Diesel Particulate Matter - Assignment Example

Hygiene and Toxicology Hygiene and Toxicology Diesel Particulate Matter (DPM) Sources of exposure Diesel particulate matter (DPM)is the solid part of diesel exhaust that consists of carbon. It also contains organic substances such hydrocarbons and inorganic ones such as sulphate compounds. Some of the occupations that increase the risk of exposure include railroad work and mine works. Other people who are at a higher risk of the exposure include trucking company workers and automobile operators. Such occupations involve using diesel powered machines. Studies show that about 1.35 individuals are exposed to the toxins in their work places in the country. It also shows that many work places in the country use diesel-powered equipments (National Toxicology Program, 2014). With the increase in the number of industries globally, the rate of exposure to the particulate matter is expected to increase in future. The types of sources of the toxins can be divided into movable sources such as vehicles and immobile sources such as repair yards. Operation of the diesel machines leads to production of solid carbon and sulfur oxides due to incomplete combustion. Applicable Occupational Exposure Limits (OELs/PELs) The occupational exposure limits of the toxin In Singapore is based on the US Environmental Protection Agency (EPA). The limit of exposure is set at 15 ug /m3 which is long term (EPA, 2014). The exposure to the toxin is usually observed using the model DPM- 4000. This is a portable device that measures the level of particulates in a place in order to ensure that an industry operate in environmental friendly ways. By using the machine, the industries and authorities can know if an industry is maintaining the occupational exposure limits set by environmental and health agencies in the country. The toxin is likely to be human carcinogenic (Day, 2013). It can be carcinogenic to humans though long term inhalation. Among the organs that are more likely to be affected are lungs. Toxico-kinetics 1. How DPM gains entrance to the body The DPM enters the body through inhalation. After breathing air that contains the particulate matter, they enter the respiratory system. The amount entering the body depends on the amount of matter in the environment. The particulate enters the body in the same manner as cigarette smoke. However, unlike cigarette smoking, the inhalation of the DPM is not voluntary (Bull, 2007). The particulates can also enter some parts of the body directly. For instance, they can enter the eyes through wind. 2. How and where is it distributed After entering the body, the particulates are usually distributed through the respiratory system that is divisible into two. The particulate are first distributed in by the upper airway passage. This part of the passage consists of nose, mouth, and the pharynx. From the upper passages, the particulate go to the lower passage that consists of the vocal cord, windpipe, alveoli, and the bronchial trees (Smita, Gupta, Bartonova, 2012). 3. Sites of accumulation The site of accumulation can be either along the respiratory track or in the lungs. The places the particulates are deposited are determined by the size and density of the particulates. If the particles are small and lighter, they will be deposited in the lungs or on the lower side of the respiratory track. However, if the particulates are larger and heavier, they will be deposited on the upper side of the track. They also enter the lungs in other ways such as diffusion. If the particles are not eliminated, they continue to accumulate in the lungs. 4. Pathways for its elimination from the body The particulates can be eliminated from the body in various ways. They can be eliminated through the respiratory system that is also the entry route. This can occur when one sneezes or through coughing. If the toxins are absorbed in the blood stream, they can be excreted from the body through liver just like other toxins. Toxico-dynamics Once the particulates have entered the body they can cause serious health effects. They have both cancerous and non cancerous effects. Among the non cancerous effects include allergic reactions such as coughing and sneezing. They can also cause other illness such asthma and bronchitis. Continuous exposure to the particulates may cause a long-term damage of the tissues. The particles deposited in the eyes cause irritation. The particulates can also cause other chronic illnesses such as cancer that affects people who are continuously exposed in their occupations. A study conducted on rats proved that the particulates are carcinogenic. They increase the rate of cell mutations. Studies also show that the particulates are responsible for the deaths of many people globally. For instance, in the US alone, many premature deaths are reported to be caused by the diesel particulate in the air (Genc, Zadeoglulari, Fuss et al, 2011). Mercury as Hg (Vapor) Sources of exposure Mercury is one of the most toxic substances that exist in various forms. One of the common forms of the toxin is vapor. The vapor usually forms when the metallic mercury is exposed to high temperatures. As the temperature increases, a larger amount of vapor is released in the air. People are also exposed in various ways in their occupations. Examples of workers who are more vulnerable to the exposure are those who work in mercury mining firms. At the mining firms, the substance is usually extracted as cinnabar ore. The ore placed in a place with above 1000 degrees (Park & Zheng, 2012). This causes the production of mercury vapors that affects the mining workers. Those working in fossil fuel companies are also at a higher risk of being exposed. For instance, burning of coals that contain some mercury in them produces mercury vapor. Workers in fertilizer companies are also highly exposed to the vapor. Some farm chemicals such as fungicides contain mercury in them. During their production, large amounts of mercury vapor are usually released in the air that affects workers and those living near the factories. Farmers may also be exposed to the toxins if the mercury in the fungicides evaporates. Other vulnerable workers include doctors. Health experts can be exposed to the substance when making amalgam fillings. Occupational exposure limits (OELs /PELs) Singapore federal agencies are working to reduce the amount of exposure to the mercury vapor by setting exposure limits. The exposure limits of mercury are also based on the policy used by EPA in the US (Singapore, 2006). The permissible level of the toxin is 0.1 mg/cm3 of air (EPA, 2014). This is a short term permissible level since it is applicable for eight working hours. Studies prove that the vapor is carcinogenic. A study showed that among a group of workers exposed to mercury vapor on long term basis, many of them died of lung cancer (Park & Zheng, 2012). Due to the little amount evidence about the carcinogenetic property of the mercury vapor, mores studies need to be conducted to confirm it. The vapor also causes skin conditions. For instance, short term exposure to the vapor causes skin rashes while long term exposure may cause skin cancer. Toxico- kinetics 1. How the substance gain entry to the body The substance enters the body through various routes. One of the routes entails the respiratory system just like the Diesel particulates. It enters the respiratory system after one inhales the air that contains the mercury vapor. The substance can also enter the body through skin. If one’s skin comes into contact with the vapor, it gets absorbed into the blood system. The substance can also be ingested. Studies show that the largest amounts of mercury vapor enters the body through inhalation. For instance, when inhaled about 80 percent of the substance enters the blood while 40 percent may enter the blood through swallowing (Bernholf, 2012). 2. Pathways of the mercury vapor Once on a person’s skin, the vapor is absorbed in it through the skin pores. In the skin, they usually get absorbed in the blood through the veins. When inhaled, the substance enters the body through the upper and lower respiratory system just like in diesel particulate (Bernholf, 2012). The substance can reach the body when eating foods that are contaminated. From the mouth, they reach the stomach through the intestines. When passing through the intestine, some amounts of the substance are absorbed into the blood. 3. Sites of accumulation After entering the body, the substance accumulates in different organs and tissues. The inhaled substance usually accumulates in the lungs. Some of the substance stored in the lungs can be absorbed into the blood. Long term exposure to the substance may lead to its accumulation in the blood. Some of the substance may accumulate in the kidneys, especially those that reach the body through ingestion. 4. Pathways of elimination The substance can be eliminating from the body through urine. It can also be eliminated through sweating. Toxico-Dynamics Mercury vapor damages cells and hinders the processes taking place in the cells. For instance, it reduces the level of hemoglobin in the blood. The substance also damages the muscles tissue in the heart. It also damages blood veins and the lining of the mouth and lungs. Some of the health effects caused by the substance include kidney failure and cardiovascular illnesses (Rowland, Baird, Weinberg et al., 2004). It also causes hypertension and eye irritation. References Bernholf, R. (2012). Mercury toxicity and treatment: A literature review. Journal of Environmental and Public Health, 12: 10. Retrieved from: http://www.hindawi.com/journals/jeph/2012/460508/ Bull, S. (2007). Inorganic mercury/ elemental mercury. Health Protection Agency. Retrieved from https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/337741/hp a_mercury_general_info_v2.pdf Day, J. (2013). Diesel exhaust: Health assessment, Regulation, and litigation. Retrieved from; http://www.jonesday.com/files/Publication/95925a1c-0582-41f4-9bdf- 008d9f7f4821/Presentation/PublicationAttachment/8d3ac7a3-7ba8-492d-bf88- 3cd2c513b372/Diesel%20Exhaust.pdf EPA. (2014). How people are exposed to mercury. Retrieved from http://www.epa.gov/mercury/exposure.htm#epa Genc, S., Zadeoglulari, Z., Fuss, S. et al. (2011). The adverse effects of air pollution on the nervous system. Journal of Toxicology, 2012: 23. Retrieved from: http://www.hindawi.com/journals/jt/2012/782462/ National Toxicology Program. (2014). Diesel exhaust Particles. Carcinogen report. Retrieved from http://ntp.niehs.nih.gov/ntp/roc/content/profiles/dieselexhaustparticulates.pdf Park, J. & Zheng, W. (2012). Human exposure and health effects of inorganic and elemental mercury. Journal of Med public health, 45(6): 344-352. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3514464/ Singapore. (2006). Country synthesis report on urban air management. Retrieved from http://cleanairinitiative.org/portal/sites/default/files/documents/singapore_0.pdf Smita, S., Gupta, S., Bartonova, A. (2012). Nanoparticles in the environment: Assessment using the causal diagram approach. Environmental Health, 11 (1): 13. Retrieved from: http://www.ehjournal.net/content/11/S1/S13 Rowland, A. , Baird, D., Weinberg, C. et al. (2004). The effects of occupational exposure to mercury vapor on the fertility of female dental assistants. Journal of Occupational Med, 52 (1): 28-34. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1127897/ Read More