Mercury is an element that has many uses and which becomes a toxic pollutant in a variety of ways. Methylmercury, the form mercury often takes in the environment, is toxic to human nervous systems and immune systems and creates a risk for hypertension and renal damage. Animal studies, including non-human primates, have found reproductive problems including decreased conception rates, early fetal loss, and stillbirths (Burbacher et al., 1988). Based on human exposures, there is suggestive evidence of a negative effect on human fertility (National Research Council, 2000). The largest contributors of mercury in our environment are the coal-fired power plants (in which naturally-occurring mercury is found in coal and released into the atmosphere when the coal is burned) and municipal and medical waste incinerators (when mercury-containing products are burned). Mercury contamination in the health care industry comes from the incineration of some of the products listed in the box below.

Mercury may exist in a number of different chemical forms but usually is released into the environment as a metal or an inorganic compound. When it is dispersed into the atmosphere, it can travel widely to all reaches of the earth, and when it lands on a body of water, it is converted by bacteria into methylmercury, an organic form that is highly toxic. Organic mercury is the most dangerous form of mercury because, like many environmental toxicants, it crosses into the brain and into the fetus so easily.

Mercury contamination of our waterways is now so severe that over 40 states have issued health advisories warning pregnant women or women of reproductive age to avoid or limit fish consumption. To find out about the specific fish advisories in your community, see www.epa.gov/ost/fish. A drop of mercury as small as 1/70 of a teaspoon can contaminate a 25-acre lake to the point that the fish will be unsafe to eat (Thompson and Erickson, 1999). Alarmingly, ten states have issued advisories for every lake and river within their state's borders.

According to the EPA, over 1 million women in the United States of childbearing age eat sufficient amounts of mercury-contaminated fish to risk damaging brain development in their children (NRC, 2000). The National Academy of Science report on methylmercury states that "over 60,000 newborns annually might be at risk for adverse neurodevelopmental effects from in utero exposure to MeHg [methylmercury]" based on consumption of mercury- contaminated fish (NRC, 2000).

Nurses need to understand the implications that the fish advisories have for their patients and communities and the contribution that the health sector has in creating this health risk.

FDA's Fish Advisory CONSUMER ADVISORY Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration March 2001 AN IMPORTANT MESSAGE FOR PREGNANT WOMEN AND WOMEN OF CHILDBEARING AGE WHO MAY BECOME PREGNANT ABOUT THE RISKS OF MERCURY IN FISH Seafood can be an important part of a balanced diet for pregnant women. It is a good source of high quality protein and other nutrients and is low in fat. However, some fish contain high levels of a form of mercury called methylmercury that can harm an unborn child's developing nervous system if eaten regularly. By being informed about methylmercury and knowing the kinds of fish that are safe to eat, you can prevent any harm to your unborn child and still enjoy the health benefits of eating seafood. HOW DOES MERCURY GET INTO FISH? Mercury occurs naturally in the environment and it can also be released into the air through industrial pollution. Mercury falls from the air and can get into surface water, accumulating in streams and oceans. Bacteria in the water cause chemical changes that transform mercury into methylmercury that can be toxic. Fish absorb methylmercury from water as they feed on aquatic organisms. HOW CAN I AVOID LEVELS OF MERCURY THAT COULD HARM MY UNBORN CHILD? Nearly all fish contain trace amounts of methylmercury which are not harmful to humans. However, long-lived, larger fish that feed on other fish accumulate the highest levels of methylmercury and pose the greatest risk to people who eat them regularly. You can protect your unborn child by not eating these large fish that can contain high levels of methylmercury: Shark, Swordfish, King mackerel and Tilefish. While it is true that the primary danger from methylmercury in fish is to the developing nervous system of the unborn child, it is prudent for nursing mothers and young children not to eat these fish as well. IS IT ALL RIGHT TO EAT OTHER FISH? Yes. As long as you select a variety of other kinds of fish while you are pregnant or may become pregnant, you can safely enjoy eating them as part of a healthful diet. You can safely eat 12 ounces per week of cooked fish . A typical serving size of fish is from 3 to 6 ounces. Of course, if your serving sizes are smaller, you can eat fish more frequently. You can choose shellfish, canned fish, smaller ocean fish or farm-raised fish--just pick a variety of different species. WHAT IF I EAT MORE THAN 12 OUNCES OF FISH A WEEK? There is no harm in eating more than 12 ounces of fish in one week as long as you don't do it on a regular basis. One week's consumption does not change the level of methylmercury in the body much at all. If you eat a lot of fish one week, you can cut back the next week or two and be just fine. Just make sure you average 12 ounces of fish a week. Some kinds of fish are known to have much lower than average levels of methylmercury and can be safely eaten more frequently and in larger amounts. Contact your federal, state, or local health department or other appropriate food safety authority for specific consumption recommendations about fish caught or sold in your local area. WHAT ABOUT THE FISH CAUGHT BY MY FAMILY OR FRIENDS IN FRESH WATER LAKES AND STREAMS? ARE THEY SAFE TO EAT? There can be a risk of contamination from mercury in fresh waters from either natural or industrial causes that would make the fish unsafe for you or your family to eat. The Environmental Protection Agency provides current advice on fish consumption from fresh water lakes and streams. Also check with your state or local health department to see if there are special advisories on fish caught from waters in your local area. For information about the risks of Mercury in Seafood, call toll-free 1 (888) SAFEFOOD U. S. Food and Drug Administration Center for Food Safety and Applied Nutrition Food Information Line 24 hours a day Or Visit FDA's Food Safety Website www.cfsan.fda.gov FURTHER INFORMATION IS ALSO AVAILABLE: Environmental Protection Agency www.epa.gov/ost/fish

Methylmercury bioaccumulates in the food chain, magnifying in dose as it goes up the food chain to larger and larger species. Humans typically eat fish that are high on the aquatic food chain, resulting in high mercury contamination. "There are extensive data on the effects of MeHg [methylmercury] on the development of the brain (neurodevelopmental effects) in humans and animals" (NRC, 2000). Through two tragic environmental exposures in human populations, we have first-hand knowledge of both the acute and chronic effects of methyl-mercury poisoning.

In the 1950s, in Japan, Minamata Bay was severely contaminated with mercury from an industrial plant. Although the women in the area showed no symptoms, the children born to the women developed a heartrending array of developmental symptoms including mental retardation, disturbances of gait, speech, sucking and swallowing, and abnormal reflexes (Harada, 1978). In another instance, in Iraq in the 1970s, where bread was baked with grain that had been sprayed with organic mercury as a pesticide to treat fungus, acute symptoms included visual disturbances, with blindness in several instances. The effect on children born to poisoned mothers was psychomotor retardation with delays in walking and increased incidence of seizures (Amin-Zaki, 1976).

When there is a mercury spill in a hospital room, the indoor air can become contaminated. "If mercury is inhaled, as much as 80% of the inhaled mercury may be absorbed into the blood stream, thus creating the following:

• Short-term exposures can cause poisoning, pneumonitis, bronchitis, and bronchiolitis.
• Repeated exposure to relatively low toxic levels can cause muscle tremor, irritability, personality changes, and gingivitis.
• Nerve damage from mercury may start as a simple loss of sensitivity in hands and feet, difficulty in walking, or slurred speech.
• Mercury has also been known to affect the development of prenatal life and infants." (Shaner, 1997)

When a mercury thermometer breaks, it is difficult and very expensive to clean up properly. If mercury spills from a thermometer and is not cleaned up, it will all eventually evaporate, potentially reaching dangerous levels in indoor air. A single broken fever thermometer containing 0.5 to 1.5 grams of mercury is enough to create a health risk when it evaporates into a small, poorly ventilated room ("How to Plan and Hold a Mercury Thermometer Exchange," Health Care Without Harm, 1999). Mercury clean-ups can be extremely expensive. If a carpet is affected, it must be removed, disposed of as hazardous waste, and a new carpet laid, creating clean-up costs in the thousands of dollars.

Given the highly accurate, non-mercury thermometer choices that are on the market, all health care institutions should be selecting non-mercury alternatives. Several hospitals have made great strides in mercury reduction, becoming virtually mercury-free in all of their medical equipment.

Saint Mary's Duluth Clinic

Saint Mary's Duluth Clinic in Minnesota is a small hospital that has made large reductions in its mercury use. The clinic instituted a mercury-free purchasing program in 1991 after participating in an educational seminar on the link between mercury use and pollution in Minnesota's lakes and streams. Saint Mary's stopped purchasing mercury thermometers and blood pressure units in the first year of their program and has since nearly eliminated mercury batteries, rubber cantor tubes, and mercury fixatives. In addition, the clinic has started an aggressive fluorescent light recycling program and has stopped sending mercury thermometers home with patients (this is now Minnesota law).

(Case Study from Protecting by Degrees: What Hospitals Can Do To Reduce Mercury Pollution by Environmental Working Group, 1999)

Actions

• Hold a mercury thermometer exchange
• Provide annual mercury training/spill/labeling program
• End the purchase of new mercury-containing equipment and implement a mercury-free purchasing policy for vendors that includes reagents and other background uses of mercury
• Create a replacement plan and budget for elimination of mercury-containing equipment
• Collect all wastes from processes involving the fixative B5 and designate a team to investigate the use of mercury-free alternatives
• Set up a fluorescent bulb (and other mercury containing bulb) recycling program
• Establish a battery collection program
• Develop a waste trap cleaning/replacement plan
• Implement a labeling and replacement plan for other mercury-containing devices (mechanical equipment).

In several cities around the country, nurses and others have organized mercury thermometer exchanges in their communities. In Washington, DC, the DC Hospital Association along with the local Health Care Without Harm Campaign and the City Health Department, supported by the city firehouses, did a city-wide mercury thermometer exchange whereby people brought their mercury thermometers to local firehouses and were given mercury-free thermometers. Health Care Without Harm has created a very helpful guide to implementing an exchange--see www.noharm.org to download the pamphlet "How to Plan and Hold a Mercury Thermometer Exchange." A community exchange program, in combination with elimination of all mercury-containing medical equipment, can make a significant impact on reducing mercury contamination in our rivers and lakes, which will translate to healthy people.

Don't send mercury thermometers home with new moms!

In a recent study, Carpi and Chen found that 10% of the homes they evaluated had indoor air levels of mercury exceeding the EPA's reference concentration (300ng/m3) due to historic accidents with mercury-containing devices. Exposure to mercury via indoor air is seen as second only to fish consumption as a source of mercury in the general population (Carpi & Chen, 2001).

DEHP

The chemical compound DEHP, Di(2-ethylhexyl)phthalate, is contained in many of the common plastic products found in health care settings. It is in a category of toxic chemicals known as pthalates, which are commonly added to polyvinyl chloride (PVC) plastic to make the plastic product flexible and strong. It allows the otherwise stiff PVC to be molded into a variety of products such as IV tubing, IV bags, and feeding tubes. By weight, DEHP comprise 20-40% of the PVC products on average. There is new evidence regarding the human toxicity associated with exposure to DEHP that should help to inform our product selection in the health care setting.

"DEHP does not bind with plastic, so it can leak out of PVC medical products during medical procedures, or when PVC objects such as toys are chewed. Everyone is exposed to DEHP through off-gassing from vinyl products in the home and workplace, as well as from industrial emissions. However, some infants and especially pre-term neonates are receiving, in some cases, megadoses of DEHP. Neonatal nurses should know what they can do to protect their tiny patients from the potentially harmful effect of DEHP. The multiple and relatively high exposures that may occur in neonatal intensive care units (NICUs) are significant. Many of these babies are exposed during blood and other intravenous infusions, respiratory therapy, enteral feedings and extra corporeal membrane oxygenation (ECMO)" (quote from Ann Melamed in The American Nurse, December 2000, online at www.nursingworld.org/tan/novdec00/pollutio.htm).

The National Toxicology Program's Expert Panel who reviewed DEHP studies only looked at reproductive and developmental effects. Based on animal studies, there are concerns that there may also be effects on the liver, kidneys, and lungs, as well as effects on heart rate and blood pressure. (See insert "Relevant Animal Studies" for review of animal study results.) Nonetheless, the Expert Panel noted the following:

So how does the chemical DEHP create a risk to humans when it is in PVC medical devices? When it is in PVC, it is not actually bound chemically. It can therefore escape the PVC product under certain conditions such as when the product is heated, or when the medical device contacts fluids--such as the fluids that would be in an IV or blood bag. DEHP migrates into a variety of fluids including blood, plasma, and total parenteral and enteral nutrition solutions. During medical interventions that require long-term IV interaction such as hemodialysis or ECMO, DEHP exposure is significantly enhanced. Pediatric exposures are of the greatest concern. Sick newborns and infants face the greatest risk of exposure from medical interventions and may also be the most vulnerable to the toxic effects of DEHP because of their stage in human development.

During critical stages of development, pre-term babies, and neonates may be exposed to DEHP, a reproductive and developmental toxicant. This occurs because of the ubiquitous presence of DEHP in their environment. The multiple and relatively high exposures that can occur in the NICU are potentially at or in excess of levels known to cause adverse health effects in relevant animal studies.

In fact, a recent study finds that infants in NICUs who are treated with DEHP-containing products have high levels of MEHP (a DEHP metabolite) in their bodies and investigators have directly linked MEHP excreted in urine with the use of DEHP-containing products in the patients’ treatment. (Hu et al 2005).

"Since DEHP releases to vinyl products are not easily controlled, prevention should be the primary management option" (Rossi, 2000). To ensure that our patients are not exposed to DEHP, we will have to demand DEHP-free health care products, particularly in those settings where our smallest and most vulnerable patients are cared for. Using PVC-free products virtually assures that the product will be DEHP-free because the other plastics rarely add DEHP. "In addition, PVC-free products avoid the lifecycle hazards of vinyl, including the use of a known carcinogen to manufacture vinyl (vinyl chloride monomer) and the downstream formation of dioxin when vinyl is burned in a medical waste incinerator" (Rossi, 2000); Thornton et al., 1996; Wagner and Green, 1993).

PVC is the most widely used plastic in medical products. It accounted for 27% of all plastic used in durable and disposable medical products in the United States in 1996 (Schettler et al., 2000). Approximately 445 million pounds of PVC were consumed in the manufacture of intravenous (IV) and blood bags, tubing, examination gloves, medical trays, catheters, and testing and diagnostic equipment in 1996. Tubing, IV and blood bags, and gloves are the primary end- uses for PVC in disposable medical products. Both patients' health and safety, as well as the public's health, are of concern regarding PVC.

In January 2002, the Health Canada Expert Advisory Panel recommended that health care providers not use DEHP- containing devices in the treatment of pregnant women, breastfeeding mothers, infants, males before puberty, and patients undergoing cardiac bypass, hemodialysis, or heart transplant surgery. They recommended the alternative measures be introduced "as quickly as possible."

Actions

Elimination of DEHP exposure can occur when DEHP-free products are selected.

The Sustainable Hospitals Program at the University of Massachusetts, Lowell, can be an invaluable resource to assist you in selecting alternatives. They have been researching and evaluating hospital products and have created a list of DEHP-free alternatives for a vast array of products. They provide the product type and the manufacturer information, including phone numbers and Web sites. See its Web site: www.sustainablehospitals.org for product information regarding DEHP (as well as mercury-free choices, latex alternatives, safer needle devices, and other extremely useful information).

Dioxins

Dioxins are a family of highly toxic chemicals that are in our environment--in our air, water, soil, and food supply, as well as in our bodies. Dioxins are not intentionally produced, but rather are by-products of combustion and industrial processes, including the manufacture of chlorinated chemicals, the bleaching of paper products, and the incineration of waste (municipal, hazardous, and hospital waste). Dioxins are one of a grouping of toxic pollutants that are persistent in our environment, as well as in the human body. Once they get into the environment and into our bodies, they do not quickly biodegrade into something less toxic, and they have extremely slow natural paths for removal or excretion. They are believed to have a half-life of seven to twelve years in the human body (Wolfe et al., 1995).

Dioxin bioaccumulates in such a manner that it biomagnifies up the food chain. Contamination in the food chain begins with dioxin particles in water or soil and then proceeds up the food chain through fish and livestock, ultimately reaching human tissues through the food we eat. It becomes increasingly concentrated in living tissues as it moves up the food chain (Oris, 2000).

Approximately 90% of human exposure to dioxin comes from food, specifically in the form of beef, fish, and dairy products. According to the EPA, beef and dairy products remain among the leading sources of dioxin exposure to adults. In 1998, Consumer Reports assayed the dioxin content in a dozen brands of baby food jars of meat. They projected that "a baby who ate one jar--just 2.5 ounces--of an average meat-based baby food on a given day would consume around 100 times the EPA's daily limit of dioxins. No brand was significantly more contaminated than another" (Consumer Reports, 1998). When dioxin is consumed by humans, it is stored in the fatty tissue--it is lipophilic. Human babies who are breastfed can receive 10% of their lifetime exposure to dioxin from their mother's fat-laden milk. As nurses, we should continue to advocate that women breast feed, as we concurrently advocate for policies and practices that will decrease the dioxin levels in our environment.

Studies of humans occupationally exposed have shown dioxins to be associated with cancer of the lung, thyroid gland, hematopoietic system, and liver, as well as connective and soft tissue sarcoma (Thornton et al., 1996). According to the EPA draft report on dioxin's health effects, the levels of dioxin-like compounds found in the general population may cause a lifetime cancer risk as high as one in 1,000. This is 1,000 times higher than the generally "acceptable" risk of one in a million. For the most recent EPA statements on dioxin, see the draft reassessment report, http:/cfpub.epa.gov/ncea/cfm/dioxreass.cfm?ActType=default.

In addition to dioxin's carcinogenicity status, it is also a known endocrine disruptor, a chemical that mimics or otherwise disrupts normal hormone activity. Endocrine disruption can occur at extremely small doses of exposure. Theo Colborn, in her 1996 book "Our Stolen Future," describes the amassing research on endocrine-disrupting chemicals in our air and water and their effects in nature and on human health. While early discussions of endocrine-disrupting chemicals focused on estrogenic effect of environmental contaminants, more recent research extends concerns to anti- estrogens, androgens, or anti-androgens, as well as thyroid hormone, cortisone, and others (McLachlan, 1985). Animal studies confirm a wide range of reproductive and developmental effects of dioxin in different species, some occurring at very low exposure levels. They include changes in hormone levels, fertility, sexual behavior, litter size, ability to carry pregnancy to term, birth defects, learning disabilities, and endometriosis. A potential connection existing between exposure to dioxin and endometriosis is based on primate studies wherein dioxin exposure increased the incidence and severity of endometrosis in monkeys and in rodent populations (Birnbaum and Cummings, 2002).

"Human studies designed to examine reproductive or developmental effect of dioxin exposure have produced mixed results. The studies are often limited by inadequate exposure information, incomplete recognition of health outcomes, or low power to detect rare events, and they virtually always lack an unexposed control population. Nevertheless, there is now sufficient evidence to conclude that dioxin is probably a cause of some birth defects. There is also evidence that testosterone levels are depressed in occupationally-exposed workers, and thyroid hormone is depressed in infants exposed at ambient levels through breast feeding." (Schettler et al, 2000)

The EPA has been in a multidecade-long process to assess (and reassess) the health risks of dioxin. The discussions and debates are often as influenced by economics and politics as they are by science. Dioxin is one of the 12 chemicals covered by the United Nation's Stockholm Convention on Persistent Organic Pollutants (POPs), which the United States signed in May, 2001. This Convention calls for the reduction of industrial dioxin releases, including those from medical waste incinerators.

Action

In the health care industry, dioxin is primarily a product of waste incineration. Therefore, the prime action is to discontinue the incineration of hospital waste and choose non-incineration alternatives. During the manufacture of (PVC) plastics, dioxins are created, as they are when incinerated. Therefore limiting the use of plastics is recommended:

• Eliminate plastic utensils and replace them with stainless steel.
• Eliminate plastic covered "chux" and replace them with washable, cotton p ads.
• Request that products have only essential packaging, thereby reducing redundant plastic packaging.

Incineration

During the combustion process of incineration, new chemical compounds can be created. It is during this process that dangerous dioxins are unintentionally created. Dioxins, which are chlorine compounds, are created during combustion in the presence of chlorinated waste such as bleached white paper and polyvinyl chloride plastic. The EPA has identified medical waste incineration as the third largest source of dioxin air emissions and as the contributor of about 10% of the mercury from human activity (US EPA, 1997).

Plastics comprise roughly 15—30% of the medical waste stream, roughly twice as much as is found in municipal waste streams. Polyvinyl chloride plastic ( PVC) is approximately 50% chlorine by weight. Paper and cardboard comprise 45—50%, food waste 10%, glass 7%, wood 3%, metals 10%, and other materials approximately 10% (Shaner, 1993).

Actions

Careful waste segregation provides an opportunity to select the most environmentally safe disposal for each category of waste. Nurses can play a pivotal role in the process of identifying opportunities for improving waste segregation, including decisions about products for reuse, recycling, and the safest methods of disposal.

Stephanie Davis (ScD18@WasteReductionRemedies.com), a waste management specialist, has created a ten-item set of guidelines for systematically reducing regulated medical waste; available in Going Green: A Resource Kit for Pollution Prevention in Health Care: www.noharm.org.

There are a variety of alternatives to incineration for the treatment of waste. Although each of them has its own pros and cons, none creates the same level of environmentally unhealthy consequences as incineration. The alternatives include autoclave/steam sterilization, microwave, and chemical disinfection. When any of these methods are chosen, the treated waste is then placed in a landfill. An extensive and technical discussion on alternatives to incineration can be found in the report, "Non-Incineration Medical Waste Treatment Technologies: A Resource for Hospital Administrators, Facilities Managers, Health Care Professionals, Environmental Advocates, and Community Members" (2001) found on the Web site: www.noharm.org/library/docs/Non-Incineration_Medical_Waste_Treatment_Techn.pdf

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