. Gum disease is likely to strike anyone who neglects oral hygiene or eats a poor diet. Particularly at risk are people with alcoholism, malnutrition, or AIDS/HIV infection or who are being treated with steroid drugs or certain cancer chemotherapies. Regular brushing and flossing help to prevent puffy, sore, and inflamed gums.

10 tips to keep your teeth Strong

Follow our 10 tips below for an overview of how to keep your teeth strong and healthy and how you can improve your oral and overall general health.

1. Nutrition
What you put in your mouth can affect the health of your teeth and gums. Choosing the right foods early in life can be especially beneficial throughout your whole life. Your mouth is full of germs and bacteria (plaque) that thrive on the starches and sugars produced that are found in the food you eat. When you don’t remove the plaque an acid is produced that attacks your enamel and eventually causes decay. Choosing foods that are low in sugar and starches will reduce the acids produced.

2. Floss
Whichever ‘gizmo’, gadget or bit of tape you choose to use – will do nothing to reduce your risk of tooth decay or gum disease if you don’t use it properly. Majority of the population that do use floss on a regular basis do not use it correctly. I liken bad flossing to trying to clean a pool with a scrubbing brush. If you don’t clean between the teeth, you’re cleaning only 60 per cent of the tooth’s surface. To effectively remove plaque, you need to hook the floss like a C around the tooth, so it hooks out the plaque from between the contact points of the teeth. The dental profession has been pushing it for 20 years, yet we’ve got only five per cent of the population to do it — because it’s fiddly. Most dentists recommend interdental brushes — small brushes that can get right below the gum line. They are much easier to use, and get into the curves of teeth so it’s easier to clean each side of the tooth.

3. Regular dental visits
There are two reasons people do not visit their dentist regularly. One is ‘The Nervous Patient’. A bad experience and fear of injections are the two most common reasons for this nervousness. And then there’s the ‘patient dreading the pain to hip pocket’. However, spending money on maintaining your oral health now will save you big bucks in the end, and your teeth will thank you for it by staying put!

4. Grinding and clenching
You have a 3 o’clock deadline and your boss just throws more work at you. Clench! You’re concentrating so hard on that cross-stitch you’re going cross-eyed. Grind! Now not all of us know that we do this. Sometimes it happens while you sleep. Clenching and grinding can make you wake up in the morning with sore facial muscles and can also crack, chip and wear your teeth. Not many people know that your dentist can help with this. If you experience any of these problems, ask you dentist how they can help.

5. Smoking
You don’t have to be a genius to know that smoking is bad for your general health but did you know that smoking reduces the blood flow to your mouth, resulting in greater chances of developing periodontal disease and oral cancers. Not only that, if you are a smoker and have any type of surgery or dental treatment, smoking reduces the ability of revasularisation (healing) of bone and soft tissue. Plus don’t forget the bad breath, stinky clothes and yellow teeth.

6. Chewing Gum
If you watch television you know that chewing gum after meals produces saliva flow, but did you know that chewing gum can actually improve your alertness by 10% by improving blood flow to the brain according to a recent study in Japan. So besides neutralizing acids and cleaning your teeth, chewing gum improves motor skills. Happy chewing!

7. Soften your toothbrush
You should never use a hard toothbrush. Hard toothbrushes cause abrasion to your enamel, which then exposes your dentine making your teeth appear more yellowish. Rinse your toothbrush with hot water before using it to soften the bristles.

8. Change your toothbrush
Changing your toothbrush is vital in keeping your oral hygiene in a good condition. Toothbrushes should be changed every 3 months due to the ineffectiveness after this. Also your mouth is full of bacteria, which transfers to your toothbrush after every use. And did you know that 80% of bacteria found in your mouth is not on your teeth? They are in the hard to reach places and soft tissues in your mouth such as the tongue cheeks and gums.

9. Use a straw
When drinking every dentist’s worst nightmare – soft drink or soda; use a straw. Using a straw will bypass the acid to your teeth. You still need to rinse your mouth with water after drinking these nasties, and if you are regular consumer you should use fluoride toothpaste and see your dentist for regular check-ups.

10. Limit snacks
If you eat 3 meals a day with no carbohydrates or sugar in between meals, then no need to read on. However, if you are like most of the population and cant resist a bit of snacking between meals then continue reading. The more snacks with sugar you have between meals (fruit, juice, sugared coffee, soft drinks etc.) the more holes you are likely to get. If you are a compulsive grazer it is important that you remember these 10 keys to keeping your teeth strong

Fresh juices are good for health

Whole fruits are great to eat because they have insoluble fibre that helps with digestion. Author and natural medicine expert Dr. Michael T. Murray says as a complement to eating fresh fruits and vegetables, we should also consider drinking fresh juices to get our recommended seven to 10 fruits and veggies a day. Fresh juices are also packed with soluble fibre -- a type of fibre that's been shown to lower cholesterol.

Juice Helps With Digestion 
If you're having digestion problems, drinking fresh juice may help. Murray says since juice is easier for our bodies to digest than whole fruits, we're more likely to get the nutrients we need to help us poop.

Your Body Saves Energy 
There's a reason why your body feels good when you eat healthy foods — and why you feel so tired after eating junk. According to Murray, our bodies use energy to convert the foods we eat into liquids to be absorbed. When you drink juice, your body is essentially skipping this step and saving energy.

More Nutritious Than That Store-Bought Stuff 
Fresh juice contains more vitamins, minerals, and other nutritional compounds like enzymes and flavonoids than the canned or bottled options you find in grocery stores. Store-bought juices also often have added sugar -- an ingredient the World Health Organizations says we should be reducing.

More Antioxidants For Your Body
Homemade juices contain increased antioxidant, antiviral, and anticancer properties, Murray says. One study comparing commercial apple juice with freshly squeezed apple juice found fresh, raw juice had more antiviral compounds than the store-bought versions. Another study found that fresh, raw apple juice and berry juice (especially those made with raspberries and blackberries) had more ellagic acid — an anticancer and antioxidant compound that's stripped from juice when it's processed.

Can It Help You Detox? 
Murray says fresh fruits contain glutathione, a small protein composed of three amino acids which aid our bodies in the detoxification of things like lead and pesticides. Most processed fruit juices, however, do not contain this protein.

It Can Help With Weight Loss 
Studies have found diets containing a high percentage (up to 60 per cent of calories) of uncooked foods are associated with weight loss and lowered blood pressure in overweight individuals. Murray suggests making a juice with two whole apples and 1/2 cup each of raspberries and blackberries to help with weight

what is Eye Cancer?

Cancer starts when cells in the body begin to grow out of control. Cells in nearly any part of the body can become cancer, and can spread to other areas of the body. To learn more about how cancers start and spread, see What Is Cancer?

An eye cancer starts in the eye. There are different types of eye cancers. To understand eye cancers, it helps to know something about the parts of the eye and what they do

Eyeball

The main part of the eye is the eyeball (also known as the globe), which is mostly filled with a jelly-like material called vitreous humor. The eyeball has 3 main layers: the sclera, the uvea, and the retina.

Sclera: The sclera is the tough, white covering over most of the outside of the eyeball. In the front of the eye it is continuous with the cornea, which is clear to let light through.

Uvea: The uvea is the middle layer of the eyeball. It is where most melanomas of the eye develop. The uvea has 3 main parts:

• The iris is the colored part of the eye (most often blue or brown). It surrounds the pupil, the small opening that lets light enter the eyeball.
• The choroid is a thin, pigmented layer lining the eyeball that nourishes the retina and the front of the eye with blood.
• The ciliary body contains the muscles inside the eye that change the shape of the lens so that the eye can focus on near or distant objects. It also has cells that make aqueous humor, the clear fluid in the front of the eye between the cornea and the lens.

Retina: The retina is the inner layer of cells in the back of the eye. It is made up of specialized nerve cells that are sensitive to light. These light-sensing cells are connected to the brain by the optic nerve. When light enters the eye it passes through the lens, which focuses it on the retina. The pattern of light (image) appearing on the retina is sent through the optic nerve to an area of the brain called the visual cortex, allowing us to see.

Cancers that affect the eyeball are called intraocular (within the eye) cancers.

Orbit

The orbit consists of the tissues surrounding the eyeball. These include muscles that move the eyeball in different directions and the nerves attached to the eye.

Cancers of these tissues are called orbital cancers.

Adnexal structures

Adnexal (accessory) structures include the eyelids and tear glands. Cancers that develop in these tissues are called adnexal cancers.

Cancers in the eye (intraocular cancers)

Two types of cancers can be found in the eye.

Primary intraocular cancers start inside the eyeball. In adults, melanoma is the most common primary intraocular cancer, followed by primary intraocular lymphoma. These 2 cancers are the focus of this document.

In children, retinoblastoma (a cancer that starts in cells in the retina) is the most common primary intraocular cancer, and medulloepithelioma is the next most common (but is still extremely rare). These childhood cancers are discussed in Retinoblastoma.

Secondary intraocular cancers start somewhere else in the body and then spread to the eye. These are not truly “eye cancers,” but they are actually more common than primary intraocular cancers. The most common cancers that spread to the eye are breast and lung cancers. Most often these cancers spread to the part of the eyeball called the uvea. For more information on these types of cancers, see our documents on them.

Intraocular melanoma (melanoma of the eye)

Intraocular melanoma is the most common type of cancer that develops within the eyeball in adults, but it is still fairly rare. Melanomas of the skin are much more common than intraocular melanomas.

Melanomas develop from pigment-making cells called melanocytes. When melanoma develops in the eye, it is usually in the uvea, which is why these cancers are also called uveal melanomas.

About 9 out of 10 intraocular melanomas develop in the choroid or ciliary body (which are parts of the uvea). Choroid cells make the same kind of pigment as melanocytes in the skin, so it’s not surprising that these cells sometimes form melanomas.

Most of the other intraocular melanomas start in the iris (also part of the uvea). These are the easiest for a person (or their doctor) to see because they often start in a dark spot on the iris that has been present for many years and then begins to grow. These melanomas usually are fairly slow growing, and they rarely spread to other parts of the body. For these reasons, people with iris melanomas generally have a good prognosis (outlook).

Intraocular melanomas are generally made up of 2 different kinds of cells.

• Spindle cells: These are long, thin cells.
• Epithelioid cells: These cells are almost round but with some straight edges.

Most tumors have both kinds of cells. The outlook is better if the tumors are mostly spindle cells as opposed to mostly epithelioid cells. Epithelioid tumors are more likely to spread to distant parts of the body (such as the liver). If you have intraocular melanoma, your doctor can tell you which type of cells were found.

Primary intraocular lymphoma (lymphoma of the eye)

Lymphoma is a type of cancer that starts in immune system cells called lymphocytes. Most lymphomas start in lymph nodes, which are bean-sized collections of immune system cells scattered throughout the body. Lymphomas can also start in internal organs such as the stomach, lungs, and rarely, in the eyes.

There are 2 main types of lymphoma: Hodgkin disease and non-Hodgkin lymphoma. Primary intraocular lymphoma is a type of non-Hodgkin lymphoma. Most people with primary intraocular lymphoma are elderly or have immune system problems such as AIDS. Primary intraocular lymphoma is often seen along with lymphoma of the brain, known as primary central nervous system (CNS) lymphomaCancers of the orbit and adnexa develop from tissues such as muscle, nerve, and skin around the eyeball and are like their counterparts in other parts of the body. These are described in our other documents on cancers of muscle, nerve, skin, etc. For example, cancers of the eyelid are usually skin cancers, which are described in our documents on skin cancers (Melanoma Skin Cancer and Skin Cancer: Basal and Squamous Cell). Muscle cancer is described in Rhabdomyosarcoma.

what is an Actinic Keratosis?

Actinic keratoses are scaly, crusty skin patches that can develop into skin cancer if left untreated.

A growth known as an actinic keratosis — a scaly, crusty skin patch — can result from exposure to the sun.

More than 10 million Americans are believed to have one or more actinic keratoses and, besides being unsightly, they put you at risk for .

Symptoms of Actinic Keratoses

An actinic keratosis most often develops on an area of skin that receives frequent sun exposure, such as your:

• Scalp
• Face
• Hands
• Forearms
• Shoulders
• Neck

An actinic keratosis starts out small — you might feel it before you see it because the little skin patch feels much rougher than the surrounding skin.

They slowly grow up to a quarter of an inch in diameter, and they may become red, tan, brown, or pink in color.

An actinic keratosis can itch and develop a tender or prickly sensation; it also can become inflamed or bleed.

Current studies show that about 10 percent of actinic keratoses will advance to a type of skin cancer called squamous cell carcinoma.

Squamous cell skin cancer, as opposed to basal cell carcinoma, moves quickly and can invade nearby tissues.

In rare cases, it can even metastasize to other body areas.

Causes and Risk Factors

Actinic keratoses are caused by years of sun exposure.

They form due to ultraviolet (UV) light damage to the skin cells called keratinocytes, which make up 90 percent of the outermost layer of your skin, the epidermis.

People at risk for developing actinic keratosis include:

Seniors: Actinic keratoses develop due to lifetime sun exposure, making the growths more likely as you become older.

They are much more common in people over age 50, and chances are that everyone over age 80 has at least one such growth somewhere.

People with less pigment in their skin: Those with fair skin are at greater risk because they have less protective pigment and are more likely to have been sunburned.

If you have blonde or red hair, or eyes that are blue, green, or gray, you are at high risk.

People with immune deficiencies: If your immune system has been suppressed by disease or medical treatment, your body is less able to repair the damage done by sun exposure.

People undergoing chemotherapy for cancer, taking medication to keep their bodies from rejecting an organ transplant, or who are infected with the HIV virus are also at higher risk.

Treatment Options

A number of treatments are available to remove an actinic keratosis:

Cryosurgery: Your doctor will freeze the growth using liquid nitrogen or some other extremely cold substance.

The frozen skin patch will die and flake off, and will be replaced by fresh, healthy skin. This is the treatment most often used.

Laser surgery: Doctors can use a laser beam to cut out the growth.

This precision technique is particularly effective for actinic keratosis located in narrow areas, particularly on the face.

Chemical peel: Acids are applied to the rough lesions, causing them to peel off and be replaced by new skin.

Topical medications: Prescription creams are available that can attack the growths, either by destroying the damaged cells or prompting the immune system to target them.

Most of these medications must be used for long periods of time and can cause reddening and mild discomfort, but are very effective.

Photodynamic therapy: A light-sensitizing solution is applied to the growths. When exposed to strong light, the activated solution destroys the lesions.

Surgical removal: Doctors can use a scalpel to shave away the actinic keratosis lesion.

Doctors often will combine some of these treatments to make sure the actinic keratosis has been totally removed.

How to Prevent Actinic Keratosis

To prevent an actinic keratosis, as well as any type of skin cancer, take steps to limit sun exposure:

• Stay indoors or in the shade during the hours the sun is strongest, usually from 10 a.m. to 4 p.m.
• Shield skin by wearing sunglasses, long-sleeved shirts, pants, and wide-brimmed hats.
• Apply sunscreen whenever outside, even if it's a cloudy day. Sunscreen should have a sun protection factor of 30 or higher and be reapplied every few hours.

And if you’re tempted to use a tanning bed, resist the lure — those ultraviolet lights can cause the same damage as the sun.