Reprinted with permission of The Dallas Morning News 03/30/98
THE DALLAS MORNING NEWS
Length:34 Byline:Randy Lee Loftis
Credit:Environmental Writer of The Dallas Morning News
A popular fertilizer used this time of year by organic gardeners contains elevated levels of lead and arsenic, tests show, but company officials say the forms found in the product are nontoxic and pose no risk to people or plants.
Some experts, however, said they wouldn't automatically consider any form of lead or arsenic nontoxic.
The Dallas Morning News commissioned tests on Ironite and reviewed tests performed by a university geochemist and those provided by the manufacturer.
The test results were consistent: Samples of Ironite in its granular, boxed form contained an average of 2,677 parts per million of lead and 3,972 parts per million of arsenic, in addition to the iron that is the fertilizer's namesake.
Experts disagree on how many years of repeated use it might take to raise soil concentrations enough to be of concern.
In West Dallas and other neighborhoods, the Environmental Protection Agency has launched cleanups of residential yards if soil had more than 500 parts per million of lead or 35 parts per million of arsenic.
Ironite is marketed nationally as a nonpolluting, environmentally safe alternative to chemically produced fertilizers. And its manufacturer, Ironite Products Co. of Humboldt, Ariz., said that's exactly the case.
Ironite Products said the forms of lead and arsenic in Ironite pose no risk to people or plants. An executive said the company has investigated and determined that the lead and arsenic are in forms that cannot escape into the environment.
"You can eat them and they'll pass right through you," said Rob Morgan, Ironite's executive vice president and chief operating officer. "They're not harmful."
Gardeners have used Ironite since 1956, and the company has never been sued, fined, cited or linked with any health concerns regarding lead or arsenic, he said.
Several experts and a number of published reference works confirm that the lead and arsenic in Ironite - basically, raw ores of the metals - are in the least toxic forms of those materials.
But experts said weather, erosion, local soil and water chemistry and even microbes in the soil can change a fairly safe form to a more toxic one.
"I have not found any form of lead that is not bioavailable to some extent," said Christopher Weis, a toxicologist with the EPA who has spent a decade researching the relative dangers of different forms of lead. "Bioavailable" means a substance can be absorbed by the body.
Of particular concern to scientists studying toxic materials is their effect on children. In the case of lead, for example, Dr. Weis said a child's rapidly developing body mistakes the toxic metal for calcium.
Because the body needs calcium for growth, he said, a child's body "grabs" and keeps nearly all the lead the child ingests. "Children are basically little lead sponges," Dr. Weis said.
Ironite's label, like those of nearly all fertilizers, does not disclose the presence of possibly harmful materials. Neither federal nor Texas law requires such disclosure. Fertilizer makers need only list ingredients that are claimed to be beneficial.
Ironite's label does not advise users to take any precautions during or after use, such as keeping children or pets away and washing hands after touching the product.
The label recommends amounts to use on lawns, flowers and vegetables and trees, but adds: "Will not burn! Even if you use 2 or 3 times the recommended amount. And if you apply too much, it won't be wasted. It means Ironite will continue to nourish your plants even longer."
The Environmental Working Group, an advocacy organization that studied the legal, unregulated use of toxic waste as raw material in fertilizers, is urging the federal government to require full disclosure on fertilizer labels.
Ironite doesn't use any such waste, Mr. Morgan said. Instead, the product comes from tailings of an old mine, the Iron King, in Arizona.
Paul J. Eberhardt, an environmental scientist from Phoenix, tested Ironite's effects on soil, water and vegetables at the company's request and reported no problems. In 1990, he prepared a report for Ironite that concluded: "Using all of the published government information available, it does not appear there is any danger from your product when used as directed."
"Obviously," Dr. Eberhardt added, "Ironite should not be ingested directly, as with any fertilizer." Mr. Morgan provided a copy of the report to The News . Dr. Eberhardt calculated that if a customer used Ironite at the recommended rate, it would take 794 years to give soil a potentially toxic lead level. For arsenic, he concluded, it would take 277 years.
At the request of The News , James L. Carter, a geochemistry professor at the University of Texas at Dallas, also examined Ironite.
The two scientists asked different questions and got different answers. Dr. Eberhardt asked how much of the lead and arsenic might escape in a toxic form into the environment. Dr. Carter asked how much total lead and arsenic, in all forms, would wind up in the soil.
Dr. Carter's question is the same the EPA asks when considering a soil cleanup. Dr. Carter wanted to see how long it might take for soil in a garden or on a lawn to reach the lead and arsenic levels that the EPA used to trigger the West Dallas cleanup.
West Dallas was polluted by air emissions from a lead smelter. The EPA cleaned up residential areas there in the early 1990s.
Dr. Carter considered 22 different scenarios based on how much Ironite was used, how often it was used and how deeply it was worked into the soil. Working it in more deeply would reduce the concentrations.
The longest time to reach the West Dallas cleanup levels would come from using 2 pounds a year for every 100 square feet of lawn, working the fertilizer into the top six inches of soil. At that rate - the minimum recommended - Dr. Carter found that it would take 584 years to reach the West Dallas lead level. However, the West Dallas arsenic level would be reached in just less than 28 years, he found.
A gardener who used much more Ironite - 16 pounds a year for every 100 square feet - and left it on the top centimeter of soil would have West Dallas-type lead and arsenic levels much faster, Dr. Carter concluded.
For lead, the top centimeter of soil would reach the West Dallas level in just under five years; for arsenic, in less than a single growing season.
Neither Mr. Morgan, the Ironite executive, nor Dr. Eberhardt, the consultant, had seen Dr. Carter's figures last week. They did confer by telephone, and Mr. Morgan invited the UTD professor to come to the Ironite plant for further research.
Some experts said that the presence of any form of lead and arsenic in a home-use garden product raises questions - and all endorsed Dr. Eberhardt's advice not to swallow any.
David Shields, a geologist with a Dallas engineering firm who has worked on lead cleanup projects, said the key question for consumers is not which forms of lead or arsenic are the most or least toxic. The EPA does not make that distinction when it plans residential cleanups, he noted.
Instead, Mr. Shields said, the important question is whether consumers can make an informed choice. "I'm not telling anyone they shouldn't use any particular product," Mr. Shields said. "But lead is lead is lead."
Mr. Morgan, however, urged consumers to consider the benefits of his company's product against the well-documented harm that synthetic, chemically based fertilizers have done to the environment. Nitrates in synthetic fertilizers are known to have contaminated lakes, rivers, drinking-water supplies and wetlands across the country, posing a potential health risk to children.
"Using a product like Ironite is not going to contribute to that," he said. "That ought to be part of the picture."