Pollutants & Human Health
As has been discussed earlier any change in the environment has deleterious effect on human health. Ingredients in health care waste (HCW) contain chemical and biological pollutants which cause morbidity and diseases. Environmental pollution as such also causes disease and infirmity. Pollution of Air, Water, soil, and aquifer are a reality today. Aquifer of West Bengal and Bangladesh are heavily polluted with arsenic. Arsenic poisoning amongst the population in villages in Bangladesh, West Bengal (India), and in many other parts are causing great concern today, and requires substantial resources of the society to deal with this menace.
Foot Note:A newly formed organization in Bangladesh-
‘Forum for Arsenic patients’ has threatened to sue the UNICEF for compensation of the 30,000 wells dug in Bangladesh by UNICEF. 63% were found contaminated with Arsenic.
-Source: DTE, August 31, 1999
Other metallic chemicals such as cadmium, chromium waste etc; also have toxic effects on human health. Test conducted in Medak district of Andhra Pradesh, India showed mercury content was 115 times the permissible limits (WHO permissible limit (recommended) is 10 ppb). The National Geographic Research Institute (NGRI) found arsenic level as high as 700 ppb. Manganese level in ground water in Bangladesh was 15 times the permissible limits and nickel was 4 -20 times . All these chemicals cause sub-clinical & manifest disease and afflictions. Sub-clinical concentration may not manifest as a disease but may manifest as behavioral changes and aberration in personality disposition. WHO’s Report on violence indicates that there has been an increase in violence the world over. Every hour 28 persons die of violence in South East Asian (SEA) countries. 600-1100 requires hospitalization 19. As per Uton Muchtar, former Dir WHO, SEARO, globally one in seven deaths among women is caused by violence in the age group up 15-44 (Most productive years of life). 317,000 deaths are caused due to violence in the SEA Region .
Pollution of aquifer by resistant strain of bacteria has been reported in a study conducted in the USA. Terramycin has been used in farms as growth promoters. Researchers found resistant strains as far as one-sixth of mile downstream from two swine facilities that used antibiotics as growth promoters. Use of tetracycline has been pushing the evolution of these resistance genes. The genes are transferred to bacteria where they can travel long distances in the environment. There may also be horizontal transfer of resistant genes . Researchers in US have uncovered new route of bacterial transmission.
Growth Promoter antibiotics in food Pigs Pigs Guts
Excreta soil underground water human beings.
Once transferred, the resistant genes of the bacteria in hardier soil-waterborne ones pass to underground water. Nearly 70% of all antibiotics produced in the US are fed to animals as growth promoters .
Human health is greatly influenced by air pollution and by biological contents of HCW. Easily it can be said that 30% of all respiratory group of diseases are caused by air pollution. Children and elderly people are specifically vulnerable to air pollution. There have been many acute air pollution episodes during last century caused by human activity where people have died in great numbers: -
Place Date Excess deaths in numbers
Meuse Valley, Dec. 1930 63
London , U.K. Dec. 1952 3500
New York, USA Nov. 1953 200
London, U.K. Dec. 1962 700
Osaka, Japan Dec. 1962 60
And, recently the great Bhopal gas tragedy caused by leakage of Methyl Isocynate (MIS) gas from Union Carbide Pesticide Plant in Bhopal, India in December, 1984 where about 7000 people died, lakhs maimed, and thousands borne thereafter with birth defects. Population of the city still continues to suffer delayed effects of the pollutant.
The interesting point to note is that all the air pollution tragedies took place in the winter months. It was due to temperature inversion (a meteorological phenomenon where the natural dissipation of heat and hot or warm air (with pollutants) is stopped and do not dissipate to the upper atmosphere. The trapped heat waves get reflected back on the surface of the earth thus causing global warming .
Normally warm air rises up carrying particulate pollution with it. But due to meteorological phenomenon called ‘Inversion’ a layer of cool air gets entrapped between layers of warm air. The warm air thus does not rise trapping particulate pollution. Inversion has been responsible for air pollution tragedies in Meuse valley, New York, London etc. All have occurred in winter months is a point to note.
Many chemicals are used in hospitals which have adverse effect on human health. Gases and particulates as pollutants in the air cause adverse effect on human health. These are generated by burning HCW as well. Emissions from stack of incinerator burning health care waste and chemicals used in a health care establishment are as follows:-
GASES & VOLATILE ORGANIC COMPOUNDS (VOC)
(a) Carbon monoxide:
Carbon monoxide (CO) is produced by internal combustion engines, burning of coal etc. In fact the greatest concentration of CO in day to day life is found in commuting, and in proximity of motor vehicles. Regular accidents leading to death takes place in winter in India when poor people sleep with burning coal/ wood/cow dung cakes inside a closed room or ill ventilated enclosures. CO combines with hemoglobin to produce carboxyhaemoglobin thus denying carriage of oxygen. Brain and heart are specifically susceptible to lack of oxygen caused by CO in blood which reduces oxygen carrying capacity of the hemoglobin, and also, the ability of tissues to extract oxygen present in the hemoglobin at low pressure. Carbon monoxide also interferes with intracellular transport of oxygen in muscles.
(b) Carbon Dioxide:
Carbon dioxide or CO2 is a naturally occurring component of atmosphere. Directly it does not have any adverse effect on human health but its concentration in the atmosphere may give rise to conditions not conducive to human health. It is an important Green House Gas hence higher concentration of CO2 would have all the ill effects of GHG as has been described previously. CO 2, (along with CO) is also a marker for measuring combustion efficiency of an incinerator.
Note: - CO2 and CO, both are emitted from burning of carbonaceous contents in health care waste.
(c) Nitrogen Dioxide.
Nitrogen dioxide is a gas highly reactive, and in presence of sunlight and oxygen combines with hydrocarbons to form ozone, and other photochemical gaseous species. At times and during certain meteorological phenomenon it may combine with aerosols to form nitrous and nitric acids and give rise to secondary acidic particles. Principal sources of NO2 emission in the atmosphere are aircrafts, automobiles, power plants, and burning of fossil fuel. NO2, NO and SO2 get oxidized and hydrolyzed to form secondary pollutants such as H2SO4, HNO3 and HCL. NO2 can travel long distances as primary or secondary pollutants. Measures such as raising the height to stack only dissipate these obnoxious gases to wider and distant areas, mostly downwind. The possible advantage of raising the stack height is that the emission from the stack could be above inversion level in the atmosphere . It helps the pollutants to travel longer distances. Similarly Sulfur dioxide is mainly a product of combustion process, burning of fossil fuel, and activities related to power generation. It has been established that long exposure of as little as 0.1ppm of NO2 in air can result in increase in incidence of bronchitis and have adverse effect on performance of lungs over a period of 2 -3 years. This basically is due to inflammatory changes. NO2 may be emitted from burning of HCW with fossil fuel, and in certain other conditions.
Another important gaseous pollutant is ozone. Ozone is an oxidant gas generated in the atmosphere by chemical reaction of volatile organic compounds, and nitrogen oxides in presence of sunlight. It may not be in the emissions but may get formed by chemical reaction of other gaseous emissions from incineration. It is a naturally occurring gas in the upper atmosphere and protects from the damaging effects of ultraviolet radiation of sun. There are other man made sources as well, industrial activities such as manufacturing etc. Health effects are immediate but transient reduced lung function. Long term exposure is suspected to lead to chronic lung disorders such as asthma and chronic bronchitis. It accelerates the ageing process of the lungs. In certain Health care establishments ozone is used for sterilization & disinfection.
(e) sulfur oxide.
Emission of sulfur oxide increased steadily during the last century in the USA, reaching a peak of 32 million tons per year. After the ‘Clean Air Act’ was passed in 1963 it declined, and is estimated to be stable at 23 million tons per year. Accidental exposure to high concentration can cause severe airway obstruction, and pulmonary dysfunction for up to a year. Studies of alveolar lavage have demonstrated increase in macrophages and mast cells indicating inflammatory process. Severe wheezing has been noticed due to bronchial constriction at exposure to 0.5 ppm and exposure to 1ppm during moderate exercise in adolescents with asthma demonstrated 25% decrease in FEV1 (forced expiratory volume per second), 67% increase in respiratory resistance and 50% decrease in maximum flow rate . Exposure of humans and animals to sulphur dioxide particulates and acid aerosols has been associated with respiratory morbidity. Unplanned disposal and treatment of health care waste would give out sulfur dioxide in gaseous emission from burning the waste in incinerators.
(g) Dioxins & Furans.
Dioxins & Furans are compound organic gases of the family of Persistent Organic Pollutant, (also known as ‘dirty dozen’) normally produced by burning of waste with insufficient control and supervision. These gases are compounds of chlorine and are emitted when polyvinyl plastics (PVC) are burnt. It may be recalled that health care waste contain higher percentage of plastics as compared to municipal waste and therefore it is important that its implication be fully understood since even in low concentration it has the potential to cause serious impairment of human health. But PVC is not the only source. Burning of many other items at lower temperature in the range of 2500C to 4500C may lead to formation of these gases. In the context of dioxin formation this is commonly known as ‘window temperature’. Organic carbon & copper act as catalysts for dioxin formation (both are contained in the fly ash) if the flue gas contains chlorinated organic compounds or metal chlorides and is cooled slowly in an oxygen rich environment . Once formed these gases do not degrade easily. In other words the formation may be easy dictated by certain conditions but the destruction or degradation is relatively immune to environmental changes. Dioxins and furans are stable gases, once produced. Both these group of gases have been implicated in adverse impact on human health, including causation of cancer. There are more direct evidences of Dioxins causing cancer than furans. Dioxins are highly carcinogenic to guinea pig but less to mice and humans. Individual susceptibility plays an important role.
Dioxin emission is important to understand since in very minute concentrations it is potentially hazardous to human health – as an immediate as well as delayed effect, but at the same time production or emission of dioxin is totally preventable. Dioxins can cause cancer, is toxic to reproductive system, suppresses the immune system, is hepato-toxic, causes neurological dysfunction, and is toxic to skin. It is not soluble in water, has prevalence for deposition in the fatty tissues including lipids, crosses the placental barrier, is secreted in breast milk, and is terotogenic. It is quite a stable gas once formed and is cumulative. It enters the food chain, bio-magnifies and cause delayed effects on humans. In a study undertaken by Institution of Medicine of USA it was concluded that “there were sufficient evidence of an association” between exposure of herbivores contaminated with dioxins and increased risk to soft tissue sarcoma, non-Hodgkin’s lymphomas, Hodgkin’s disease and chloracne linked evidence of respiratory cancers, prostate cancer, multiple mycloma, spina bifida in children borne to exposed parents; and acquired porphyrea & birth defects. Immune system disorders and male infertility also have been described as effects of dioxin exposure. Exposure is estimated by chemical analysis of either adipose tissues or lipid fraction of serum . However the testing for dioxins is very expensive. One test may cost as much as $1000 to $3000. Not more than 50 laboratories are there in the world which can test for dioxins, and all of these laboratories are located in USA, Europe and Japan. Half life of Dioxin is reported to be 6-12 years .
Cumulative effect of dioxins can be well understood by going through the story of what happened in ‘Love Canal’ New York USA. In a report it has been stated that in ‘Love Canal, New York’ waste containing approximately 200 tons of dioxins were dumped in landfill during 1940-70 by an industrial unit. Later houses and schools were built. When waste began oozing and collecting in puddles in late 70’s the neighbor hood was evacuated. This happened despite the fact that dioxin is not soluble in water. It also indicates the sustaining quality of the pollutant against the decaying properties of nature. Dioxins can find its way into body by many routes. It could be by ingestion (through food chain), inhalation (directly from atmosphere), or through skin when children play on grass contaminated with Dioxins.
Despite knowing the carcinogenic nature of dioxins there has hardly been any concern for human life during war, as is evident from the fact that during the Vietnam War the US spread ‘Agent Orange’-a potent dioxin emitting chemical over Vietnam to destroy the vegetations which was obscuring aerial view of hide outs. Report of the EPA prepared in 1980 states that dioxin poses a threat to human health. The green peace released a report saying “No margin of safety” revealing there is no safe level for dioxins exposure.
Sources of Dioxins have been studied and it has been found that medical waste incinerators give out 130 to more than 10,000 g TEQ per year. The other sources are as follows :-
SOURCES OF DIOXINS
Municipal Waste 1000-10,000 g. TEQ/Year
Cement Kilns & Boilers 90 – 1000 g. TEQ/Year
Wood Burning (Industrial) 30-1000 g. TEQ/Year
Forest Fire 40 – 900 g. TEQ/Year
Wood Burning (Residential) 30 – 150 g. TEQ/Year
Sewage Sludge Incineration 10 – 100 g. TEQ/Year
Coal Combustion 50 – 150 g. TEQ/Year
Incinerators have been implicated in dioxin formation in a big way, and more and more evidences are surfacing regarding emission of dioxins by medical waste incineration. As per a report in India “another well known source of dioxin is the biomedical waste incineration”. A PIL was filed by BI Wadhera, a Delhi based environmentalist and lawyer in Delhi High Court in 1998. CPCB undertook a survey as directed by the court and found no single incinerator maintained proper temperature in the secondary chamber as specified. In another study undertaken by SHRISHTI–a Delhi based NGO, 60% of the 59 BMW incinerators were located in North Delhi hospitals, and 38% were incinerating plastics. In Mumbai too it was found that out of 10 BMW incinerators eight lacked basic design parameters and burning of PVC plastics was a practice going on unabated. This appears to be the Indian reality.
POPs are a group of toxic chemical pollutants harmful to human health and wild life (in fact all animals, birds, plants, and the human beings)
12 POPs also known as “dirty dozens” are listed by UNEP:-
- Hexachlor benzene
- Polychlorinated biphenyles
POPs are found in blood and in tissues in humans in all parts of world. It Transfers through placenta. There is a strong evidence of association between blood level of DDT/DDE, dioxin etc and elevated incidence of breast cancer. India has banned use of 9 out of 12 POPs. Not banned so far are: DDT, PCBs, dioxins & furans. Stockholm convention on POP was finalized after 2½ years deliberation at Johannesburg in Dec. 2000. Ninety one countries have signed the treaty. India is yet to ratify .
Health Care Waste contains a lot many metallic ingredients which when converted to gas dissipate in the atmosphere finally settling on foliage etc. and enter the food chain. Even if not burnt these metallic chemicals when released in the drains cause accumulation in the water bodies and enter the food chain.
All these gaseous pollutants may be directly responsible for health effects or indirectly as a part of particulate matter due to toxic effects of its components. So, discussions on impact on human health will have to be with the understanding of gaseous pollutants combined with particulate pollutants.
Most dangerous of air pollutants are particulates. Sources are many: power generation plants, incineration, open burning, cooking with fire wood and cow dung (biomass) industrial activity etc, and natural phenomena such as storm, gusty, wind, hurricane etc. The particulates vary in sizes and normally are expressed in µm dimension. In 1987 the Environmental Protection Agency (EPA) of the USA restructured National Ambient Air quality to PM10. In 1997, the EPA proposed new standard for PM less than 2.5µm in aerodynamic diameter . Now the particulate matters in nanometer are considered dangerous and harmful to human health. Particulates are harmful as such and as mechanical carriers of many chemical pollutants which piggyback on the particulates. Impact on health would therefore be combined. It causes respiratory morbidity and mortality. Larger particles may get trapped in upper respiratory tract such as nostrils and trachea, but smaller ones find their way to alveoli. Some researchers (Seaton & Colleagues) have hypothesized that alveolar deposition of ultra fine particulates cause inflammation and release of systemically active cytokines .
Dispersion by wind play a major role in spreading microbes as particulates form garbage dumps, and therefore insistence on secured landfill. Impact of particulate matter is mainly on respiratory system. Respiratory infection & inflammation due to exposure to ambient air having higher content of particulates is well known. In a study funded by US based Health Effects Institute has shown 0.5% increase in overall mortality for every 10 µg per m3 increase in PM10. This effect was slightly greater for deaths due to heart and lung disease than for total deaths. The researchers found that these tiny particles were wreaking havoc on human health quite independently of other air pollutants. It was found that in cities there was 1% increase in hospital admissions, and about 2% increase in cases of pneumonia and COPD in the population above 65 years of age for each 10 µg/ m3 increase in PM10 level. Curiously, the study found more hospitalization at lower level of particulate pollution . Health effects of ultra fine particles less than 0.1micron in diameter has also been studied, and it has been found that there is a delayed effect as against immediate effect for fine particles. Exposure to biomass smoke, outdoor and indoor air pollution in urban and rural areas has also been studied. One study in Western India found 50% increase in still birth in women exposed to indoor smoke during pregnancy. Considerable amount of carbon monoxide was detected in the blood stream of women cooking with biomass. Annual deaths due to air pollution in urban areas in developed countries was found to be 294 per year (252 in urban indoor), and much higher in developing countries –as much as 2706 per year (644 in urban indoor, and 1876 in rural indoors) . In a study carried out by TERI, India, it has been estimated that industrial activity may have been responsible for increase in PM level from 2 lakhs tons to 30 lakhs tons in 1997. It is to be noted that population increase has been only 1.0-1.2% per year vehicular pollution has increased from 15 million tons in 1947 to 1030 million tons in1997.
Liquid particulate matter generally categorized as “mist” includes rain drops, fog and sulfuric acid mist. Some particulate matter is biological, such as viruses, bacteria, spores, fungus and pollens. Particulate matter may be organic or inorganic; both types are very important environmental pollutants. Concentration is expressed in micrograms per cum or µg/m3.
This clearly indicates damaging effect of biomass burning for heating and other purposes. Deaths due to indoor pollution in the developing world has been estimated by a study on Indoor Air quality by ESMAP, World Bank in September 2000, in which estimated deaths in India has been found to be 28%; figures for China is 29%; Sub-Saharan Africa is 22%; as against 1% in Latin America. A major portion of mortality due to indoor air pollution is by particulate matter. Larger particulates get trapped in nostrils while breathing at rest. But smaller particles get through the filtering mechanism of the body and alveolar deposition is appreciable at particulate diameter between 2 µm and 4 µm. During breathing at rest 10% of compact particles of 0.5 to 1 µ diameter tends to be deposited in the alveoli. Alveolar macrophages (AM) in deep sputum are bio-indicator of health impact due to particulate deposition. Those exposed to air pollution of higher density and for a longer duration do show raised AM in sputum. Concentration of air pollutants including particulate matter remains higher in winter months as this very much depend upon aero- dynamic profile of the atmosphere. There is reduced effect of these pollutants during rainy season as the air pollutants get washed down on the surface with rain . Coastal settlements are less vulnerable to air pollution due to dissipation by air currents from over the oceans and seas. Inhabitants in tropical zones have the advantage of not having to face the adverse impact of meteorological phenomenon of ‘Inversion’. But in hilly terrain, and defiles effects will be more pronounced due to reduced air movement. Therefore ecosystem of a hilly or mountainous region is considered more fragile.
Effects of Air pollution on individuals will depend upon: -
(a) Nature of pollutant,
(b) Concentration of Pollutants,
(c) Duration of exposure,
(d) State of health & susceptibility of receptor,
(e) Age group of the receptor.
Impact on health will also depend upon frequency and depth of breathing. An adult and healthy human being breaths about 22,000 times per day and consumes about 16 kg air per day . Two aspects are important to understand. One is that children are more vulnerable to pollution since they consume more air, water and food in volume to volume ratio as their basal metabolic rate (BMR) is higher. And second is that elderly people are more vulnerable to air pollution as health of respiratory system of elderly population remains compromised to an extent as such. Air pollution may therefore cause critical damage amongst elderly people earlier than in healthy young adults.
Adverse impact of particulates can be very well appreciated by comparing what happened during 1952 & 1962 coal gas tragedies in London. Maximum and average smoke measurements were more or less the same, but the particle concentration was only 20% in 1962 episode compared to 1952 episode. Result was much lower casualties (3500 excess deaths in 1952 and only 700 in 1962) .
LONDON GAS TRAGEDY
OF 1952 & 1962:
(excl. 2000in the county)
24 hrs average 4000 µg/m3 800 µg/ m3
SO2 (Max) 1.5 ppm 1.5 ppm
SO2 (Average) 0.95 ppm 0.80 ppm
Inference: - Particulates play a dominant role in causing mortality/morbidity.
It is thus well established that particulates cause high incidence of morbidity & mortality hence burning of waste must be avoided.
Volatile Organic Compounds (VOC)
Lead is one of the components of health care waste. It is toxic to human beings. Effects of lead positioning are known since the BC era and it is well documented. It is known to cause toxicity in the humans either as a slow poison or as an instant poison. Though main source of lead pollution is gasoline, medical waste also contributes to lead air pollution, mostly from waste generated on dental procedures. The ingress to human body is by inhalation, ingestion, and absorption through skin. Deposition rate of airborne lead is about 40% . Absorption rate in children is greater since they inhale greater volume of air in relation to body mass as compared to adults. Absorption through GI tract is about 10 to 15% greater in children due to higher absorption rate.
Organic lead compounds such as Tetra ethyl and Tetra methyl get absorbed through skin. The effects of lead positioning are on the central nerves system, the urinary system and the gastro intestinal system. On the Central nervous system the victim may complain of headache, dizziness, sleep disturbance, and memory deficit etc. Changes in personality, such as increased irritability to convulsions and delirium have been reported. More severe cases of poisoning may lead to coma, and death. Rarely, it leads to acute encephalopathy. Effects in urinary system are damage to the proximal tubule and urinary dysfunction. On the gastro intestinal system it produces epigastric discomfort, nausea, anorexia, and dyspepsia, all resulting in weight loss. At higher blood concentration levels beyond 80µg/dl these symptoms may be accompanied with severe abdominal cramps usually associated with constipation. The patients may also suffer from arthralgia.
Lead crosses the placental barrier resulting in pre-mature membrane rupture and pre-term delivery which have been associated with high lead contents in the foetal membrane . In some reports lead has also been considered as terotogenic. Insufficient intake of iron, calcium and vitamin D amongst children in the disadvantaged group may further enhance the effect of lead positioning. It has become increasingly clear that adverse and subtle neurological effects can be demonstrated at lead exposures which are prevalent in the modern western society. Obviously the situation in the developing countries would be worse.
Lead reduces the hemoglobin formation thus causing anemia. Organic lead is soluble in fat hence preferentially accumulates in brain.
Mercury is one of the ingredients of hospital waste which has been a matter of great concern all over the world. Mercury is released in the atmosphere when health care waste having mercury content is burnt & enters the food chain same way as other pollutants. Mercury also enters the food chain when waste effluents are discharged in drains. Uses of mercury in the health care establishments are plenty and it is difficult to totally eliminate it. By and large 10% of all mercury pollution in the atmosphere is attributed to burning of hospital waste. Mercury is a globe trotter and can travel far and wide. Raising stack height on the incinerators only helps in horizontal spread of gaseous form of mercury. Mercury gets absorbed by inhalation, ingestion, and through skin and mucus membrane. Alkyl mercury compounds are most toxic, accumulates in both soft and hard tissues. Inorganic mercury is converted to more toxic compounds primarily by methylation by anaerobic micro organisms in the rudimentary layer of sea and lakes. Merely one Gm of mercury is enough to pollute a lake bigger than 8 hectares . A typical large hospital may be discharging as much as 3-8 Kg of the metal annually. In a study conducted by an NGO-‘Toxics Link’ only thermometer breakage in one hospital accounted for about 70 Gm of mercury in the hospital waste per month . In another study they also found that 45 Kg of mercury waste is generated from all the dental care establishments in Delhi during a year . Study in the USA has indicated that even if use of mercury is stopped in dental treatment today it will take about 15 years to rid the denture of US citizens having dental amalgam in their mouth, and may generate about 1000 MT of mercury waste over this period of 15 years
Once mercury compounds (and all such pollutants) accumulate on the foliage and water it egresses in the food chain; and through trophic levels reach higher concentrations by a process known as bio-magnification. It would therefore be correct to assume that large fish such as Tuna Fish etc. at the top of marine food chain would have higher concentration of mercury compound (methyl mercury). Marketing of sea foods has been regulated where the content of methyl mercury has been ordained to be less than 1 PPM. One would recall the Minimata episode where factories in Japan using mercury & chlorine to produce vinyl chloride were discharging effluents in the sea. This resulted in methyl mercury concentration in fish which when consumed by the humans caused food poisoning of a severe nature resulting in many deaths, not only in Japan but in different parts of world.
Mercury compounds pass through placental barrier and have been found in mother’s milk. Mercury has deleterious effects on urinary system (causes proteinuria, tubular and glomerular dysfunction). It is neuro-toxic causing changes in neurological functions, and causing emotional changes such as anxiety and timidity, changes in personality and behavior, deficit in performance level, parasthesia, hypotonia, tremor and visual impairment.
It has been reported that eating sea food with high level of mercury can affect brain development of older children as indicated in a study published in the online edition of journal ‘Nature’. The finding intensifies the ongoing debate about the health effects of mercury. Some researchers advocate that methyl mercury is toxic only to foetus & infants, and older children are unlikely to have developmental problems. But the study conducted by researchers from Harvard School of Public Health at the Faroe Islands in North Atlantic (where inhabitants eat a lot of sea food and whale meat) found that children aged seven had a slower transmission of electric signal along a particular circuit in their brain than was normal. When children became 14 years old the disruption became even worse. The findings suggest that safety messages about mercury should also highlight the toxin’s potential impact on children of all age group .
India does not produce mercury and relies totally on imports. During 1998-2001 the annual import stood at 170-190 tons which is 10% of global consumption. Mercury consumption by Indian Caustic –Chlorine companies is at least 50times higher than the average European consumption. Though mercury is not consumed in the process it gets lost during operation as soon as it is used. 70 tons of mercury thus enters the environment every year. And this trend is increasing. Mercury is used in clinical thermometers, sphygmomanometers, bulbs, dental amalgam etc. which adds to environmental mercury load once discarded. Thus total environmental mercury would be about 125 tons per year of elemental mercury. This would be about 5 times than the total mercury discharged in Minimata Bay in 36 years. In India, 44% of mercury goes unaccounted .
Gases & Chemicals Used in Hospital Environment.
Many types of gases and chemicals are used in the hospital environment for patient care and investigation, disinfection, and sterilization. Some can be said to be the end product of a procedure. For example, the photographic development solutions used in x-ray departments have fixer and developer. The fixer contains hydroquinone, potassium hydroxide, and silver. The developer contains gluteraldehyde. Acetic acid is used in the process of developing x-ray films. While silver is recovered other chemicals are normally discharged in the sewer. Therefore here chemical waste is generated in a process. These chemicals and gases have peculiar chemical properties and impact on health. Mercury by far is the most potent source of environmental degradation. Primary source of mercury in a hospital include broken thermometers, blood pressure instruments, and gauges etc containing mercury. Mercury spills must be recovered by containment, and reused after distillation. Distillation is a simple procedure which can turn waste mercury waste to useful & reusable recovered mercury. In fact in one hospital in Israel it has been tried and implemented resulting in a saving of $ 37,000 per year. There are many solvents used in the hospital. These include solvents used in Path Labs, in histology departments, embalming procedure etc. The solvents used include halogenated compounds such as methyl chloride, chloroforms, freons, trichloethylene, and trichlormethane. The non-halogenated ones are xylene, acetone, ethanol, methanol, and ethyl acetate etc. Xylene and ethanol are used in the histology and cytology departments. Tissues on which a chemical has been used would be considered hazardous waste. So far all these chemical wastes are discharged in the drains at least in the developing countries. To achieve proper disposal it would be necessary to contain all these chemicals and bring them to reuse after proper treatment. Distillation may be a viable option. Some have reported availability of fractional distillation system which is equipped with a microprocessor and automatically distill, fractionate, and purify solvents . Formaldehyde is used in pathology labs, in dialysis unit, for preserving specimens, and in embalming. By and large formaldehyde waste is discharged in the sewer-a practice which is not eco-friendly. Formaldehyde must be contained and reused after purification. Radioactive waste gets generated in the nuclear medicine and clinical testing departments. It is normally contained in leak proof lead containers and buried till these decay in the normal process. Chemotherapy wastes are contained in almost all ingredients of HCW, personal protective clothing, gauze pads, sharps used for injection of the chemotherapy agent etc. The method of disposal followed is either landfill or incineration. However it must be appreciated that the latter option may not be acceptable at many places considering views against incineration, and landfill may not be a viable option in developing countries due to lack of available secured landfill sites. Anesthetic gases are nitrous oxide, ethrane etc, and other gases used as inhalation anesthetics. Exposure to these gases may result in acute toxic effects, and possibly reproductive disorders as well as carcinogenic effects. There are other chemicals used for cleaning and disinfection purposes such as hypochlorite solution. Since it is a chlorinated compound it must be handled with due precaution.
Thus one can see that chemicals used in a hospital are essential to patient care but all cannot be disposed in eco-friendly manner. Therefore principles of management of this type of waste have to be precautionary, i.e. better control and management, minimization, and better inventory control. Thus it would be apparent that health care waste has greater potential to cause ill health & environmental damage. This happens largely because one tends to ignore nature’s limitation and finite quantum. In fact one must consider nature as a part of existence along with all of us. Nature and the mankind are not in a duel across a fence for survival, but are together for existence. Nature and the mankind, in fact all that is there are part of co-existence; and no part can be classed adversarial. When the humans set to exploit the environment they lose something of their own as well. When water is taken out in greater quantity than what is replenished a disproportionate equation gets created which in the long run harms the all living species, and at all levels. When economic development takes place ignoring human development unstable societies are created. It is therefore necessary to follow rules of the nature for environmental protection, which in turn is poignantly basic to enjoyment of highest standard of health.
Lalji K Verma