“Millions of Americans are being involuntarily exposed to nitrate, and they are also the ones paying the heavy costs of treating contaminated tap water,” says a toxicologist who co-authored a recent study in the journal Environmental Research.
Where is this nitrate coming from? Primarily agricultural runoff, according to the Environmental Working Group, the nonprofit that conducted the study. The runoff, which contains fertilizers and manure, is heavy in nitrates.
The study found that nitrate-polluted tap water could be causing over 12,000 cases of cancer each year, focused in rural areas. The researchers estimate it costs $1.5 billion annually to treat those cases.
Four-fifths are expected to be colorectal cancers. The remainder will likely be made up of ovarian, thyroid, kidney and bladder cancers.
In addition, the researchers linked serious neonatal health problems to nitrate in household water. The study estimated that 3,000 infants will have low birth weight and 2,000 others will be born prematurely due to nitrate in tap water.
The EPA standard for nitrate was set in 1962
In 1962, the Environmental Protection Agency set a standard of no more than 10 parts per million of nitrate in drinking water. It was planning to reevaluate this outdated standard this year, but those plans have been suspended.
Meanwhile, several well-founded epidemiological studies have linked cancers and other health issues to nitrates in drinking water that were at one tenth the legal limit.
The researchers in this study identified a level of nitrates in drinking water that would be safe. To cut the cancer risk to one in a million, the scientists estimate, the nitrate level would have to be as low as 0.14 milligrams per liter, which is 70 times lower than the EPA’s current limit.
Who is responsible for keeping our drinking water safe?
There are several players with responsibility. As you can see, the EPA is responsible for setting reasonable limits for toxins in drinking water. Municipal water providers must ensure the water they provide meets EPA safety limits. The agricultural industry may be responsible if its use of nitrate fertilizers is unreasonable or if it hasn’t tried to prevent undue runoff into our streams and rivers.
Potential liability in this area may share similarities with how asbestos diseases are evaluated and handled. There might be specific bad actors, but maybe the practices of an entire industry are putting people at increased risk of cancer, low-birth-weight babies and premature births. It could be difficult to tie an individual health outcome to the actions of any agricultural concern.