Waste Incinerator

A visit to the hospital does not usually reveal what happens at the back. It is here where discarded blood and body tissues and parts from surgeries, pharmaceuticals, medicine bottles — tonnes of hospital waste — go through. In the case of the Kenyatta National Hospital, this could be as much as one tonne a day estimated to be half the medical waste generated in the city. Quite understandably, it is not usually open to the public.

Most of these normally end up in incinerators — the most affordable medical waste disposal method for most hospitals. But a lot of it slips through the system to get us worried.

Incinerating waste at temperatures between 800-1,100 degrees Celsius kills viruses, bacteria and other pathogens but the ash still contains dangerous heavy metals like mercury and cadmium. Best practice dictates that such ash be buried.

But as this writer found out, this is better said than done. Lack of adequate equipment to safely dispose of waste and failure to observe best practices was a common feature in most hospitals visited in this survey.

From releasing dangerous fumes and ash openly to the environment to dumping medical waste together with general waste, the local medical waste management scene still has a long way to go.

Raw medical waste and toxic ash from incinerators ends up in open dumps like Dandora and Eastleigh posing a health risk to thousands of people salvaging plastic and metal for recycling and residents living nearby. Major hospitals like Kenyatta National Hospital which otherwise have good incinerators have run out of grounds to bury toxic ash. Few hospitals have a scrubber system where fumes are filtered to remove potentially toxic gases including dioxins from burning plastic — a common material discarded by hospitals.

A recent report on the global status of waste management ranks Nairobi as one of the worst in waste management. Residents living near Dandora reported a high number of respiratory diseases and were found to have unacceptably high levels of heavy metals like lead in their blood. Dandora dumpsite reeks of heavy metals which can hinder brain development as our independent tests confirmed.

“Most health facilities take ash from their waste to municipal dumpsites directly or through collectors,” says Mary Kinoti, a lecturer on environmental and occupational health at the University of Nairobi.

Walking through the dumpsite opened during the 1970s reveals unlikely materials that end up here. Lying in the pile of an unsightly mix of plastic bags and organic waste, one often finds bloodied gloves, dressing bandages, needles, discarded drugs and a host of other metals tucked away.

From their small quantities, it is easy to conclude that this come from smaller hospitals, clinics and dispensaries not willing to spend on the proper disposal of waste. Level five hospitals, formerly called provincial hospitals like Nakuru, are mostly well equipped with incinerators that can combust pathological waste into water and ashes, says Kinoti.

A peek at the Dandora dumpsite reveals an unsightly mix of plastic, food remains, animal products and all manner of waste the city discards. Every few minutes a truck makes its way through the mountains of garbage the city has accumulated over decades. The steady stream of trucks falls silent at dusk.

But as dark falls, another set, mostly lone trucks hurriedly enter the dumpsite, quickly offload their contents and make their exit, all within a few minutes — well aware of their wrongdoing. A closer look at the dumped material reveals used needles, bloodied bandages, pharmaceuticals and a host of other waste from hospitals. We even found syphilis and HIV test kits.

Early in the morning, a County Government of Nairobi earth mover turns over the waste mixing it with garbage ready to receive the next batch for the day.

Tens of people descend on the site, sorting the garbage with their bare hands. Their interests are different. While some solely focus on milk packets which they wash in a sewage tunnel, others are interested in salvaging metals from the burnings heaps, fuelled by the excessive gas underneath.

Still others are after the food remains which they collect to feed animals — all determined to make a living. A prick from an infected needle and they could end up with serious infections including HIV.

They all seem too aware of the danger, but they have to feed their children, a man, protected only by a pair of gumboots, says.

The National Environmental Management Authority and the County Government of Nairobi did not respond to our enquiries.

Yet the danger of medical waste in the country does not start or end here. Medical facilities try to safely dispose of their waste to various levels of success. A large number incinerate their waste, but lack the prerequisite air pollution control equipment to guard against materials such as sulphur, known collectively as flue materials, getting into the environment.

In such cases, residents living near such facilities are prone to respiratory infections. Dioxins from plastics are known to cause serious respiratory complications and cancer. A study carried out by a Yale University student recently found that high levels of toxic fumes from incinerators rending the air were responsible for respiratory infections among residents living near such facilities.

A recent report detailed the high levels of heavy metals such as lead in vegetables grown and sold in Nairobi. Lead is a dangerous metal that can cause retardation in children. Some farmers in Kinangop were recently in the spotlight for using sewage to grow their crops largely sold in the city.

Incinerators below standard

Dumping of toxic ash is not the sole problem facing the medical waste management scene. The state of equipment is wanting, some dating several decades ago and ill equipped to minimize pollution.

Most public hospital below level five have de Montfort incinerators where temperatures are not controlled and are likely to pollute as they lack scrubber systems. “Unfortunately this type of incinerators are common in district hospitals and health centres,” Kinoti says.

“A wet scrubber is a compartment where the emissions are sprinkled with water to dissolve air pollutants, and what is released to the environment is clean,” Kinoti explains. Workers are also not well protected in mid-level hospitals. Because of the design of the incinerators, medical waste is loaded manually and workers who mostly do not have protective gear are exposed, she says.

A medium size incinerator costs an average of Sh20 million before installation, clearly a high shot for hospitals. Add the high maintenance costs and the fact that these facilities guzzles several thousands of litres of fuel to run per day and you end up with a very high bill.

“But the high cost of incinerators is no excuse for polluting the environment,” says Kinoti. “Hospital waste contains mercury and can produce furans which are very toxic and can cause cancer and acute respiratory diseases,” she says.

Medical facilities which do not have incinerators are required to have contracts with specialised waste disposal companies to handle their waste. For some, this is just an unnecessary hurdle they have to undergo before acquiring a license to operate a hospital. Little is done to comply. A number do not follow through with these requirements posing a huge health risk to the public and the environment.

Hospitals categorize their waste differently for their safe handling during transport, storage, treatment and disposal, says Bernard Runyenje, assistant chief public health officer, Kenyatta National Hospital.

Highly infectious waste are those expected to be containing highly infectious pathogenic organisms such as bacteria and viruses while general waste may consist of office paper. Usually in red packages, infectious waste require special care throughout the process of waste disposal and are supposed to be treated at source. It is not however unusual to find a worker carrying a yellow or red disposal bag without gloves or any other protective gear.

Tissues that decompose quickly such as amputated limbs are disposed of quickly or put under refrigeration. Most of these highly infectious waste — except radioactive waste — should most appropriately end up at the incinerator, Dr Runyenje says. Most African countries use incineration to dispose of medical waste.

According to Dr Runyenje, incineration should be a controlled process and should happen in an enclosure. But he also admits that incinerators in rural areas do not meet these specifications.

A good incinerator should have more than one chamber where waste is burned in the first chamber, so that there is increased temperature in the second chamber and gases can be burned in the third chamber, he says. At the end of the process, most of the waste has been burned to an acceptable level. Clinics and dispensaries often operating in highly populated areas often flout the regulations, openly burning their waste using paraffin and charcoal to avoid the cost of safe disposal. Half burned waste is easy to spot in dumps on roadsides and quite visible in municipal dumpsites.

Incineration however does not get rid of toxic fumes and heavy metals — if anything it can disperse toxic fumes to a wide areas if not done properly. The scrubber system is designed to reduce such pollution but the system is expensive and most hospitals visited do not have it. The gas from the incinerator is passed through fluid to remove any particulate matter — inside a scrubber system. Such gases may include carbon monoxide, carbon dioxide, dioxins and furans which can cause serious diseases such as cancer.

The minimum height of a chimney should be at least 10 feet above the tallest building around to minimise direct exposure to residents. Anything that comes out of the chimney should be dispersed away from nearby buildings.

“Sometimes it is difficult to know what you are emitting to the environment. If you release it directly to human beings, then you expect to have some health issues, whether it is inhalation of carbon monoxide, carbon dioxide, dioxins or furans,” Dr Runyenje says. A high chimney should not however be seen as a replacement for a scrubber system, adds Kinoti. A high chimney only disperses fumes further to residents who may not even be aware of them, she observes.

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To many, including waste managers interviewed, ash from incinerators, or any ash for that matter is not harmful — a misplaced notion that could be contributing to its dumping. The truth is that they contain harmful metals like mercury, lead and cadmium as our independent tests confirmed.

Incineration reduces the waste to about 10 per cent of the original volume. But the remaining ash usually contains very high content of heavy metals. How hospitals and waste disposal companies handle this will determine the health of our environment. Such should usually be buried in sanitary landfills to prevent it from leaching to the ground, but this practice appears rare in the country.

Whether through sheer negligence, or lack of space and facilities or reluctance to meet the associated costs, medical waste nevertheless ends up in our environment. When disposed in open ground, heavy metals easily leach to the groundwater or make a direct way to our food chain.

Bottom ash under normal circumstances should be buried, but most health facilities do not have disposal grounds. These burial grounds are not present either at Dandora where officials claimed the ash was taken to be buried.

Some companies are licensed to handle hazardous waste. However, Dr Runyenje however notes that not many handle general medical waste.

A number of incinerators in public hospitals were in a state of disrepair leaving tonnes of toxic waste piling up and posing a danger to the public.

Kenyatta National Hospital has a ground where tonnes of waste are kept awaiting disposal. Two of its three incinerators are awaiting repair causing a backlog estimated at 170 tonnes.

Its newly acquired incinerator from India is the most advanced among the hospitals visited consisting of two chambers for maximum combustion. The wide network of smoke pipes leads to a chamber where the smoke is passed through a fluid to remove fumes and other residue.

The resulting black slime contains some of the dangerous metals. But the design and structure of the holding area does not meet specifications and some of it seeps to the ground, a source tells us. Its aging incinerators dating back to when the hospital was started are awaiting repair.

The incinerator cannot be operated during the day because the nursing school is just metres away.

The location of incinerators in relation to hospitals, offices and other residential is a common problem in many facilities. The one at the Chiromo School of Physical and Biological Sciences for example is not in operation as it sits near an embassy.

One incinerator in Nakuru County is perilously close to the maternity ward, some smoke go directly to patients.

The scenario plays out in many other hospitals around the country who also lack additional air pollution control equipment.

Ash dumped in open ground are an open feature in a number of leading facilities that could potentially poison ground water through leaching.

Ideally, ash from such waste should be buried in landfills, a practice that was long abandoned in the country.

With people living near such facilities, they are inevitably exposed, and risk serious respiratory infections and serious diseases including cancer. The Kenyatta National Hospital incinerators operate at night to minimise exposure to the students at the School of Nursing barely a dozen metres away.

A source told this writer that the soils were so contaminated they will have to be skimmed off and buried. Meanwhile, residents will have to contend with dangerous, possibly carcinogenic, ash emanating from such facilities.

Larger hospitals like Nairobi Women’s Hospital are stepping in to help smaller ones incinerate their waste. “The cost of the incinerator is too high for them to afford,” says Thomas Imboywa, who is in charge of one of these at the Nairobi Women’s Hospital, one of the largest in the region. On a daily basis, he oversees the safe disposal of the days waste.

The incinerator, a huge blue structure sits on about 100 square metres of space slightly off the main building and sports a high chimney, towering above the nearby building.

“Medical waste is ideally incinerated within 24 hours,” says Imboywa. But when a clinic or hospital does not turn in any waste for weeks on end, it raises eyebrows, Imboywa says. He is familiar with many such cases and the hospital is quick to repudiate such contracts as per their policy. Some medical facilities may just secure a contract with them to wade through National Environmental Authority (Nema) regulations but have no intention to safely dispose of their waste, Imboywa observes.

Those who do not have incinerators are required by Nema to have a contract with hospitals like Nairobi Women’s Hospital to dispose their waste. However, not all medical waste ends up in such specialised facilities. Instead, in places like Kibera they are doused with paraffin and burned in the open.

“But in this case, sharps will remain and the waste can still remain infectious because they cannot reach the required temperature,” Imboywa said. In fact the material can remain infectious because they may not reach the required temperatures.

Devolution could make it worse

As more hospitals come up in tandem with the growing population, a rethinking how medical waste is handled will be inevitable. The devolution of resources has seen more clinics and dispensaries put up in previously unreached areas. But the resources are so limited to put up waste disposal facilities such as incinerators.

Besides being expensive, Dr Runyenje agrees that even if these facilities were to put up their own incinerators, there would be more pollution and authorities will have more difficulty supervising them.

“There is need to pool incineration facilities for medical and hazardous waste,” he says. These centres can serve as emission monitoring points for authorities. “It will then be easier to put controls from such a central facility. “At the Technical Working Group, we are looking at how counties can pool their facilities together and have their medical waste incinerated at a central point. It will be very expensive in the long run to have every facility to have its own incinerator that cannot run at full capacity,” he says.

The best waste disposal method is controlled tipping being practiced in most of Europe and North America where it is buried in layers, Dr Runyenje says. “The advantage with this method is that the land can still be used for other activities. It is the only assurance of disposal of any form of waste,” he says.

Kariobangi, which now hosts light industries, used to be a controlled tipping site before open dumping at Dandora. “Counties should be thinking of controlled tipping instead of investing heavily in incinerators,” he says.

General waste can have many recyclable materials but proper segregation which can make this possible is still lacking in the country.

The effectiveness of recycling is determined by the effectiveness of segregation.

The problem, according to Kinoti, is enforcement of the law. While bigger hospitals are trying to properly dispose of their waste, some smaller clinics may be spoiling it, she says. The fact that generators cannot monitor their waste once it is given to waste collectors is also another problem according to her.

“There are many quacks doing waste management mixing household waste with hazardous waste. This can pose a serious health problem,” says Kinoti. Since they empty waste bins from homes, waste collectors can cause serious contamination in households. “Waste collectors who are collecting hazardous waste should be dedicated waste handlers and should not handle other general waste,” Kinoti says.

Effluent from the scrubber system should be taken for treatment to remove heavy metals and other pollutants. But the sewerage system is broken and a lot is discharged on the way. Sewage pipes are sometimes deliberately punctured and effluent used as fertiliser for crops.

“The law on sound medical waste disposal should be enforced, district and healthcare centres should install larger incinerators to handle waste from smaller fee. We should have dedicated healthcare waste managers,” Kinoti says.

by: http://allafrica.com/stories/201411111021.html