Describe the management of solid waste and biomedical waste.

Solid Waste Management

• The sources — domestic (garbage, rubbish and ash), street sweepings, market waste, industrial waste, construction debris, agricultural waste and health-care waste
• The composition in India is characteristically high in organic (biodegradable) matter and moisture, and lower in paper and packaging than in developed countries
• That composition has practical consequences — the high organic and moisture content makes Indian waste well suited to composting and poorly suited to incineration, which requires dry, high-calorific waste and otherwise consumes fuel and produces poor combustion
• The management hierarchy should be stated in order, since the order is the point — refuse and reduce; reuse; recycle; recover (energy and compost); and finally dispose
• Segregation AT source is the single most important practical step, and the reason should be given — once wet and dry waste are mixed, the dry fraction is contaminated and becomes unrecyclable, and the wet fraction cannot be composted cleanly
• Separation after mixing is expensive, unpleasant and never complete, so everything downstream depends on what the household does
• The Indian rule requires segregation into — wet (biodegradable), dry (recyclable) and domestic hazardous waste (batteries, tube lights, expired medicines, paints and sanitary waste)
• The methods of disposal:
• Sanitary landfill — waste deposited in a prepared, lined site in layers, compacted and covered with earth daily
• The daily earth cover is what distinguishes a sanitary landfill from a dump, since it prevents fly and rodent breeding, odour, fire and windblown litter
• Its requirements — an impermeable liner and leachate collection to protect groundwater; landfill gas (methane) venting or recovery; siting away from habitation, water bodies and airports; and capping and post-closure monitoring
• Composting — aerobic decomposition of organic matter into a stable, humus-like manure, by the bangalore (anaerobic, hot fermentation) or INDORE (aerobic) methods, or by mechanical composting and vermicomposting
• The heat generated destroys pathogens and helminth ova, and the product is useful rather than merely disposed of
• Composting is the method best matched to Indian waste, and can be done at household, colony or municipal scale
• Biomethanation — anaerobic digestion producing BIOGAS and slurry
• Incineration — controlled burning at high temperature, which reduces volume greatly and destroys pathogens, but is expensive, requires dry high-calorific waste, and produces ash and air pollutants including dioxins if temperature control is poor
• Open burning and open dumping must be named as what must not be done, being the commonest practice and a major source of air pollution and vector breeding
• The rag PICKER and informal waste worker deserve mention — a large part of India’s recycling is achieved by informal workers at considerable personal risk from sharps, infection and toxic exposure, and integrating and protecting them is both a health and a justice issue

Biomedical Waste Management

• Biomedical waste is waste generated during the diagnosis, treatment or immunisation of human beings or animals, or in related research
• The essential fact to state first is that only a small fraction — roughly 15 to 20% — of hospital waste is actually hazardous; the remainder is ordinary general waste
• The consequence is that segregation is everything — if the hazardous fifth is mixed with the general four-fifths, the entire quantity becomes hazardous, and the cost and risk of treatment rise fivefold
• Segregation must therefore occur AT the point of generation, by the person generating it, at the moment of generation — not later and not by someone else
• The colour coding under the Biomedical Waste Management Rules, 2016, must be known exactly:
• Yellow — human and animal anatomical waste; soiled waste (dressings, cotton, items contaminated with blood or body fluids); expired and discarded medicines; chemical waste; microbiology and laboratory waste; and soiled linen. Treated by incineration, plasma pyrolysis or deep burial
• Red — contaminated recyclable plastic — tubing, bottles, intravenous sets, catheters, urine bags, syringes without needles, and gloves. Treated by autoclaving or microwaving, then shredding and sent for recycling
• White (translucent, puncture-proof) — sharps — needles, syringes with fixed needles, scalpels and blades. Treated by autoclaving or dry heat sterilisation, then shredding or encapsulation
• Blue (puncture-proof box or bag) — broken or discarded glassware including medicine vials and ampoules, and metallic implants. Disinfected, then sent for recycling
• The mnemonic that helps is that yellow is what is burnt, red is plastic that is recycled, white is sharps, and blue is glass
• The 2016 rules introduced several changes worth naming — pre-treatment of laboratory and microbiological waste at source; phasing out of chlorinated plastic bags and gloves, since burning PVC generates dioxins; bar-coding and GPS tracking of waste bags; annual health checks and immunisation (hepatitis B and tetanus) of waste handlers; and reporting of major accidents
• Needles must not be recapped, and should be disposed of directly into a puncture-proof container at the point of use, or destroyed with a needle destroyer or hub cutter
• Recapping is the commonest cause of needle-stick injury, which carries risk of hepatitis B, hepatitis C and HIV, of which hepatitis B is the most transmissible and is also the one that is vaccine-preventable
• The steps of biomedical waste management in sequence — segregation; collection in the correct container; in-house transport in closed trolleys; storage for no more than 48 hours; transport to a common biomedical waste treatment facility; treatment; and final disposal
• The common treatment facility model is used because individual small facilities cannot afford or properly operate an incinerator
• The practical failures commonly observed — mixing of general and hazardous waste; overfilling of sharps containers; recapping of needles; absence of liquid waste and mercury management; untrained and unprotected handlers; and illegal repackaging and resale of disposables, which puts contaminated syringes back into circulation and is the most serious harm of all
• Only a fifth of hospital waste is hazardous, and mixing makes all of it hazardous, which is why segregation is everything
• Yellow burns, red recycles, white sharps, blue glass, which is the quickest way to hold the colour code
• Never recap a needle, since recapping is the commonest cause of needle-stick injury
• Hepatitis B is the most transmissible of the needle-stick risks and is also the vaccine-preventable one
• Segregate at the point of generation, by the person generating it, at the moment it is generated
• Indian waste suits composting, not incineration, being high in organic matter and moisture
• Daily earth cover distinguishes landfill from dump, preventing flies, rodents, odour and fire
• Leachate collection protects groundwater, and its absence is what makes an unlined dump dangerous
• Mixing wet and dry destroys recyclability, which is why segregation at source determines everything downstream
• Chlorinated plastics are being phased out, since burning PVC generates dioxins
• Immunise and health-check waste handlers annually, which the 2016 rules require and facilities often omit
• Store biomedical waste no more than forty-eight hours, after which decomposition and odour make handling hazardous
• Illegal repackaging of disposables is the worst failure, putting contaminated syringes back into circulation
• Common treatment facilities exist for good reason, since small hospitals cannot operate an incinerator properly
• Rag pickers do much of India recycling at considerable personal risk, and integrating them is a justice issue
• Incineration produces dioxins if poorly controlled, which is a real objection rather than a theoretical one
• Composting destroys pathogens by heat, and yields a useful product rather than merely reducing volume
• Refuse, reduce, reuse, recycle, recover, dispose is the hierarchy, and the order is the substance of it
• Domestic hazardous waste needs separate handling — batteries, tube lights, expired medicines and paints
• Open burning is the commonest bad practice, and a major source of both air pollution and vector breeding
• Bar-coding tracks bags to the facility, which the 2016 rules introduced to prevent diversion
• Biomethanation yields gas and slurry, and suits the wet fraction particularly well at institutional scale