Nitrate and nitrite are about to reemerge as groundwater and drinking water chemicals of concern.

Our new research reveals that current nitrate and nitrite drinking and groundwater standards do not reflect a true weight of evidence analysis of the peer-reviewed literature and government documents. As a result, such noteworthy authorities as U.S. Environmental Protection Agency (EPA), the World Health Organization, California EPA, Health Canada, Minnesota Department of Health, and Wisconsin Department of Health Services rely on a curated list of papers or follow the lead of other agencies in their deliberations and conclusions.

Furthermore, it is the papers and data not cited or ignored by these authorities that demonstrate a very different story concerning the risks posed to infants by ingestion of nitrate and/or nitrite contaminated drinking water through their infant formula or directly.​

Since the 1940s it has been felt, then believed, then codified into enforceable drinking water standards, guidelines, advisories, limits, etc. that the right concentration to protect infants from nitrate's injurious potential was, and is, 10 ppm nitrate-N. Vast numbers of learned papers and government technical support documents have been written supporting 10 ppm nitrate-N as the boundary between safety and unacceptable risk.

What if “lost” blue baby cases were discovered from the 1940s to 1950s, the same timeframe as those cases used as the basis for the nitrate standard? What if these “lost” cases are of equal or better quality than those used to establish the nitrate standard? We have found such lost cases. They are at concentrations below the current nitrate drinking water and groundwater standards.

In our book we will present data that changes our understanding of the lowest concentration of nitrate known to cause cyanosis in infants, the key visual observation used to identify a likely case of blue baby syndrome. This brings the scientific validity and basis of the nitrate standards around the world into question, since the nitrate standard is based on the Lowest Observed Adverse Effect Level (LOAEL) identified. We have uncovered blue baby cases that occurred at nitrate concentrations more than 10 times lower than the current nitrate standards for drinking water and groundwater. This data could dramatically lower the federal drinking water standard and Wisconsin’s drinking water and groundwater standards for nitrate.

As a derived standard, typically a percentage of the nitrate standard, the nitrite standard would also decrease.

Reducing nitrate’s standard to between 1 to 5 ppm nitrate-N, perhaps lower, would mean that uncountable wells would now be at unacceptable risk levels. The same is possible for many public drinking water supplies. Agricultural use of fertilizer and manure would need to be further restricted.

Why Nitrate and Nitrite Levels Matter

Why are nitrogen fertilizers, in the form of inorganic fertilizers and animal manure, still used so heavily, given the threats they represent to environmental quality and human health?

The literature we reviewed has many answers to this question. The most compelling is the fact that we have degraded our agricultural soils from a lack of regenerative practices. Degraded soil produces less crops and forage. As yields drop, farmers apply more fertilizer to increase or maintain yields, ensure productivity and protect their economic future for their farms and communities. Yet, as soil degrades, it appears less able to retain nutrients farmers apply. This allows nutrient runoff or leaching into groundwater.

This conundrum, the need to ensure crop and forage yields, while knowingly harming soil and degrading surface water and groundwater quality has led us to the nitrate problem widely discussed in media and professional publications. This conundrum cannot be solved by scientists. It is a risk management determination, a matter for resource managers and politicians.

Modern Monitoring Misses the Point

Current groundwater monitoring programs for public drinking water systems and private groundwater wells tend to use “nitrate plus nitrite as N,” a cheap and convenient analytical chemistry technique that does not provide nitrite concentration data. The pervasive, mistaken belief among too many modern scientists is that nitrite isn’t present in groundwater or, if present, nitrite isn’t at levels of health concern and is, at best, transitory.

Hence, the common practice in many localities is to rarely measure or monitor for nitrite as a separate chemical entity, particularly in private rural well water. This, despite the fact that nitrite is a direct human toxicant, not nitrate, and the fact that nitrite in drinking water has been reported associated with cases of blue baby syndrome.

By relying on ‘nitrate plus nitrite as N’ as a monitoring method of convenience, private well owners and governments prevent calculation of risks from a mixture of nitrate and nitrite in a water supply. This is especially distressing given that these standards exist to protect against blue baby syndrome and that many of the case histories of blue babies, including the first case, reported significant amounts of both nitrate and nitrite in the source water.

It Started with Blue Babies

The North American blue baby outbreak led to a flurry of research into blue baby syndrome. Blue baby syndrome is rare in the U.S. today, but was all too common immediately after World War II. It remains quite common elsewhere in the world. This is especially distressing given that each standard, nitrate and nitrite, was established to protect infant health and both chemicals have been reported in cases of blue baby syndrome from 1945 to the present. 

While many cases of blue baby syndrome were reported in North America in the years immediately following World War II, the vast majority of cases lacked detail.​ Factors typical of blue baby cases include:

• under three months old, although some were older;

• bottle-fed infant formula products diluted with well water contaminated with nitrate, many with bacteria and some with nitrite;

• reliant on water from shallow, poorly constructed private wells in proximity to either inorganic fertilizer or animal or human wastes.

Whenever a case occurs, it is nitrite formed from nitrate either in the infant gastrointestinal tract, or directly ingested from drinking water, that crosses into the bloodstream and converts hemoglobin into methemoglobin.

Methemoglobin cannot release oxygen to the cells. As a result, the infant becomes oxygen starved, a serious and potentially deadly disease state. While numerous hypotheses exist as to how exactly this process occurs, they have not yet been reconciled.

Blue baby syndrome can occur within 24 hours of ingestion. Severity can increase dramatically in a short amount of time. Some infants get so sick that they require emergency care and an antidote. Some live, some die. Those babies that survive are assumed to have no future health concerns despite demonstrating signs of oxygen deprivation perhaps for days, weeks or months.

Since not all infants get sick from drinking nitrate or nitrite contaminated drinking water in their formula, there are other factors at work that we still do not understand. This is termed uncertainty.

From Blue Babies to Drinking Water And Groundwater Standards

How did the EPA write their standards for nitrate and then nitrite? Nitrate's standard was directly calculated from blue baby summary statistics. Nitrite's standard was set as a percent of nitrate's standard using many unproven assumptions.

EPA’s drinking water standards for nitrate-N, nitrite-N and nitrate plus nitrite as N​ were adopted as Wisconsin groundwater standards, under Wis. Stat. chapter 160.07. Wisconsin, therefore, employs the EPA’s maximum contaminant levels as the Wisconsin Groundwater Enforcement Standards, as follows:​

• nitrate:

  • ​enforcement standard= 10 mg/l (as nitrate-nitrogen)
  • preventive action limit = 2 mg/l (as nitrate-nitrogen)

• nitrite:

  • enforcement standard= 1 mg/l (as nitrite-nitrogen)
  • preventive action limit = 0.2 mg/l (as nitrite-nitrogen)

• nitrite + nitrate

  • enforcement standard= 10 mg/l (as nitrogen)
  • preventive action limit = 2 mg/l (as nitrogen)

What’s the Problem?

The dominant paradigm followed by EPA and other indicates that:

• nitrate from inorganic fertilizers or fecal material containing bacteria contaminates groundwater;

• contaminated water contains nitrate and perhaps bacteria;

• contaminated water is mixed with liquid or powdered milk products that is then fed to infants;

• nitrate in the formula converts in the infant gastrointestinal tract to nitrite, primarily by bacteria; then

• nitrite crosses into the bloodstream, forms methemoglobin and may cause blue baby syndrome.

​This widely held paradigm fails to recognize that nitrite can be present in groundwater and public drinking water supplies and might be unknowingly ingested by infants. Why? Because of a general, erroneous belief that nitrite does not occur in groundwater or, if it is present, it occurs at levels below health concern and it is transient, mentioned above.

Our findings refute this belief and hold that, under certain conditions, nitrite can be present and pose infant health risks alone or in combination with nitrate based on 1980s chemical mixture risk assessment techniques.

What do we know about nitrite that government and nongovernmental organizations have overlooked or rejected?

• Nitrite’s presence was reported in source water in numerous blue baby cases, including the first report ​​published in 1945.

• Nitrite was reported in Wisconsin groundwater at current levels of health concern.

• Data from North America, Europe, the Middle East, Africa and Asia support the fact that nitrite occurs in groundwater.

When nitrite is present, it is likely to occur as a mixture with nitrate, and perhaps other chemicals, such as pesticides, veterinary medicines, etc., and perhaps bacteria.

As previously noted, the resulting mixture can pose an unrecognized risk, unless the chemicals and their breakdown products are analyzed and reported as individual analytes, to allow calculation of a mixture’s risk to infant health.

How Bad Is Bad?

Other major issues hidden behind the federal drinking water standards for nitrate and nitrite are questionable data quality and associated uncertainty in the publications cited to suport the standards.

Nitrate and nitrite epidemiology papers and toxicology reports and blue baby case history data are riddled with uncertainties. Modern data quality requirements were years away during the 1940s blue baby outbreak. Water quality monitoring is not the same as proven data quality.

Little or nothing is said about how well water samples were collected, handled, and analyzed in the blue baby cases cited to support standards calculation or selection. By today’s standards, perhaps by 1990 or earlier, nitrate and nitrite concentration data from the blue baby cases would likely be deemed highly suspect and probably considered unusable.

The EPA has never admitted to any uncertainties in the blue baby case data it used to calculate standards. If EPA acknowledged these uncertainties, the use of uncertainty factors (like safety factors used by engineers to construct buildings and bridges to ensure they won’t collapse) would reduce the drinking water and groundwater standards by a factor of 10 or 100 or 1,000 or more, depending on the amount of uncertainty perceived and the uncertainty factors selected.

Given the appalling technical quality of the blue baby “epidemiology” papers that the EPA relies upon to support their standard calculations, the nitrate then nitrite drinking water and groundwater standards could be dramatically lowered to compensate for their obvious lack of data quality (e.g., lack of materials and methods and QA/QC documentation in the EPA’s cited “principal” studies). Using uncertainty factors in chemical contaminant standards calculation is standard practice. Other government and nongovernmental analyses are no better than the EPA’s.

Modern data exists from which to calculate updated standards.

We Are Not Protecting All Babies

Our research into blue baby syndrome cases uncovered reports by credible government agencies of blue baby cases at exposures far below the federal 10 ppm nitrate drinking water standard. How the EPA and other major government agencies missed these low-exposure blue baby cases is a mystery. They’ve declined to explain.

Drinking water standards are set to protect all age groups. By protecting the most vulnerable humans, all others are protected. What if the standards are not set properly because of paradigm blindness, “me-too” writing of technical support documents, conceptual errors, epidemiological errors, or other factors? This is how the current standards were set, as our new research has found.

Given the unpredictable nature of blue baby syndrome cases, it would be prudent to monitor nitrate and nitrite groundwater concentrations in timeframes that reflect this unpredictability.

We have informed Wisconsin's Department of Natural Resources (DNR) of this need in public testimony. Yet, DNR’s permits require monitoring only for nitrate using various methods of analysis, and apparently not for nitrite, at regulated animal facilities. It seems that DNR decision-makers don’t believe nitrite is present in groundwater or fail to grasp the need to match monitoring schedules to how quickly a blue baby case can develop.

No one knows exactly why the U.S. blue baby outbreak started or why it stopped. No one knows why some babies became ill, severely ill, or died, while others showed no effect. Our research has led to some possible explanations, to be presented in detail in our upcoming book, along with recommendations on how to nail down these questions in a scientific manner. In short, the syndrome might reflect a constellation of issues specific to the time and place of the outbreak.

What Should We Do?

Attorneys representing plaintiffs, potentially responsible parties or those seeking permits for releases to soil and groundwater, now have new concerns to deal with. These include higher risks at a given nitrate concentration, missing nitrite data, and greater liability risks. While the standards’ concentrations have yet to be revised, the implications of nitrate and/or nitrite drinking water and groundwater contamination have changed. Due diligence calls for staying ahead of potential liability for these reemerging contaminants.

Conclusion: There’s More To Be Done

Clearly, nitrate and nitrite standards are not “settled and done” – their rightful status is urgent. Additional research is needed on drinking and groundwater contaminants because the existing regulatory standards for drinking water and groundwater protection were not correctly calculated in the first place.

The risks of nitrate and nitrite contamination might be higher than currently understood, and there may be other toxic effects in noninfant populations we don’t know about.

Note: Belluck and Benjamin’s forthcoming book, "Nitrate and Nitrite Impacts on Water and Public Health" from CRC Press - Taylor & Francis Group, ​provides in-depth discussion of findings summarized above, in addition to many others. They hope that their book will redefine what it takes to be a toxicology or epidemiology expert for nitrate and nitrite contamination in drinking water and groundwater.

This article was originally published on the State Bar of Wisconsin’s Environmental Law Section Blog. Visit the State Bar sections or the Environmental Law Section webpages to learn more about the benefits of section membership.