Physical Carcinogenesis

Carcinogenesis is defined as the process of cancer growth. Specifically, the term refers to the process by which normal cells in the body mutate into cancer cells. In order for carcinogenesis to occur, damages in healthy cell DNA must occur. For this reason, carcinogenesis is often tied to genetics. However, exposure to certain chemicals and other hazardous materials can also cause cell damage that can lead to cancer.

Factors That Contribute to Carcinogenesis

While the factors that contribute to cancer growth are complex and still being studied by the research community, a number of contributing factors have been identified that increase a cell’s risk for carcinogenesis. These factors include genetics, environmental exposure and age. Regardless of the instigating cause of cancer growth, proliferation is dependent on the ability of the cancer cells to:

  • Grow quickly and inappropriately
  • Avoid cell death via the body’s defense systems
  • Stimulate their microenvironment
  • Spread to new areas of the body

Based on research, the biological contributing factors that foster carcinogenesis include:

  • Errors in gene expression due to faulty chromatin structure
  • Improper signal transduction between cells
  • Unhealthy hormone exposure
  • Improper metabolism of fatty acid
  • Damaged DNA or repair responses

The Importance of Proto-Oncogenes

Proto-oncogenes are a specific subcategory of genes that are responsible for inducing cell growth. A series of mutations in this key gene category is typically where carcinogenesis begins. Due to one or several of the contributing factors listed above, these proto-oncogenes become damaged in a way that accelerates cell growth. This, in turn, provides the rapid growth necessary for cancer cells to flourish, grow and spread throughout the body at such a rate that the natural immune system cannot adequately defend itself.

Damage to tumor suppressor genes often works in tandem with damaged proto-oncogenes to create cancer. Tumor suppressor genes are designed to clean up any DNA damage that may occur during cell replication. When damage to these tumor suppressors occurs, DNA damage proliferates, which can lead to mutations that ultimately give rise to cancer cells.

Other Instigators of Cancer

Mutation of proto-oncogenes and tumor suppressor genes are thought to be the most common cause of carcinogenesis. However, there are other non-mutagenic effects that also are believed to cause cancer. For example, an increase in estrogen in the body is thought to increase the rate of cell mitosis without causing gene mutation. This increase in mitosis proliferates cell growth much in the same way as damaged proto-oncogenes. Excessive consumption of alcohol can also stimulate mitosis.

To a lesser degree, bacteria and viruses have also been known to spur carcinogenesis. For example, HPV, Hepatitis B and EBV are all known illnesses that can directly cause cancer. It is believed that the reason for this is the virus’ ability to promote cell proliferation by inserting a portion of its own DNA into healthy human cells.

Difference Between Benign and Malignant Tumors

There are three stages of carcinogenesis – initiation, promotion and progression. Initiation results when a cell experiences damaged DNA. Promotion exacerbates cell damage and growth by altering gene expression, suppressing an immune response and enhancing cell division. While in the promotion stage, tumor cells are said to be benign. This means that they are non-cancerous, yet still unhealthy and growing at an abnormal rate.

Once the damaged cells begin to exchange DNA between chromosomes, express oncogenes and exhibit additional mutations, the progression stage of carcinogenesis is achieved. It is in this third stage that malignant tumors begin to grow.

Resource:

http://www.niehs.nih.gov/research/atniehs/labs/escbl/

BAC Cinema Owner Unknowingly Disperses Asbestos

It was a sweet deal, with the city of Belleville, Illinois offering to pay half the cost of demolition of an old theater for the owner if he would simply add a third screen to his drive-in.

The cost of the asbestos remediation and demolition combined was $81,000, with the asbestos remediation occurring first, as required by NESHAP (National Emissions Standards for Hazardous Air Pollutants), a set of regulations established and enforced by the U.S. Environmental Protection Agency, or EPA, to insure that deconstruction of public (and private) buildings does not adversely impact the health of the American public.

NESHAP regulations include specific instructions on how to handle asbestos, including wetting it to prevent it dispersing into the air; not using certain power tools or equipment in the presence of friable asbestos (any material containing more than one percent asbestos) to prevent dispersing fibers into the air and onto surfaces; and putting it into EPA-designated containers after bagging it in plastic, and marking both the bags and the containers.

Asbestos-containing materials, or ACMs, if badly handled, can release asbestos fibers that have been implicated in a number of diseases, including asbestosis, small cell and non-small cell lung cancers, and malignant mesothelioma.

The first is a progressive respiratory disease whose symptoms are similar to other breathing disorders like asthma. The second are, of course, cancers. The last is also a form of cancer, but one that is particularly insidious and disturbing. Unlike most cancers, which manifest rather rapidly, mesothelioma can lie dormant for up to five decades before exploding into the sort of aggressive cancers for which the typical prognosis, after diagnosis, is about a year to live.

Sources: Belleville News Democrat, EPA

New Polymer Test Improves Lung Cancer Diagnosis, Says Experts

A new technique used for testing for the presence of lung cancer could potentially reduce diagnosis time from six months to four weeks, according to researchers at the National Institute of Standards and Technology (NIST).

This dramatic improvement in diagnosis time comes courtesy of a three-dimensional testing technique known as volumetrics. The procedure involves taking numerous CT scans from a variety of angles to produce a 3-D cross sectional image of the internal body. Through early research, the NIST team found that CT scan accuracy and amount of time needed to identify signs of lung cancer increased dramatically compared to current testing techniques.
To achieve these advancements, the research team used volumetrics to identify polymer-silicate ellipsoids present on the lungs. These polymer growths look similar in shape to a medical pill and range in diameter from four to 11 mm. As lead researcher Zachary Levine indicates, ” For diagnosis in the earliest stage of cancer, other studies have shown this is the size of nodule you want to be looking at.”

Presently, the most widely lung cancer diagnosis procedure is something known as RECIST. This process involves measuring the distance across suspect lung nodules as they are displayed in two-dimensional format. If a nodule is identified within a certain size range, then it may warrant additional tests to confirm lung cancer.

Through clever comparison tests, the team was able to show that volumetrics are capable of identifying signs of lung cancer that are ten time smaller than those visible via RECIST. According to Levine, “This implies that you could notice life-threatening changes from a follow-up scan performed only weeks after the first, instead of months.”

One potential downside of the new diagnosis technique is the fact that lung cancer does not always grow in the shape of elliptical pills. As such, diagnosis of certain cancer cases may remain more difficult.

Sources: http://www.newstrackindia.com/newsdetails/161031 http://www.nist.gov/pml/div685/ct_042710.cfm

British Contractor Fined for Illegal Asbestos Removal

A judge at the Caerphilly Magistrates’ Court fined a building contractor £2,500 (US$3,893) for disregarding regulations governing asbestos remediation. Ron Couch Building Contracts Ltd. of Pontypool paid the fine after pleading guilty to two counts of violating the country’s Control of Asbestos Regulations. The firm was accused of taking on asbestos removal projects without a license.

According to reports, workers were replacing a boiler in a central heating unit at a private home. One of the workers was said to have detached a door containing asbestos-laced insulation to make room to move the old boiler. Another contracting firm working on a nearby project had an asbestos specialist on site. The asbestos specialist noticed the door sitting outside the house, saw the asbestos and alerted authorities to the danger. The magistrate also ordered the company to pay £1,250 (US$1,947) to cover cleanup costs.

Steve Richardson, who works with the British Health and Safety Executive (HSE) as an inspector, said that the Ron Couch project managers were “well aware” of the legal requirements surrounding asbestos removal projects. Mr. Richardson said that the firm had previously carried out a similar project involving a boiler flue. In that project, they followed the regulations on asbestos remediation and employed licensed specialists to handle the toxic insulation.

Mr. Richardson also said that the process used to remove the door exposed its edge. The door contained asbestos insulation board, also called AIB. Once the insides of the door were exposed, the asbestos insulation board inside would have been disturbed. When asbestos-containing materials are disturbed, the microscopic asbestos fibers become airborne and create a health hazard. Workers who handle asbestos are required to wear protective breathing masks and special coveralls to prevent exposure to the fibers.

Scientific studies have established a link between asbestos exposure and lung disease. The most serious disorder related to asbestos exposure is pleural mesothelioma, a type of cancer that targets the soft tissue surrounding the lungs. Recent reports from public health officials state that mesothelioma and other asbestos-related diseases are the number-one workplace killer among Britons. Mesothelioma also has a long latency period, so the number of deaths from the disease is expected to rise for the next ten to twenty years.

In 2006, the HSE updated the Control of Asbestos Regulations. The new rules stated that commercial property owners must conduct asbestos assessments on their buildings. These assessments should include the likelihood of asbestos exposure and methods for any future asbestos remediation. Violators may face up to two years in prison. The successful prosecution of these violations is the latest sign that the HSE and other British agencies are getting tough on asbestos.

Asbestos was banned in Britain in 1999, but many of the country’s buildings constructed over the last century still contain asbestos. The mineral was widely used in construction applications such as insulation, fireproofing, and concrete mixing. The source mineral was cheap and plentiful. Its fibers were lightweight and could withstand extreme temperatures, which made it a highly desired material in the construction trades.

Sources: safetysignsupplies.co.uk, theconstructionindex.co.uk, access-legal.co.uk

Canada Aims to Save Lives With Standardization of Mesothelioma Data

Canada, a leading exporter of asbestos,  has announced a nationwide initiative that is designed to give cancer researchers and health officials improved access to research data.  Known as the National Staging Initiative, the project will serve to enhance the sharing and cooperation of cancer research across all provinces and territories.

Specifically, the initiative will focus on the collective gathering of staging information for prostate cancer, colorectal cancer, breast cancer and lung cancer. These four cancers are the most common cancer types in Canada (94,600 new cases of these cancers are estimated to occur within the country for the 2010 year).

The Canadian Partnership Against Cancer worked cooperatively with the Canadian Association of Provincial Cancer Agencies to create the initiative. Collectively, the organizations have pledged $20 million towards the campaign.

Labeled as an initiative that is “first of its kind,” Canada’s Federal Health Administrator, Leona Aglukkaq, states, “The national staging initiative will generate better data and better evidence which will improve the cancer system and ultimately save lives.”

Staging is the process of assessing how far along a particular case of cancer has progressed. Recommended treatment options vary depending on which stage a patient’s cancer has progressed. As such, a nationwide collection of staging info provides researchers with a deeper well of data that can be used to more easily identify trends within cancer populations.

According to Caroline Heick, VP of knowledge management at the Canadian Partnership Against Cancer, “This information plays an important role in helping health system planners answer questions like ‘Are screening programs effective in saving Canadians’ lives?’ and ‘Which treatments are helping people live longer?”

Staging data will be collectively pooled for all patients diagnosed with one of the four cancers on or after January 1, 2010. Data related to the initiative is estimated to be available in 2012.

Sources: Montreal Gazette, New Brunswick Business Journal

Nearly Half of Deaths in Turkish Town Caused by Mesothelioma

In most of the world, mesothelioma is an extremely rare type of lung cancer that accounts for less than one of every 100,000 deaths. However, in the Turkish region of Cappadocia, instances of death related to malignant mesothelioma hover at an astonishing rate of 48 percent.

Mesothelioma has been linked to the inhalation of asbestos fibers – a naturally occurring mineral that is used in a variety of heat-resistant products. A similarly fibrous material – erionite – is abundant in the Cappadocia region and has been used for decades as a resource for building homes and roadways.

Unfortunately, the frequent use of erionite in the Cappadocia region has exposed most of the residents to hazardous levels of this toxic material. The towns most dramatically affected by the fiber include Tuzkoy, Sarihidir and Karain.

While erionite is found in a number of regions globally (for example, Nevada), “the cancerous material is generally found far deep underground,” according to Izzetin Baris (a retired professor with a long history of mesothelioma research). “In Turkey, however, it is very close to the surface.”

Look at the numbers, and it becomes evident that, “The number of cases of mesothelioma in Tuzkoy has been about 600 to 800 times higher than world standards,” says Murat Tuncer of the Turkish Health Ministry department.

Due to these alarming numbers, government authorities have initiated a relocation plan to move all 2,350 remaining residents of Tuzkoy to a nearby location. As with the 250 families that have already been relocated, the costs associated with the move will be subsidized by the state. The new housing facility is located approximately one mile away from the current city’s location.

While this relocation is believed to move Tuzkoy villagers properly out of harm’s way, officials are still unsure about plans to demolish the current city. Present plans suggest the entire village will be demolished, buried in a thick layer of uncontaminated earth and then re-planted. However, other ideas include paving over the city with asphalt or doing nothing and simply prohibiting entry into the area.

Sadly, the knowledge of environmental hazards in Tuzkoy has been known for quite some time. In fact, relocation efforts first began back in 1999. However, little progress has been made thanks to various government difficulties and financial constraints.

Currently, government authorities hope the relocation will be completed by 2012. Even when such relocation occurs, however, a decline of cancer rates may not be noted for decades – mesothelioma often does not manifest until 20 to 50 years following initial exposure.

Source: ABCNews

Madison Square Garden Closed Due to Asbestos Cleanup

Officials at Madison Square Garden ordered the postponement of a scheduled game between the NBA’s Orlando Magic and the hometown New York Knicks due to dust falling from the arena ceiling during an asbestos cleanup project. Work crews at the Garden were converting the arena floor for the basketball after a game featuring the NHL’s New York Rangers. During the conversion and subsequent cleanup, dust and debris from the ceiling hit the floor.

According to a statement from the Knicks, the cleanup included cleaning out areas of the ceiling that held “asbestos-related materials”. The statement also said that the team and the arena would work with city officials and independent environmental testing services to “determine the most appropriate course of action”. The team said that they would not reopen the arena until they had received assurances that no fans, players or staff would be exposed to any health hazards from the debris.

Madison Square Garden has long been considered a New York City landmark and is known to sports fans as “The World’s Most Famous Arena”. With the start of the NBA, NHL and college basketball seasons, the building is experiencing one of its yearly peaks in terms of use and attendance. The arena serves as the home to the Knicks, Rangers, and the St. John’s University Red Storm basketball games.

The current schedule calls for another NBA game between the Knicks and the Washington Wizards on Friday (5 November), a concert by former Pink Floyd guitarist Roger Waters (6 November) and a day-night double-header between the Knicks and the Philadelphia 76ers at noon, followed by an NHL contest between the Rangers and the St. Louis Blues at 7:30pm (7 November).

Constructed in the late 1960s, the newest version of the venerable arena opened in 1968. During the construction project, as was typical at the time, workers used asbestos-laced materials as insulation and fireproofing materials. The Garden is the oldest building still in use in the National Hockey League and the second-oldest still in use by the National Basketball Association. The recent asbestos scare came during efforts to remove the carcinogenic substance from the building as part of a major renovation project.

An official with the New York Department of Environmental Protection said that their office investigated the incident. Investigators found that “no asbestos (was) released” and declared that there was “no health concern” for anyone who worked in or visited the building.

MSG officials have yet to announce when or if they will reopen the arena for any upcoming events. However, one executive said that they expect the debris to be cleared away by today (3 November) and that the only event effected by the scare would be the Knicks/Magic game.

If officials later decide to keep the building closed until further notice, a spokesman said that they have contacted arena owners in New Jersey and Connecticut to house the NBA and NHL games. Ticket holders are urged to check with the team web sites to find out when or where their games will be rescheduled or relocated.

Sources: New York Post, CNN, ESPN, NorthJersey.com

Asbestos Exposure and Health

What are my risks of asbestos exposure?

We all face exposure to asbestos in the air we breathe, but this type of exposure is low-level, ranging from 0.00001 to 0.0001 fibers for every millimeter of air and usually these are highest in industrial areas and cities.

Individuals working in industries where asbestos products are manufactured or used or those who may be deployed at asbestos mining sites can face high levels of exposure to asbestos. People who may be living in areas adjoining these industries may also face high level of exposure to asbestos.

Asbestos fibers can get released into the air due to the disturbance of materials that contain asbestos. This can occur during product use, demolition activity, or building or home repair, renovation and remodeling. Usually, exposure occurs only in specific situations when asbestos-based materials are disturbed in such a way that it leads to the release of asbestos fibers and dust into the air.

Asbestos can be found in drinking water, and this may be due to asbestos coming from natural sources or via cement pipes that contain asbestos.

How will my health be affected due to asbestos?

In most cases, asbestos affects the lungs and also the membranes which surround the lungs. Inhaling asbestos fibers in large quantities over long periods can lead to the development of scar-like tissue in the lungs as well as in the pleural membrane (lining) that covers the lung. This disease is referred to as asbestosis and is normally prevalent amongst workers who were exposed to asbestos. However, it is not prevalent in the general population. Individuals diagnosed with asbestosis face breathing problems, usually have a cough, and in more serious cases, are detected with heart enlargement. Asbestosis is a critical disease and may eventually result in disability or death.

Inhaling asbestos fibers or dust in smaller proportions can lead to specific changes referred to as plaques in the pleural lining. This type of pleural plaques can be found amongst workers and sometimes in individuals who may be living in areas that have high levels of asbestos in the air. Breathing problems, if any, resulting from pleural plaques are generally not serious, but higher levels of exposure can result in the thickening of the pleural lining which may restrict breathing.

Asbestos Exposure in the Home

How to reduce asbestos exposure risks in families?

Asbestos-containing materials generally do not cause any harm as long as they are in good condition and are not disturbed. Hence, they can be left alone. You need to do this to find out the right way to test your home and also to find a company that offers safe containment or removal of asbestos fibers.

Can a medical test reveal whether I have faced asbestos exposure?

Asbestos fibers at low levels can be detected in urine, feces, mucus, or lung washings of the general public. When more than average levels of asbestos fibers are found in tissue, it can substantiate exposure, but it may not be indicative of any health effects that you may experience.

A detailed history, physical examination and diagnostic tests are required to assess asbestos-related disease. Chest x-rays have proved the most effective screening tool to detect lung changes caused by asbestos exposure. CAT scans and lung function tests are also helpful in the detection of disease caused by asbestos exposure.

What steps have been taken by the Federal government to protect human health?

The EPA banned all new types of asbestos usage in the year 1989. However, uses that existed prior to this date are still permitted. Specific regulations were established by the EPA, for instance regulations that mandate school systems to check for damaged asbestos and to reduce or eliminate the exposure by safely removing or covering up the asbestos. To avoid asbestos from entering the environment, the EPA regulates the amount of asbestos being released from factories and during demolition or renovation of buildings.

The EPA has proposed a contamination limit of 7 million asbestos fibers for every liter of drinking water in case of long fibers (fibers that are greater than or equal to 5 µm).

As per the Occupational Safety and Health Administration (OSHA), the limit for fibers greater than or equal to 5 µm is 100,000 fibers for every cubic meter of workplace air, applicable to shifts of 8 hours and weeks of 40 hours.

Exposure to Toxic Asbestos – Millions of Veterans Were Affected

Use of asbestos increased significantly during and after the Second World War. This was mainly due to the asbestos manufacturing companies that mass-produced asbestos based products for use on U.S. Navy ships. This led to thousands of sailors and workers getting inadvertently exposed to lethal asbestos dust while cutting and modifying insulation products. Decades later, many of these individuals would contract asbestos-based complications and diseases.

Avoidable exposure

For around 5 decades, just before the mid-1970’s, insulation products manufactured by the asbestos industry were installed in most homes, schools, buildings, cars, planes, and ships in America. Notably, asbestos manufacturers were well aware of the long-term consequences of asbestos exposure, but they simply ignored them. The U.S. Navy came to know about the dangers of asbestos exposure only after the 1970’s. But this came a bit late for the hundreds of thousands of veterans who developed asbestos based diseases such as mesothelioma, lung cancer, and asbestosis due to the unnecessary exposure.

Asbestos cancer reduced the average life span of Veterans

After serving the country and retiring from active duties, most veterans belonging to the asbestos era started a life outside the military. Most of them married, took up new careers, and raised families – without ever knowing that the type of asbestos exposure they had in the military can cruelly reduce their life span. Several decades later and nearing retirement, many of these veterans could not have the pleasure of spending their golden years in the company of family and friends.

No location was safe aboard ships

The occupational diversity recorded amongst victims of asbestos diseases is evidence to the fact that no one was immune. In many cases, even family members were affected. Although the risk of developing asbestos related diseases was more for workers deployed in fire and engine rooms, there was no safe location aboard ships, be it the mess halls, navigation rooms or the sleeping quarters. Thousands of workers deployed at dry docks and shipyards were exposed to asbestos.