by Heather Hansen
Environmental problems often pose themselves in a way that’s almost impossible to unravel. The question often is just how much of a pollutant is bad – and even the most rigorous science doesn’t always yield an answer. Add the economic interests of the polluters (not to mention the taxpayers) and mix it with compelling evidence of severe health problems suffered by a few people, and you get an almost insoluble issue.
So it is with the relatively recently discovered threat of ammonium perchlorate. It’s both a naturally occurring and a man-made chemical, and has been used for many decades as an additive for rocket fuel. It’s known to damage the human thyroid gland. But tests to measure accurately its presence have only been around since 1997, and the EPA issued rules on allowable perchlorate levels only last month. Now the battle has been joined in earnest – and depending on whom you ask, the country, and especially Western states, may now be facing a public health crisis, a $20 billion clean-up bill…or nothing of the kind.
The Giant Plume
Henderson, Nevada was born to defend America. The modest, dusty town just seven miles south of the Las Vegas strip grew up during World War II, the spawn of a government factory that processed magnesium and built airplane parts. After the war, the plant changed hands several times finally resting in the palm of its current owner, the Kerr-McGee Chemical Corp., in 1967.
For over 50 lucrative years the production ammonium perchlorate was central to the Henderson operations, and to the nation’s defense and space industries. Manufactured perchlorate is used in relatively small quantities for making pyrotechnics like flares, fireworks and explosives, and in paint, enamel and rubber. About 90% of all the perchlorate made in this country has been used, as in Henderson, to accelerate solid rocket fuel.
It is widely accepted that high doses of perchlorate in humans block the thyroid’s uptake of iodide. A lack of iodide harms the body’s ability to make thyroid hormones, which regulate metabolism and mental function. The hormones are critical to pre- and postnatal growth and development; doctors have known for a half-century the effects of perchlorate, having used it at one time to treat hyperthyroidism.
Scientists have shown that the rocket fuel additive damages the development of rats, amphibians and, possibly, fetuses and newborns. Perchlorate has turned up in food, including many fruits and vegetables, and in dairy and the breast milk of nursing mothers.
Henderson is the single largest source of perchlorate contamination in the country. When Kerr-McGee dumped its perchlorate business in 1998, the company immediately began decommissioning the Henderson plant by capturing and removing massive quantities of perchlorate from the groundwater. In the summer of 2003, EPA scientists estimated that Kerr-McGee had poured 20.4 million pounds of perchlorate into unlined ponds. From there it leached into the soil and dissolved in the near-surface aquifer. Based on the level of toxin in the largest outwash (there is another smaller but still significant plume) the EPA said it would take about 24 years to clean the site, removing 2,400 lbs of perchlorate per day.
If not for the mighty Colorado River the story might have ended there. But as a recent Kerr-McGee report simply states, “Perchlorate has been detected in nearby Lake Mead and the Colorado River.”? Before Kerr-McGee was legally bound to treat the water around the plant, the Colorado ferried the contaminant south into the water supply of an estimated 20 million people in Nevada, Arizona and California.
From Lake Mead, perchlorate streams through the Hoover Dam and flows 155 miles downstream into Lake Havasu, a 45-mile long reservoir from which Los Angeles and San Diego siphon water. Just south of Havasu thousands of acres of Native American farmland cling to the banks of the Colorado in pockets that stretch for hundreds of miles to the Mexican border.
According to Mojave legend, the Colorado River was created by the spirit Mutavilya who gave them gifts of water, plants and animals, and agriculture defines life on the Fort Mojave reservation to this day. On the four reservations that straddle the Colorado, crossing in and out of Arizona, Nevada and California, wheat, cotton and alfalfa are irrigated with hard-won water. The Colorado River Indian Tribe (CRIT), on their land south of the Mojave, now has water rights to nearly one-third of all of Arizona’s water, to quench what could soon be 135,000 acres of crops.
But for years the farmers have felt their health and livelihoods are threatened by a burden their ancestors never shouldered: perchlorate. “It’s a big issue for our tribes,”? says Deborah Patton, water quality program administrator for the Inter Tribal Council of Arizona, “especially along the Colorado River. Because of the health results it does cause a concern.”? Perchlorate has crept into their wells, from which drinking and irrigation water is pumped, she says.
The tribes have struggled to keep their heads above the flood of information regarding the chemical’s toxicity. “There are a lot of studies coming out but a lot of unknowns still,”? says Patton.
A Widespread Problem
It’s clear that perchlorate pollution is widespread. At least 75 release sites have been identified in 35 states, with several western states bearing the brunt of the Cold War chemical.
According to the EPA’s latest inventory, New Mexico has 12 sites on the map, with the most worrisome being the White Sands Missile Range in Las Cruces. There were significant perchlorate plumes at three locations in Washington, two in Oregon and another two in Utah.
In Colorado the EPA is currently monitoring two sites. Its main concern is the Pueblo Chemical Depot (also called the Pueblo Army Depot), in the southeast corner of the state, where full-scale remediation of soil contaminated with explosives is underway. According to EPA documentation from January 2004, “These soils are now known to also be contaminated with perchlorate. Analyses of treated soils are underway to assess the effectiveness of the composting process in reducing perchlorate concentrations. Results [are] unavailable.”?
Several other locations of concern to officials and local residents are all less than 25 miles south of Denver, near the historic town of Louviers, where DuPont ran an explosives plant from 1908 to 1971. In 2002 DuPont donated 855 acres of the site to the county; elk, black bear and people now wander there in the prairie, among cottonwoods and along Plum Creek.
Molycorp, which nearly abuts the donated land, is the other hot zone where perchlorate measurements mirror those at DuPont. The state department’s director of Hazardous Materials and Waste Management division, Gary Baughman said the company is currently putting together a plan for dealing with onsite perchlorate. At a third nearby site, where an explosives plant now operates, no perchlorate has been found, but environmental advocates are wary.
“The state has been lax and negligent in confirming where [perchlorate] might be,”? says Adrienne Anderson, an environmental activist and a former instructor in environmental studies at the University of Colorado at Boulder. Anderson believes that she was fired from her position at CU because of her indictment of polluting businesses. Anderson filed a federal whistleblower case with the Department of Labor earlier this month in hopes of recouping her position at the university, where she taught for 11 years.
Baughman, however, insists that the area’s Plum Creek and reservoirs are not contaminated. When asked if perchlorate poses any danger to Colorado residents he said, “We have to acknowledge that perchlorate can present health risks. But based on [the DuPont and Molycorp] sites it is not presenting a current threat to anyone.”?
The sites do, however, show levels of perchlorate far above the controversial EPA safety standards released last month.
The EPA, working largely from a National Academy of Sciences study, pegged the safety level at an official reference dose (RfD) of .0007 mg/kg/day and a Drinking Water Equivalent (DWEL) of 24.5 parts per billion (ppb). In Nevada, perchlorate has been found at an astonishing 3.7 million ppb in the groundwater, and at a nearby former PEPCON plant the groundwater has been tested at 600,000 ppb. At its worst, Lake Mead had around 480 ppb of the stuff, according to the Arizona Department of Environmental Quality – and from there it flows down the Colorado to the Indian agriculture lands and ultimately to the drinking water of Southern California.
In California, in fact, the Department of Health Services has detected perchlorate in 370 drinking water sources. While some of it came from the Colorado River, much of it also comes from groundwater wells that were polluted by local industries making or using perchlorate.
That’s what state health officials suspect happened in Redlands, 60 miles east of Los Angeles, where Adrienne Wise-Tates grew up. Lockheed Martin began using perchlorate in the production of solid rocket fuel at their nearby Lockheed Propulsion Company (LPC) when Wise-Tates was child. When Lockheed ceased operations at the location in 1974, Wise-Tates was 22.
Up until three months ago Wise-Tates, 49, had been waging a legal battle (along with about 800 other plaintiffs) with the company. She says that she was thrown out of the case because the statute of limitations on reporting her injuries had passed. She insists that the charge is bogus. “It’s just that we didn’t know anything about this until we were grown,”? says Wise-Tates. “When I started having all of these health problems a friend said to me, ‘Do you think it’s because of the water?’ Then I was in my early 20s. I had to do some investigation. I guess they claim that I should have known all along. But I didn’t know,”? she says.
Over the years Wise-Tates has suffered a string of ailments including, “thyroid problems, surgery on a goiter, cancer in my throat, open brain surgery and three breast cysts,”? she says, all of which she believes was a result of drinking water tainted by Lockheed. “Something we all have to have is water,”? she sighs, “and when that’s messed up we’re all in deep trouble.”?
While full-scale remediation of perchlorate is currently in progress at the former Lockheed site, according to California’s State Water Resources Control Board, the company adamantly denies that the chemical release had any adverse effects on the local population. A recent cleanup order from the California Regional Water Quality Control Board says there is circumstantial evidence that the facility discharged perchlorate into the water, but Lockheed has disputed the findings.
Research and Policy
For nearly a decade debate over what amount of perchlorate a human body can tolerate without adverse effects has raged. The EPA’s early studies on the effects of perchlorate on rats yielded alarming results. In one experiment the drinking water of pregnant and nursing females was laced with perchlorate. The mothers and their newborns were then scrutinized for damage.
Talking about that initial research, Kevin Mayer, an EPA Superfund manager who has a long history studying perchlorate said, “They were showing that these newborn rats have thyroids that were clearly under stress. It was clear that there was a change in newborns whose mom’s were tested.”?
The findings led the EPA to set a tentative guideline for human exposure to perchlorate in 2002. At that time the EPA suggested that the limit should be 1 ppb, roughly a couple of drops of the chemical in an Olympic-sized swimming pool. The meant that a 154-pound person could drink two liters of water per day tainted with 1 ppb of perchlorate for 70 years and experience no adverse effects.
The stringent limit pleased many environmentalists but infuriated defense contractors and the Pentagon, for whom the majority of perchlorate was made. The study had been funded, in part, by the Perchlorate Study Group (PSG), an organization made up of several of the major polluters. “In fact, they didn’t like the number,”? Mayer says.
Industry had insisted that perchlorate was safe in drinking water from 200-300 ppb, a level that would have exempted them from mopping up much of the discarded perchlorate at sites nationwide. Despite the release of EPA’s most recent guideline of 24.5 ppb, the PSG (with the exception of Lockheed Martin) maintains that 10 times that amount is safe. In a February 23, 2005 memo to the California Office of Environmental Health Hazard Assessment the PSG implored the state to set a standard of 236 ppb, “less perhaps a scientifically justified amount to account for exposure through food.”
Critics suggest that the government and its contractors continue to be motivated by the specter of cleanup costs that may rise as high as the rockets that perchlorate fueled. The cost of tidying up decommissioned bases and industrial locations, where perchlorate was made, tested or stored, to meet the EPA’s initial standard of 1 ppb would have been staggering — close to $20 billion — by some estimates.
Last year the deputy undersecretary of defense at the DOD, Raymond DuBois, testified before the House Armed Services Committee about the DOD’s growing stake in the numbers game. “The Department has invested $27 million to research potential health effects, environmental impacts, and treatment processes for perchlorate,”? he said.
By March 2004 the DOE had only reimbursed Kerr-McGee $44 million toward their $109 million bill for perchlorate remediation, according to the company’s most recent annual report. They are currently suing the government for the rest. Insisting that the EPA had used bad science to arrive at their conservative number of 1 ppb in 2002, some of the same parties paid to have the issue resolved by the NAS, a highly regarded forum for such debate. The NAS study, whose results will now govern the allowable level of perchlorate in this country, was funded by the EPA, DOD, DOE and NASA, fueling speculation that it was initiated by the White House to set a perchlorate standard that would ultimately lessen the cost of remediation.
The 15-member NAS panel was under suspicion from early on. California Senators Dianne Feinstein and Barbara Boxer charged that two members of the study group had conflicts of interest that would favor polluters. One doctor resigned as a result.
The Water-to-Food Chain
What troubles many — from reservations to research centers — about the EPA’s new standard for perchlorate is that it fails to reflect a deepening pool of data regarding chemical’s omnipresence and toxicity. Are the risks to vulnerable populations clear? Has the issue been studied for long enough? What does it mean to consume milk and produce infused with perchlorate? Do the EPA’s numbers account for a person ingesting the chemical daily from a number of sources? Countless studies are underway to answer such questions.
In a presentation given to the National Alfalfa Symposium last December Michael Payne, a toxicologist from the University of California, Davis and Charles Sanchez, director of the Yuma Agricultural Center at the University of Arizona, gave a synopsis of the ways in which perchlorate travels through the food chain. “It is well established that some plants irrigated with contaminated water will take up and concentrate perchlorate, sometimes to high levels. Perchlorate uptake has been documented in a variety of crops including alfalfa, lettuce, wheat, various berries, soybeans, strawberries and cucumbers.”?
Researchers have honed in on lettuce because, unlike berries or tomatoes, humans eat its foliage, which generally has the highest concentration of the chemical. In findings that he will soon present to the American Chemical Society, Sanchez reveals that perchlorate in lettuce is a national phenomenon.
“I was surprised that [perchlorate in lettuce] seemed to be ubiquitous across the country,”? he says. But because perchlorate was detected at low levels (less than 10 ppb) in many of the 400 samples that he collected from fields and farmers’ markets around the country, he insists that it should be less of a concern. “You could eat about 10 servings a day [of lettuce] and drink two liters of Colorado River water a day and still be below the level that’s considered safe,”? says Sanchez, “With lettuce we’re really off the table in terms of risk.”?
But, not surprisingly, perchlorate has been found in higher concentrations in lettuce grown in the West. In exploratory data that the Food and Drug Administration (FDA) published last November, several samples from Yuma had more than 10 ppb of the chemical. One bit of red Romaine lettuce measured 129 ppb. And Yuma calls itself the ‘Winter Lettuce Capital of the World.”
When asked what the measurements mean given the EPA’s new standards, FDA spokesman Michael Herndon said, by e-mail, “We are currently evaluating the perchlorate levels found in all the foods (not just lettuce) from our survey as well as the NAS report recommending the RfD that EPA recently adopted. As such, we have not yet determined what the health risk would be from dietary exposure to perchlorate, including lettuce, in light of EPA’s official RfD.”?
At a meeting of alfalfa growers in December, Charles Sanchez raised another important question: “Because some of these crops [with detectable levels of perchlorate] are utilized as animal feed and because perchlorate is known to concentrate from the blood and into the milk of rats, surveys into perchlorate contamination of cow milk were implemented.”?
By phone two weeks ago Sanchez said, “We do have some preliminary numbers [on alfalfa]. They’re higher; they’re probably double lettuce because alfalfa is like a straw that sucks up water and concentrates in the shafts and leaves.”?
The apparent chain of perchlorate from alfalfa hay to dairy cows is certainly a concern on the Mojave reservation, where alfalfa takes up half of their acreage. John Argots, physical resources director for the Fort Mojave tribe said that their alfalfa hay is shipped exclusively to dairies within a few hundred miles for feed. The milk from those cows then hits regional markets. “Of course [the milk] goes to the big markets in LA, Phoenix and San Diego,”? he says, “So what you’ve got then is people drinking this milk who are also drinking Colorado River water.”?
Just last month scientists at Texas Tech University in Lubbock released startling findings from a study done on dairy and breast milk. The study discovered that “Perchlorate is present in virtually all milk samples, the average concentration in breast milk is five times higher than in dairy milk.”?
Studies like the one done at Texas Tech get to the heart of one main criticism of the NAS study: it did not adequately account for the risks to vulnerable populations, like pregnant women, fetuses and newborns. For its part the NAS said that it built in a “10-fold uncertainty factor for susceptible populations.”? The study results assured: “The RfD should protect the health of even the most sensitive populations …”? But it also said, “The evidence is insufficient to determine whether or not there is an association between perchlorate exposure and adverse neurodevelopmental outcomes in children.”?
The other major weakness of the NAS study, suggest its critics, is that it wasn’t nearly lengthy enough to assess perchlorate’s long-term effects. The EPA’s Mayer also wonders about the possible subtle effects of perchlorate in the long run. “We’re not seeing these gross effects in large populations of animals or humans. That’s not jumping out on us,” he said, “But might there be subtle effects that don’t show up until these kids are ready to take their SATs? All we have is a resounding, ‘Well, maybe’.”?
In the meantime, at Fort Mojave, the alfalfa is getting high. They should be ready for the first cut at the end of April, John Argots says. Six more harvests should follow before the summer sun sets. Like many others, Argots wonders if there will ever be certainty about the effects of perchlorate. From among the purple blooms of the alfalfa, he says, “We’ll just have to wait it out, I guess.”?