Understanding the health risks of solid waste

management practices – applying evidence to

Bangalore’s context

Adithya Pradyumna, SOCHARA, Bangalore (January 2013)

Bangalore has come face-to-face with the shortcomings of waste management practices of

dumping thousands of tonnes of wastes in the city’s outskirts. This is an opportunity to make

radical changes in the way the city thinks about and handles waste. The stiff opposition

towards dumping of wastes and poorly managed “landfills” were made primarily on grounds

of loss of health, quality of life and impact on local environment and livelihood. While new

plans are being made, it is important that the energy for change is sustained. The municipal

corporation should avoid the tendency to revert back to obsolete and unsustainable practices.

To contribute to the discussion from a health perspective, an effort has been made to report

existing evidence on the health risks of solid waste management. These should be considered

while making new plans.

An effort towards analysing the health risks of suggested alternative approaches to solid

waste management is also underway. This review focuses on issues related to past and

ongoing waste management practices in Bangalore. The main objective is to identify the

areas of concern with respect to public health impacts of municipal solid waste.

The paper is primarily concerned with municipal solid wastes (MSW) in urban areas, which

is defined as “everyday trash items, such as packaging, yard wastes, glass, paper, food scraps,

appliances, and batteries” (1).

Review of literature

The questions that are of immediate interest to Bangalore’s situation are:

What is the association between delayed waste collection and vectors such as

mosquitoes, flies, and rats?

What are the hazards of setting fire to municipal solid wastes?

What are the potential hazards of landfilling and waste dumps?

What hazards are waste collectors exposed to during collection and segregation of

mixed municipal wastes?

A few relevant reviews and articles from a google-scholar search (with search words such as

“solid waste management health impacts” and “solid waste vectorborne disease”) and a hand

search of some Indian journals (IJCM, IJPH, NMJI, ICMR Bulletin, IJOEM and JESE) of

editions from last 15 years. As the search led to reviews on health impacts of solid waste

management from reputed institutes, no further searchers are necessary.

FINDINGS

Waste presents several challenges and concerns which range from quality of life to more

hazardous situations such as groundwater contamination and increased prevalence of disease

vectors (1). Increasingly, the approach of placing MSW in dumps have become less socially

and environmentally acceptable (1). The problem with Bangalore is that which has been faced

by cities facing rapid development in general, where infrastructural development has not kept

pace with growth in population, especially in the fringe areas (2).

A World Bank paper (3) has profiled the various health risks of waste and waste

management:

The nature of raw waste, its composition (e.g., toxic, allergenic and infectious

substances), and its components (e.g., gases, dusts, leachates, sharps);

The nature of waste as it decomposes (e.g., gases, dusts, leachates, particle sizes) and

their change in ability to cause a toxic, allergenic or infectious health response;

The handling of waste (e.g., working in traffic, shoveling, lifting, equipment

vibrations, accidents);

The processing of wastes (e.g., odor, noise, vibration, accidents, air and water

emissions, residuals, explosions, fires);

The disposal of wastes (e.g., odor, noise, vibration, stability of waste piles, air and

water emissions, explosions, fires).

It has been found that medical wastes (including needles and infectious bandages), hazardous

solvents, chemical pesticides, harmful construction materials and other chemicals were

present in MSW, most of which require manual handing and emptying, presenting an

increased occupational health risk to sanitation workers (3).

Unplanned expansion of the town and the urbanisation of peripheral villages in an unchecked

manner contributes to poor waste management (4). Due to lack of sanitation systems in

slums, defecation along roads leads to mixing of municipal wastes with fecal matter when

roads are cleaned (3). Wastes tend to accumulate near settlements, which are available to

vectors (rodents, insects and animals) (3).

Uncleared wastes tend to get washed into drainage systems, which create additional problems

(5). The case study of Surat City and its experience with the plague outbreak in 1994 provides

lessons on secondary impacts of waste management and governance (6).

Evidence also suggests that MSW in developing countries contains hazardous components,

primarily because of non-existent or dysfunctional frameworks and systems of waste

segregation and management regulation (3,4).

A World Bank report (3) also summarised the hazards and health risks from solid waste

management practices:

• Contaminated leachate and surface runoff from land disposal facilities affecting

downgradient ground and surface water quality;

• Methane and carbon dioxide air emissions from land disposal facilities adding to global

warming, and subsequently vector-borne disease abundance and pathogen survival;

• Volatile organic compounds in air emissions and inconclusive evidence on altered cancer

incidence, birth defects, and infant mortality, as well as psychological stress for those living

near solid waste incinerators or inadequately controlled land disposal facilities;

• Animals feeding on solid waste providing a food chain path for transmitting animal and

human diseases;

• Uncollected wastes retaining water and clogged drains, thus leading to stagnant waters

which encourage mosquito vector abundance;

• Uncollected wastes providing food and breeding sites for insect, bird and rodent disease

vectors

A figure by Birley and Lock (7) provides an overview to the links between MSW and health:

[from Birley and Lock, 1999. Permission not taken]

Internationally, waste management practices have seen an evolution. It started with open

dumps which needed to be covered with soil daily, and moved onto controlled landfills, and

later to sanitary landfills to reduce water pollution from landfills (3), and now some countries

even adopting zero waste approach (e.g.: New Zealand).

It is an important aspect for health systems to be ready to respond to health impacts of poor

waste management (6), which adds to the costs of the system.

What is the association between delayed waste collection and vectors such as

mosquitoes, flies, and rats?

“Lapses in the storage, collection, treatment and disposal of solid wastes can lead to

pollution of the soil, water and air, which often results in the creation of breeding grounds

for biological vectors, such as insect pests and rodents” (4).

Summary of diseases from vectors in contact with solid waste (3):

• Leptospirosis, Hanta Virus, Plague increase with exposure to rat droppings and urine

• Dengue Fever increases where uncollected solid waste (i.e., tires, cans) holding water

providing mosquito breeding sites

• Bacterial infections spread by houseflies that have come in contact with fecal matter in

solid waste

Mosquitoes:

Items such as plastic bottles, disposable cups and used tyres provide breeding grounds for

vectors such as mosquitoes(4). Also, uncollected wastes get carried into drainage canals and

blocks them, creating additional breeding grounds for mosquitoes, mainly culex (4)(5). Drains

need flowing water to prevent growth of mosquitoes (4). It was seen in Pondicherry that the

density of culex mosquitoes has doubled during the last few decades, and interventions such

as insecticide spraying were inadequately effective (4). Culex mosquitoes are not however an

immediate concern for Bangalore as they are not found here.

Evidence suggests that dengue was also associated with poor waste management practices.

Aedes aegypti, the vector of dengue breeds in small, clean water pools, including containers,

tires, and tin cans which are found in waste piles (3,4). Such breeding sites were found to be

abundant in sites with poor waste collection services based on a study (3). Aedes mosquitoes

are vectors also for several other arboviral infections such as Chikungunya; there are other

infections such as urban yellow fever which are not of direct concern to Bangalore at the

moment (5).

Malaria was not found to be associated with waste management practices.

Rats:

Rodent population is also supported by uncollected solid wastes, which are the vectors of

leptospirosis. Rats are also associated with more severe epidemic diseases such as plague (3).

The experience from Surat in 1994 shows the importance of both good waste management,

and good healthcare response team for epidemics (2).

Flies:

The survival and capacity of houseflies, the potential vectors of infections such as dysentery,

diarrhoea, typhoid, food poisoning, cholera, worm infection, poliomyelitis and certain skin

diseases, are directly linked with solid waste disposal (4). Stagnant pools are also associated

with flies (5). Cholera and typhoid especially have epidemic potential.

Other potential vectors of concern which are associated with waste collections are: sandflies,

vector of leishmaniasis, bartonellosis, and several arboviruses; and reduviid bugs. These are

however not of direct concern with Bangalore as they are not found in this region (5).

Rationale for daily collection:

A need for daily collection is additionally emphasised in hot climates such as the one in

Bangalore, as it takes as less as two days for uncollected waste to attract rats and flies (5).

Importance of protecting drains from solid waste:

In Surat, sewerage network coverage itself was less (30 percent), and this got overwhelmed

by solid wastes which entered them (2). A similar situation could happen in Bangalore if

wastes are not managed well.

From the equity perspective, it is also noticed that areas of lower socioeconomic status

(including labourers’ camps) is more exposed to these disease vectors (4). Additionally,

fringe areas which have poorer waste collection and sanitation facilities are more prone for

epidemic situations such as plague as was seen from the Surat experience. The poorer

communities tend to live in low lying areas prone for drainage problems (2).

Good solid waste management practices reduce the potential for growth of disease vectors,

and consequently of vector borne diseases. Collaboration between civil society and local

municipal bodies has been suggested (4).

What are the hazards of setting fire to municipal solid wastes?

Though literature on road-side burning of wastes was not found, evidence suggests that

burning of wastes through incineration is a process by which toxic substances are potentially

produced when the operation is not optimal: dioxins and furans. It has also been suggested

that incineration of mixed municipal wastes is not recommended for developing countries due

to the high content of organic matter. There is also the issue of particulates and heavy metals,

besides other air pollutants (3). Through appropriate control mechanisms, these hazardous

exposures could be reduced but not eliminated (3).

On incineration, a WHO report suggested that studies conducted so far do not show any

increase in respiratory diseases and reproductive health impacts, some increase in cancer

incidence is noted (8). The available evidence however is scanty and not of the highest

quality and there is need for more research as there is biological plausibility of health risk (8).

What are the potential hazards of landfilling and waste dumps?

Landfills, when improperly operated according to scientific guidelines, were found to be

linked with soil and water (surface and ground) contamination. Additionally, the process of

contamination is found to continue following the closure of the landfill (1). Communities

around such facilities are considered at risk for health problems and accidents due to landfills

(3). Proximity with landfills blurs the lines between occupational impacts on scavengers and

environmental health impacts on surrounding communities (3).

Heavy metals and toxic chemicals:

In relatively new non-scientific dumps, it was found that heavy metal levels were not

elevated, but their bioavailability was increased (9).

Liquid from the mixed municipal wastes leaches out and is collected as leachate. These have

the potential to contaminate ground and surface waters around the landfill, especially when

the design and operation of landfill is inappropriate (1). Heavy metals and harmful chemicals

(solvents and pesticides) are found in leachate (1,3). Fecal bacteria are also found typically in

leachate (3). Health risks of living downstream of open dumps have not been adequately

documented, but it does not rule out exposure risks (3).

Landfill gas and air pollution:

Organic matter in mixed municipal wastes in landfills decomposes to form methane, which

collects in pockets and create likelihood of explosion under certain conditions. Methane from

these pockets can also enter neighbouring properties and create dangerous situations (1).

Other gases which are of concern at landfills are: benzene, toluene, carbon tetrachloride etc;

and at open burning dumps are: volatilised heavy metals (3). Respiratory illness has found

some association with open dumps as follows: one survey from Calcutta showed increased

respiratory illness (71%) among waste pickers as compared to controls (34%). Another

descriptive survey in Mumbai showed that waste workers had increased incidence of

respiratory complaints (over 26%) and reduced lung functions, especially when at work (over

73%).

Animal infections and accidents:

As several domesticated animals may scavenge on dumps, there is likelihood of infections

such as Trichinosis and tape worm (taeniasis) (3).

Incidents of toppling of waste heaps killing two children in Calcutta is recorded (3).

Carcinogenesis:

Several hazards from landfills and waste dumps have carcinogenic potential at higher

concentrations (3) – these include heavy metals and chemicals (organic solvents, pesticides

etc). Review of epidemiological studies on association between landfills and cancers provide

inconclusive results. While some suggest an increase in cancer rates, there are also several

methodological issues with those papers to make definitive conclusions (8).

Birth defects:

The evidence on the effect of landfills on birth defects among women living close to landfills

is suggestive, but causal pathways are not clear (3,8). Additionally, these studies were from

developed countries, and similar evidence from developing countries was not found (3).

Nuisance factor:

Local populations may develop physical and mental symptoms due to the sight and smells

around the area of the landfill (8). These too have an important bearing on the quality of life.

Management plan for landfill:

There is a need for monitoring of soil and water contamination around landfills for which a

board should be instituted. This monitoring should continue even after the decommissioning

of the landfill for a period of minimum 30 years (1). In addition, a leachate management plan

and a gas management plan should be drafted (1). Only non-hazardous wastes that are non-

reducable, recyclable, compostable or processed in any other manner are suggested to be

landfilled (1).

What hazards are waste collectors exposed to during collection and segregation of

mixed municipal wastes?

As workers are in direct contact with wastes and associated hazards, without any protective

safety equipment, they are vulnerable to various health risks. This was found to be the case in

developing countries (3). In addition, this section is already rendered more vulnerable to

disease due to their socioeconomic situation (10).

A survey found that a significant number of waste pickers were pregnant women and

children. Children are more vulnerable to toxic substances as their exposure per unit body

weight is higher and the in-built mechanisms for detoxification are less active. Their nervous,

endocrine and reproductive organs are more impacted (3).

Risk to health of waste handlers occur through several sources: the content of waste (toxic

and infectious wastes), handling process (muscular problems), accidents (poor infrastructure)

and noise (3). The risk for various disorders was found to higher based on evidence from

various countries (3): infectious disease (6 times), allergic lung disease (2.6 times) and non

allergic lung diseases (1.4 to 2.5 times), hepatitis (1.2 times), parasitic infestation (3 times),

diarrhoea (10 times), heart attacks (2 times), injury (1.3 times), accidents (5.6 to 10 times),

musculo skeletal problems (1.9 times). In addition, HIV, tetanus, and lead poisoning were

also reported due to occupation. Heavy metals were found to 2.5 times higher in children

picking waste in Philippines, upto three times higher among incineration workers in US and

were also detected among waste segregators in Denmark (3). Parasitic infestation was found

almost universally in studies in developing countries (3).

Evidence from a survey in Bangalore and Delhi also report similar conditions among waste

handlers – predominant concerns were respiratory diseases (TB, Bronchitis, Asthma,

Pneumonia), gastrointestinal diseases (dysentery and diarrhoea and malnutrition), child loss

(seem in 38% of women waste workers) and musculoskeletal problems. High incidence of

skin diseases were also found in a survey in Manila. Chronic cough and jaundice was seen in

a high proportion of workers in Calcutta (3). From the organic wastes, the main hazards are

bacteria (gram positive and gram negative), actinomycetes and fungi (3).

It is suggested that the risk can be reduced by increasing worker protection, liftable load

sizes, collection of segregated wastes, preventing the exposure of vulnerable groups (prevent

child labour), use scientifically sound disposal methods (3).

Discussion – relevance to policy in Bangalore

Literature suggests that solid waste management has an important link with public health.

Communities exposed to poor waste management suffer from increase in vector borne

diseases (dengue and chikungunya from mosquitoes, diarrhoeal diseases from flies and

leptospirosis from rats), exposure to hazardous chemicals (and consequently potential for

birth defects, cancers and respiratory illnesses), and poor quality of life. In addition,

occupational injuries and diseases are seen commonly among waste workers. Most of these

conditions are already prevalent in Bangalore and it is likely that poor waste management

practices are contributing to them.

The evidence itself is sparse, and most of it is anecdotal, especially from India. Keeping the

precautionary principle in mind, and the presence of hazardous components of solid waste,

prevention of exposure to communities and workers should be the priority. Source

segregation and reduction in burning and dumping of wastes are recommended.

Environmental methods for reduction of dengue and chikungunya are more sustainable than

other methods of control – an improvement in waste management practices (especially source

segregation, timely collection and recycling) would reduce the number of vectors (aedes

mosquitoes).

It is also important to understand that waste management and related health impacts are also

influenced by health determinants that are more difficult to address, such as corruption,

health rights and equality (11). The ability to regulate and manage waste at community level

depends on some of these factors. A comprehensive quantification of impact of waste dumps

on the lives of surrounding communities is not possible to undertake due to the complex

nature of interactions. In addition, most of these communities already suffer from lack of

basic facilities and services.

While health hazards faced by pourakarmikas have been listed, it is important to realise that

this is their only livelihood option – and a change in the existing approach will significantly

impact their livelihoods and consequently their health. Two approaches could be used to

assess these kinds of impacts – participatory research with all stakeholders, and the

livelihoods model to analyse the new project. Therefore, any new waste management policy

should ensure that they have safer, dignified and sustainable jobs, by improving household

waste segregation, providing safety equipment, improving pay scales and health benefits.

Children are especially vulnerable to hazardous components of waste, and they should be

rehabilitated appropriately through a community health approach.

Newer management plans should be subjected to a health impact assessment, so that areas of

concern can be identified, and appropriate steps be taken to mitigate those concerns. This

HIA should include (like in any HIA) the voice of all stakeholders getting affected by the

new policy.

BBMP’s “interim plan for SWM in Bangalore” – a brief critique:

Phases of intervention were proposed – Phase 1 was to end on 31st of December, by when

several preparatory works for phase 2 were to be carried out. The focus was to promote waste

segregation, partnership with NGOs, commissioning of several wet waste processing centres

and dry waste collection centres etc. Biomethanation has been considered. Landfilling is to be

brought down to 10% from the current 95%, and this method will only be for materials that

are forwarded from dry waste centres for which recycling/reuse has not been possible. The

failure of waste to energy plants in other parts of India has been noted.

Detailed recommendations have been laid out for phase 2 for management of wet, dry and

hazardous wastes at individual, apartments, hotels and institutions; and a timetable for

collection and transport has also been made – with daily collection for wet and sanitary

wastes, and occasional collection of dry and other hazardous waste. This is appropriate based

on health considerations.

The important aspect of how the existing rag pickers and pourakarmikas will be included in

the new plan has not been adequately discussed, and is an important aspect. Also, to facilitate

and improve compliance of source segregation, capacity building and incentives of Bangalore

residents should be thought through in detail. Additionally, capacity building and incentives

for waste collection agents is very important to ensure that the process is functional.

BBMP should set realistic timelines for the project and implement it in a systematic manner

with an iterative process – they have not been able to fulfil their 1st phase objectives

satisfactorily, as can be seen from the situation of waste management at the moment. The

process of transformation itself should be monitored to ensure that it is being carried out

appropriately and effectively, and this could be handled by an independent body.

Experience has shown that waste managed well can generate wealth (for the community) and

reduce disease. What is needed now is political will to mobilise the process and the

community.

References

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