What happened: The Environmental Protection Agency (EPA) has officially announced that it will not regulate perchlorate, a common ingredient of explosives and rocket fuel, in the nation’s drinking water supplies. This decision fails to consider scientific evidence from EPA scientists showing that perchlorate is widespread and can lead to serious harms to the brains of fetuses and young infants. This action also defies a federal court order that the EPA regulate perchlorate by setting a drinking water standard.
Why it matters: The EPA has chosen to sideline its own scientists and defy a court ruling despite the fact that there is robust evidence suggesting that perchlorate is widespread and poses substantial harm to one of our most vulnerable populations, young children. Through failing to consider the best available science in its decisionmaking, perchlorate will continue to endanger the health of millions of people across the US who are exposed.
The Environmental Protection Agency (EPA) has failed to consider the best available science in its decisionmaking on the toxic chemical perchlorate, despite a prior EPA analysis suggesting that five to 16 million people in the US face substantial harm from exposure to perchlorate in their drinking water. States like California, Massachusetts, and New Jersey have created their own perchlorate drinking standards, which the Trump administration’s EPA is attempting to use as justification for why it does not need a perchlorate safeguard to protect public health.
In 2008, the EPA had issued a preliminary regulatory determination for perchlorate and at the time had determined that the drinking water contamination did not rise to a public health concern. However, in 2011, the EPA revised this determination because of its own analysis, which showed that “there is a substantial likelihood that perchlorate will occur in public water systems with a frequency and at levels of public health concern… [and] that regulation of perchlorate presents a meaningful opportunity to reduce health risk for persons served by public water systems.” The EPA’s analysis also showed that perchlorate contamination in public water systems was widespread across the country. Twenty-six states and two territories had public water utilities that recorded samples of perchlorate that reached a level of public health concern. This led the agency to conclude that 5.1 million to 16.6 million people could be potentially exposed to dangerous levels of perchlorate in their drinking water supply.
The 2011 EPA analysis triggered a legal duty under the Safe Drinking Water Act for the EPA to regulate perchlorate. When the agency failed to carry this out in a timely manner, a federal court pushed the agency to set a drinking water standard for perchlorate by June 2020. Instead, Administrator Wheeler decided to upend this process by completely withdrawing the EPA’s 2011 determination and nixing the safeguard. According to the EPA, the decision was based primarily on the fact that three states (California, Massachusetts, and Nevada) already had some perchlorate protections in place. Therefore, the EPA’s decisionmaking process failed to consider the agency’s own scientific evidence showing that millions of people in twenty-six states and two territories are likely facing increased health burdens from perchlorate.
Perchlorate can cause harm to the human body by clogging up the proteins that normally transport iodide into the thyroid gland, thereby affecting the normal production of thyroid hormones. In adults, this hormone dysregulation can result in changes in weight and cholesterol, but the effects in young children and fetuses are believed to be much more extensive, resulting in negative changes in normal brain development. For instance, a 2014 study in the UK and Italy with nearly 500 mothers as participants found that women with the highest levels of perchlorates in their urine during pregnancy were three times more likely to have children whose IQ levels ranked in the bottom 10 percent of those studied.
Due to this evidence, the American Academy of Pediatrics, other medical experts, and a tribal community in Arizona – the Salt River Pima-Maricopa Indian Community – have concluded that there is a pressing need to regulate perchlorate. When the EPA refuses to regulate a chemical that the best available science suggests causes harm to young children, they are shirking their duty to protect people from a clear environmental harm, an action that will continue to place undue health burdens for up to 16 million people living in the US.