Can asbestos cause heart disease?
Yes, evidence shows that asbestos causes cardiovascular disease. Exposure to asbestos has been linked to a variety of health issues, including heart disease. It is scientifically proven that asbestos exposure can significantly increase the risk of cardiovascular-related diseases. A meta-analysis by Yi Rong et al. of 16 studies found that workers exposed to asbestos had an 11% higher risk of dying from cardiovascular-related diseases compared to those not exposed [1].
A study on shipyard workers exposed to asbestos was performed. It found that men with asbestosis or suspected asbestosis had a 3.1 times higher risk of dying from ischaemic heart disease than men without asbestosis [2]. Another study found significant excess mortality from cerebrovascular disease and ischaemic heart disease among asbestos workers [3].
Contact with asbestos can also lead to pericardial involvement. This can affect heart function too. For instance, a study found that 45.2% of patients with cancer caused by asbestos exposure (peritoneal mesothelioma), had pericardial involvement. They had pericardial effusion and thickening of the pericardium [4]. Another case study reported a rare case of haemorrhagic pericardial effusion in an asbestos worker [5]. All the effusions lead to restriction of the space in which the heart expands. Without the space, the heart cannot pump out sufficient amounts of blood. This is especially visible when the affected individual does physical activity.
What is asbestos?
Asbestos is a group of naturally occurring silicate mineral fibers. They are found in many regions of the world [6]. This mineral is known for its durability and ability to withstand very high temperatures. Due to this, they were used in the last century as fire isolators and retardants in buildings [7]. Asbestos fibers are so small that they can't be seen by the naked eye. Not only are they small but also very light. When scattered, these fibers float in the air and are easily inhaled and stuck in the deep lung tissue [8]. Because of these fine characteristic abilities exposure to asbestos has been linked to several diseases. Particularly, those affecting the lungs and pleura. Sometimes it takes years for the manifestation of such diseases. They include asbestosis, lung cancer, and mesothelioma [7].
Even though this mineral was very useful, the health hazard was recognized and action was taken to ban it. In 1987 the World Health Organization recognised asbestos as a Group IA carcinogen. Following this decision, bans for utilization were introduced all around the world [9].
Nevertheless, the use of this wonderfully dangerous material before the bans left many places where it is still present. Those still pose a big health risk to anyone in its vicinity [6].
How does asbestos cause heart disease?
Although asbestos is mostly easily linked with pulmonary disease it can also cause heart problems. The mechanism by which it causes cardiovascular disease involves many factors and is complex.
Inflammation and the fibrosis of tissues are one of the main mechanisms of damage. Upon inhalation, the small fibers travel deep into the lungs. There they get stuck and are recognised as foreign bodies by the immune cells. Here, the inflammation reaction starts. The result of the inflammation is also damage to the delicate and thin lung tissue. Scares and fibrosis substitute the before healthy functional tissues. This inflammation and fibrosis affect first only the lungs. However, with time the activated immune system can cause unjustified responses in other organs like the heart. This can lead to conditions like pericarditis, an inflammation of the pericardium, the sac-like structure that surrounds the heart [6]. This impedes the normal work of the heart as the surface against which it is rubbing with each beat is now inflamed.
Additionally, asbestos exposure can lead to atherosclerosis. In this condition, plaques build up in the arteries. This can occur due to the size of the mineral, which is so small that it can cross into the bloodstream. Once there, the fibers can inflict direct inflammation and damage to the blood vessels, resulting in the formation of the plaque. Those plaques can obstruct the blood flow in small or even bigger arteries. In cases an obstruction occurs in the coronary arteries it can lead to myocardial ischemia and a heart attack [7].
Another mechanism involves the immune system. Prolonged asbestos exposure can lead to a chronic and strong immune response. During such a response, many inflammatory particles, like cytokines, accumulate in blood. They travel through the organism and can impact the heart muscle. This leads to damage to the heart tissue leading to fibrotic changes, similarly to the lungs. The fibrotic heart walls become thicker and the muscle stiffer, which results in a lower stretching ability and strength of the heart. Both those new characteristics in the heart limit the amount of blood that can flow in and out [8].
Lastly, the effect of asbestos on the lungs also affects the heart. A fibrotic asbestosis lung can cause an increase the blood pressure in the lungs. This condition is known as pulmonary hypertension and chronically leads to right heart failure. This kind of heart failure is also known as cor pulmonale [9].
Symptoms of asbestos heart diseases
As we mentioned, asbestos can cause many heart conditions. One of the most common is ischemic heart disease (IHD). It arises due to atherosclerosis and the symptoms are:
Another heart condition linked to asbestos exposure is constrictive pericarditis. It limits the working space of the heart and causes symptoms such as:
Asbestos exposure can lead to heart tumors. Symptoms of such a tumor depend on its size and locatio, and can mimic heart failure and arrythmias. Thus, symptoms can be shortness of breath, chest pain, fatigue, and irregular heartbeat (heart palpitations) [10]. All these can be accompanied by fainting, swollen legs and others, all depending on the tumor.
During chronic inflammation due to asbestos, myocardial fibrosis can develop. The heart muscle is filled with scars and fibrotic tissue. Such changes in the structure make it stiff and thick. It is presented with symptoms like fatigue, shortness of breath, edema (swelling) of the legs and around the abdomen as well as heart palpitations [11].
How to protect from asbestos?
Because of the serious bad health effects linked to asbestos exposure, it is crucial to mind places known for its presence and protect against it. The highest-risk individuals with occupational exposure as industrial workers should pay attention to always wearing protective clothing and air filters. Workers in construction, shipyard repair, or boiler maintenance are at the highest risk [12].
Also during the asbestos removal, it's essential to use appropriate respiratory protection. Best are high quality supplied-air respirators and powered air-purifying respirators [13].
It is important to pay attention not to the distribute of asbestos-containing materials. It can happen during renovations, repairs, or demolitions. In a situation like this, the space containing the asbestos should be sealed from the environment. This can be done by special tapes and other sealing techniques [14].