Asbestos: What Is Asbestos and How Does It Cause Cancer

Asbestos: What Is Asbestos and How Does It Cause Cancer

Asbestos: What Is Asbestos and How Does It Cause Cancer

Asbestos is a group of six naturally occurring fibrous minerals composed of thin, needle-like fibers. Exposure to asbestos causes several cancers and diseases, including mesothelioma and asbestosis. Although asbestos strengthens and fireproofs materials, it is banned in many countries. Asbestos is not banned in the United States.

Decades of research has proven exposure to asbestos, a naturally occurring mineral, causes cancer and other serious diseases. Knowing key asbestos statistics can help you understand the health risks and why it is so important to avoid asbestos exposure.

Asbestos served a central role in American commercial product manufacturing throughout the 20th century. It was used in thousands of products before regulations were implemented in the 1970s.

Americans who worked in construction, manufacturing and other blue-collar industries were most at risk of asbestos exposure. Research shows approximately 20 percent of asbestos workers develop a related disease later in life.

Asbestos Facts 

                         

Learning important asbestos facts helps people reduce their exposure to asbestos and may help prevent public exposure when whistleblowers speak up about dangerous working conditions.

Exposure Facts

Asbestos has been banned in more than 60 countries, but not in the U.S.

Asbestos exposure is the No. 1 cause of work-related deaths in the world.

Approximately 90,000 people die from asbestos-related diseases globally each year.

An estimated 125 million people worldwide remain at risk of occupationalexposure to asbestos.

About 1.3 million U.S. workers in construction and general industry are at risk of exposure today.

Types of Asbestos

The term asbestos refers to six fibrous minerals that occur naturally throughout the world.

• Chrysotile
• Tremolite
• Crocidolite
• Amosite
• Anthophyllite

Chrysotile is by far the most widely used type of asbestos. It accounts for approximately 95 percent of asbestos used around the world.

Asbestos fibers are naturally resistant to heat, fire, electricity and chemicals. These properties made it an ideal additive in products to prevent fire and chemical corrosion.

Who Is at Risk of Asbestos Exposure?

People who worked with asbestos products are the most at risk of exposure. Occupations that presented the greatest risk of asbestos exposure include:

• Miners
• Millers
• Insulators
• Boilermakers
• Auto mechanics
• Electricians
• Plumbers
• Firefighters
• Construction workers
• Industrial workers
• Shipyard workers
• Power plant workers

Anyone who lived with an asbestos worker was at risk of secondary exposure. This kind of exposure happened to many household members of asbestos workers. Washing the worker’s clothing was a particularly common source of secondary exposure.

Diseases Caused by Asbestos Exposure

Countless scientific studies have proven exposure to asbestos causes cancerous and noncancerous diseases.

• Asbestos-Related Cancers
• Mesothelioma
• Lung cancer
• Ovarian cancer
• Laryngeal cancer
• Noncancerous Conditions
• Asbestosis
• Pleural plaques
• Pleural effusions
• Pleuritis
• Diffuse pleural thickening
• Atelectasis

Asbestos Statistics

Learning more about asbestos statistics paints a realistic picture about the devastating impacts of asbestos exposure and its related diseases.

While there has been a fall in asbestos production throughout the world, certain countries — including the U.S. — have significantly increased importation of asbestos. Asbestos lobbyingorganizations play a major role in keeping asbestos trade alive.

Global asbestos production fell from 2.1 million tons in 2012 to 1.4 million tons in 2015.

In 2018, the U.S. chemical industry quadrupled its importation of asbestos compared to the year before.

A 2018 study published in the International Journal of Environmental Research and Public Health reported that for every 20 tons of asbestos produced and consumed a person dies of an asbestos-related disease somewhere in the world.

More than 2 million tons of asbestos is currently consumed each year throughout the world.

Asbestos Exposure Studies

Exposure studies reveal a lot about the health effects of asbestos including who may be at risk of developing an asbestos-related disease. These exposure studies focus on specific types of asbestos work. They uncovered how much exposure translates into cases of disease among the workers.

For example, insulators are among the most studied population of asbestos workers because exposure levels were high in this field of work. Studying asbestos insulators tells us a lot about what can happen when a person is exposed to high levels of asbestos for years.

A 1990 study published in Annals of the New York Academy of Sciences reported on insulation workers with 20 years of experience. More than 80 percent developed asbestosis and 40 percent died of asbestos-related diseases.

Some exposure studies have evaluated the risk of disease among people who live in a contaminated area. For example, studies have been conducted on Libby, Montana. The town is home to an asbestos-contaminated vermiculite mine that closed in 1990.

A 2013 study by the National Institute of Environmental Health Sciences found 18 to 20 percent of adult residents in Libby have asbestos-related disease.

Asbestos-RelatedDisease Statistics

Statistics on asbestos-caused diseases uncover an epidemic of tragic proportions. Thousands of Americans are diagnosed with asbestos-related conditions each year. Hundreds of thousands of people are diagnosed with these conditions around the globe.

Around 3,000 Americans are diagnosed with mesothelioma every year.

Asbestos exposure causes at least 90 percent of all mesothelioma cases.

From 1999-2010, approximately 6,300 Americans lost their lives to asbestosis.

Asbestos-Related Death Statistics

Out of all the conditions, asbestos-related lung cancer claims the most lives, followed by mesothelioma.

A study published in 2017 claimed the annual global death rate caused by asbestos exposure is around 237,000.

A 2018 study reported asbestos-related diseases killed 39,275 people in the U.S. and 222,321 people throughout the world in 2016.

Despite these shocking statistics, the U.S. Environmental Protection Agency announced in June 2018 it would consider new uses of asbestos with a specific review process. Organizations around the world, such as the International Ban Asbestos Secretariat, continue to advocate for a worldwide ban to protect future generations from asbestos-related diseases.

Asbestos: What Is Asbestos and How Does It Cause Cancer

COVID-19: 'I’ve never seen such sticky blood’ says thrombosis expert

COVID-19: 'I’ve never seen such sticky blood’ says thrombosis expert

COVID-19: 'I’ve never seen such sticky blood’ says thrombosis expert

COVID-19 leads to blood clots in a significant number of people who have a severe form of the disease. In an interview  thrombosis expert Prof. Beverley Hunt explains why blood clots are dangerous for those with the new coronavirus.

As news of a SARS-CoV-2, the new coronavirus, traveled across the globe, many experts thought that they would primarily encounter respiratory symptoms.

And little did we expect to be hearing about cardiovascular complications, digestive symptoms, the loss of smell and taste, and the likes of “COVID toe,” one of a collection of skin symptoms that some people with COVID-19 develop.

Blood clots are another complication that has been making headlines.TG reported on a series of articles in the journal Radiology that suggested that a significant number of people with severe COVID-19 develop life threatening clotting.

But why would a virus that primarily infects the respiratory tract cause blood clots? And how is this putting patients at serious risk?

Prof. Beverley Hunt is the medical director of the British charity Thrombosis UK, as well as chair of the steering group for World Thrombosis Day. She is a professor of thrombosis and hemostasis and works for the United Kingdom’s National Health Service (NHS) in London.

Prof. Hunt told about the biology of blood clotting, her surprise at how the new coronavirus changes the properties of the blood in those with severe disease, and why we should keep moving, even during lockdown, to reduce our risk of thrombosis.

‘The conductor of the blood clotting orchestra’

Prof. Hunt: In 1846, the German pathologist [Rudolf] Virchow described three things that predispose people to venous thrombosis.

They are: changes in the flow of the blood, changes in the stickiness of the blood — although he didn’t use the word “sticky” then — and changes in the blood vessel wall.

Of these, probably the most important one for the average member of the public is flow. Just sitting here for 90 minutes without moving my legs, blood flow crashes. It drops by about 50%.

When you walk, every time your muscles contract, they squeeze the veins and push the blood back up toward the heart.

There isn’t a natural muscular system within the veins, unlike within the arteries. We’re totally dependent on movement to keep the flow going.

This is a major risk factor for hospital patients, for someone who is sick, but also for anyone sitting for long periods of time.

As far as the stickiness is concerned, we are talking about changes in the blood proteins. The commonest cause of these changes is being ill.

If you’re ill, you produce chemical cytokines that tell the liver to make more clotting proteins. Then your blood is full of clotting proteins that make it very sticky and very ready to clot.

The last thing is the lining of the blood vessel. It’s very susceptible to hormones, particularly in people who are ill and people who take hormone replacement therapy. Those cytokines make it much, much more liable to form a clot.

When we come to COVID-19, we know that the new coronavirus can enter the lining of the blood vessels. The new coronavirus behaves in some way like the conductor of the blood clotting orchestra.

‘I’ve never seen such sticky blood’

Prof. Hunt: The issue with COVID-19 is that the blood is incredibly sticky.

We are seeing people in hospital with pneumonia. They are in hospital because they are short of oxygen, and they need extra oxygen. That’s really why they are coming in.

We know that most people who get COVID-19 get better in about 7–10 days, and we have about 5% who develop pneumonia.

Their immune system is reacting very strongly to the pneumonia, and the lungs are full of immune cells that produce cytokines. In turn, these tell the liver to make clotting proteins. The inflammatory mechanism leads to what we call a “prothrombotic state.”

Let me give you an example. The main clotting protein in the blood is fibrinogen. It’s soluble, and you have 2–4 grams per liter in your blood.

The clotting factors switch soluble fibrinogen to insoluble fibrin, and that is the clot.

The level is 2–4 grams per liter in most people. If you are pregnant, or as you get older, the levels get higher. They might go up to 5, 6, or even 7 [grams per liter].

Inflammation and thrombosis

Prof. Hunt: I haven’t seen these values before in this many patients. Occasionally, you get a patient who has really high levels. But all of them have these really high levels. That is a major issue.

But we didn’t know that this was going to happen until the patients arrived. The initial reports from China, which we had a little bit of, suggested there were major clotting problems, but they called it something else, and I think they didn’t quite get it right in those early stages.

Now we know that these patients have incredibly sticky blood. This stickiness is causing them to have deep vein thrombosis. And of course, if you have a deep vein thrombosis, bits of it can break off and travel through your body and block some of the blood supply to the lungs.

And because the lungs aren’t working properly in the first place, this really isn’t a good thing in a really sick patient.

So, we are giving all of the COVID-19patients small doses of blood thinners to reduce the risk. But really, the question is, should we be giving them more?

We know that the doses that we give under normal circumstances have minimal bleed risk. Their advantage is that the risk of blood clots is reduced by 50%. But should we perhaps be giving these patients a little bit more because their blood is so sticky? That’s currently the big research question.

The other thing that we’re seeing, which caught a lot of people out, is blockages in tiny vessels. Normally, if you do imaging of the lungs and you look for blockages in the blood vessels — with a pulmonary embolism, you typically see blockages in a few of the big ones.

What we are also seeing are blockages of tiny little vessels, in what we call subsegmental branches of the pulmonary artery. That’s not really a pulmonary embolism.

When we look at the postmortem reports from Chinese studies and from other studies out there, from the United States, Argentina, and Italy, we know that if there is really profound inflammation in an area, that can lead to thrombosis.

There is so much inflammation in the lung, and then we see small pockets of thrombosis caused by inflammation.

Blood thinners and mortality

Prof. Hunt: At the moment, we know that we can give patients oxygen. We also give everyone small doses of blood thinners, and we know that will reduce their thrombotic risk.

But we don’t have an effective antiviral, and we don’t have data on the anti-inflammatories yet.

We are just starting a trial to see if giving bigger doses of blood thinners will improve outcomes in these patients.

Prof. Hunt: I campaigned for years to make sure that NHS England gives effective blood thinners to all the patients at risk in hospitals.

In fact, NHS England is the world leader in preventing hospital-acquired venous thromboembolism or hospital-acquired thrombosis.

In our system, everybody has to have a risk assessment when they arrive at a hospital, and they get blood thinners if they are at risk.

We did this for the COVID-19 patients right from the start, so we don’t have comparative data.

But interestingly, looking at the Chinese data from Wuhan, they do not routinely use blood thinners. [But] they gave a small proportion of the patients blood thinners, and they showed that they had lower mortality.

Stay mobile to reduce blood clot risk

Prof. Hunt: That’s right. There is one proviso, though. During lockdown, a lot of people aren’t moving around very much.

If someone is working at their desk, really, they should be getting up every hour or 90 minutes to move around a little, so that their blood is squeezed up and moved around, and they are not increasing their risk of having a clot.

This is called seated immobility syndrome, and under this, we would include people who sit for long times at their desks, on airplanes, or on long journeys in busses or cars.

Prof. Hunt: With COVID-19, we need to look at the whole patient journey. If you already have some level of sticky blood, which 6% of the population do, then we might think about giving you a blood thinner, just in case you develop pneumonia.

This means we need research in ambulatory care to prevent these issues, in case people go on to have pneumonia.

For those patients who do go on to the hospital, they get blood thinners there. Then we discharge them. But, they still have really sticky blood. We know that if we look at hospital-acquired venous thromboembolism, the risk extends right out to 90 days post-discharge. In fact, 60% of clots actually occur after discharge.

We need to think about giving these patients blood thinners after they go home. We do not normally do this in what we call “medical patients,” patients who haven’t had surgery.

But there is a recommendation coming out from NHS England that we should be doing exactly that, and most centers are now giving patients blood thinners for 2 weeks after their discharge to reduce the risk of clots.