Air quality is alarming, scientists warn of diseases caused by dust pollution

Dust pollution in the air is really more dangerous than what the general readers understand. They can cause disease and incubate for a long time for nearly 10 years, making many people subjective because they do not see immediate harm.

The following article would like to introduce some common diseases due to airborne dust pollution. Hope to help readers equip themselves with knowledge to protect their health.

Digital respiratory system anatomy is built on CT scan.(Source: Nguyen Lu Phuong et al, 2016).

Only 10% of the dust in the lungs is enough to cause illness

The respiratory system is able to block and eliminate 90% of dust sized over 5 µm. Smaller particles of less than 5 µm (especially particles smaller than 2.5 µm (one tenth of the diameter of a human hair) present in the atmosphere will follow the inhaled air as far as the alveoli, here also the mucous membranes, macrophages eat and remove about 90% of dust particles in the lungs.

However, the residual dust deposited in the upper respiratory tract can still cause many diseases such as respiratory disease, asthma, bronchitis, emphysema, musculoskeletal disease, firstly the infected lung disease. dust.

Dust-infected lung disease

As a major problem in occupational diseases, in recent decades, dust-infected lung diseases account for about 40% -70% of occupational diseases. The statistics clearly show its serious nature: pneumoconiosis causes many dangerous complications and can lead to death.

Common illnesses such as dirt, sand or wood dust usually only cause bronchial obstruction, blockage of airways in the lungs or contaminate the surface of alveoli. But dust that contains a high proportion of free silicon dioxide (which does not exist as a molecule but exists as a crystal) in the air causes lung damage.

When attacking the lungs, they cause wounds, which then form calluses on the lungs, enabling the germs to be at risk of superinfection with other germs such as tuberculosis, pneumonia, pneumonia. governing.

One of the characteristics of lung disease is that it is irreversible once infected but can only treat symptoms, helping patients with less breathing problems, less cough, less infection (if any). In the long run, patients with severe respiratory distress must support oxygen.

Here are some important pneumonia diseases:

Silicosis (Silicoisis)

Silicosis is a pulmonary condition caused by inhaling dust containing high levels of silicon dioxide. The anatomical characteristic of the disease is fibrosis and the development of particles in the lungs, clinically it is difficult to breathe.

In countries with modern industries, silicosis thrives and is a burden to society.

In Vietnam in recent decades, the survey data, although incomplete, but many authors show the number of patients up to thousands of people.

For example, the survey showed that coal miners had a rate of 0.7% -3.5% of coal and stone dust lung disease, bricklayers in Thanh Tri and Cau Duong suffered from silicose from 10.2% -12, 9%. In mechanical casting industry, the disease rate is up to 40%. In the Central region, the disease rate is 14.08%.

The main cause is exposure to free silicon dust (SiO2).

Who is susceptible to pneumonia?

People working in mines such as coal mines, metal mines, exploiting construction stone. Metallurgical mechanic industry, especially workers in foundries, mold making, cleaning by sand blasting. Workers in glass, porcelain, pottery industries.

In the cement industry, the rate of silicosis - silicon is low because cement dust has low silicon content.

Factors affecting

A dust size of 0.5–5 µm is most dangerous because it is absorbed in the alveoli. The greater the dust concentration, the greater the risk of disease. Especially, the free SiO2 content in dust is the most important factor that determines its toxic properties.

In addition, individual factors such as chronic respiratory infections, pulmonary tuberculosis are favorable factors for the development of silicosis.

Symptom

Early clinical symptoms are easy to identify, and appear very late. Mainly shortness of breath, then coughing, chest pain. These are atypical symptoms that can be seen in any respiratory disease. Silicosis does not cause haemorrhage (hemoptysis).

The patient's condition in the early stage is normal, in the severe stage, the condition gradually decreases to collapse, physical examination rarely shows abnormal signs.

Currently, there is no specific treatment but mainly symptomatic treatment. The disease continues to progress although the patient was no longer exposed to dust. Therefore, it is still important to take precautions and provide safety measures for workers exposed to silicon dust.

The miner's lungs have silicosis and tuberculosis.(Source: Basque Museum of History of Medicine and Science, Spain).

Asbestosis (Asbestosis)

Asbestosis is the second most serious lung disease, after silicosis. The disease is caused by long-term exposure to asbestos dust during production. The pathological lesion in this disease is pulmonary fibrosis, which leads to a decrease in respiratory function. In addition, asbestos dust also causes pathological lesions in the pleura, peritoneal: causing mesothelioma.

Asbestose (Asbestose) is a widely used industrial material due to its alkali, non-flammable properties, resistance to high temperatures and to chemicals such as acium, which can withstand friction. Asbestos is used to weave cloth for insulation, fireproof rugs, insulated ropes, soundproofing materials, construction materials (asbestos tiles, asbestos cement), cardboard boards, automobile brake pads. .

Workers working in these industries and in the mining and quarrying industry with asbestos processing asbestos ore can get asbestosis.

The first cases of asbestosis - described in 1906 in France (Auribault), 1907 in England (Murray), Pancoast et al. In 1927 describe the radiological changes of the disease.

From 1950 onwards, people began to recognize asbestosis - asbestos. In 1967, there were an estimated 20,000 sick workers in the UK. In Vietnam in the early 70s of the 20th century, several cases of Asbestose pneumonia were detected in fibrocement factory (5.5%).

Pathogenesis

In the lung, asbestos fibers ( After some time, this will lead to pulmonary fibrosis.

Symptom

Clinically: The disease appears very late, usually after 7-10 years of exposure to risky environments, so it is very dangerous. The first phase is slow and difficult to recognize, manifested by coughing, shortness of breath, chest tightness.

At first, coughing is just a reaction of larynx and trachea (due to dust stimulation) that appears during working time, then stop coughing due to dust adaptation. After about 4 to 5 years of exposure to the at-risk environment, the person coughs again and more often, or relapses back into the winter, so it is likely due to the weather. Shortness of breath on exertion, at first mildly easy to overlook because it is due to old age (because frequent asbestos is not a disease of young people) and often accompanied by chest tightness.

Scars and tumors in human lung tissue due to asbestos dust exposure form asbestos pneumonia. (Source: http://qbm.com.au/asbestos-disease/)

Other diseases caused by dust

In addition to invading the respiratory tract, dust is splashed into the eyes causing irritation, stinging, discomfort, even scratching the cornea. In case the dust carries pathogens, the victim is prone to eye infections, red eyes, and blisters.

Alkaline dust or acid dust can cause corneal burns, leaving a large scar that reduces vision or blindness. Metal dust, such as chip shavings, shavings or splashes into the eye, causes wounds on the conjugate membrane and can damage the cornea, leaving behind scars that reduce vision. More severe can cause blindness.

Dust pollution can even cause your heart to stop suddenly and increase blood pressure. Increased dust in the air is one of the causes of the 4% -10% increase in cardiac arrest outside the hospital.

Skin diseases

Copper dust can cause very difficult skin infections to treat.

Dust also affects the greasy glands, drying out the skin, giving rise to skin diseases such as acne, dermatitis, found in boiler burning workers, mechanics, cement production, crockery .

Dust from lime, tin, pharmaceuticals, pesticides, sugar . also irritates the skin, causes pimples, sores .

Gastrointestinal disease

Dust also pollutes foodstuffs at roadside stalls, street food establishments, street vendors, etc. if not well preserved. There are many types of pathogens in the dust that can be harmful to the digestive tract such as acute diarrhea, dysentery, cholera, typhoid, helminths, etc.

Metal dust, sharp mineral dust with sharp edges enter the stomach causing gastric mucosa inflammation, digestive disorders.

Lead dust causes anemia, erythrocytes, and kidney disorders.

Microbiological dust has many harmful effects on human health, causing diseases, respiratory diseases, eye pain and gastrointestinal diseases.

Cardiovascular disease

The likelihood of death and cardiovascular disease is often associated with (super) fine particulate air pollution (Seaton et al., Donaldson et al., Utell and Frampton, Nemmar et al., Pope et al., Schwartz and Morris).

While explanations for the mechanisms of cardiovascular action are still being investigated, it is thought to be due to the stimulating reactions in the lungs and also because the particles move into the bloodstream, reducing the activity of the system. Cardiovascular system (Utell and Frampton).

As described, fine dust particles are able to bypass the protection of the respiratory system entering blood vessels (Kreyling WG, SemmlerBehnke M, Moller W). Studies in the 70s of the last century show that dust particles can penetrate into blood vessels after inhalation exposure within 30 minutes.

These particles are found in platelets in capillaries (Berry et al. 1977). Once in the bloodstream, they are distributed in other internal organs, including the heart.

However, at present, science does not yet know the direct effects of fine dust particles on blood or heart in particular. This explains why lung diseases such as chronic obstructive pulmonary disease (COPD) are often accompanied by cardiovascular disease.

Moreover, when the lungs are damaged, pumping blood through the pulmonary circulation becomes more difficult, resulting in an enlarged heart. Heart disease itself can also cause lung problems because the pressure increases in the pulmonary circulation, causing an increase in the amount of blood being pushed from the capillaries to the alveoli.

Dust pollution impacts on the central nervous system (Central Nervous System)

Most recently, the central nervous system being considered may be another target of ultrafine particles (Oberdorster and Utell, 2002).

More than 60 years ago, neuroscientists Bodian and Howe showed that polio virus can travel along the axon of a neuron (Bodian and Howe, 1942). Evidence shows that when the virus enters the monkey's nose, the symptoms of polio appear only when the respiratory link is intact. This indicates the importance of the pathway between the nervous system and respiration when the source of the pathogen is penetrated.

Other investigators cited that ultrafine particles such as gold dust and magnesium oxide can also enter the nervous system via the olfactory nerve (Oberdorster et al., 2005).

Respiratory exposure experiments to the olfactory nervous system were performed on rats with gold dust, cadmium, magnesium oxide and pure carbon (Dorman et al 2001, Tjalve et al 1996, Oberdorster and et al 2004).

Elder et al. Showed that when exposed mice to Mn ultrafine dust through the nasal respiratory tract (with the right nostril closed), the level of manganese oxide increased on the left nasal cavity at the olfactory gland located close to brain (Elder et al., 2006). An increased number of particles was also found in the fringe, the frontal cortex and the cerebellum to a lesser extent.

Therefore, although there is a difference between the human respiratory system and rodents, in general, the super-fine dust path to the human olfactory route is significant (Oberdorster et al., 2005). Chronic mucositis is often accompanied by disruption of the integrity of the epithelium (septum between the nose and brain), creating favorable conditions for ultra-fine dust particles to reach the central nervous system.

As described above, ultra-fine particles can pass through the protective layer in the respiratory system and into blood vessels (Oberdorster and Utell, 2002). The blood-brain septum is the gland that ultrafine dust needs to pass to reach the central nervous system, in fact Lockman et al found surface-charged superfine particles that can penetrate through the brain-nasal barrier.

Many researchers have reported that air pollution may play an important role in causing neurodegenerative diseases such as Alzheimer's and Parkinson's (Oberdorster and Utell, 2002, Calderon-Garciduenas et al. 2002). Nervous system degeneration has only a small part of genetic cause, so environmental factors will likely contribute to the disease quickly or slowly.

In addition, there is a study by Calderon-Garciduenas et al. (2008) that shows the combination of air pollution and inflammatory diseases of the nervous system in children and dogs (which are healthy).

In this experiment, dogs raised in polluted areas in Mexico City suffered from nasal epithelial lesions, pneumonia, cardiomyopathy with an increase in encephalitis compared to dogs living in less polluted areas. than. In the frontal lobe of the brain they appear super-fine particulate matter.

Healthy children living in heavily polluted areas also exhibit significant epithelial and pulmonary lesions, accompanied by mitotic imbalances and systemic inflammation.

Brain responses in children, studied by MRI imaging, show a relationship between city of residence and brain damage. Children in Mexico also have significant low levels of cognitive development.

The olfactory system consists of olfactory nerves in the nasal cavity and the journey of exposure to ultra-fine dust particles that enter the brain (adapted from Collins, 1999).