What is Mesothelioma

Mesothelioma is a cancer of the mesothelium. The mesothelium is a thin membrane that lines the chest and abdomen and surrounds the organs in these areas. The lining around the lungs is called the pleura and in the abdomen it is known as the peritoneum. 

About 2000 people in the UK are diagnosed with mesothelioma each year.

Mesothelioma of the lining of the lungs, known as pleural mesothelioma, is much more common than mesothelioma in the peritoneum. For every one person with peritoneal mesothelioma, there will be about 12 people who have pleural mesothelioma.



Pleural mesothelioma

The pleura has two layers: the inner (visceral) layer, which is next to the lung; and the outer (parietal) layer, which lines the chest wall. The two layers of the pleura are usually in contact and slide over each other as we breathe. The membranes produce fluid, which allows them to slide over each other easily.

When mesothelioma develops in the pleura (pleural mesothelioma), the delicate membranes thicken and may press inwards on the lung. Fluid may also collect between the two layers of the pleura: this is known as a pleural effusion.


Peritoneal mesothelioma

The lining of the abdomen is known as the peritoneum. It also has two layers: the inner (visceral) layer, which is next to the abdominal organs, and the outer (parietal) layer, which lines the abdominal wall.

If the mesothelioma is in the peritoneum it is called peritoneal mesothelioma and causes thickening of the membranes surrounding the abdominal organs and a collection of fluid in the abdomen. The collection of fluid is called ascites and causes swelling of the abdomen.
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Causes of mesothelioma

                                                  
 
                                 

Causes of mesothelioma

Asbestos is the most common cause of mesothelioma. Up to nine out of ten cases of mesothelioma are caused by exposure to asbestos. Asbestos is a natural mineral, mined from rock found in many countries. It is made up of tiny fibres that are as strong as steel but can be woven like cotton and are highly resistant to heat and chemicals.

During the 1960s the first definite link between mesothelioma and asbestos was made. In the past asbestos was imported to the UK in large quantities. It was used in construction, ship-building and in household appliances. Asbestos was very widely used in insulation materials, such as amosite insulation board, and building materials, including asbestos cement. types of Asbestos  
   
When asbestos is disturbed or damaged, it releases tiny fibres that can be breathed into the lungs. Asbestos fibres are very fine and, when breathed in, they can make their way into the smallest airways of the lung, so they cannot be breathed or coughed out. Once the fibres are in the lungs, the body's defence mechanism tries to break them down and remove them, which leads to inflammation in the lung tissue.





                                     
                                                   Roof made of asbestos



   
The asbestos fibres can also penetrate through the lung tissue to settle in the pleura (the membrane around the lung). Over many years they can cause mesothelioma or other lung diseases to develop.

Asbestos fibres can also be swallowed, and some of the fibres can stick in the digestive system. They can then move into the membrane that lines the abdomen (the peritoneum), where they cause inflammation.

The people most likely to have been exposed to asbestos

The people most likely to have been exposed to asbestos include:

• construction workers

• plumber

• electricians

• boilermakers

• shipbuilders

• demolition workers

• people who worked in other places where asbestos was present and
  people who lived near to asbestos factories.


Family members of people who worked with asbestos and brought the dust home on their clothes have also sometimes developed mesothelioma.  

   

                    


   
   

 


  There are three types of asbestos:

blue, brown and white. Blue and brown asbestos are the types most commonly linked with mesothelioma. They are now very rarely used and cannot be imported into the UK. Originally, white asbestos was thought not to be dangerous but recent studies have now shown that it is also harmful.

In the 1980s, imports of blue and brown asbestos into the UK were stopped, and in 1999 the importation and use of all asbestos was banned. However, as mesothelioma develops so slowly, it is estimated that by 2015 approximately 3000 people will be diagnosed with mesothelioma each year. The number of people who develop mesothelioma will then start to reduce each year.

Mesothelioma does not usually develop until many years after exposure to asbestos. It can take any time from 10 to 60 years, although the average is about 30 to 40 years after exposure to asbestos. 

Occasionally, mesothelioma develops in people who have never been exposed to asbestos. The other causes of the disease are not fully understood, but in rare cases the development of mesothelioma has been linked to exposure to radiation.

Research has not found any evidence that smoking increases a person's risk of developing mesothelioma. It is also thought that exposure to other building materials such as fibreglass does not increase the risk.

Mesothelioma is not contagious and cannot be passed on to other people. It is not caused by inherited faulty genes and so family members do not have an increased risk of developing it, unless they have been in contact with asbestos.


  Materials Containing Asbestos 

Most insulation materials before the mid-1970s contained asbestos. Many other construction materials also contained asbestos. Some of the most common products were:
• Insulation on pipes 
• Boiler insulation 
• Insulating cements, plasters, and joint compounds that came in powder form and created a lot of dust before being completely mixed with water. 
• Fireproofing spray 
• Firebrick and gunnite used for internal insulation of furnaces, boilers, and other vessels 
• Roof, floor, and ceiling tiles. 
• Transite siding 
• Brakes and clutches

Industries at Risk

                                          

                                          

Industries at Risk 

So who can get mesothelioma?  

Some cases require prolonged and high exposure levels, such as those of people who worked, unprotected, in industries using asbestos prior to 1970. These industries include: 

• factories 

• shipyards 

• mines 

• military 

• engineers 

• pipe fitters 

• steel workers 

• auto mechanics 

• construction
                                                

How Much Exposure is Dangerous ?

How Much Exposure is Dangerous?

                             

 patients received relatively short exposure, sometimes only months or weeks. Cases have been recorded of patients whose only exposure was when changing the brake linings on their cars and breathing the dust. 

Others had "passive" exposure, such as women who washed their husbands and son's work clothes. 

The disease can appear 20 years after exposure or as long as 50 years after, and some experts believe that cases will continue to rise until at least 2020. 

Always seek competent medical advice so your doctor can make an accurate diagnosis. The earlier you're diagnosed, the better your chances.