The Environmental Health Issues involved in a hospital or clinic of the developed world are necessarily complex and detailed, usually building on already existing systems and reflective of the high priority placed on these issues by our society. In a less developed world, these issues are no less important but pose a much greater challenge due to the relative lack of infrastructure and resources available.
In 1997, I was involved in a primary health care program with a medical aid agency, in the western districts of Afghanistan. An important part of that program was rehabilitation of a clinic, development of the necessary water and sanitation systems, and the solving of unexpected environmental health issues.
The clinic that was to be the focus of the program had been built during the time of Russian occupation, and renovated 6 years prior by the UNHCR. There was a plumbing system in place, however the town’s water system had been destroyed during the fighting that occurred between the various Mujahadeen groups after the withdrawal of the Russians. Consequently, the clinic’s sole source of water was from an unprotected well in the clinic grounds. Water was drawn from the well as needed and placed in 2 metal containers in each of the dressing rooms. While this system was simple and seemed to work, the quality of the water was poor, collection was labor intensive, and it took no advantage of the existing plumbing system.
In general, there are 3 potential sources of water: surface water, rainwater and groundwater. Surface water is the least preferable of the three, as it is frequently the most contaminated source. Rainwater is usually unpolluted in non-industrialized areas and can be used to supplement a more permanent source. Groundwater is the cleanest and most reliable source if properly collected.
A tank was installed on the clinic roof to collect rainwater, and this was then connected up to the existing plumbing system. As the success of this system was reliant on adequate rainfall, which was unlikely to provide enough water for the clinic for most of the year, a generator was also installed to pump water from the well to the tank. The mixing of groundwater with rainwater in the tank had the added beneficial effect of reducing the acidity of the water and thus the corrosion of the metal pipes used in the plumbing.
Given appropriate protection of a well, the quality of water taken from the ground can be considered adequate for consumption without further treatment. We decided to fill-in the existing well due to heavy contamination and lack of protection, and a second hand-dug well was constructed to replace it. The well was disinfected with a 1% chlorine solution before first use and subsequently tested for coliforms every month to ensure water quality.
In creating any new well, there are 4 important steps, which require consideration:
This is of particular importance when sinking a well that is to be used by a community, as issues of appropriate access and well maintenance need community input for success. For example, in Afghan society at that time, there was strict enforcement of separation of men and women in public. Consultation was required to know who would be collecting the water, and where to place the well in order to minimize contact between men and women.
Other than the cultural considerations affecting access, there are several physical requirements for the siting of a well. It must be preferably uphill and at least 30 m from pit latrines. The water table must be at least 3 m below ground level in all seasons, as above this, the water quality is equal to that of surface water. In balance with this, a site needs to be selected that provides easy access to the water table, as the deeper the well, the more sophisticated the equipment needed to dig it. The presence of existing vegetative growth is an important clue as to the height of the water table.
Design and construction
The choice of well design and construction is largely dependent on the resources and skills available to the community, but also on geographical characteristics of the location.
This is a very important aspect of well management as a contaminated well has the capacity to affect the health of a large number of people before detection of a problem. There are several protective components of the well structure that are evident from the design given above. The apron of the well is a circular concrete plate that surrounds the opening of the well. It functions as a barrier to contaminated water that leaches down from around the entrance of the well. It must cover at least a 1.5 m radius extending from the well opening, and should include a channel that diverts the wastewater to a soak away pit that is at least 10 m from the apron. The well casing consists of concrete rings that line the well from top to bottom. Like the apron, it functions to prevent contamination from leaching through surrounding soils. A well cover and pump can be added to stop any gross contamination from above. Finally, if there is no pump, there should only be one rope and bucket used to collect the water, suspended from the wellhead so that it cannot be removed or touch the ground.
Effective excreta disposal takes on added importance in the setting of a clinic, where the combination of patients with weakened immunity and the presence of more virulent pathogens demands extra care be taken. In the clinic, there were already a couple of flush latrines connected to septic tanks, however these had not been emptied for a long period, effectively rendering them unusable. There were 2 external pit latrines in the compound, which were also full.
Standalone latrine systems can be divided into 2 broad categories, those that require water and those that don’t. Within these groups there are a variety of models, each suited to particular situations and needs.
As with the choice of a well design, community consultation is paramount when deciding which type of latrine to install, as this ensures suitability of design for local customs. Consideration must also be given to the resources available, geographical aspects of the location, and social acceptability of the work required to maintain the latrine.
The existing pit latrines were closed and 2 new twin pit latrines installed, one for each sex. The twin pit latrine is a non-water requiring system that has the main advantages of providing a long-term solution, with minimal maintenance requirements. It consists of 2 basic pits used in alternation over a 2-3 year cycle. When the first pit becomes full, it is temporarily closed off and the contents allowed to biodegrade for 2 years. Meanwhile, the second pit is opened for use. At the end of the 2-year period, the compost is removed from the closed pit, the pit re-opened and the neighboring pit closed for biodegradation. The most important aspect of this system is the appropriate calculation of the pit size required for the population expected to use it. While this is very difficult to estimate in a clinic setting, the following formula can be used as a guideline:
V = N x S x Y
V = volume in m3
N = number of users
S = solids accumulation rate m3/mann/yr = 0.04 for dry pits
Y = lifetime of latrine in years = 2 for the double pit latrine
Siting of the pit should be so that it is at least 30m from groundwater sources and the bottom of the pit at least 1.5m above the water table in the wettest period.
Wastewater coming from the clinic is of concern for the following reasons: the water contains biological and chemical contaminants which can pollute the surrounding environment, and poor handling of water can create stagnant pools which make potential vector breeding sites. A wastewater treatment system is thus essential for protection of the environment and prevention of disease.
There are a variety of systems available, each growing in complexity and the level resources required, as the quantity of water to be processed increases.
A very simple system is that of the run-off drain to a soak away pit. This consists of a hole filled with rocks, with the effluent coming into the center of the pit via a drainpipe. In principle, the rocks fix particles and the bacteria coating the rocks then detoxify the water as it seeps down, so that it is safe by the time it reaches the surrounding soil and water table. In regards to the siting of the pit, it should be at least 3 m from vegetation and 30m from groundwater sources. The bottom of the pit should be at least 1m above the water table during the wettest period, and 1m above impermeable layers of soil.
Rubbish from the clinic is of 2 types: hazardous waste and non-hazardous waste. The treatment of non-hazardous waste was incorporated into the existing local waste treatment system; the hazardous waste treated as specified below.
An important concept in the treatment of hazardous waste is that it be easily recognizable as such, so that people take special precautions when handling it. If separation is done at the source, there is less chance of it being inappropriately handled and this thus reduces the chance of accidental exposure.
There was no concept of this existing in the clinic when we arrived. In each of the rooms there was one bucket into which all waste materials were placed. This bucket also functioned as the receptacle for wastewater from hand washing. This was then turned out into the clinic grounds at the end of the day.
A basic system of waste disposal was initiated. Clearly labeled buckets were provided: for non-hazardous waste, disposable hazardous waste (dressings, tissue), and non-disposable hazardous materials (sheets, towels). Each of these was treated separately as detailed below.
The issue of sharps disposals had also been poorly dealt with, used needles being placed on a plate on a table, also to be thrown into a corner of the clinic grounds at the end of the day. Again a simple system was implemented using plastic buckets with a small central hole cut out of the lid. These buckets were placed in all of the rooms. Once half-full, the buckets were emptied and the needles appropriately disposed of.
Non-recyclable hazardous waste was incinerated and then buried. Recyclable hazardous waste was cleaned in boiling water. Needles and expired pharmaceuticals were incinerated then buried.
A basic wood-fired incinerator built from local bricks was installed.
Incinerated materials were buried in a refuse pit. Due to the potential of leaching of toxins into the water table, the pit had to be at least 1.5m above the water table at its highest level during the wettest period and 30m from groundwater sources. A fence was placed around the pit to prevent accidents or entry of animals.
In order to protect the staff and other patients, the system of universal precautions was introduced. This basically describes a system of handling of bodily fluids, which assumes that any patient could carry infectious blood-borne disease. It encourages people to take precautions with all patients, regardless of their known disease status. Needles were used once only, disposed of immediately into clearly marked plastic bins, infectious materials into another container, and gloves to be worn at all times of potential exposure to bodily fluids. This was at first difficult to implement due to ingrained bad habits of the staff and the perception of excessive waste of resources.
Surgical instruments were sterilized in an autoclave at the end of the day. All instruments were cleaned in soap and water prior to autoclaving as this allows for maximal contact of the hot air to the surface of the instruments. A kerosene-fuelled autoclave was used with instructions written and translated into Farsi. Due to the expense of kerosene, instruments were only autoclaved once a day. After use, they were immediately cleaned and immersed into a chlorine-based disinfectant for half an hour, in the case that they were required again in the same day. Immersion in a 0.1% active chlorine solution after physical cleaning destroys bacteria and viruses, including HIV and Hepatitis B. However, it is not generally effective on bacterial spores.
Floors and surfaces were cleaned once a day with a chlorinated solution.
The siting of the laboratory was an important issue as there was a facility for tuberculosis diagnosis, and thus chance of cross infection to patients and staff entering the lab. A partition wall was placed so that the only entrance to the lab would be via an external door, and blood collected only in the dressing rooms.
In the broader context of environmental health, the health of the whole community should be considered when assessing the health of an individual, and the health of an individual reflective of the health of the community. By establishing a disease surveillance system by recording the diagnosis of every patient seen in the clinic, it was possible to gain an idea of the general trends of diseases, which diseases predominated in the community, and thus what type of programs could be used to target those diseases. Disease surveillance also allows for early detection of outbreaks/epidemics of disease and an early response to reduce their impact.
Cholera is a common disease in Afghanistan due to the extremely poor quality of the surface water combined with the lack of access to wells. Consequently, there is usually an outbreak of cholera roughly every second year. In order to be able to respond quickly and effectively to an outbreak, a plan was developed which detailed actions to be taken in event of an epidemic. Calculations were made of the stocks required and these were kept separately from the clinic’s usual stock. A site was identified within the clinic grounds that would be suitable for setting up a makeshift tent clinic specifically for the treatment of cholera patients. The outlay of tents and toilets were specified on the plan, the water drainage systems and soak pits built in advance. Basic guidelines for an environmental and epidemiological survey were included.
Screens were placed on all windows, curtains on external doorways, to prevent the entrance of flies. Fortunately, malaria was not a large problem and there was no other major vector to deal with.
An education room at the entrance to the clinic gave 5-10 minute demonstrations to all patients passing through the clinic. Messages of basic hygiene and sanitation were the mainstay of the curriculum.
Chlorine was relatively cheap and easily available to our program and was consequently the main chemical used in cleaning and disinfection. Large drums of chlorine were kept at a distant storage site with only smaller containers kept at the clinic, to avoid any large-scale accidents in the clinic.
Cleaners were given plastic gloves, buckets and spoons, for preparing the solution. Instructions were written and translated into Farsi to avoid misunderstandings.
Chlorine exposure can lead to the following: skin burns, conjunctivitis, pharyngitis, chest pain, cough shortness of breath and hemoptysis. In extreme cases it can cause cardiac arrest due to hypoxia.
Burning plastics releases a concoction of potentially dangerous chemicals into the air. Unfortunately, with our limited resources, we were not able to install tall chimneys or air cleaners to aid in dispersal of pollutants, and it could be argued that it would have been safer to bury the medical waste rather than to burn it. In fact, little attention was given to minimizing exposure from the fumes, but in retrospect, it would have been wise to limit the frequency of burn-offs, burn only on the windier days, and place the incinerator as far from neighboring dwellings as possible.
Polypharmacy -concept of essential drugs
One of the primary functions of any clinic is to diagnose illness and dispense appropriate treatment to patients. Unfortunately, for every beneficial effect of a medication there are also unwanted side effects. In Afghanistan, as is common in much of the developing world, it is not unusual for doctors to prescribe far more drugs than are indicated. The WHO has been conscious of this problem for many years, and twenty years ago, initiated the concept of the essential drugs list. This is a list of basic drugs, coupled with guidelines of their appropriate use, advised for use in clinics. It aspires to promote rational drug use, aid in professional training, restrain pharmaceutical costs and limit excessive prescribing habits.
This was employed at the clinic.
The environmental health needs of a clinic in a low resource setting, whilst challenging, can be sufficiently met with reasonably simple and cheap measures, that require above all, recognition of their importance.
Medecins Sans Frontieres (1994) Public Health Engineering in emergency situations. Medecins Sans Frontieres, Paris.
WHO (1999) EDM and Essential Drugs: Applying the essential drugs concept, www.who.int/dap/edrugsconcept.htm.