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Issue 3
, 2007
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Mercury in healthcare: Clear and present danger

Parvinder Singh
Source: Toxics Link, Date: , 2007

poster on use of mercury in dental practices Two recent studies have once again highlighted the clear and present risk of mercury exposure to medical staff and patients in everyday healthcare settings. What also makes these studies significant is the fact that while one reinforces the global impact of mercury as a contaminant, the other shows its specific threat in the Indian context in terms of its impact on a wide social and professional group associated with such facilities.

Toxics Link released a small-scale study to facilitate a wider discussion on the presence and use of mercury in healthcare facilities. The study titled 'Mercury in Hospital Indoor Air: Patients and Staff at Risk', found that the deadly neurotoxin was not only present in the indoor air, but far exceeded the acceptable standards. The presence at the two Delhi hospitals, used for the study, were particularly high in nursing station and maintenance areas. These hospitals already have mercury management policies in place. One can only imagine the state of affair in institutions that are yet to take note of the issue of mercury hazard.

Under the global study titled 'Halting the child brain drain: Why we need to tackle global mercury contamination', hair samples were collected from volunteers, mostly women working in healthcare facilities from 21 countries, including India. The findings showed that almost all the samples had presence of mercury. Thus establishing that the deadly heavy metal was a formidable occupational hazard cutting across regions. It was found that 95 per cent of women of childbearing age had detectable levels of mercury in their bodies. One in six women had mercury-level above the widely accepted or recommended safety dose. But, as experts for long have been saying: When it comes to mercury, there are no safe levels. As numerous scientific reports have shown that even trace-level exposure in the womb could cause brain damage in children.

Mercury in healthcare settings

Mercury is one of the most significant environmental offenders associated with the healthcare industry. It is mostly found in healthcare products in its elemental or liquid form. It is used in thermometers, blood pressure cuffs and esophageal dilators. It is also found in cleaning agents and fixatives used for laboratory work. In a list of more than 5,000 medical or healthcare products compiled by a technical assistance organisation more than 15 per cent contained mercury.

Since mercury is in a liquid state at room temperature. When spilt from an instrument due to breakage, it can easily disperse into the surrounding air through vaporisation. This can cause exposure to those in the vicinity through inhalation. Severity of the exposure in such cases depends on the air temperature, amount of mercury spilled, air flow in the room, and the built of the person exposed. Accidental spills can deposit mercury even in gaps and cracks in the floorings.

Studies have shown that even a single thermometer breakage can cause adverse health impacts. In a typical healthcare setting, mercury may be released from thermometers, blood pressure devices, gastrointestinal and other healthcare product. Fixatives, preservatives, lab chemicals, cleaners etc. may also contain mercury which, when discarded into the general waste stream, can result in serious environmental contamination.

According to a Toxics Link study, on an average close to 70 thermometer breakages happen every month in a regular 300-500 bed hospital facility. Further a hospital this size releases a whopping three kilos of mercury into the environment every year. Thus spillage from breakages of instruments are not just causing occupational hazard, they are also contributing to environment pollution.

Health impacts of mercury exposure

image of recent report by Health Care Without HarmMercury exists in various physical and chemical forms. The most important form, from a toxicological point of view, is its prevalence as methyl mercury. Vapour of elemental mercury gets rapidly absorbed through lungs. In a human body 75-85 per cent of an inhaled dose ends up being absorbed.

Initial exposure to high concentrations of mercury vapour produces symptoms similar to metal fume fever, including fatigue, fever and shivering. Its impact on the respiratory system could lead to cough, breathlessness, burning pain in the chest and inflammation in lungs. Occupational exposure to vapour with concentration ranging from one to 44 mg/m3 of mercury vapour for four to eight hours can cause serious respiratory disorders and symptoms. In some cases, a potentially life-threatening accumulation of fluid in the lungs (pulmonary edema) can happen.

Its harmful impact on the central nervous system is usually reflected through symptoms like tremors, initially affecting the arms and then spreading to other body parts, emotional instability, including irritability, excessive shyness, loss of confidence, sleeplessness, memory loss, muscle weakness, headaches, slow reflexes and a loss of feeling or numbness.

A revealing sign of exposure to high concentrations of mercury is inflammation in the mouth (stomatitis), sometimes with a metallic after-taste, resulting in excessive salivation and difficulty swallowing. Other related symptoms include abdominal pains, nausea, vomiting and diarrhea. Kidney damage is a common result of exposure to high concentrations of mercury, reflected in imapcts ranging from increased protein release in the urine to kidney failure.

In a review conducted by the US-EPA (1997), the reports from accidental exposures to mercury vapour have shown impact on a variety of cognitive, sensory, personality and motor functions. In general, symptoms have been observed to subside after removal from exposure. However, lasting and persistent side affects have been observed in people occupationally exposed from 10 to 30 years, even after cessation of exposure. Studies on healthcare workers exposed to elemental mercury vapour reported a clear disruption in the functioning of the Central Nervous System (CNS) at exposure levels greater than 0.1 mg/m3 and clear symptoms of mercury poisoning following four to eight hours of exposure.

A classic sign of exposure to high concentrations of mercury is inflammation in the mouth (stomatitis), sometimes with a metallic after-taste, resulting in excessive salivation and difficulty swallowing. Other digestive system effects include abdominal pains, nausea, vomiting and diarrhea. Kidney damage is common aftermath of exposure to high concentrations of mercury, ranging from increased protein presence in the urine to kidney failure.

Hazard to professionals and patients

Nurses and other medical staff work with mercury-based products on a routine basis and are in danger of inhaling toxic vapour when breakages or leakages happen. Many of them could be pregnant or of childbearing age. Developing nervous systems of fetuses are particularly susceptible to the harmful impacts of mercury, including spontaneous abortion in some cases. Exposure for the developing fetus and nursing infants can also happen through mercury present in a woman’s body prior to pregnancy.

Dentists and their support staff are among the most susceptible groups so far as potential exposure to metallic mercury is concerned. Their family members may also be in danger of exposure through indirect contamination. According to WHO, dental amalgam -- inexpensive alloy of silver, copper, tin and 50 per cent mercury -- is the largest source of human exposure to elemental mercury for those who have dental amalgam. As much as 75-85 per cent of elemental mercury vapour from dental amalgam is absorbed through breathing. Laboratory tests have shown that a person with dental amalgam receives 10 times more mercury exposure compared to a person without it.

A review published in British Medical Journal described an indicative incident, involving a nine-year-old boy, of subtle exposure to mercury. One fine day the boy began complaining of restlessness following a visit to the local hospital. His mother deemed it to be nothing more than a sign of hyperactivity and regarded his behaviour as normal in some ways. The boy's handwriting and schoolwork showed remarkable deterioration. An inquiry revealed that the boy's sibling had undergone a renal transplantation and the family had been provided with a mercury sphygmomanometer for monitoring blood pressure at home. The boy had dismantled the sphygmomanometer in his bedroom, spilling mercury on his bed and carpet. He even played with it for a day or two before informing his mother.

Substitution and management

Accuracy of alternatives

Many doctors and nurses believe that mercury is the "gold standard," by which thermometers, sphygmomanometers and other devices should be compared. However, a ream of scientific studies have demonstrated that mercury free measuring devices provide the same level of accuracy as the mercury devices they replace, provided they are properly maintained and calibrated. Furthermore, a variety of studies have highlighted inaccurate measurements from mercury devices resulting from lack of maintenance and calibration.

A mercury containing measurement device does not ensure accurate measurement. As the American Heart Association recognised with blood pressure measurement: no matter what type of blood pressure measurement device is used both aneroid and mercury sphygmomanometers must be checked regularly in order to avoid errors in blood pressure measurement and consequently the diagnosis and treatment of hypertension.

In an ideal world, considerations for selecting sphygmomanometers include purchase price, ease of use, accuracy, reliability, maintenance requirements, and health/environmental impact. The following links to the Sustainable Hospitals website of the Lowell Center for Sustainable Production in the United States provide ample documentation on the accuracy of alternative sphygmomanometers and thermometers.

Affordability and availability of alternatives

picture of conventional thermometerIn industrialised countries today, cost-effective alternatives exist for virtually every mercury-containing product used in the health care setting. In the developing world, the demand for alternative products such as digital thermometers and aneroid sphygmomanometers is just beginning to emerge, as is the supply, via both emerging national or regional industries in places such as India, East Asia and South America, as well as from European and US companies seeking markets in the developing world.

Currently both China and India produce large quantities of inexpensive mercury thermometers and other devices. However, even with these low priced products flooding the market, when the rate of breakage of a mercury thermometers in a hospital setting is compared with the longevity of the digital alternative, costs turn out to be similar.

Hospitals and health care systems in developing countries can help build the demand for alternatives by pledging to go mercury free and creating mercury-free purchasing policies. Meanwhile national industries can begin to produce the supply. National governments can implement regulation and standards to ensure only quality medical devices are available for sale. National and global regulation of the trade in mercury-containing healthcare devices, based on health and environmental imperatives, can also help stem the flood of cheap, mercury-based products and create the market for affordable alternatives.

Disposal of obsolete or broken mercury containing medical devices

Perhaps the biggest challenge to communities in some developing countries is the lack of infrastructure to collect and manage mercury containing wastes. Most industrialised countries have been able to develop policies, regulations and infrastructure to prevent mercury and mercury containing devices from entering the environment through solid waste and wastewater. Though often ineffective, this mercury is typically expected to be collected, and recycled into new products.

As mercury product bans are increasingly passed into law, there will be added pressure within industrialised countries to export the remaining mercury supplies, whether in new or used products, to the global south. This will likely add further challenges to mercury reduction initiatives in the developing countries and suggests the need for controls on trade, including export and import bans. In the long term, strategies for permanent global solutions to mercury waste are essential.

As an alternative or supplemental approach, interested countries or systems can develop engineered strategies which prevent mercury from entering the waste stream and/or the environment. These strategies do not need to be expensive or require advanced technology.

For example, a healthcare facility or Ministry of Health might develop a program which includes simple onsite storage of mercury containing wastes in sealed steel drums. These drums would likely need to be secured to prevent theft of vandalism, and placed on concrete pads in the event of a spill. Such low-tech solutions are used in industrialized countries as well. For instance, the US Department of Defense maintains a supply of elemental mercury in a similar fashion.

In July 2004, Toxics Link brought out the first comprehensive report on mercury usage in healthcare sector. Titled,‘Lurking Menace- Mercury in the health-care sector’, the report was based on a study of Delhi hospitals and dentists. It generated a lot of interest among the government as well as environmentalist. There were number of parliament queries based on the report. Some major hospitals in Delhi, St. Stephens’ Hospital Sir Gangaram Hospital Max Devki Devi and Holy Family, decided to phase out mercury and have placed mercury management policy on their facilities. But much more needs to be done on a much larger scale as we are fast losing time, lives and environmental safety.


Health Care Without Harm

Comparing Aneroid and Mecury Sphygmomanometers

Selecting non-mercury thermometers and accuracy

Five Steps to Becoming Mercury Free!

Toxics Link