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Exposure: Nitrates

Nitrate Pollution in Germany

By Marlena Bludzien

Germany is a country rich in water resources. Every year an average of 860 liters of precipitation water falls per square meter – a total of 307 cubic kilometers. However, this precipitation is distributed very unevenly from region to region. While 1,500 to 2,000 liters per square meter falls in the Central Uplands and the Alps, the figure is just 500 to 600 liters in many districts of Brandenburg and Saxony-Anhalt.

In total, just 0.3 cubic kilometers of water is currently used for irrigation in Germany. However, agriculture in Germany uses a lot more water to dispose of excess fertilizers and plant protection substances. In Lower Saxony and North Rhine-Westphalia there is a lot of pig farming which generates a lot of manure. According to the agricultural census of 2010, Germany generates about 160 million cubic meters of livestock manure per year, of which 36 million is pig manure. Livestock manure is generally well suited for agricultural fertilization and irrigation but as the soil can no longer sequester the substance, it becomes overfertilized and leads to nitrogen contaminating the groundwater. Presently, over 100 kilograms of surface nitrogen remains in the German soil.

High levels of nitrates damage freshwaters and marine environment. They increase algae’s growth which in turn destroys other life forms through process of eutrophication The increased presence of nitrogen in the soil can also have detrimental effects on human health. According to the report of the University of Nebraska, symptoms such as gastrointestinal swelling, diarrhea, protein absorption and digestion are developed as a result of drinking nitrate contaminated water. When nitrates mix with iron in red blood cells, the cells lose their ability to effectively transport oxygen. The symptoms that accompany this process are commonly recognized as “blue baby syndrome.” Elderly, pregnant women and children below one year of age are at the highest risk for developing the symptoms. In the 1990-s the European Union set up an upper limit for the nitrate concentration in the groundwater to as 50 milligrams per liter.

Germany has been on a radar for its groundwater contamination with nitrate and phosphorus for a while. In April 2016, European Commission referred Germany to the Court of Justice for the failure in executing appropriate measures in controlling water pollution and endangering human life and environment. Despite the seriousness of the problem the levels of nitrate in Germany’s water continue to increase. One third of the Germany’s groundwater is currently contaminated and the recent reports indicate that out of 700 measuring points across the country, 28 percent drastically exceeds the legal limits. This situation can result in serious damage to human health and degradation of environment. The authorities must push for stricter regulation of fertilizers used in farming and seek innovative ways to eliminate the risk that livestock farming poses on safety of water.

(c) Jason Zheng

Nitrate Directive of 1991 in Wales

By Jason Zheng

The Nitrates Directive of 1991 aim to protect water quality across Europe by preventing nitrates from agricultural sources polluting ground and surface waters. It also aims to promote positive farming methods for farmers too. However it was not until 2008 the Welsh government of Wales established as a law through the Nitrate Pollution Prevention Regulation. Member States of the European Commission are required to review their implement of the Directive every four years. Any recommendations that are suggested are used to make appropriate amendments to the Nitrate Vulnerable Zones (NVZs) and/or the Action Programme. 

When the land falls within the categories of being a NVZ, there are certain rules and restrictions that can be applied. This is also known as the “Action Programme” and it will also ensure the water qualities of Wales are suitable for use. The people of Wales can find out here to determine if their land is in an NVZ. NVZ boundaries have been draw around whole fields, so there are no fields that are partly in an NVZ.  

NVZ regulations limit the amount of nitrogen from manure that can be applied across the farm to 170kg per hectare annually. Derogation is available which allows farms in the areas of NVZs, which livestock and more than 80% of their area under grass to work to a higher limit of up to 250 kilograms of nitrogen per hectare. This derogation is only applied as long as an application is made each year and conditions are met.

Tackling nitrate pollutions can help ensure industries that need high water quality remain viable. This includes recreation and tourism, fisheries and agriculture, horticulture and food processing. As well it will maintain and improve the quality of drinking water and reduce the complexity and cost of water treatment. By reducing the loss of nitrate and other nutrients into the water environment to reduce excessive plant growth or other associated risks. Protecting habitats is important to wildlife conservation and also increases biodiversity.

The Role of Nitrates in Our Drinking Water

By Katherine Fite

If you ask someone who lived through the 1940’s about Blue Baby Syndrome, there is a distinct possibility they know exactly what you are talking about. In that decade, Blue Baby Syndrome contributed to the deaths of almost forty infants and illnesses in hundreds of others. The incidences of illness were mostly concentrated to rural households, particularly in farm and agricultural based communities. It wasn’t until 1945 when scientists finally concluded that the cause was nitrate contaminated drinking water mixed with baby formula. The source of this polluted drinking water: private farm wells that drew drinking water from a relatively shallow aquifer. (Nadakavukaren, 613)

Today, we know that Blue Baby Syndrome is a disease caused by Methemoglobinemia. Methemoglobinemia is a blood disorder that causes an excessive amount of methemoglobin to be produced, which is then stored in the red blood cells. High levels of methemoglobin (which is a type of hemoglobin) reduce the red blood cells ability to carry and release oxygen to body tissues. This can lead to anemia and oxygen deprivation in the body . Infants and newborns are susceptible the illness because of the reduced acidity of their stomach fluids. The decreased acidity means that there are more bacteria present in infants’ intestinal tract. When they consume nitrate-contaminated water, the nitrate is converted into nitrite in the intestinal tract by these bacteria. The nitrite aids in producing methemoglobin, which displaces oxygen. This causes the skin to turn a shade of blue and, in some cases, death can occur due to lack of oxygen. (Nadakavukaren, 613) In addition, women who are nursing or pregnant may risk contaminating their children. If a woman has been exposed to high levels of nitrates, they can pass the compound to their children who are vulnerable to developing Methemoglobinemia. Lastly, people who lack the enzyme methemoglobin reductase are susceptible to Methemoglobinemia through nitrate exposure. This important enzyme is responsible for reverting red blood cells back to normal after an increase in methemoglobin.

Due to the health risks associated with nitrate, it is crucial to determine its sources and how it is enters the drinking water supply. Nitrate is a naturally occurring and manufactured inorganic compound. Nitrate is also highly water soluble; which means it dissolves easily in water. The majority of nitrates are found in agricultural fertilizer, residential septic systems, and industrial and vehicular airborne emissions. During precipitation, the nitrate in fertilizer can leach through the soil and into the groundwater, shallow aquifers and private wells. In addition, runoff can flow into surface waterways that are used as the drinking water supply. Household wastewater in septic systems can also contaminate shallow aquifers. Wastewater, which contains nitrogen, can penetrate the soil surrounding the septic system. Oxygen in the soil turns nitrogen to nitrate and then enters the drinking water supply. Lastly, industrial emissions containing nitrate can be deposited on land through precipitation and leach through the ground.

Ever since the establishment of the linkage between Methemoglobinemia and nitrate exposure, the Environmental Protection Agency (EPA) has kept a close eye on nitrate. Over the past few decades, the EPA has developed laws and policies that regulate, restrictions and monitor nitrate emissions through industrial pollution. The EPA also placed regulations on nitrate levels in our drinking water and in the waterways used to supply our drinking water.

One of the earliest pieces of legislation that set regulations and restrictions on nitrate was the Safe Drinking Water Act (SDWA) passed in 1974. Under the SDWA, EPA sets standards for public drinking water quality. These standards are known as the National Primary Drinking Water Regulations (NPDWR). These regulations are legally enforceable limits on the level of contaminants in drinking water. Under the NPDWR, the maximum contamination level (MCL) of nitrate is 10 mg/ L or 10 part per million. There is also a non-enforceable level of contamination at which there are no adverse health effects likely to occur. This is called the maximum contaminant level goal (MCLG), which also happens to be at 10 mg/L or 10 ppm. The SDWA also requires the EPA to perform the Six- Year Review. Every six years, the NPDWRs are subject to review and the level of contamination is revised if necessary to fit the new current health effects assessment. The last six-year review of nitrate confirmed that the 10 ppm MCL and MCLG were still effective and protective of human health.

The Emergency Planning and Community Right-to-Know Act (EPCRA) of 1986 gave the public the right to information about toxic chemicals being released by industrial factories. One of the primary focuses of the EPCRA is to alert communities of toxic chemical releases in the area. To do this effectively and efficiently, the Toxic Release Inventory Program (TRI) was created. The enforcement of the EPCRA and TRI led to the National Nitrate Compliance Initiative. Through this initiative, 1000 facilities have been audited and the EPA has revealed that 420 million pounds of nitrate in pollution discharge had been previously unreported. The amount of reports of nitrate compound being released or transferred by industrial facilities has increased from 60 % to 98% and companies that fail to report nitrate compounds face hefty penalties and even enforcement action. Overall efforts by the EPCRA, TRI and nitrate enforcement initiative have revealed the true amounts of nitrate emission and have initiated the process of reducing these emissions.

However, there is still work to be done. A study done using 200,000 water samples found that some of the waterways used to supply drinking water to over two million people from 1986 to 1995 exceeded EPA’s maximum level of contamination. An additional 3.8 million people drank water that had high levels of nitrate from private wells and over 12 million people drank water that came from a contaminated water supply system with excessive levels of nitrate. Another study from 1994 found that 22% private farm wells had nitrate levels far exceeding EPA limitations. (Nadakavukaren, 614) A crucial design flaw of the SDWA is that it does not regulate or monitor contamination levels in private wells. The most vulnerable populations to high-level nitrate exposure and adverse health effects are those in agricultural areas that get their drinking water from wells. Without conducting their own tests, these people do not know if the water they are drinking is safe or contains an exorbitant amount of nitrate. In addition, states are responsible for their own fertilizer regulation. In a predominately agricultural state, wouldn’t it be more economically beneficial to use larger amounts of nitrate-containing fertilizer? This notion could lead to lax regulations and an abundant use of fertilizer, which could contaminant thousands of water systems. While the EPA and its rules and regulations have overall reduced the risk of adverse human health effects from nitrate, there is a ways to go.


Nadakavukaren, Anne. Our Global Environment: A Health Perspective. 5th ed. Prospect Heights, IL: Waveland, 2000. pgs 613-614.

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