EPA’s broader ban on an insecticide is overdue, court-ordered and incomplete

It should surprise no one that it took a court order to get the U.S. Environmental Protection Agency to begin implementing a wider ban on the insecticide chlorpyrifos, a nerve toxin known to cause a range of serious health problems in people – especially children.

Though pesticide manufacturers, allied agricultural interests and their political pals strive mightily to portray the American regulatory apparatus as overly aggressive, the truth is that we are slow to inconvenience companies that make, sell and apply poisons throughout the environment. This may be especially true in agriculture.

On pesticide regulation in particular, EPA has compiled a record whose hallmarks are delay, missed deadlines and years-long backlogs.

Often, EPA and its sister agencies are slower to take actions in behalf of public health than their counterparts in other countries. Often, too, the regulatory pace is slower on poisons made for the purpose than on pollution that’s merely an industrial byproduct, as with lead or PCBs.

In the case of chlorpyrifos, an organophosphate nerve poison known by such trade names as Dursban and Lorsban, alarming health data moved EPA in 2000 to ban it from most home and residential uses. In other words, they took it out of amateurs’ hands.

Agricultural application has been allowed to continue, however, and it is said to be used in more than 50 crops, including corn, soybeans, wheat and a wide variety of orchard items like apples, oranges and almonds. Even after those uses end under the ban announced last week, chlorpyrifos products will still be permitted on golf courses and in treatments of nonfood agricultural products, like ornamental plants.

That’s because EPA controls the pesticide’s use only in an indirect way, by imposing limits on its residues in food. Those limits will go to zero about a year from now, according to EPA’s timetable.

Don’t hold your breath.

A court’s patience snaps

Until quite recently, EPA’s prolonged foot-dragging on chlorpyrifos had been granted considerable deference in the courts – including the U.S. Court of Appeals for the Ninth Circuit, which rejected petitions asking that it tell EPA to pick up the pace.

That changed in August, when a three-judge panel of the appeals court concluded that the agency’s inaction had become “egregious” even by its own standards, and constituted a “cycle of incomplete responses, missed deadlines and unreasonable delay”:

Although filibustering may be a venerable tradition in the United States Senate, it is frowned upon in administrative agencies tasked with protecting human health.

Pesticide Action Network North America and the Natural Resources Defense Council have been waiting for years for the United States Environmental Protection Agency to respond to their administrative petition requesting a ban on the pesticide chlorpyrifos. Instead, they’ve received a litany of partial status reports, missed deadlines, and vague promises of future action.

We recognize the scientific complexity inherent in evaluating the safety of pesticides and the competing interests that the agency must juggle. However, EPA’s ambiguous plan to possibly issue a proposed rule nearly nine years after receiving the administrative petition is too little, too late. … We order EPA to issue a full and final response to the petition no later than October 31, 2015.

Long list of risks

Chlorpyrifos was developed in the 1960s by the company now known as Dow AgroSciences, although it is now off-patent and produced by many others as well. Among the health problems linked to it are asthma, lung cancer, low birthweight, endocrine disruption and multiple developmental and behavioral disorders in children both before and after birth.

It is also considered to be among the pesticides most toxic to honeybees and other pollinators.

And perhaps most problematically, it is a long-lived substance in groundwater. Last December an EPA analysis concluded that this rendered its residue standards inadequate, because there was no way to limit the total combined intake from both food and water. The agency also raised new concerns about risks to pesticide applicators and to people living in small watersheds, which would concentrate the residues in water supplies.

The new restrictions are subject to a public comment period, followed by preparation of a final version. As you might expect, Dow is opposing the broader ban and says additional research would prove that it’s unnecessary.

It’s also opposed by Crop Life America, a trade group that says it “promotes the responsible use of innovative, safe and environmentally sound crop protection products (including herbicides, fungicides and insecticides) that are essential in the production of food, fiber and renewable or alternative fuels.”

“It is unfortunate that court-mandated deadlines helped result in the agency’s proposal to revoke food residue tolerances for a beneficial and wide-reaching crop protection product,” the group said. “Unnecessary litigation-driven deadlines risk arbitrarily taking away valuable tools from all farmers, and this is just such a scenario. This is a drastic and unnecessary step that is caused by wasteful, agenda-driven litigation. We are confident that due legal and scientific process will make this proposed action unnecessary.”

How industry controls the inquiry

For another take on the U.S. approach to pesticide regulation, I commend a new report published by In These Times and based on a six-month investigation by Valerie Brown and Elizabeth Grossman.

Headlined “Why the United States Leaves Deadly Chemicals on the Market,” the piece covers familiar ground in describing revolving-door relationships in which regulators move back and forth between industry jobs and regulatory roles.

But the most interesting material concerns a sweeping and pre-emptive victory that industry interests won many years ago in deciding perhaps the most fundamental question of all: How shall the health effects of chemical exposure be measured in the first place?

This used to be done in the laboratory through direct observation how living things responded to carefully calibrated doses of particular chemicals. Nowadays, it’s more likely to be done through a type of computer simulation called “physiologically based pharmacokinetic modeling,” or PBPK.

Thirty years ago, Brown and Grossman write,

Corporate interests began to control not just the political process but the science itself. Industry not only funds research to cast doubt on known environmental health hazards; it has also shaped an entire field of science—regulatory toxicology—to downplay the risk of toxic chemicals.

Our investigation traces this web of influence to a group of scientists working for the Department of Defense (DOD) in the 1970s and 1980s—the pioneers of PBPK modeling. It quickly became clear that this type of modeling could be manipulated to minimize the appearance of chemical risk. …

In the mid-1980s, scientists at the Wright-Patterson Toxic Hazards Research Unit began using PBPK simulations to track how chemicals move through the body. Known as in silico (in computers) models, these are an alternative to testing chemicals in vivo (in live animals) or in vitro (in a test tube). They allow scientists to estimate what concentrations of a chemical (or its breakdown products) end up in a particular organ or type of tissue, and how long they take to exit the body. The information can then be correlated with experimental data to set exposure limits—or not.

 PBPK simulations made testing faster and cheaper, something attractive to both industry and regulators. But the PBPK model has drawbacks. “It tells you nothing about effects,” says Linda Birnbaum, director of both the National Institute of Environmental Health Sciences (NIEHS) and National Toxicology Program (NTP). Observational studies and laboratory experiments, on the other hand, are designed to discover how a chemical affects biological processes.

In essence, it seems to be widely agreed that if a PBPK model is informed with good data about how a particular organism – a human being, say – responds to a certain chemical dose, then the modeling can make reasonable extrapolations about different exposure scenarios. But if the dose-response data are poor, which can be the case with chemicals too deadly to test directly, or others whose harm becomes apparent only after prolonged exposure, then the results aren’t reliable.

Among the example substances the writers say have been shown to be riskier than PBPK modeling suggests: methylene chloride, bisphenol A, formaldehyde, styrene, trichloroethylene and – chlorpyrifos.

* * *

The full text of the appeals court order compelling EPA to finish its work on chlorpyrifos can be read here.