Rice ( Oryza sativa), the staple food of the Filipinos, is the major crop produced in the country. Philippines being the 8th top rice producer in the world, has 4. 5 million hectares of land producing rice yields with an average of 3. 59 tons of rice grains per hectare. With such great number, the country has available supply of food source. The enormous amount grains will provide the necessity and needs of the country. However, what happens with the plant body the grain was took off? What do farmers do to the bigger tons of rice straw left? Is burning the most effective and efficient solution?
Does it pose any threat on the environment? Open burning of agricultural waste is a common means of disposing crops and wood waste and for clearing land for farming. In rice, the most common way to dispose waste is by in situ burning. Many crops benefit from burning because it is an efficient, effective, and inexpensive method to remove crop residue. It is also an effective means of controlling disease and pest problems. The benefits of rice straw burning include control of the fungal diseases of rice, disposal of rice straw and facilitation of soil tillage and seedbed preparation.
It helps to reduce diseases that may occur due to reinfection from inoculum in the straw biomass. Burning is the most labor and cost efficient means of waste disposal. However, the bad effects of such practice had never been studied and analyzed. The lack of knowledge of farmers about the effects and consequences on what they do has left room for further research. First, burning emits large amount of smoke that can cause pollution. Second, pollutants present on smoke affects air circulation and quality.
According to a research, the amount of pollutants emitted by rice straw burning depends on the moisture content of the straw, the manner in which the field is burned (heading fire, backing fire, strip-light fire), and the “emission factor” (the pollution emitted per weight unit of the fuel being burned). The farmer is responsible for monitoring the moisture content of the straw and proceeding with the burn only if the straw passes the so- called “crackle” test (indicating low moisture and emission factor) in the field.
It is also up to the farmer to select the method of burning that best suits the environmental circumstances on the day that the burn is scheduled. Another study showed that this activity releases a large amount of air pollutants, which can cause serious effects on the ambient air quality, public health and climate. Health studies have reported an increase in bronchial asthma in children living close to rice fields during burning seasons. However, these studies did not show or explained the pollutants that can harm and affect the health of the people and our environment.
Therefore, the current study helps us understand the disadvantages of rice straw burning at the extent of the pollutants present in the smoke emitted in the air. This study will discuss the disadvantages of rice straw burning is primarily related to air quality. These are the following: * Generation of air pollutants * Production of polynuclear aromatic hydrocarbons in both gas and particulate forms, many of which are carcinogenic * Release of airborne silica fibers (small particles of straw ash with possible carcinogenic health effects)
Rice straw burning releases and generates air pollutants such as particulates, Carbon monoxide, Nitrogen oxides and Sulfur dioxide. Particulate is a complex mixture of extremely small particles and liquid droplets. Particle pollution is made up of a number of components, including acids (such as nitrates and sulfates), organic chemicals, metals, and soil or dust particles……..!!!! :0 Particulate matter is the term used for a mixture of solid particles and liquid droplets found in the air. Coarse particles (larger than 2. 5 micrometers) come from a variety of sources including windblown dust and grinding operations.
Fine particles (less than 2. 5 micrometers) often come from fuel combustion, power plants, and diesel buses and trucks. These fine particles are so small that several thousand of them could fit on the period at the end of this sentence. They are of health concern because they easily reach the deepest recesses of the lungs. Batteries of scientific studies have linked particulate matter, especially fine particles (alone or in combination with other air pollutants), with a series of significant health problems, including: * Premature death; * Respiratory related hospital admissions and emergency room visits; * Aggravated asthma; Acute respiratory symptoms, including aggravated coughing and difficult or painful breathing; * Chronic bronchitis; * Decreased lung function that can be experienced as shortness of breath; and * Work and school absences. Carbon monoxide is one of several pollutants that can interact in the presence of sunlight to produce ground-level ozone or “smog,” particularly on hot summer days. In addition to posing a health risk, ozone can damage buildings and harm crops. Carbon monoxide also can have health impacts on wildlife similar to those experienced by people: decreased supply of oxygen to the organs, tissues and central nervous system.
Nitrogen oxides contribute to ozone formation and can have adverse effects on both terrestrial and aquatic ecosystems. Nitrogen oxides in the air can significantly contribute to a number of environmental effects such as acid rain and eutrophication in coastal waters. Eutrophication occurs when a body of water suffers an increase in nutrients that leads to a reduction in the amount of oxygen in the water, producing an environment that is destructive to fish and other animal life.
Sulfur dioxide affects human health when it is breathed in. It irritates the nose, throat, and airways to cause coughing, wheezing, shortness of breath, or a tight feeling around the chest. The effects of sulfur dioxide are felt very quickly and most people would feel the worst symptoms in 10 or 15 minutes after breathing it in. Those most at risk of developing problems if they are exposed to sulfur dioxide are people with asthma or similar conditions.
