05
Dec
Upcoming EPA Review of Nitrates in Waterways Raises Health and Environmental Questions About Synthetic Nitrogen Fertilizer Use
(Beyond Pesticides, December 5, 2023) The U.S. Environmental Protection Agency (EPA), in a quiet reversal of a 2018 Trump administration decision, is resuming an evaluation of the health impacts of nitrates in water, reflecting the long-standing and mounting evidence of synthetic nitrogen’s adverse effects on human health and the environment, particularly in vulnerable communities. This review, which appears to be focused on what many scientists point to as outdated federal standards for allowable levels in water, brings together a confluence of issues related to the use of synthetic nitrogen fertilizer as a potent greenhouse gas that contributes significantly to the climate crisis. As reported by Circle of Blue in early November, the Integrated Risk Information System (IRIS), a research program of EPA, published a schedule on its website that it would release “Preliminary Assessment Materials/Systematic Review Protocol” in October of 2023 and then announce a schedule for public comment, external peer review, and post final assessment. EPA insiders say the review process will likely take years unless subject to intense public pressure.
While synthetic nitrogen was understood to be of high priority for review and presumably improved restrictions even before the publication of EPA’s 2011 report of the agency’s Scientific Advisory Board (SAB) documenting high levels of concern associated with a range of pollution and adverse effects, the lack of action over the last 12 years has only elevated the seriousness and urgency of health and environmental implications. The SAB report, “Reactive Nitrogen in the United States: An Analysis of Inputs, Flows, Consequence, and Management Options,” was delivered to the EPA Administrator in the Obama Administration with a sense of urgency.
In a letter accompanying the report, the SAB stated, “Excess reactive nitrogen compounds in the environment are associated with many large-scale environmental concerns, including eutrophication of surface waters, toxic algae blooms, hypoxia, acid rain, nitrogen saturation in forests, and global warming. In addition, reactive nitrogen (referred to as Nr) is associated with harmful human health effects caused by air pollution and drinking water contamination.” The board pinpoints synthetic nitrogen fertilizer and the release of nitrous oxide as a major contributor to the problem and posits a “mitigation” strategy to control the chemicals “damages as it is introduced to and cycles repeatedly through the environment in different forms and media.” The report identifies, “The largest U.S. sources of new Nr entering the U.S. environment include: the creation and use of synthetic fertilizers, Nr created by legumes, and the combustion of fossil fuels,” but assumes ongoing dependency on synthetic nitrogen. In the last decade, however, alternatives to synthetic nitrogen fertilizers and fossil fuels in organic agriculture and renewable energy, respectively, have become increasingly mainstream.
In a collaboration between the Nitrogen Initiative (INI) and the Global Carbon Project of Future Earth, the organizations point to an article in Nature, based on their estimates, that shows the increasing threat of nitrous oxide to the world’s climate crisis and stratospheric ozone depletion. INI concludes that “nitrous oxide is 300 times more potent greenhouse gas than carbon dioxide in the long run,” with a 30% increase in emissions between 1980 and 2020. The Nature article finds that a failure to address the issue of synthetic nitrogen use risks derailing efforts to meet the 2°C warming limit set by the Paris Climate Agreement, underscoring the urgent need for a reevaluation of our agricultural practices. “This new analysis calls for a full-scale rethink in the ways we use and abuse nitrogen fertilizers globally and urges us to adopt more sustainable practices in the way we produce food, including the reduction of food waste,” said study coauthor Josep ‘Pep’ Canadell, PhD. Another research finding of note, a 2018 study, concluded that the state of California was woefully underestimating nitrogen oxide emissions from agricultural sources.
In addition to synthetic nitrogen fertilizer, another source of nitrate and nitrous oxide pollution is untreated manure from large-scale, conventional livestock operations. Livestock farming produces 37% and 65% of global methane (another greenhouse gas) and nitrous oxide emissions, respectively.
EPA assessment is expected to assess a broad range of nitrate health harms
The restarted EPA IRIS assessment, last updated over three decades ago, is now expected to undertake a comprehensive evaluation of nitrate toxicity, as reported by Circle of Blue. This review may encompass a range of health concerns, including cancer risks and impacts on the reproductive system, metabolism, development, thyroid, and blood. The complexity of this assessment is heightened by the diverse sources of nitrate exposure, including food and the indirect pathways through which nitrate can cause harm. The Iowa Environmental Council published a report, Nitrate in Drinking Water: A Public Health Concern for All Iowans, back in 2016, which captured this widespread problem across the U.S. The U.S. Geological Survey (USGS), in addition to Iowa, has identified the following states as areas with high-risk clusters from nitrate contamination to groundwater: Oklahoma, Kansas, Nebraska, North and South Dakota, Illinois, Minnesota, Pennsylvania, and Maryland.
Beyond the long history of data, advocates say that EPA action on water contamination is critically needed because of emerging research linking nitrate exposure to various health issues. “There’s growing evidence of adverse effects in children exposed in utero and among adults,” Leslie Stayner, PhD, a professor emeritus of epidemiology at the University of Illinois at Chicago. Dr. Stayner’s studies in Denmark, which examined a million childbirths, find that exposure to nitrates during pregnancy correlates with an elevated likelihood of lower birth weights, premature births, and congenital anomalies in the eyes and central nervous system. Notably, these correlations were observed even at nitrate levels lower than the existing EPA standards. For instance, studies have indicated associations between nitrates in drinking water and increased rates of birth defects, pre-term births, and certain cancers, even at levels below the current EPA standard of 10 parts per million. This standard, primarily aimed at preventing blue baby syndrome in infants, fails to address the chronic effects of long-term exposure or prenatal impacts.
Moving Forward
Beyond Pesticides advocates for a fundamental shift away from synthetic, petrochemical fertilizers and pesticides toward organic food production and consumption. This approach not only addresses the immediate issue of nitrate pollution and dependency on synthetic nitrogen fertilizer but also tackles the broader environmental impacts associated with conventional agricultural practices. Organic systems, by recycling reactive nitrogen already present in the environment and sequestering carbon in the soil, present a viable and sustainable alternative. Additionally, climate-friendly organic systems are more profitable for farmers than chemical-intensive agriculture.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Sources: EPA Restarts Assessment of Health Risks from Nitrate in Water;
A comprehensive quantification of global nitrous oxide sources and sinks, Nature, 10/7/2020;
