Solid Waste Management
1. What is solid waste? The sight of a dustbin overflowing and the stench rising from it are all too familiar sights and smells of a crowded city. You look away from it and hold your nose as you cross it. Have you ever thought that you also have a role to play in the creationof this stench? That you can also play a role in the lessening of this smell andmaking this waste bin look a little more attractive if you follow proper methods of disposal of the waste generated in the house? Since the beginning, humankind has been generating waste, be it the bones andother parts of animals they slaughter for their food or the wood they cut to make their carts. With the progress of civilization, the waste generated became of a more complex nature. At the end of the 19th century the industrial revolution saw the rise of the world of consumers. Not only did the air get more and more polluted but the earth itself became more polluted with the generation of non-biodegradable solid waste. The increase in population and urbanization was also largely responsible for the increase in solid waste . 1.1Types of Solid Waste Solid waste can be classified into different types depending on their source: Household waste is generally classified as municipal wasteIndustrial waste as hazardous waste Biomedical waste or hospital waste as infectious waste Municipal solid waste Consists of household waste, construction and demolition debris, sanitation residue,and waste from streets. This garbage is generated mainly from residential and commercial complexes. With rising urbanization and change in lifestyle and food habits, the amount of municipal solid waste has been increasing rapidly and its composition changing. In 1947 cities and towns in India generated an estimated 6 million tonnes of solid waste; in 1997 it was about 48 million tonnes. More than 25% of the municipal solid waste is not collected at all; 70% of the Indian cities lack adequate capacity to transport it and there are no sanitary landfills to dispose of the waste.The existing landfills are neither well equipped nor well managed and are not lined properly to protect against contamination of soil and ground water. Over the last few years, the consumer market has grown rapidly leading to products being packed in cans, aluminium foils, plastics, and other such non biodegradable items that cause incalculable harm to the environment. In India, some municipal areas have banned the use of plastics and they seem to have achieved success. For example, today one will not see a single piece of plastic in the entire district of Ladakh where the local authorities imposed a ban on plastics in 1998. Other statesshould follow the example of this region and ban the use of items that cause harmto the environment. One positive note is that in many large cities, shops have begun packing items in reusable or biodegradable bags. Hazardous waste Industrial and hospital waste is considered hazardous as they may contain toxic substances. Certain types of household waste are also hazardous.Hazardous wastes could be highly toxic to humans, animals, and plants; are corrosive, highly inflammable, or explosive; and react when exposed to certain things e.g. gases.India generates around 7 million tonnes of hazardous wastes every year, most of which is concentrated in four states: Andhra Pradesh, Bihar, Uttar Pradesh, and Tamil Nadu.Household wastes that can be categorized as hazardous waste include old batteries, shoe polish, paint tins, old medicines, and medicine bottles.In the industrial sector, the major generators of hazardous waste are the metal,chemical, paper, pesticide, dye, refining, and rubber goods industries. 3 Direct exposure to chemicals in hazardous waste such as mercury and cyanide can be fatal. Hospital waste Hospital waste is generated during the diagnosis, treatment, or immunization ofhuman beings or animals or in research activities in these fields or in the productionor testing of biologicals. It may include wastes like sharps, soiled waste, disposables,anatomical waste, cultures, discarded medicines, chemical wastes, etc. These are inthe form of disposable syringes, swabs, bandages, body fluids, human excreta, etc.This waste is highly infectious and can be a serious threat to human health if notmanaged in a scientific and discriminate manner. It has been roughly estimated thatof the 4 kg of waste generated in a hospital at least 1 kg would be infected.Hospital waste contaminated by chemicals used in hospitals is consideredhazardous. These chemicals include formaldehyde and phenols, which are used asdisinfectants, and mercury, which is used in thermometers or equipment thatmeasure blood pressure. Most hospitals in India do not have proper disposalfacilities for these hazardous wastes. 1.2 Health impacts of solid waste Modernization and progress has had its share of disadvantages and one of the mainaspects of concern is the pollution it is causing to the earth – be it land, air, andwater. With increase in the global population and the rising demand for food andother essentials, there has been a rise in the amount of waste being generated daily by each household. This waste is ultimately thrown into municipal waste collection centres from where it is collected by the area municipalities to be further thrown into the landfills and dumps. However, either due to resource crunch or inefficient infrastructure, not all of this waste gets collected and transported to the final dumpsites. If at this stage the management and disposal is improperly done, it can cause serious impacts on health and problems to the surrounding environment. Waste that is not properly managed, especially excreta and other liquid and solid waste from households and the community, are a serious health hazard and lead to the spread of infectious diseases. Unattended waste lying around attracts flies, rats, and other creatures that in turn spread disease. Normally it is the wet waste that decomposes and releases a bad odour. This leads to unhygienic conditions and thereby to a rise in the health problems. The plague outbreak in Surat is good example. Plastic waste is another cause for ill health. Thus excessive solid waste that is generated should be controlled by taking certain preventive measures. The group at risk from the unscientific disposal of solid waste include – the population in areas where there is no proper waste disposal method, especially the pre-school children; waste workers; and workers in facilities producing toxic and infectious material. Other high-risk group includes population living close to a waste dump and those, whose water supply has become contaminated either due to waste dumping or leakage from landfill sites. Uncollected solid waste also increases risk of injury, and infection. In particular, rganic domestic waste poses a serious threat, since they ferment, creating conditions favourable to the survival and growth of microbial pathogens. Direct handling of solid waste can result in various types of infectious and chronic diseases with the waste workers and the rag pickers being the most vulnerable. Exposure to hazardous waste can affect human health, children being more vulnerable to these pollutants. In fact, direct exposure can lead to diseases through chemical exposure as the release of chemical waste into the environment leads to chemical poisoning. Many studies have been carried out in various parts of the world to establish a connection between health and hazardous waste. 4 Waste from agriculture and industries can also cause serious health risks. Other than this, co-disposal of industrial hazardous waste with municipal waste can expose people to chemical and radioactive hazards. Uncollected solid waste can also obstruct storm water runoff, resulting in the forming of stagnant water bodies that become the breeding ground of disease. Waste dumped near a water source also causes contamination of the water body or the ground water source. Direct dumping of untreated waste in rivers, seas, and lakes results in the accumulation of toxic substances in the food chain, through the plants and animals that feed on it directly or indirectly. Disposal of hospital and other medical waste requires special attention since this can create major health hazards. This waste generated from the hospitals, health care centres, medical laboratories, and research centres such as discarded syringe needles, bandages, swabs, plasters, and other types of infectious waste are often disposed with the regular non-infectious waste. Waste treatment and disposal sites can also create health hazards for the neighbourhood. Improperly operated incineration plants cause air pollution and improperly managed and designed landfills attract all types of insects and rodents that spread disease. Ideally these sites should be located at a safe distance from all human settlement. Landfill sites should be well lined and walled to ensure thatthere is no leakage into the nearby ground water sources. Recycling too carries health risks if proper precautions are not taken. Workers The contents of this page are maintained by V Bhanumathi ( E E ) No:- 9880428478
