The failure of EPA to meet its statutory responsibility to protect people and wildlife from the dire consequences of exposure to endocrine disrupting chemicals must end. Over recent decades, evidence has mounted showing that many pesticides interfere with hormones—and are therefore endocrine-disrupting chemicals (EDCs). In 1996, the promise of screening pesticides for endocrine disruption generated support from environmentalists and public health advocates for the Food Quality Protection Act (FQPA), which traded the absolute prohibition of carcinogens in food of the Delaney Clause for a risk assessment standard that is subject to manipulation and an underestimation of real-life hazards. And now, 25 years later, we have yet to see EPA use endocrine disruption findings in pesticide registration decisions.
>>Tell EPA that pesticide use cannot continue without findings of no endocrine disruption.
The endocrine system consists of a set of glands (thyroid, gonads, adrenal and pituitary) and the hormones they produce (thyroxine, estrogen, testosterone and adrenaline), which help guide the development, growth, reproduction, and behavior of animals, including humans. Hormones are signaling molecules, which travel through the bloodstream and elicit responses in other parts of the body.
More than 50 pesticide active ingredients have been identified as endocrine disruptors by the European Union and the late endocrine disruptor expert Theo Colborn, PhD. Endocrine disruption is the mechanism for several health effect endpoints. Endocrine disruptors function by: (i) Mimicking the action of a naturally produced hormone, such as estrogen or testosterone, thereby setting off similar chemical reactions in the body; (ii) Blocking hormone receptors in cells, thereby preventing the action of normal hormones; or (iii) Affecting the synthesis, transport, metabolism, and excretion of hormones, thus altering the concentrations of natural hormones. Endocrine disruptors have been linked to attention deficit hyperactivity disorder (ADHD), Parkinson's and Alzheimer's diseases, diabetes, cardiovascular disease, obesity, early puberty, infertility and other reproductive disorders, childhood and adult cancers, and other metabolic disorders.
It is not only humans who are affected. Hermaphroditic frogs, polar bears with penis-like stumps, panthers with atrophied testicles and intersex fish with immature eggs in their testicles have all been linked to endocrine disruption. The popular herbicide atrazine chemically castrates and feminizes exposed male tadpoles. The mosquito-killing S-methoprene larvicide alters early frog embryo development. Distorted sex organ development and function in alligators is linked to the organochlorine insecticide dicofol. The ubiquitous antibacterial chemical triclosan alters thyroid function in frogs, while its chemical cousin triclocarban enhances sex hormones in rats and in human cells. In her book, Our Stolen Future, Dr. Colborn states that the decline of animal species can no longer be simply explained by habitat destruction and human disturbance, but also by reproductive failures within populations brought on by the influence of endocrine disrupting chemicals.
According to FQPA, the agency must screen all pesticide chemicals for potential endocrine activity. To ensure timely follow-through, EPA was given a timeline by Congress to: develop a peer-reviewed screening and testing plan with public input not later than two years after enactment (August 1998); implement screening and testing not later than three years after enactment (August 1999); and report to Congress on the findings of the screening and recommendations for additional testing and actions not later than four years after enactment (August 2000).
Despite these deadlines, EPA is stalled and ignoring its responsibility. It started a screening program (Tier 1) and reported results in 2009. Since, according to EPA, Tier 1 Screening (which looks at high exposure chemicals) is not sufficient to implicate a chemical as an endocrine disrupting chemical, but acts as a tool for defining which chemicals must undergo Tier 2 testing, the only stage that can influence regulatory decision-making. Indeed, it is unclear when or how EPA will move forward with Tier 2 testing, and how, if at all, any Tier 2 findings will be used to inform actual regulation.
EPA now issues Proposed Interim Decisions (PIDs) on pesticide registrations making no human health or environmental safety findings associated with the potential for endocrine disruption, or identifying additional data needs to satisfy Endocrine Disruptor Screening Program requirements in the PIDs. EPA cannot make findings of no unreasonable adverse effects without findings concerning endocrine disruption.
>>Demand that EPA test for and act on endocrine disruptors as required by law.