Determination of Safe Benzene Concentration at Ciputat Gas Station

Benzene is a simple cyclic organic compounds whose concentrations are found usually low dilikungan. Benzene is often used in the industrial world, both home industry and the oil and gas industry. Benzene can enter into the body through the lungs, it can be through inhalation, gastrointestinal tract, and through the skin, If someone exposed to benzene at high concentrations, the levels of benzene into the lungs roughly half of the levels of benzene is absorbed, so that the incoming kealiran blood.This research is descriptive. The population in this study is a gas station worker Ciputat region totaling 10 people. The results of the study then analyzed quantitatively to determine the concentration secure benzene for workers obtained from the data concentration of benzene in the workplace, height workers, the weight of workers, heavy mice, respiration rate workers, time spent working, the surface area of the worker’s body surface area the body of laboratory mice, the highest dose of the toxin no effects in animal experiments (NOAEL), Km factors in animals (animal Km), Km factors in workers (Human Km), and the safe limit for workers toxin dose (SHD). The results of measurement of the concentration of benzene in petrol stations in the region Ciputat is 0,58mg / m3 (0.18 ppm), which means it is still below the Threshold Limit Value (TLV) according Permenakertrans 13 / MEN / X / 2011, the year 2011 is equal to 0, 5 ppm. In contrast to the NAB which have been set at 0.18 ppm, based on manual calculations for safe concentration limit of benzene obtained value of 0.02 ppm.


Introduction
In the era of the fastest growing technology, transportation is a very necessary thing humans in performing daily life. Means of transport is a tool that has a main component of a machine that needs fuel to run, usually referred to by fuel oil (BBM). In Indonesia alone type of fuel oil used on a variety of vehicles, such as gasoline and diesel.
There are various kinds of chemical substances contained in the fuel dinataranya benzene, toluene, xylene, ethylene, etc.which is certainly harmful to human health. The nature of the chemicals benzene, namelycolorless liquid with a sweet odor. Benzene evaporates into the air very quickly, slightly soluble in water but soluble in fats, and flammable. Benzene can be found in air, water, and soil2. Benzene is a chemical that is harmful and carcinogenic to humans and is a colorless liquid and volatile. Benzene is widely used in the rubber industry, oil refining, shoe factories, chemical plants and other industries related to oil including age refueling stations (gas stations)3. Indonesia itself has created rules limit benzene exposure in the work environment specified in the Threshold Limit Value (TLV) of benzene of 0.5 ppm in accordance with the Regulation of the Minister of Manpower and Transmigration Republic of Indonesia number PER / 13 / MEN / X / 2011 on the Threshold Limit Value Physical and chemical factors in the Workplace4.
Acute benzene exposure would have an impact like that cause disturbances in the nervous system, lack of oxygen supply to the brain, dizziness, rapid heart rate, headaches, tremors, confusion and fainting5.6, While chronic benzene exposure can cause decreased production of red blood cells causes anemia.7 Benzene can also get to the bone marrow and impair the production of blood cells so that persons exposed to benzene can suffer diseases related to decreased production of blood cells in the bone marrow.8 Some studies indicate a relationship between the quantity of benzene exposure by inhalation to the trans, trans-Muconic Acid (ttMA) as a biomarker of exposure to benzene.9 trans, trans-Muconic Acid (ttMA) is a minor metabolite of benzene that can be used as biological indicators of exposure to benzene. 9.10The occurrence of abnormalities in the hematopoietic system caused by exposure to benzene is a major concern. Examination and laboratory testing conducted on workers at risk of benzene exposure include a Complete Blood Count (CBC) with leukocyte count, hematocrit, hemoglobin (Hb), red cell count, erythrocyte indices (MCV, MCH, MCHC), and platelet counts.11-13 Based on previous studies of benzene in the workplace, there is very little research on the safe concentration (C safe) in the work environment that have exposure to benzene. Area gas stations as a working environment that has a high exposure to benzene, should the concentration of benzene in the safe limits so as not to cause health problems for workers. Therefore, based on the explanation above, the writer will measure the safe concentration limit of benzene in the area of the pump.
This study aims to determine safe concentrations of benzene in petrol stations in the region namely Ciputat. The results of this study are expected to be on filling stations in protecting workers from exposure to benzene.

Material and Method
This research is descriptive.The population in this study were gas station workers who worked at number 1 and point 2, totaling 10 people. The collection of primary data that the air concentration of benzene in the workplace, the duration of working time, and the weight of workers. It also conducted a secondary data collection on laboratory animals, namely the weight of mice.
The variable in this study is the concentration of benzene in the workplace, height workers, the weight of workers, heavy mice, respiration rate workers, time spent working, the surface area of the worker's body, body surface area of mice, the highest dose of the toxin no effects in animal experiments (NOAEL), Km factors in animals (animal Km), Km factors in workers (Human Km), the safe limit for workers toxin dose (SHD), and the concentration of benzene in the air that is safe for workers (C safe).

A. Characteristics of Animals Try and Try Animal Body Surface Area (Rats)
The toxicity of compounds in general can be interpreted by the potential chemicals that cause damage when it entered into the human body. In the implementation of toxicity tests using experimental animals are mice. In general, the human response to toxicant is qualitatively similar to the response of the animals, so that this fact is the basis of extrapolation from animal data to humans. Based on Table 2, the highest known weight of workers at gas stations Ciputat region that is 67 kg, while the lowest body weight 44 kg. The length of time worked in a day is all of 8 hours and height using the average value of height of an adult male Indonesia is 159 cm.
The results of the analysis of body surface area calculation and respiratory rate workers according to table 2 shows that the average worker's body surface area is 1.59 m2 and the average worker respiratory rate is 0.57 m3 / h.

C. Benzene concentration
The results of measurement of the concentration of benzene in the workplace stations in Ciputat area is either at point 1 and point 2 equals that is 0,58 mg / m3 (0.18 ppm) Based on the results of measurements taken, the concentration of benzene in the working environment Ciputat Regional gas station is 0.18 ppm. The benzene concentration is below the Threshold Limit Value

D. Animal and Human Km Km
The determination of safe dose limit for workers toxin begins prior to the calculation of Animal and Human Km Km.  Table  4, with an average of Animal Km on white rats is 5.81.

E. NOAEL
One objective of the research activities in the field of Tiksikologi is to be able to evaluate the safety of a substance. To determine the safety limit concentration of a chemical substance toxicity test begins with the determination of the highest dose without effect on animal or No Observed Adverse Effect Level (NOAEL). The research results Swaen et.al (2010) states that benzene NOAEL was 3.0 mg / m3, equivalent to 0,022 mg / kg obtained from the following calculation formula. To convert the units of mg / m3 to ppm use the following formula. The result of the calculation of the safety limit in the air that is safe for workers above can be used for (William, 1985in Tualeka, 2013: predict the concentration of toxins in the air a safe working environment for the workers when there has been no determination of the Threshold Limit Value (TLV), and for comparison with NAB has been established by various agencies both by Manpower, the National Standardization Agency, ACGIH, NIOSH and OSHA.

Conclusion
The results of measurement of the concentration of benzene in petrol stations in the region Ciputat is 0,58mg / m3 (0.18 ppm), which means it is still below the Threshold Limit Value (TLV) according Permenakertrans 13 / MEN / X / 2011, the year 2011 is equal to 0, 5 ppm. In contrast to the NAB which have been set at 0.18 ppm, based on manual calculations for safe concentration limit of benzene obtained value of 0.02 ppm. While based on the Minimum Risk Level (MRL) set ATSDR 2007, the concentration of 0,009 ppm benzene every day can give the effect of acute and 0,003 ppm daily for chronic effects, so as the concentration of benzene in petrol stations work environment has the potential to provide health effects for workers.
Thus the necessary control measures so that workers are protected from the adverse effects of benzene on health. Control recommendations are to consume the enzyme CYP2E1 contained in beef liver and salmon which serves to reduce the levels of benzene in the body, use of personal protective equipment appropriate in the form of half-mask respirator with organic vapor cartridge for meminimalisisr exposure to benzene, and planted a number of plants that can absorb and lowering the concentration of benzene such as Boston and Golden Phothos 14 ,