Washington News

Staff at the Environmental Protection Agency have recommended tightening air quality standards for lead.

Today the Office of Air Quality Planning at the Environmental Protection Agency released a final staff paper, Human Exposure and Health Risk Assessment (see it here), and in it they recommend EPA tighten lead standards. The staff basically says that the evidence of lead's health effects, particularly on children, "clearly calls into question the adequacy of the current standard."

The lead standard was developed in 1978. That standard helped get the lead out of gasoline, a major step forward in environmental health policy. The use of lead as a gasoline additive started in the 1920s, and went into hyperdrive in the 1940s. In spite of the 1978 standard, lead wasn't completely removed from gas until 1996. But in the 18-year period in which it was being phased out, the Centers for Disease Control reported a 90% reduction in kids' blood-lead levels. That's good news—a 90% reduction—but it isn't zero, and when it comes to lead, that's the only safe number. As the EPA staff says, "Current health-effects evidence does not indicate a level of lead exposure below which adverse health effects may not occur." They also say, according to a large and fast-growing body scientific studies, that "adverse effects in young children occur at much lower blood-lead levels than was understood when the current standard was set in 1978."

What does the lead do? Well for one thing, lead has been shown in several studies published in the last couple of years to significantly reduce IQ, depending on the dose and the timing of the exposure (high maternal lead exposures in the first trimester of pregnancy, for example, tend to have greater impact than later in pregnancy, and exposures earlier in childhood have greater affect.) It is clearly associated with other mental health problems and behavioral disorders: lead is implicated in ADHD, for example. It is also associated with infertility problems, birth defects, high blood pressure, and renal failure to name just a few of the long list of health disorders and diseases.

The EPA staff paper recommends "appreciably lowering the level of the current primary standard for lead (the current standard is 1.5 micrograms per cubic meter (μg/m3)." A staff recommendation does not mean that the standard will be changed, but it should fuel a dialog that really needs to happen.

A Bit of Good News on the Mercury Front

Today I received an email from the staff at Oceana, the group whose report I referred to in the post about mercury releases from chlorine product. They were updating me with this bit of news: The Number One Source of Mercury Air Pollution in Wisconsin Commits to Switch. According to Oceana, this single action will result in a full 28% reduction in mercury air emissions in Wisconsin, nearly cutting the state’s emissions by a third.

I think this is evidence that open dialog and freely available information about the environmental health issues we face can result in change.

From a Utah Coal Mine, To Your Plate, Coal Is Dangerous Stuff

With the trapping of six miners in the collapse of Murray Energy’s Utah coal mine, we are again hearing about the hazards of mining for mine workers. My sympathies extend to the families of the trapped miners, but this incident highlights for me the need for us to move away from coal-fired energy production and into safer—and cleaner—alternatives.

Coal is not only hazardous to those working in the industry, but is also hazardous to all of us. For most of us, coal is unseen, and unthought about, yet in 2005, coal production in the United States peaked at over a billion tons, with almost 92% of it going to use in electrical generation plants. In fact, 1,522 coal-fired plants around the country supply almost half of the US demand for electricity. Some are small local operations, but most are monster facilities that eat pulverized coal dust like candy.

Mercury

Although each ton of coal the monster eats has but a trace of mercury in it, the total impact adds up: globally, burning coal for power and heat accounts for the greatest addition to the global mercury pool each year, and in the US, approximately a third of our annual contribution comes from our coal-fired power industry. When coal is burned in power plants, traces of mercury, which were captured millions of years ago when the coal was formed,are vaporized and released to the atmosphere.

The mercury released by coal burning, as well as mercury released in industrial processes, mining, and the burning of waste, joins the global mercury pool, making it available to the mercury cycle. And one in the mercury pool, it rains down on land and water, to be taken up by microorganisms, and then by higher organisms, including the fish we eat.

Dioxin

Then there’s also the problem of dioxin produced by burning coal. The term dioxin is actually a catch phrase used to denote several hundred chemicals that have similar chemical structure. Most dioxins fall into three main families—the CDDs, the CDFs, and the PCBs. The ‘C’ in all three acronyms stands for chlorine.

“Everybody in toxicology knows that if you add chlorine to something, you make it toxic,” says Suzanne Wuerthele, a career toxicologist with the Environmental Protection Agency in Denver.

CDDs and CDFs are mainly accidental chemical creations that come from (again) the burning of coal, the burning of municipal and medical waste, and certain industrial processes, while PCBs were manufactured and widely used in industrial transformers until they were banned in 1979. All three families of dioxins are found throughout the natural world, and in all individuals who have been tested by the CDC in quantities that are “at or near the level where effects of dioxin and related compounds, such as enzyme induction, changes in hormone levels, and indicators of altered cellular function, have been observed in laboratory animals and humans.” And, according to EPA’s analysis, potentially adverse effects are associated with exposure to dioxin in human populations at or near the background levels we now see in the environment. Like mercury, dioxin family members accumulate in fat, and work their way up the food chain.

Other Contaminants

Coal-fired plants also spew 59% of total U.S. sulfur dioxide pollution and 18% of total nitrous oxides every year, and release about 50% of our particulate pollution, as well as other toxics, such as arsenic and cadmium. Oh, yeah: They also release about 40% of total U.S. carbon dioxide emissions, a prime contributor to global warming.

When the nitrous oxides that they emit react with volatile organic compounds and sunlight, they form smog, or ground level ozone. Of the six major criteria air pollutants regulated by the EPA, nitrous oxide emissions have historically been the hardest to control, in part because emissions from dirty coal plants in one region can easily pollute areas hundreds of miles downwind. The American Lung Association estimates that almost half of Americans live in areas with unhealthy levels of smog. Just last week, the State of Delaware confirmed in cancer cluster near the Indian River Power Plant that regulators believe is connected to the plant.

Protecting yourself

So what can you do to protect yourself: First, you can reduce exposures by watching what you eat. Several fish species are known for having high levels of dioxins (particularly of the PCB family) as well as mercury. Meat and dairy products also contain elevated levels of dioins, so the best way to reduce you personal dioxin exposure is to reduce the amount of animal fats in your diet: drink low-fat or reduced-fat milk and eat leaner cuts when you select meat.

Also, encourage your state and federal elected officials to close loopholes that allow coal-burning plants to continue spewing noxious and dangerous emissions into our air. To learn more, go to Clear The Air. Check out their power plant locater to learn about dirty plants where you live.

Mercury levels in fish eaters

This week the New York Department of Health and Mental Hygiene issued a report on mercury levels in the city's population. Taken from the city's Health and Nutrition Examination Survey (HANES), the report found that "among women 20-49 years old in New York City, the average blood mercury level is 2.64 µg/L (micrograms per liter), three times that of similarly-aged women nationally (0.83 µg/L)," and "approximately one quarter of New York City women in this age group have a blood mercury level at or above 5 µg/L."

Another interesting fact from the HANES study: "Higher-income New Yorkers have higher mercury levels; New Yorkers in the highest income bracket average 3.6 µg/L, compared to 2.4 µg/L among the lowest income group."

We usually think that high-income people are healthier because they have access to better food and better health care. So why do high income New Yorkers have higher mercury levels? Because... they have access to better food. High-income people tend to eat more fish, and more expensive fish (can you say sushi?) and it is this fish that is contributing to higher levels of mercury in these women's blood.

I met Dr. Jane Hightower earlier this year at a conference. In the mid-to-late 1990s, Hightower, a thin, dark-haired woman with the intensity of a bloodhound following a choice scent, had dozens of patients being referred to her who had similar yet indistinct symptoms. Other doctors may have finally given these patients a diagnosis of something—Lyme’s disease, chronic fatique, fibromyalgia—but the patient’s tests didn’t quite fit the normal profile for the diagnosis that they had received; nor had treatment seemed to make them any better. Desperate for help, and often years into their hunt for an answer, they’d show up in Hightower’s office.

“I enjoy problem solving,” Hightower, an internist at San Francisco’s California Pacific Medical Center, explains, “so I get a lot of patients that have been through numerous doctors, and through even more numerous tests. These patients were coming in and saying to me, ‘I just don’t feel well. I have a headache all the time, and always feel like I have a hangover. My stomach’s upset. I have muscle and body and joint pains, and I have trouble thinking.’

These patients were a mixed lot: they spanned all age groups, from young kids to the elderly, included both men and women, and represented various ethnic groups. There were CEOs and physicians, secretaries and soccer moms. Many mentioned loss of motor control, and a number added hair loss to their complaints.

“All these patients had one thing in common—they had a laundry list of non-specific symptoms,” Hightower says.

For a long time, her patients’ symptoms had Hightower stymied, but one day in 1999 one of her colleagues, dermatologist Kathy Fields, mentioned that on a recent trip to Idaho she’d heard a call-in radio program about people with high mercury levels in their hair and blood. The common denominator among the callers was that they fished in Idaho lakes, and ate the fish. One symptom really piqued Fields’ attention: hair loss. Dermatologists frequently deal with hair-loss patients, and Fields knew that at least some of Hightower’s mystery patients reported hair loss.

The two doctors teamed up, arranging to test just one of Hightower’s patients who was suffering from hair loss. “We didn’t even really know what test to ask for,” Hightower says. “But we checked her blood, and it came back with what seemed like a high organic mercury level.”

With the results in hand, Hightower had to figure out what they actually meant. She tried to search the medical literature, but there was a paucity of information on mercury in the common texts that doctors refer to. Next, she checked with the California Department of Health; they said organic mercury could go up to 200 µg/L in blood, so mercury wasn’t the patient’s problem. But Hightower did a little more research, and found that the Environmental Protection Agency put the safe level for blood at less than 5 µg/L. The lab, which typically tested occupational exposures, told Hightower they use 13 µg/L ‘at the end of the work week,’ as the safe figure. Hightower pauses in telling her tale: “I scratched my head, and said, ‘Houston, we have a problem. No one is on the same page.’

Hightower reported the patient’s results to the regional poison control center. They put together a team, and went to the patient’s home and place of business. They searched for a source—and didn’t find one. But they tested all the employees at the business, and found two that also had high levels of mercury. The common denominator seemed to be the same one the Idaho callers had talked about on the radio program: high-mercury results corresponded to frequent fish consumption. Hightower tested a few more patients from the laundry-list group; they too had high levels of mercury.

Knowing that a few of her patients indeed had high mercury—which appeared to be associated with their fish consumption—Hightower decided to look more closely at mercury across the spectrum of patients coming into her practice. She designed an experimental program that involved all 720 patients who came to her office for a one-year period. Each patient was asked to complete a survey that asked questions about fish consumption, vaccination history, and about the number of amalgam, or silver fillings the patient had in their teeth because amalgam is another source of mercury. Her findings: patients who ate a lot of fish had significantly higher mercury levels than patients who consumed little or no fish, frequently exceeding the mercury levels EPA reported to be safe.

Mercury releases from chlorine production

This week, Oceana, a nonprofit that works to protect the world's oceans, released a new report, Cleaning UP: Taking mercury-free chlorine production to the bank. Their report outlines how a handful of producers are still releasing large amounts of mercury when there are cost-effective alternatives. According to their report, "Globally, the chlorine industry had largely moved to mercury-free technology by the turn of the 21st century. In the United States, the industry reported that by 2004, 90 percent of its chlorine was produced using mercury-free technology and no new mercury-cell plant has been built since 1970. Oceana’s Campaign to Stop Seafood Contamination targets the plants responsible for the remaining 10 percent."

Why does this matter? Because mercury is a known toxic, and persistent chemical: once it is released into the global mercury pool, it doesn't go away. Mercury is then deposited in the oceans, where it is taken up at first in microorganisms. These are eaten by higher organisms, which are eaten by higher organisms, which in turn are eaten by even higher organisms. The mercury eventually finds its way into the fish we eat. The predator species in the oceans, such as tuna, shark, and swordfish, have some of the highest levels of mercury in their flesh.

In 2004, the Food and Drug Administration and the Environmental Protection Agency jointly issued an advisory on fish consumption to begin addressing mercury concerns. The mercury in fish can be dangerous to anyone, but babies in the womb and small children are particularly vulnerable, so the federal advisory recommends that women who may become pregnant, pregnant women, nursing mothers, and young children avoid some types of fish and eat fish and shellfish that are lower in mercury.

By following these 3 recommendations for selecting and eating fish or shellfish, women and young children will receive the benefits of eating fish and shellfish and be confident that they have reduced their exposure to the harmful effects of mercury.

1. Do not eat Shark, Swordfish, King Mackerel, or Tilefish because they contain high levels of mercury.

2. Eat up to 12 ounces (2 average meals) a week of a variety of fish and shellfish that are lower in mercury.

   • Five of the most commonly eaten fish that are low in mercury are shrimp, canned light tuna, salmon, pollock, and catfish.

   • Another commonly eaten fish, albacore ("white") tuna has more mercury than canned light tuna. So, when choosing your two meals of fish and shellfish, you may eat up to 6 ounces (one average meal) of albacore tuna per week.

3. Check local advisories about the safety of fish caught by family and friends in your local lakes, rivers, and coastal areas. If no advice is available, eat up to 6 ounces (one average meal) per week of fish you catch from local waters, but don't consume any other fish during that week.

The Environmental Defense Fund has a great site on fish consumption recommendations at their Oceans Alive website.

Fish advisories may help reduce problems, but reducing mercury emissions from sources such as the chlorine-production industry is a real key to long-term environmental health--for us and the fish!