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UNIT IV ESSAY 2

UNIT IV ESSAY 6

Silica is a chemical hazard that is considered to be a significant occupational hazard. The chemical formula of silica is based on the chemical compound silicon dioxide (SiO2). The physical structures of silica include crystalline and amorphous. Crystalline silica is found abundantly in the earth’s crust (OSHA, n.d.).

Silica is grayish in color and odorless. The key property of silica is the vapor pressure is approximately 0 mmgHg and the molecular weight is 60.1. Silica dust, even very small particles, can be extremely hazardous if inhaled. It can be inhaled deeply into the lungs when is a respirable size of less than 10 um (Glenn, 2008, p. 37). There are other routes of exposure which can include skin and/or eye contact. The main exposure of silica is through inhalation.

Based on the various components of silica, dermal exposure can occur via extremely fine particles that can stay on the skin and into the skin through breaks or cuts. There have been few studies on dermal exposures, which try to show that there may be some connection to dermal exposures and autoimmune disorders (Cable, 2005, p. 1). Dermal exposures seems minimal compared to the inhalation exposures of silica.

The respiratory system is divided into three regions; the nasopharyngeal region, the tracheobronchial region and the alveolar region (Fuller, 2015, p. 141). The smaller the particle, the deeper it can go inside the lungs reaching the alveolar region. In the case of silica inhalation, the small particles end up in the alveolar region of the respiratory system. In the alveolar region, the deposition occurs primarily through sedimentation and Brownian diffusion (Fuller, 2015, p. 142). In the sedimentation process is when the aerosol is still in the air and under the force of gravity it gets pulled in. the motion in which an aerosol is placed on a surface by a random air motion is known as Brownian diffusion. With Brownian diffusion, it is seen more with dealing with smaller particle deposition such as silica dust particles.

Tuberculosis

When defining biological hazards, those hazards include bacteria and viruses that can cause harmful effects to the human body. Tuberculosis is an occupational hazard associated with health care setting. Tuberculosis is considered to be a biological hazard because it is caused by a bacteria called Mycobacterium tuberculosis. Hence biological hazards include bacteria, this is the determining factor in deciding whether the substance of tuberculosis is a chemical or biological hazard.

The most common pathway for tuberculosis is that the substance can be found in the air. Other biological hazards are unable to stay viable in the same conditions and environments as tuberculosis can. It is one of the few biological hazards that can survive in the environment without having be immediately tied to a host to continue to live. The bacteria are contained in the droplets that are coughed or sneezed out of an infected person. Those particles are then breathed in through the nose and pass through the pharynx through the trachea and the bronchioles to the alveoli deep into the lungs (Fuller, 2015, p. 352). How tuberculosis is transmitted shows how easily it can be done via air pathways.

The bacteria is mainly transmitted through the aerolsolization which leads to the tuberculosis disease. It is quite possible that another mode of transmission can be via the dermal route. The dermal route of exposure can occur when there are breaks in the skin or when there is an invasion of the mucus membrane ("The University of Iowa," n.d.). The normal exposure to tuberculosis is through direct contact with a person who is infected. So the most important viable route of exposure is through the air.

This is how tuberculosis runs its course through the human body. Once a person inhales the bacterium, the immediately become infected with tuberculosis. Whether or not they are able to spread the infection depends on factors that occur within the own body’s immune response. Once the body’s immune response kicks in, then the person develops latent tuberculosis infection (CDC, 2016). Those people who have the latent infection do not show symptoms and are unable to spread the infection to others. For the people whose immune system cannot get the bacterium under control, the tuberculosis bacteria start to multiply and kill lung tissue. At this point, the person is showing signs that they are infected with tuberculosis and can infect others with the disease.

Benzene

Benzene is a chemical substance that is highly flammable, colorless and has a sweet smell. It is an organic compound that shows up in the form of a vapor substance, which is derived from coal and petroleum (OSHA, n.d.). It can also be found in small amounts in cigarette smoke and drinking water that is contaminated. The chemical formula for benzene is C6H6. Benzene is also known as benzol.

The key chemical properties for benzene include the molecular weight of 78.1, the vapor pressure of 75 mmHg and its water solubility is 1750 mg/L. Based on the chemical property make up, the most important exposure route for benzene is through inhalation. Hence benzene is heavier in the air, it is easier to inhale the vapors. The threshold for vapors is rated at 1.5 – 5 ppm. A massive exposure via inhalation to benzene can cause suffocation due to the buildup of fluid in the lungs (ATSDR, 2014). There are other substantial routes of exposure which include dermal and oral ingestion.

The fact that benzene may be utilized as an industrial solvent, a dermal route of exposure is possible. A dermal route of exposure occurs when a person skin comes into contact with the benzene in its liquid form. Benzene can be absorbed through the skin via cuts or abrasions. Since it is a liquid solvent, benzene can cause skin irritation and degrease the skin if there is prolonged contact (ATSDR, 2014). Most of the exposures to benzene occur via inhalation. The reasoning behind inhalation and not dermal exposure is due to the fact that benzene is so volatile. Benzene exposure is a concern of public health due to it being a carcinogen. Even small doses of benzene can cause lasting effects on the human body.

References

ATSDR (2014). Benzene. Retrieved from www.atsdr.cdc.gov/mmg/mmg.asp?id=35&tid=14

Cable, J. (2005, October 10). Study looks at Possible Link Between Skin Exposures to Silica and Autoimmune Disorders. EHS Today. Retrieved from www.ehstoday.com/news/ehs_imp_37830

CDC (2016). Basic TB Facts. Retrieved from www.cdc.gov/tb/topic/basics/default.htm

Fuller, T. (2015). Essentials of Industrial Hygiene. Itasca, IL: National Safety Council.