The Vital Lung Capacity of Employees with Risk Factors for Potential Exposure to Ammonia Gas

The fertilizer industry produces several pollutants such as ammonia gas, urea dust, smoke, particulates. Workers are exposed to air inhalation at work, entering the respiratory system, which is the main toxic entry point. The risk of workers being exposed to lung disease due to inhalation of dust/ smoke/ harmful gases in the work environment. It will increase if workers do not comply with protecting themselves from risk factors and potential accompanying factors such as smoking habits excessive body mass index. Lung ventilation is the entry and exit of air between the atmosphere and the pulmonary alveoli. This study aimed to determine the correlation between body mass index, smoking habits, and hemoglobin levels with vital lung capacity to P.T. Pupuk Sriwidjaja Palembang employees. The design of this study is a cross-section. The research was conducted at P.T. Pupuk Sriwidjaja for 30 days. The research sample was 78 employees of the ammonia unit. Data analysis found a significant correlation between vital lung capacity with body mass index (p-value = 0.009), and hemoglobin levels (p-value = 0.039). There was no significant correlation between smoking habits and vital lung capacity values (p-value = 0.449). It can be concluded that body mass index, smoking habits, and hemoglobin levels correlate with vital lung capacity.


INTRODUCTION
A polluting work environment, such as the fertilizer industry, can affect lung function.
The fertilizer industry produces several pollutants, such as ammonia gas, urea dust, smoke, and particulates (Dwiputra, 2019;Thakkar, A., 2013). Ammonia gas is a gas that is colorless and has a powerful odor.
Exposure to ammonia gas at a certain level disrupts lung function and sensitivity of the sense of smell (Dwirani, F., 2017). Lung disease that results from occupational hazard (hazardous material) exposure has a significant impact on workers' health (Jurniawidjaja, 2010). Workers are exposed by inhalation of air in the workplace into the respiratory system, which is the main route of entry for toxins, due to its wide surface contact with outside air, high blood flow, and very thin alveolar epithelium.
The risk of workers getting lung disease due to inhalation of dust/ fumes/ hazardous gases in the work environment. It will increase if workers do not comply with ways to protect themselves from risk factors (Jurniawidjaja, 2010) and potential co-factors such as smoking (Oviera, A., 2016) and excess body mass index (Pinzon, R., 1999).
The American Lung Association divides lung diseases into two broad groups, namely pneumoconiosis caused by dust getting into the lungs, and hypersensitivity, such as asthma, caused by an overreaction to air pollutants. The most common pneumoconiosis experienced by workers is silicosis, a lung disease caused by inhaling silica dust. Some lung cancer cases and bronchitis cases are also classified as occupational lung diseases (Buchari, 2007 (Guyton and Hall, 2012). The lung's vital capacity is the sum of the tidal volume, the inspiratory reserve volume, and the inner expiratory reserve volume (Guyton and Hall, 2012;Bakhtiar, A., 2016). The lung's vital capacity reflects the change in the maximal volume of the lung, which is useful for confirming the picture of the lung's functional capacity. The vital capacity of the lungs can be measured using a pulmonary function test kit. The most basic test used is spirometry (Sherwood, 2014;Pellegrino. R., 2010;Smeltzer, SC., 2002). The measurement of vital lung capacity is the most massive air expelled volume after the deepest inspiration is capable of. There will be suction pressure during inspired breathing, which will affect the increase in lung volume and capacity (Bakhtiar, A., 2016).
The value of vital capacity is influenced by age, gender, body weight (Pujiastuti, BE., 2012;Zulfrianingrum, H., 2016), body position, respiratory muscle strength, lung, and chest cavity ability to expand (Bakhtiar, A., 2016) ). Decreasing hemoglobin levels can affect the mechanisms of oxygen and carbon dioxide transport in blood and body fluids to cells and vice versa (Bakhtiar, A., 2016). The fatigue factor affects the decrease in the blood muscles' ability to supply oxygen (Sapada, 2019). Workers who have maximum concentration resistance and cardiorespiratory resistance have normal levels (Sapada, 2019). The lungs' vital capacity is reduced if there are lung and heart disease, which causes lung congestion and weakness of the respiratory muscles (Hapsari, R., 2009).
According to Pinzon's study (1999), a decrease in the percentage of vital lung capacity in individuals with excess body mass index is suspected due to a decrease in elasticity and the ability to expand the chest wall and a decrease in the ability of the diaphragm to drop to its level. So that the intra-thoracal pressure will be less negative than average, according to research by Hapsari, R (2009)

Excess body mass index and obesity tend
to decrease the value of vital lung capacity due to the disruption of the lung walls, which affects lung ventilation (Pinzon, 1999  Oxygen is carried to body tissues through two mechanisms: it is physically dissolved in plasma and chemically bound to hemoglobin as oxyhemoglobin (HbO2).
Oxygen is needed by body cells as a source of energy. In the respiratory system, oxygen enters the lungs and oxidizes the nutrients that enter the digestive system (Pinugroho, B., 2017).  (Oviera, A., 2016).
Histological changes in small airways occur after two years of smoking (Aunillah, 2015). According to Kurniawidjaja, LM., (2010) Cigarettes cause an abnormal lung inflammatory response to toxic particles from cigarettes (Sidikin, M., 2001).  (Sidikin, M., 2001). An iron that is in the hemoglobin molecule is essential for carrying out the function of binding and releasing oxygen. Although not directly binds to the molecule oxygen, globin is a crucial part of hemoglobin. It helps determine the iron atom's binding power in these molecules (Sidikin, M., 2001).
Occupational health is necessary in the world of work-control using risk management. The concept of risk management is to manage risk so that the risk is lost or minimized at a level that is not dangerous. Primary prevention aims to prevent workers from being exposed to disease-causing agents, in the form of particles/ vapors and gases in the work environment, by increasing workers' knowledge of risk factors and increasing compliance with personal protective equipment. Secondary prevention uses early detection of occupational diseases and handling cases as soon as possible so that the disease does not become severe.
Tertiary prevention aims to protect workers who are already affected by lung disease so they can return to work and not become disabled (Kurniawidjaja. LM., 2010).

CONCLUSION
Based on the discussion analysis results, it can be concluded that there is a significant correlation between body mass index and hemoglobin levels with the value of vital lung capacity. There is no significant correlation between smoking habits and vital lung capacity. It is suggested to do further research on the molecular level of the TNF-α parameter.