Waste evaluation options in India
The problem of municipal solid waste management has acquired alarming dimensions in India especially over the last decade, before which waste management was hardly considered an issue of concern as the waste could be easily disposed of in an environmentally safe manner.
The physical and chemical characteristics of Indian city refuse, nonetheless, show that about 80% of it is compostable and ideal for biogas generation due to adequate nutrients (NPK), moisture content of 50-55% and a carbon-to-nitrogen ratio of 25-40:1. Therefore, the development of appropriate technologies for utilisation of wastes is essential to minimize adverse health and environmental consequences. Against this backdrop, let us discuss below the quantum of wastes generated in India, their composition, disposal methods, recycling aspects, and health and environment impacts:
(i) Waste quantum: The per capita waste generation rate is about 500 g/day.
This along with increased population has contributed to higher total waste
(ii) Waste composition: Studies reveal that the percentage of the organic matter has
remained almost static at 41% in the past 3 decades, but the recyclables have increased from 9.56% to 17.18%.
Garbage in Indian cities is estimated to contain about 45-75% biodegradable waste
(as against 25% of US city-garbage) with 50-55% moisture; 35-45% being fruits, vegetable and food biomass; and 8-15% non organic materials like plastic, metal, glass, stones, etc. Refuse from Indian cities also contains high organic and low combustible matter, if the studies carried out in six cities are of any indication.
(iii) Waste disposal methods: Waste disposal is the final stage of the waste management cycle. About 90% of the municipal waste collected by the civic authorities in India is dumped in low-lying areas outside the city/town limits, which have no provision of leachate collection and treatment, and landfill gas collection and use.
(iv) Recycling: This involves collection of recyclables from various sources, which ultimately reach recycling units. It is estimated that about 40-80% of plastic waste gets recycled in India, as compared to 10-15% in the developed nations of the world. However, due to lack of suitable government policies, incentives,
subsidies, regulations, standards, etc., related to recycling, this industry is still far behind itswestern counterparts in terms of technology and quality of manufactured goods. Nevertheless, recycling in India is a highly organised and profit-making venture, though informal in nature.
(v) Health impacts: Due to the absence of standards and norms for handling municipal wastes, municipal workers suffer occupational health hazards of waste handling. At
the dumpsites in the city of Mumbai, for example, 95 workers were examined and it was found that about 80% of them had eye problems, 73% respiratory ailments, 51% gastro intestinal ailments and 27% skin lesions. Also, municipal workers and rag pickers who operate informally for long hours rummaging through waste also suffer from similar occupational health diseases ranging from respiratory illnesses (from ingesting particulates and bio-aerosols), infections (direct contact with contaminated material), puncture wounds (leading to tetanus, hepatitis and HIV infection) to headaches and nausea, etc. Studies among the 180 rag pickers at open dumps of Kolkata city reveal that average quarterly incidence of diarrhoea was 85%, fever 72% and cough and cold 63%.
impacts: In addition to occupational health, injury issues and environmental
health also need to be mentioned in the context of waste management.
Contaminated leachate and surface run-off from land disposal facilities affects
ground and surface water quality. Volatile organic compounds and dioxins in
air-emissions are attributed to increasing cancer incidence and psychological
stress for those living near incinerators or land disposal facilities. Drain
clogging due to uncollected wastes leading to stagnant waters and subsequent
mosquito vector breeding is a few of the environmental health issues, which
affect the waste workers as well as the public.