Sacramento, CA / August 1, 2019 / — A recent study conducted by researchers from the University of California, Davis found that a previously unrecognized source of nitrogen oxide (NOx) air pollution is actually accounting for as much as 40 percent of all NOx emissions in California. The researchers traced the source of NOx emissions to fertilizer-laden soils in the Central Valley region, a finding that highlights the importance of air filters in the state, which continues to struggle with air pollution from wildfires and traffic.
The study, published in the January issue of the journal Science Advances, saw the researchers comparing computer models with air pollution data gathered through scientific flights over the San Joaquin Valley. Both data collection methods suggested the soils were generating at least 25 percent and up to as much as 41 percent of the state’s NOx emissions due to the heavy application of nitrogen fertilizer.
“NOx refers to a family of chemical compounds that are key to the formation of smog pollution,” said Mark Davidson, Food and Beverage Segment Manager at Camfil USA. “NOx also plays a central role in the formation of ground-level ozone, which increases the risk of asthma, heart disease and other respiratory issues.”
In fact, the World Health Organization estimates that around one in eight premature deaths can be directly linked to exposure to high levels of NOx.
Why Fertilizers Are Dangerous to Outdoor and Indoor Air Quality
The UC Davis study is just one of many reports linking the effects of fertilizer application to outdoor and indoor air quality issues. In 2015, another study found that emissions from farms outpace other sources of particulate air pollution in the United States, Europe, China, and Russia.
Not surprisingly, the culprits for these high levels of farm-related air pollution were nitrogen-rich fertilizers and animal manure, which combine in the air with industrial runoff to create the same solid particles that pose a risk to public health.
“Long-term exposure to ultrafine solid and liquid particles can cause all kinds of respiratory and cardiovascular conditions,” explained Davidson. “This is particularly true for PM2.5, or particulate matter with a diameter of 2.5 microns or less, which is small enough to reach deep into the lungs and cross into the bloodstream.”
The study, however, also revealed an important silver lining: if we can reduce our production of industrial emissions, fine-particle air pollution will decline even if fertilizer use rises. But it’s important to note that this only applies to particle pollution—NOx from fertilizers can still lead to the creation of toxic ground-level ozone.
Buildings Near Farms May Need Commercial Air Filters More
Buildings near farms may have a higher need for commercial air filters due to the high levels of ammonia produced by these facilities. Ammonia gas is especially common in heavily fertilized fields and farms, which also generate significant amounts of livestock waste.
The ammonia, in turn, combines with airborne pollutants generated by the burning of fossil fuels in cars, power plants, and other industrial processes. The resulting byproducts are solid particles or aerosols known as PM2.5.
While California cities like Los Angeles and San Francisco have gone to great lengths to reduce air pollution levels in urban areas, some of the state’s worst air quality issues are still affecting rural areas like the San Joaquin Valley, which is also home to many low-income families in California.
The problem of fertilizer-caused air pollution is unlikely to go away anytime soon, as the Central Valley in California, is one of the world’s most productive agricultural areas, plays a vital role in the U.S. agriculture industry. It’s where almost all of the country’s tomatoes, avocados, walnuts, and almonds among other crops are grown.
The challenge facing state officials, as pointed out by the authors of the UC Davis study, is finding ways to continue increasing food production but doing it on the limited land available and with the use of improved techniques and better forms of fertilizer management.
Better Fertilization Methods Can Ease Dependence on Industrial Air Filters
The UC Davis study’s authors also provide potential solutions for reducing NOx emission from fertilizers, which in turn, circumvent the need to turn to industrial air filters to capture these airborne pollutants.
For example, a perennial issue with fertilizer application is that the plant actually may absorb only about 50 percent of the nitrogen in crop fertilizer. The more efficient alternative is to use slow-release fertilizers, which, as the name suggests, release nutrients at a slower rate, which mimics what happens in nature, thereby making it more efficient and less polluting.
Another solution is for California farms to observe a healthy soils program designed to return carbon to the soil. A healthy soils program not only has the effect of improving nutrient retention and absorption in crops, but it also helps offset their carbon footprint and fight climate change.
Fortunately, California has already started addressing their agricultural problem by creating a program that encourages growers to work together and share ways to improve the efficiency of their fertilizer use, which in turn, helps the state evaluate how and where it needs to manage nitrogen in agricultural areas.
How Commercial HEPA and Molecular Air Filters Maintain Indoor Air Quality in Agriculture Buildings
Given the presence of high levels of ammonia gas, nitrogen oxides, and particle pollution in and around agriculture facilities, it’s important that buildings handling agricultural processes be outfitted with commercial HEPA and molecular air filters to protect the health of staff. Industrial air filtration, along with proper ventilation, will go a long way toward reducing the level of dangerous airborne pollutants in the air by trapping airborne particles and toxic gases and bringing in fresh air from the outside.
Commercial HEPA and molecular filters are designed to reduce levels of dangerous pollutants in the air by very small particles in the filter fibers or adsorbing gases into an adsorbent media. The HEPA filter media itself is capable of trapping up to 99.97 percent of particles below 0.3 microns. Other high efficiency filters, such as those rated MERV14/14A or ISO16890 ePM1, capture 70 percent of particles 1 micron or smaller. When paired with molecular filters this helps create an air purification process that ensures workers inside agricultural buildings are continuously supplied with clean, safe, and breathable air.
Commercial Air Filtration Systems Only Address One Side of the Fertilizer Problem
However, all that being said, air pollution is just one side of the problem associated with fertilizers. Even if you installed the world’s best commercial HEPA air filtration systems in your buildings, you still have to deal with the fact that applying too much fertilizer can cause them to wash over fields and pollute watersheds. One need only to look at the dead zone that appears each summer on the mouth of the Mississippi River caused by excess nitrogen from farms upstream.
For this reason, improved fertilizer management and application, as suggested by the UC Davis study, is so important. In the meantime, however, air filtration systems play a critical role in ensuring that agriculture workers and nearby residents are kept safe from the health risk of exposure to fertilizer-related air pollution.
For more than 50 years, Camfil USA has been a global leader in the design and manufacturing of high-quality air filtration systems and air filters for all kinds of industrial facilities and manufacturing process and manufacturing processes in North America. To learn more about filtration solutions for agricultural buildings and the importance of indoor air quality control on farms, talk to Camfil USA.