Smog pollution is a main problem in this planet is suffering everyday. It has affected our homes, weather and health. It is a very hazardous condition for us if we do not do anything about it. Smog is combination of smoke and fog. It also used to describe the type of fog that have smoke or soot in it. Smog is a yellowish or blackish fog that are formed by a mixture of pollutants in atmosphere which contain of delicate particles and ground level ozone. Smog which happen mostly because of air pollution, also can determine as a mixture of several gases with dust and water vapor. Smog also can refers to hazy air that makes breathing difficult and harmful for health. The atmospheric pollutants and gases that are released in the air when the fuels are burnt is called smog. Smog is formed when the sunlight combined with the heat and the gases also the delicate particles in the atmosphere. It is caused by air pollution. Ground level ozone and delicate particles are liberate in the air due to complex photochemical reactions between volatile organic compounds (VOC), sulphur dioxide (SO2) and nitrogen oxides (NOx). The main sources of VOC, SO2 and NOx are pollutants released directly into the air by gasoline and diesel-run vehicles, industrial plants and activities and heating due to human activities.
The are many difference between smog, mist, fog, vog and haze. Mist and fog are caused by water droplets in the air, and the only difference is how far you can see. Haze is the reflection of sunlight off air pollution, while smog is what happens when pollution causes low-lying ozone and vog only happens when a nearby volcano is releasing sulfur dioxide into the air to react with what’s already there.
Figure 1: Smog happens in the cities.
First recognized of smog occurs in Los Angeles in 1943, the scientists that a few years to solve that car are the culprit. But now, chemical plant is suspected as the point that cause of the brown hue in San Fernando Valley skies. In October, country supervisors choose a Smoke and Fumes Commission to analysis the dense of smoke. In 1947, the laws setting up an Air Pollution Control Districts was endorse by California Governor Earl Warren in L.A. County. Caltech chemistry professor Arie Haagen – Smit was finds the sources of ozone, that bleaching solution odor and the nature and causes of photochemical smog in 1948. The workers in L.A County Air Pollution Control District reveal their eyes to smog, while others hold the stopwatches, to see how long the it takes to tears to stream down their faces in 1952.
In 1954, APCD executive officer S. Smith Griswold found bronchitis after voluntarily breathing in considerably high levels of ozone in a Plexiglas chamber. L.A County Medical Association finds that 94.7 percent recognize the “smog complex” by the survey of doctors which are irritated eyes, respiratory tract, chest pains, cough, nausea and headache in 1956. The nation’s last note the Stage Three smog alert occurs in Upland. Ozone levels hit 51 parts per millions. Gov. Ronald Reagan urges residents to “limit all the absolutely necessary auto travel” and advocates that people drive slower to reduce emissions in 1974. In 1984, The California Smog Check program goes into impact to recognize vehicles in need of maintenance and to convince the advantages of their emissions-control systems.
By 1987, lung autopsies on more than 1100 young people who died in accidents or were victims of homicide find that 27 percent had severely damage lungs. AQMD start a landmark ride share program requiring companies employing at least 100 people by offer incentives to encourages workers to carpool or use public transport. Employers protest that it should not be their job to change worker’s driving behaviour and the project goes away in a few years. In 1989, some restaurants using char-broilers must outfit exhaust heads with devices to collect reactive organic gases and particles. President George Bush was needs new programs aimed at curbing ozone, acid rain and toxic air pollutants and establishing a uniform national-permit system by signing into law the Clean Air Act Amendments of 1990.
A program that accept major polluters to trade emission credits among themselves by bowing to pressure to do its part to recuperate the stagnant economy in 1993. No Stage One smog alerts this year, compared to 42 days in 1990, when people with respiratory problems were insist to stay indoors in 2000. In 2001, USC scientists learning about the health of children over an eight-year period find that teenagers who live in smoggy situations are nearly five times as likely to have clinically low lung function. Statewide, 9600 people die every year from air-pollution-caused ailments. Each year, 3200 die in car crashes and 2000 are victims of homicide in 2005.
Figure 2: Difference between during the smog (right) and without the smog (left) in Beijing.
TYPE OF SMOG
There are the type of smog which are sulfurous smog or London smog and photochemical smog. Sulfurous smog or London smog is occurs in the area where emissions of the sulphur containing compounds is high due to burning of coal to produce heat and energy and air contains high liquid water contents like fogs. It leads to the production of high concentrations of sulfuric acid in fog droplets. These acidic particles, along with high densities of smoke, inhibit the normal functioning of the lungs and can cause death. In the atmosphere, sulfuric acids particles can be establish in two ways which are direct dissolution of SO2 into water drop and subsequent aqueous-phase oxidation to sulphate and the gas-phase changing of SO2 to sulfuric acid gas (H2SO4), which has a low surface vapour pressure and therefore easily condenses onto particles. The gas phase conversion requires three steps:
SO2 + OH + M –> HSO3 + M
HSO3 + O2 –> SO3 + HO2
SO3 + H2O –> H2SO4
Photochemical smog is occurs in the regions where high emissions of automobiles, large concentration of reactive hydrocarbons (RH) from automobile exhaust or from other neutral or anthropogenic sources and plenty of sunlight that has high level of UV radiation. It forms primarily as a result of interactions among nitrogen oxides (NOx = NO + NO2), reactive hydrocarbons and sunlight. Photochemical smog works by primary pollutants NO and reactive organic vapors, RH are emitted from automobiles. First, RHs are chemically transformed to radicals , denoted R. Next, the organic radicals react with nitric oxide, NO, to form nitrogen dioxide, NO2. However, in urban air the sun breaks NO2 back to NO and O. Atomic oxygen produces ozone , O3, which is of primary concern in photochemical smog. Most of the world’s energy comes from the burning of organic compounds, whether they represent the organic matter of wood or the hydrocarbons of natural gas, coal, petroleum (oil), and other fossil fuels.
RH + OH –> R. + H2O
R. + O2 + M –> RO2 . + M
RO2 . + NO –> RO. + NO2
NO2 + hv –> NO + O, at wavelength O3 + M
RH + HO + NO + hv –> … –> O3 + NO2 + HC (overall process)
Comparison the characteristics between sulfurous smog and photochemical smog. The primary pollutants of the sulfurous smog is SO2 and soot particles while photochemical smog is NOx and organics. For secondary particles is H2SO4 and sulfate aerosol for sulfurous smog and O3, PAN, organics and aerosol acids for photochemical smog. The temperature of sulfurous smog is cool which is below 35oF and the temperature of photochemical smog is hot which is above 75oF. The relative humidity of the sulfurous is high, usually foggy while photochemical smog is low, usually hot and dry. For sulfurous smog, the type of temperature inversion is radiation inversion while for photochemical smog is subsidence inversion. Time air pollution peaks is early morning for the sulfurous smog and noon-evening for photochemical smog.
FACTOR THAT CAUSED SMOG
Many factors that cause smog which are automobiles, factories, chemicals and corporations. Most of the problem related with smog occur in the summer month. Smog is often caused by heavy traffic, high temperature, sunshine and restful winds. These are the few factors that increasing level of air pollution in atmosphere. High temperature will makes the highest levels of smog on hot summer days. During the winter months when the wind speed are low, it help the smog to became trapped at a place forming smog and increasing pollution levels near the ground closer to where people are respiring . It hampers visibility and disorder the environment. The time that smog takes to form depends directly on the temperature. Temperature inversions are conditions when warm air does not increase instead stays closed the ground. During this conditions of temperature inversions if the wind is restful, smog may get trapped and remain over a place for days. Automobiles and factories that cause the smog because of the smoke that contains many hazardous gases released in the air.
There also have factors to determine the unhealthy smog to human. First, the amount of ozone in the air. Since the heat is usually connected with ozone, it will make the impact of smog greater. Second, the length of the exposure, if the longer a person is exposed to smog the symptoms is greater. Lastly, how deeply a person is breathing when exposed to the smog. The often an individual breathes, the bigger dose of smog is going into their lungs and may affected the lungs.
Figure 3: Factories that released dangerous smoke that can caused smog.
EFFECT OF SMOG
Smog is very dangerous. Many effects that caused by smog toward human and environment. For human, they will get health problems like difficult to breath, eyes and skin irritations, coughing, asthma, lung cancer, heart problems, pneumonia, bronchitis and last but not least death. Asthma happen when someone much more sensitive to the smog. The highly affected people include old people, kids and those have cardiac and respiratory complications as they have easy tendency to be at disadvantage of asthma. Gas that are contain in photochemical smog can encourages the growth of cancer, decrease resistance to infection and provide to lung issues. Effect of smog due to environment are inhibits the plant growth and create immense damage to crops and forests. Crops and vegetables such as peanuts, soybeans, wheat and cotton are things that will get impact when there are revealed to the smog. Besides that, by killing innumerable animal species and green life will take time to adapt to breathing and remain alive in such toxic environment. It also can happen forest fire because of smog. Visibility of human also affected by the smog. It is going to be difficult to see. That means that is impossible to drive the car if smog is going to be there for a few days. People cannot go to work and they will lost of earnings. They just need to stay at home and won’t be able to go to work. Others is could be that everyday living slow down because the transport won’t be running, people won’t be able to go to work, that means that the shops will not be open and this could cause people to run out of food if the smog will be there for a few days or weeks.
Everyone can do their part to reduce smog by changing a few behaviour such as drive less, take care of the car, fuel up during the cooler hours of the day like early morning or night, away the products that release high levels of VOC, avoid gas-powered yard equipment like lawn mowers. The factories that released the dangerous gases can reduce the smog by using filter on chimneys so that there are not many gases out into atmosphere. Besides that, carpooling, walking or biking or using public transport rather than use the car all of the time especially during the summer will control the ozone production. These would minimize the amount of car fumes polluting the earth. In addition, decreasing household electricity use and keeping vehicles fuels efficiency reduces ozone-producing greenhouse gases. Fuels efficiency can preserve by checking tire pressure, oil level, air filters, coolant hoses and belts and getting regular tune-ups. Next, to overcome the smog is the industry is built away from the people or the residential area. So that, health problems due to smog will decrease. People need to wear face mask when going out during the smog. It will protects us from the disease during the smog. By warning people to stay indoors and avoid outdoors activities when there is a smog happen in the cities.
Figure 4.1: People wear face mask when going out. Figure 4.2: People use bike to go to somewhere.