On a sunny afternoon in Wichita Falls, Amy Martz pushes her son on the Lucy Park swings.
Neither have a care in the world.
But a new study out of Texas Tech suggests those blue skies Martz's son is playing under could contain airborne particle pollution from cattle feed yards. Scientists estimate that over 46,000 pounds of PM2.5, or very small particles, are released into the air every day from feedlots across the Southern Plains.
You could fit over 7,500 particles of PM2.5 on one penny. But don't underestimate them based on size. This brand of particulate matter is the type that you can breathe deeply into your lungs, and if you're exposed to enough fine amounts of it, it can aggravate asthma, bronchitis, and even can cause a heart attack.
“As a mom, I would be concerned, and I guess I really never thought about it before,” Martz said. “It kind of raises some questions about air quality.”
But is this new study really a cause for concern? We went directly to the source, the Institute of Environmental and Human Health in Lubbock, to talk to two of the study's authors, environmental toxicologists Phil Smith and Greg Mayer.
“There are lots of sources of air pollution, and one of those sources is agricultural production,” explained Smith.
Smith and Mayer collected dust samples around cattle feed yards. We told you last month that the two scientists found antibiotic resistance in the air downwind of the feedyards. They also found large amounts of particulate matter in the dust.
But, where do these particulates come from?
“The majority of the particulates that were sampled we're likely emanating from the south end of a northbound cow,” Smith said, somehow keeping a straight face.
When cattle do their business, what comes out forms a layer of material over the feedyard pen. The pen floor dries out throughout the day, and the shearing action of the cow's hooves breaks the material up, some of which becomes suspended in the air.
A natural follow up question is: how far can these disgusting and potentially harmful particles travel?
“We know from other studies that these very fine particles can travel essentially globally.”
Smith and Mayer say that Texomans should not worry about potentially being downwind of the 23 tons of dried fecal matter being pumped into the air each day.
“I think we're breathing stuff in all the time, sure. Is it awful? I don't think so,” Smith said.
“This is not something that just started,” added Mayer. “Cattle production like this has been going on for a long time. We just happened to put some metrics into it.”
A similar sentiment shared by Texoman Jose Zambrano.
“The earth we live in has been messed up enough to where we're breathing in worse than just cow crap,” Zambrano said. “We're breathing in the toxins from our vehicles, so cow crap is the least of my worries.”
Zambrano is on to something. In fact, almost all of the particle pollution in the United States comes from sources other than cattle. The Environmental Protection Agency has both daily and annual limits to the amount of PM2.5a state can produce. Texas has not had to revisit those limits in the last five years. The EPA also tends to focus on population exposure, not a single source that may be impacting an area.
“A lot of the area in West Texas would not have monitors because the population is not as high,” explained Guy Donaldson of the EPA's Region 6 office in Dallas.
“I would guess that feedlots are a lot lower than the other sources we look at combined,” added Region 6's Joe Kordzi.
Although 46,000 pounds of cow feces seems dramatic, according to Smith, that number is across five states with very large surface areas.
“You could spread that over the large area and it be virtually unnoticeable,” Smith said.
Unnoticeable, for now. The study hypothesized that the amount of PM2.5 suspended in the air could increase in times of prolonged drought. The authors hope that, in this case, knowledge is power.
“We are in the business of providing information that goes into good decision making on environmental stewardship,” both Smith and Mayer said.
Smith said the cattle industry has already enacted strategies at their production facilities to minimize particulates and odors from getting in the air. They want to be good neighbors and good citizens, and now, armed with this information, good environmental stewards.