Asbestos (also known as asbestos) is a set of fibrous natural minerals, composed of named substances silicates (or silicon salts) in association with various metals (aluminum, iron, manganese, magnesium, calcium). It is extracted in different forms (eg chrysotile, serpentine, tremolite) from mines and quarries both in the open and in depth.
The term asbestos comes from the Greek "amiantos”, Ie incorruptible, while the synonym asbestos comes from the Greek word "asbestos", That is inextinguishable, characteristics that have enormously spread its use. In fact, since asbestos fibers, in addition to being flexible and light, are particularly resistant to fire, heat and chemicals, in the past asbestos has been used in the production of more than 3000 products, especially in the construction sector. In fact, asbestos was used for the construction of roofing and flooring materials (about 80% in the form of asbestos-cement products, known as eternit); in railway carriages; as insulation material (thermal and electrical), also for workers' protective suits; for furnace linings and for the production of containers and pipes for the storage or distribution of drinking water.
Starting in 1994, Italy, thanks to law no. 257 of 1992, prohibits the extraction, import, marketing and production of asbestos and all products containing this mineral. Our country, until that moment, was one of the largest producers and users of asbestos in Europe, with more than 3.5 million tons of raw asbestos from the second post-war period onwards.Exposure to asbestos
Exposure to asbestos
Asbestos fibers can be breathed in, if dispersed in the air, or ingested if dissolved in water.
Before asbestos was banned, workers in the places of extraction and processing of asbestos were the most exposed to the inhalation of thin and long fibers dispersed in the air; however, even in non-professional life it was possible to breathe asbestos fibers released from the various materials containing this mineral. Despite the current ban on the use of asbestos, the possibility of breathing in its fibers remains even today, due to the existence of products not yet replaced, or not disposed of properly and present in landfills or in contaminated places.
If you breathe in, asbestos fibers can enter the body differently depending on their length and diameter. Those with a diameter of up to 0.015 mm and between 0.08 and 0.2 mm in length penetrate deeper into the airways (for this reason they are defined breathable). The particles of greater diameter and length instead stop in the upper airways (nose, trachea) and are eliminated.
In the case of asbestos-cement pipes, following erosion by water or damage, there may be a release in drinking water of asbestos fibers of a different shape than those dispersed in the air. Their greater diameter and shorter length makes them less "dangerous" for the body than those dispersed in the air. Consequently, the inhalation of airborne fibers due to domestic use of contaminated drinking water for washing or cleaning clothes, floors or surfaces, is not as dangerous as the breathing of long and thin asbestos fibers.Effects on health
Effects on health
Respirable asbestos fibers reach and are deposited in the pulmonary alveoli (deep areas of the lung) where oxygen is transferred to the blood and the elimination of carbon dioxide. During transport inside the lungs, the asbestos fibers, however, can also stop in the bronchi by the tip of the fiber on their wall. The cells called macrophages, which deal with the body's internal defenses, are able to eliminate only some of them, depending on their shape and composition; the remaining asbestos fibers can penetrate the spaces between cells or be transported to the pleura (membrane that surrounds the lungs) or reach other parts of the body.
Their accumulation causes: permanent inflammation, thickening of the wall and a specific pulmonary fibrosis called asbestosis. This condition limits the respiratory function of the pulmonary alveoli, causing a progressive disease of the respiratory system which, over time, passes from pulmonary fibrosis to emphysema, chronic pleurisy up to respiratory failure.
Asbestosis is associated with a high incidence of lung, laryngeal, ovarian and mesothelioma tumors, malignant tumors of the pleura and peritoneum (membrane that surrounds the abdominal organs). The appearance of the tumor can occur years after exposure to asbestos and even in the absence of pulmonary asbestosis.
The situation is different when asbestos fibers are ingested orally, through drinking water. The size of the fibers does not favor their deposit and accumulation in the organism and in fact, in these cases, the appearance of fibrosis in the gastrointestinal tract has never been observed. The consumption of highly contaminated water can cause the formation of benign polyps. "intestine, but there are no indications of intestinal and stomach tumor formation. The only limit value available to prevent these effects is that adopted in the United States by the EPA of 7 million fibers / liter of water: the monitoring data recorded in Italy are generally well below this value.Symptoms
The disorders (symptoms) caused by asbestosis begin to appear slightly after about 20 years have passed since the first exposure to asbestos.
They are characterized by: difficulty in breathing (dyspnea), initially after physical exertion then also at rest; cough; chest pain. Progressively there is a worsening of the general condition of the patient and, in the advanced stages of the disease, respiratory and / or heart failure.If the disease worsens causing the onset of a lung or other type of tumor, the disorders (symptoms) of the specific tumor disease will be added.Therapy
There is no specific therapy to treat asbestosis, however some measures are useful not to aggravate the symptoms and to slow the progress of the disease. The first two actions to do are: stop exposure to asbestos, if still in progress and, in the case of a smoker patient, stop smoking immediately.
Considering the ailments caused by asbestos, all drugs that improve respiratory capacity such as bronchodilators are helpful for the patient.
It is also important to try to prevent and reduce the chances of lung infections and other respiratory diseases by getting the flu and pneumococcal vaccines.
To combat any acute bronchitis you can use (always under medical prescription) antibiotics and, if useful, cortisone.
In case of severe respiratory failure, you can switch to the administration of oxygen (oxygen therapy).Diagnosis
The assessment (diagnosis) of asbestosis is carried out with a medical and specialist examination (pulmonologist).
Initially, we rely on the first complaints (symptoms) felt and communicated by the patient trying to associate them with the personal circumstances of exposure to asbestos fibers dispersed in the air (professional and non-professional history).
Subsequently, the diagnosis is eventually confirmed by performing radiological examinations such as: X-ray and CT scan of the chest. Specifically, it will be good to carry out this last examination in "high resolution", so as to be able to view the patient's pulmonary situation in a more complete way. It is useful to emphasize that, in general, effects such as pulmonary and pleural fibrosis and thickening or effusion of the pleura are visible 10 years after exposure.
It is also possible to request a further examination: spirometry, capable of evaluating the current respiratory function (how much oxygen you can inhale and how much carbon dioxide you are able to exhale).Bibliography
Ministry of Health. Asbestos
US Environmental Protection Agency (EPA). Asbestos (English)
National Cancer Institute (NCI). Asbestos Exposure and Cancer Risk (English)
Agency for Toxic Substances & Disease Registry (ATSDR). Asbestos (English)In-depth link
Ministry of Health. State of the art and perspectives in the field of contrasting asbestos-related pathologies
US Environmental Protection Agency (EPA). Drinking water contaminants - Standards and regulations (English)
World Health Organization (WHO). Guidelines for Drinking-water Quolity: Chemical Aspects.
International Agency for Research on Cancer (IARC) - World Health Organization (WHO). A review of human carcinogens. Part C: Arsenic, Metals, Fibers, and Dusts. (Monographs on the Evaluation of Carcinogenic Risks to Humans).