Environmental activists were skeptical about the statement, but, surprisingly, so were some EPA scientists. In May, nine presidents of EPA scientist unions and risk managers wrote a letter to Johnson expressing concerns about the EPA considering approval of organophosphate (OP) and carbamate pesticides. These chemicals can be neurotoxic, especially in developing fetuses, infants and children.
"We think there's a lot of work that remains to be done in terms of getting (adequate) developmental neurotoxicity data," said William Hirzy, a senior scientist in the EPA's Office of Toxic Substances and vice president of the National Treasury Employees Union Chapter 280. He added that union leaders are concerned that the EPA is putting too much focus on "avoiding lawsuits from the regulated community," and may be making decisions tailored toward reduced restrictions rather than increased precautions.
The pesticide review was prompted by the 1996 Food Quality Protection act, which required the EPA to reassess the safety of tolerance levels for pesticides used in or on processed foods. The EPA looked at tens of thousands of studies conducted by EPA scientists, pesticide companies, and other governmental agencies, and new risk-assessment tools were developed to better identify chemicals that could harm human health or the environment. The agency also considered opinions from public health watchdog groups, interested industries, and their own advisory committees before announcing a decision on each pesticide's allowable tolerance, followed by a 60-day public comment period before finalizing the decisions.
Congress required the EPA to be finished by Aug. 3, at which point the EPA reported it had completed 99 percent of its review. In all, the EPA evaluated about 230 pesticide active ingredients and 870 inert pesticide ingredients with nearly 10,000 tolerances, according to Anne Lindsay, deputy director of the EPA Office of Pesticide Programs. On Aug. 3, the EPA announced they were banning carbofuran and lindane -- which is banned in 52 other countries -- although lindane is still allowed for use directly on children with scabies and lice, because the FDA regulates that particular use.
Carbofuran and lindane were not the only cancellations the agency made over the 10-year review period, as 17 OP pesticides had been banned during the process and the use of 15 more had been regulated, but both environmental groups and some scientists were hoping no OPs would be allowed to reregister.
"The OP decision, I think, is a bad one," said Margaret Reeves, a senior scientist with Pesticide Action Network North America, noting her organization supports the EPA scientists' letter to Johnson.
The letter says that too few studies have been done on food use and the developmental neurotoxicity of food-use OPs and carbamate pesticides, which usually means the EPA is required to use an additional 10-fold safety factor for assessing the risks of pesticide tolerances, as per the FQPA. The letter urged the EPA to use the 10-fold safety factor for the remaining OP and carbamate pesticides under consideration, but Reeves said that might still be inadequate, as some animals, people and age groups are better able to break down the chemicals in their bodies than others.
"The intraspecies variability is much greater than often considered and much greater than would be (covered by) the FQPA 10-fold factor," Reeves said.
In the wake of the criticisms from environmental activists and their own scientists, the EPA administrators supported the assessments made in the review, maintaining that approved pesticides pose no health risks.
"We think we have really set a very high bar for pesticide safety in this country," said Lindsay. "If you are eating food purchased in the U.S., it's really safe."
Many people disagree. Brenda Eskenazi, director of the NIEHS Center for Children's Environmental Health Research at the University of California, Berkeley, said that it was a well-known fact that acute, high-level exposure to OP and carbamate pesticides caused profound neurotoxicity, but added that some evidence suggests lower-level exposure could cause neurotoxicity in fetuses. A number of studies are now being conducted to measure potential health consequences in older children, Eskenazi said, but noted that, because most people are exposed to multiple pesticides simultaneously, it is hard to pinpoint a single agent as the cause of an observed health problem.
The union leaders within the EPA have said that the uncertainty surrounding many of the pesticides is grounds enough for their banning.
"Until EPA can state with scientific confidence that these pesticides will not hurt the neurological development of our nation's born and unborn children, there is no justification to continue the registration of the use of the remaining OP and carbamate pesticides," the letter states.