Heavy Metals: A Centuries-Old Story Centuries-Old Story

Erika Schreder has worked for the Washington Toxics Coalition as a staff scientist since 1997. She has a Master’s Degree in resource ecology and management and a B.S. in molecular biology. She currently directs the Clean Water for Salmon campaign, which aims to end pesticide uses that pollute water and threaten salmon.

Editor’s Note: Whatcom Watch will publish most of the 64-page report “Pollution in People” released in May by the Toxic-Free Legacy Coalition. The entire report is available as a pdf file at http://www.pollutioninpeople.org.

Part 4

Since 1970, when he coordinated the first Earth Day, Denis Hayes has been dedicated to making our planet a healthy place. Raised in Camas, Washington, marked by the grandeur of the Columbia River and the pollution of a major pulp mill, he grew up with an appreciation for nature and an understanding of how humans can degrade it. Today, Denis is the chair of the International Earth Day Network; he also presides over the conservation-minded Bullitt Foundation, and in various posts has spent decades promoting renewable energy sources around the world. His accolades are impressive: he’s been named a “Hero of the Planet” by Time magazine, awarded the Sierra Club’s John Muir Award and dubbed one of the 20th century’s environmental heroes by the National Audubon Society.

Although he recently began sporting a buzz cut to please his wife, Denis generously donated enough hair for the Pollution in People study to discover that he has accumulated a significant amount of mercury in his body — in fact, the highest level in our group. At 2,020 ppb, his hair mercury level is more than three times the median for his age and gender (Environmental Quality Institute 2005).1 Most likely his high level results from his fish-rich diet, not uncommon in the Pacific Northwest.

The chart on the facing page shows our study participants’ levels, which ranged from 59.5 to 2,020 ppb, with a median of 887 ppb. We also tested our participants for lead and arsenic. Four tested positive for arsenic; one, nurse Karen Bowman, tested positive for lead.2 Karen also had the second-highest mercury level, and the highest among the study’s women. Her level of 1,880 ppb puts her above EPA’s reference dose, or “safe” level, for women of childbearing age (1,100 ppb) (NAS 2000). The National Academy of Sciences has concluded that exposures above this level may harm neurological development in the developing fetus. Bill Finkbeiner’s mercury also exceeded the safe level, and Lisa Brown’s mercury, at 1,080 ppb, is just below the benchmark. For centuries, humans have known that heavy metals such as mercury, lead and arsenic can seriously harm our health. Lead’s effects on the brain were noted as early as the second century B.C.E., and arsenic has been notorious as a poison since the Middle Ages. The ancient Romans noted mercury’s harmful effects when slaves mined the metal in Spain. The Incas used mercury to extract gold in the 1500s, and despite a well-developed reputation for harming the brain and causing birth defects, mercury continues to be used in mining, in addition to other industries and consumer products. Mercury, lead and arsenic are naturally occurring elements, but our bodies don’t need them in any way. And at very low levels, all three can be toxic.

Today, mercury is found in electrical fixtures, switches, medical equipment and amalgam fillings; the metal is also used in battery, chemical and paper production, and, in many countries, gold extraction (Gilbert 2004). In Washington, mercury is emitted by the coal-burning power plant in Centralia, and by manufacturers, oil refineries, medical waste disposal facilities, dental offices and cremation facilities (Ecology 2003). The largest amount of Washington’s environmental mercury from in-state sources likely comes from the combustion of diesel, jet fuel and heating oil. Mercury from these sources often circulates in the atmosphere and deposits on land and water, where it increases in concentration as it moves up the food chain.

Bacteria in water convert mercury to toxic organic mercury, which builds up in fish. When we eat fish — particularly long-lived fish that have accumulated mercury from a lifetime of eating other fish — the mercury tags along and settles in our bodies. The Washington State Department of Health has issued warnings about eating fish from Lake Whatcom, Lake Roosevelt, Sinclair Inlet, the Duwamish River and Eagle Harbor because of mercury contamination (WDOH 2006). The department has also warned women of childbearing age and children under six not to eat any shark, swordfish, tilefish, king mackerel or tuna steaks (WDOH 2001).

More so than mercury, lead turns up in a frighteningly large array of consumer products, from art supplies and automobile components to PVC clothing, building materials, toys, lunchboxes and even candy. Gasoline and paint are now lead-free in the United States and many other countries, but lead continues to be added to certain hair dyes and specialty paints (FDA 2002). And despite a 1978 ban, lead paint on the walls of old homes and buildings continues to be a primary source of lead exposure for children. Because of its slightly sweet taste, children commonly eat peeling lead-paint chips if they have access to them.

Most of us are exposed to lead through direct contact with lead-containing products, drinking lead-contaminated water, and through house dust into which lead from indoor and outdoor sources has settled. In certain areas and homes, contaminated soil and dust from lead paint are a significant source, particularly for children. Two of Washington’s now-shuttered smelters (facilities that process metals) emitted lead that deposited in soil. Soils are also contaminated by past use of the pesticide lead arsenate in orchards. Lead then enters our homes when we track it in on the bottom of our shoes.

Lead in the workplace can cause elevated levels both in the worker and in the worker’s family members (MMWR 2001). Workers can bring lead home on clothing and shoes. In our study, because the test was only sensitive enough to pick up relatively high levels, the only participant who tested positive was nurse Karen Bowman. Karen has regular occupational exposure through her nursing visits to workplaces such as machine shops and metal fabricating companies.

Arsenic-treated wood is a fixture in many of our homes, where it has commonly been used to construct tough, long-lasting decks, fences and play structures. But arsenic leaches from treated lumber and rubs off the wood when people or animals come in contact with it.

In 2002, after various risk assessments indicated elevated childhood cancer risk from arsenic exposure, EPA reached an agreement with manufacturers to phase out the use of arsenic for residential wood treatment. However, many homes still have arsenic-treated wood in place, as well as soil contaminated from this lumber. As with lead, Washington’s soils are tainted in many areas with arsenic from smelters and pesticides. Arsenic continues to be used in other products, too, including paints, dyes, metals, soaps and drugs (USEPA 2005). Other major sources of arsenic, depending on diet and location, are drinking water and seafood. While seafood may contain large amounts of arsenic, most of its arsenic is believed to be in the less-toxic inorganic form. The test in our study analyzed for the toxic, inorganic form found in drinking water and other sources.

Lead, mercury and arsenic may occur naturally in the earth, but just because they’re natural doesn’t mean they’re harmless. And because we have found such countless uses for these metals throughout the ages, today’s children, adults and wildlife must contend with their effects on health.

Like many other chemicals, lead and mercury exact their most devastating toll on the developing brain. Children exposed to lead at a young age are more likely to suffer from shorter attention spans and are less able to read and learn than their peers (Gilbert 2004). A recent analysis of multiple studies by scientists at the Cincinnati Children’s Hospital found that lead has a significant effect on brain development at blood levels below 10 µg/dL, the current level at which public health agencies take action. In fact, they found no level that did not have an impact on intellect as measured by a decrease in IQ scores (Lanphear 2005).

Research on mercury shows similar effects. Mass poisoning episodes, like that in Japan’s Minamata Bay community in the 1950s, have proven that mercury can cause birth defects including mental retardation and deformed limbs, and studies on children with above-average mercury exposures show that the metal can affect their ability to learn. In a study published in 2005, Harvard Medical School researchers tested mercury in new mothers’ hair at the time of childbirth and found that infants exposed to less mercury in the womb scored better in intellectual tests (Oken 2005). Arsenic may also affect the developing brain: a recent study found that children with greater exposure to arsenic had deficits in intelligence compared to their less-exposed peers (Wasserman 2004).

Lead, mercury and arsenic do not stop at harming the developing brain. Their health effects have been well studied, and are summarized in the table on the next page. It should be noted that many of these effects occur only at relatively high exposure levels.

Heavy metals have a long history of industrial and personal use — and just as long a history of harming human health. People have only relatively recently begun to take action to curtail their use. Decades of evidence on lead’s health effects were amassed before the metal was banned in paint and gasoline, and lead is still allowed in many consumer products. Arsenic-treated wood was extremely widely used before manufacturers agreed to phase it out. Recently, a number of states, including Washington and Oregon, have passed legislation to address mercury use in products such as thermometers and thermostats, but major sources like coal burning continue.

Local advocacy and legislation have made a difference in reducing continued pollution with these metals. In 2005, an independent consumer watchdog group found high levels of lead in children’s soft vinyl lunchboxes. In response to a request by the Washington Toxics Coalition, the Washington State Department of Ecology took action in late 2005 to prevent the sale of such lunchboxes in the state.

King County has had tremendous success in reducing mercury pollution from dental offices by cracking down on dentists to keep mercury out of their wastewater. Mercury in dental offices comes from amalgam fillings, which are about half mercury by weight. State law requires dentists to use devices called separators, which remove mercury from wastewater, but compliance in the past has been poor. By conducting inspections and threatening fines, King County was able to achieve 97 percent compliance and a 50 percent reduction in mercury in wastewater between 2000 and 2003 (King County 2005).

The following actions would reduce ongoing exposure to these toxic heavy metals:

•Lead, mercury and arsenic should be phased out of products.

•Coal burning should be replaced with conservation and cleaner sources of fuel for energy production. In the meantime, existing coal-fired power plants should be required to install the best technology to limit mercury emissions.

•Contaminated sites should be cleaned up promptly and fully. Where a large geographic area is contaminated, state government should take measures to ensure facilities such as schools and daycare centers are not sited on contaminated soil.

•Solid-waste and medical-waste incinerators should be shut down and replaced with waste and toxicity reduction, reuse, recycling and composting programs.

•Health care facilities, including hospitals and dental offices, should phase out mercury-containing products in favor of safer alternatives.

•Government agencies should expand programs to remove, collect and safely store mercury from thermostats, thermometers and switches.

School districts should take remedial action to eliminate lead exposure to children from school drinking water.

We come into contact with lead, mercury and arsenic in many aspects of our lives, but there are some steps we can take to reduce our exposure.

Remove Treated Wood. Remove wood treated with the preservatives CCA or ACZA, which contain arsenic. If removing arsenic-treated wood is not an option, you can paint or seal the wood to reduce leaching and contact exposure. Choose semi-transparent deck stains for deck surfaces and play structures, and latex paint for fences, tables and other furniture. Reapply the coating when it shows signs of deterioration.

Avoid Fish High in Mercury. Avoid fish high in mercury, such as king mackerel, tilefish, swordfish, orange roughy and marlin. Limit consumption of tuna, especially steaks and canned ‘white’ albacore. Lower-mercury choices include wild salmon, sardines, anchovies, Atlantic herring, Dungeness crab, Pacific cod, Alaskan black cod, farmed striped bass, tilapia, farmed catfish, clams, mussels and Pacific oysters. If you eat sport-caught fish, check the Department of Health’s fish advisories for specific guidance on Washington waterbodies or coastal waters. Fish and shellfish consumption advisories are available at htp://www.doh.wa.gov/ehp/oehas/EHA_fish_adv.htm.

You can find additional guidance on fish choices at the following Web sites:

•Environmental Defense’s Oceans Alive: Best and Worst Seafood: http://www.oceansalive.org/eat.cfm

•Environmental Working Group: Mercury in Seafood (includes Tuna Calculator): http://www.ewg.org/issues/mercury/index.php

Fish are an excellent source of nutrients, including protein, omega-3 fatty acids, and vitamin D, and we encourage people to continue eating fish while observing the following precautions. Limiting mercury intake from fish is especially important for young children and women who are pregnant, nursing, or of childbearing age.

Watch for Lead Paint. If you live in a home built before 1978, it is likely to contain lead-based paint. If the paint is chipping, peeling or otherwise deteriorating, or if you want to remodel, hire a certified abatement worker to remove or contain contaminated paint. Also, use doormats, remove shoes at the door, and vacuum and clean regularly to reduce lead that accumulates in house dust.

Protect Drinking Water. Flush your cold water pipes (run water until it becomes as cold as it will get) before drinking, and only use cold water for drinking or cooking, to reduce exposure to lead that may be leaching from plumbing.

Avoid PVC. Choose alternatives to products made of PVC, which often contain lead. This is especially important for items that are likely to come into direct contact with children’s hands and mouths, such as toys, teethers and lunchboxes. Also, check to make sure that you don’t own children’s products that have been recalled due to high levels of lead. Old toys and furniture made prior to 1978 may contain lead-based paint. For consumer product safety information, visit the Consumer Product Safety Commission’s Web site at http://www.cpsc.gov.

Watch for Lead in Dishware. Do not use old, imported or homemade ceramic dishware, unless you know that the glazes do not contain lead. Avoid leaded crystal, as well as imported food cans, which can contain lead solder.

Make Sure Medicines Are Free of Toxic Metals. Some home remedies, as well as drugs and cosmetics, can contain these metals. Look at ingredient lists, talk to your doctor, and avoid folk remedies and other medicines that contain lead, arsenic or mercury.

Be Cautious With Mercury-containing Products. When possible, choose products without mercury, such as digital thermostats and thermometers. Be careful not to break fluorescent light bulbs, mercury thermometers or other household items that contain liquid mercury. These products release harmful mercury vapors when broken. If they do break, use appropriate cleanup methods, found at http://www.epa.gov/epaoswer/hazwaste/mercury/faq/spills.htm.

Check Paints and Art Supplies. Avoid paints containing mercury compounds, which were used in the past as fungicides and are still found in some paints as pigments. Also avoid lead solder and artists’ paints and glazes that contain lead. Information on some products containing these ingredients is available from the Household Products Database: http://www.householdproducts.nlm.nih.gov. Otherwise, ask the manufacturer.

Skip Herbicides With Arsenic. Avoid arsenic-containing herbicides, which have ingredients listed as monosodium methanearsonate (MSMA), calcium acid methanearsonate or cacodylic acid.

Consider Composite Fillings. Consider choosing composite dental fillings rather than mercury-containing amalgam fillings. §

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