INCONCLUSIVE: Blood testing hasn’t answered questions about threat of lead toxicity from Exide plant
(Below is a copy the July 17, 2011, story written by Dallas Morning News reporter Valerie Wigglesworth)
Blood testing hasn’t answered questions about threat from lead smelter
By VALERIE WIGGLESWORTH
Published 17 July 2011 12:49 AM
Blood tests may alleviate individual fears about contamination from a lead smelter in Frisco, but they do little to address questions about any broader health threat to the community.
Testing so far has been voluntary. Those living closest to the Exide Technologies battery recycling facility are believed to be most at risk, yet testing isn’t limited based on proximity to the plant. And efforts for testing have attracted far more adults than children, who are most vulnerable to lead’s toxic effects.
“You really can’t take that kind of data and draw any formal conclusions about whether or not the people are or are not at risk due to the plant,” said Laura Plunkett, owner of a Houston-based health and environmental sciences consulting firm that’s been working with the city of Frisco to do a larger study.
Preliminary results have been released on the more than 600 Frisco-area residents who turned out in March for free blood-lead testing from the Texas Department of State Health Services. The tests were offered in response to community concerns over lead being emitted from Exide’s plant, which is near downtown and surrounded by dozens of homes, businesses and schools.
A 1.3-square-mile area around the plant is one of 16 in the country that does not meet the federal air-quality standard for lead. (Five other areas — none of which are in Texas — were identified last month as also exceeding the standard and could be formally designated later this year.)
Results from the Frisco blood-lead tests became public during last month’s Texas Commission on Environmental Quality meeting in Austin. The commission voted at that time to move forward with a plan to reduce lead emissions from the Frisco plant.
TCEQ toxicology division director Michael Honeycutt told the commission that blood tests in Frisco “found background levels” of lead for all but two adults whose higher levels were due to exposure at their jobs. He declined through the agency’s spokesman to elaborate on his comments.
A week later, the state health department released a one-page fact sheet summarizing the test results. It stated 594 people (98 percent) of those tested “had blood lead levels consistent with those found in people in their respective age groups throughout the United States.”
The U.S. Centers for Disease Control and Prevention considers levels at or above 10 micrograms of lead per deciliter of blood in children to be elevated. The level of concern for adults is 25. Because of that benchmark, blood-lead levels below 10 are routinely interpreted as no problem. But a growing body of research has found health effects at very low lead levels. There is no known safe level of lead exposure.
Twelve people tested in Frisco had blood-lead levels less than 10 but higher than what was expected, the agency reported.
“These results do not indicate any unusual communitywide exposure to lead,” according to the health department, which plans to release its complete findings in August.
Plunkett said the test results are a snapshot in time. Blood-lead levels generally indicate recent exposure. They don’t measure past exposure. Nor can the test results point to the source of any lead exposure. And because the testing attracted people from all over Frisco, the results are limited.
“You may be lucky enough if you have enough people come in that live in the impacted area,” she said. “But then again you may not.”
Separate from the state’s efforts, Exide has offered free blood tests to any Frisco resident since November. The company funds similar tests in other communities where it operates, including Muncie, Ind.; Reading, Pa.; and Petone, New Zealand.
Its test results from Frisco show nearly 92 percent of the 223 people tested in the past nine months had lead levels of 2 or less. The highest level was a 7 for an adult between 50 and 59 years old.
The Department of State Health Services also maintains a registry of all blood-lead tests done on children younger than 15 in Texas. Those tests are typically performed by private physicians.
The registry reported that 24 percent of the 711 children tested in Frisco last year had blood lead levels greater than 2. That compares with 15 percent of the 485,274 children statewide who had blood-lead levels greater than 2.
State health officials said the higher percentage in Frisco is not a concern because the numbers vary from year to year. In six of the past 10 years, a lower percentage of children in Frisco had blood-lead levels greater than 2 when compared with the state.
Children most at risk
While children are most vulnerable to the effects from lead, they have been less likely to turn out for the free tests in Frisco.
Children age 14 and younger made up about one-third of those tested by the state health department in March. Exide’s program has tested 25 children younger than 10.
“When you have mostly adult samples, that tells you something about the background levels of lead in adults in the community,” Plunkett said. “But the real population that we are concerned about is kids.”
That’s because children absorb three to four times more lead than adults, Plunkett said. Of particular concern are children ages 2 to 6, whose minds and bodies are still developing. They also tend to put their hands and other objects in their mouths more often.
Lead has been linked to lowered academic performance, behavioral problems and learning disabilities in children. Research in recent years has found that IQ loss is greater in children with blood-lead levels below 10 than in children with blood-lead levels above 10.
Lead’s potential effects on children are also what prompted the federal government’s more stringent air-quality standards that triggered Exide’s noncompliance. That in turn fanned the community’s concerns.
Plunkett said the blood-test results are valuable to those who were tested. “They have an understanding of where they are today,” she said.
But a lot of questions remain. City of Frisco officials still hope to find funding for a more comprehensive health-risk study.
Said Plunkett: “We still haven’t done the study that’s definitive to tell us — would we expect there to be any further impacts for people that live there?”
The Texas Department of State Health Services offered free blood-lead testing to Frisco-area residents over four days in March. Preliminary results from 608 blood samples tested show:
193 children (age 14 and younger) and 382 adults had blood-lead levels less than 2 micrograms of lead per deciliter of blood.
Six children and 25 adults had blood-lead levels between 2 and 9.
Two adults had blood-lead levels between 10 and 15.
Exide Technologies has offered free blood-lead testing to any Frisco resident since November. Results from 223 blood samples tested show:
41 children — 24 children age 9 and younger and 17 children ages 10 to 19 — and 130 adults had blood-lead levels less than 2.
3 children — 1 child age 9 and younger and 2 children ages 10 to 19 — and 31 adults had blood-lead levels of 2.
18 adults had blood lead levels between 3 and 7.
SOURCES: Texas Department of State Health Services; Exide Technologies Inc.