A current research project based in the Great Plains Center for Agricultural Health (GPCAH) is investigating methods to improve air quality in swine farrowing buildings1. The research team developed models to estimate room concentrations of multiple indoor contaminants [ammonia, dust, hydrogen sulfide, carbon monoxide, and carbon dioxide (CO2)] and conducted field monitoring to evaluate the effectiveness of using ventilation and engineering controls.
In both modeling and field work, the researchers found that CO2 concentrations exceeded recommended workplace limits for swine workers2 (1540 ppm) over the entire winter season and also exceeded one-half the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL=5000 ppm), which is based on exposure to a single contaminant (unlike what exists in swine buildings). Sources of CO2 in livestock production include both animal respiration (exhaled breath) and combustion products from heaters.
Since controlling animal breathing is infeasible, the team evaluated whether the unvented heaters commonly used throughout the Midwest (e.g., LB White heaters) were a significant contributor to high CO2 levels measured in livestock buildings. In fall 2014, researchers installed new gas-fired heaters, the Effinity93 (60K BTU, approximately $500 more than equivalent LB White unit), in a test barn. The team measured concentrations throughout the following winter, comparing them to that of the previous winter with traditional unvented heaters.
To protect the unit from dust, fresh air intake to the combustion device was from outside the farrowing building, and combustion gases were exhausted from the unit to outside the building. The investigators identified that CO2 was reduced by 800 ppm with the new heaters.
Another 200 ppm difference in CO2 between seasons was attributed to colder outdoor temperature and larger in-room animal population in the winter with the older unvented heaters. Other vented gas-fired heaters are available, and the researchers recommend substituting unvented heaters with vented units that have stainless steel internal components, which should improve the lifespan of the heater when used in livestock environments containing ammonia.
1. See www.public-health.uiowa.edu/gpcah/center-projects/intervention-to-reduce-exposures-in-cafos/ for more details on this larger project.
2. Donham K, Haglind P, Peterson Y, et al. (1989) Environmental and health studies of farm workers in Swedish swine confinement buildings. Brit. J. Industr. Med. 46:31–37.
This story originally appeared in the September 2015 issue of Farm Families Alive & Well
Although farming is a rewarding career critical for Iowa and the nation, it can be dangerous work. Estimates suggest that 2 of every 20 farmworkers are likely to be injured in the United States each year.
Tractors are a particularly dangerous source of injury. While national databases keep track of tractor-related fatalities, the number of people sustaining severe injuries and how these injuries occur is less clear. What is known is that nonfatal tractor-related injuries are common and preventable, with some suggesting the rate is 30 times that of fatal tractor injuries.
Types and causes of tractor injuries
In an innovative, first-of-its-kind study, University of Iowa researchers led by Amanda Swanton, a doctoral student and researcher with the Injury Prevention Research Center (IPRC), and Corinne Peek-Asa, professor of occupational and environmental health and director of the IPRC, analyzed 513 cases of nonfatal injury from the Iowa Trauma Registry, the database of the Iowa Trauma System, to examine the types and causes of tractor injuries that required emergency care. The cases were from 2002–2012. The study was published in the Journal of Safety Research.
Study results showed that tractor rollovers were the primary cause of the most severe injuries. As recent technical innovations have focused on reducing the number of tractor rollover deaths, it may be that fewer fatalities have meant a higher number of severe injuries. Other frequent causes included jumping/falling/being thrown from the tractor, being run over, and collisions, often with non-farm vehicles on roads.
Bone fractures were by far the most common type of injury (almost 50%). Other common injuries included internal or open wounds. While most of the injuries were not that severe, the average hospital stay was 3 days, and could range up to 68 days. Notably, 23% of patients required at least one day in the intensive care unit.
Age and injuries
Age affected type and severity of injury. Children were most likely to be hurt falling or jumping from a tractor, young adults by rollover or collision. Those ages 25-44 were most frequently involved in collisions, suggesting that this age group is responsible for transporting farm goods on roadways. Farmworkers in their 40s were injured often but not severely, while those over 55 had a lower risk of injury but a higher risk of being badly hurt, perhaps due to being less resilient and more fragile.
According to Swanton, “the tractor is an everyday part of farm life, and it can be hard to imagine that such a trusted piece of machinery can be dangerous. Tractor injuries are usually sudden and unexpected, but they are also preventable. Making sure tractors have rollover protective structures, are kept in good working condition, and using common sense when working with tractors can go a long way in preventing injuries.” Swanton is a student in the UI Medical Scientist Training Program that provides training for both the MD and PhD degrees.
Studies like this are critical to the effort to reduce the number of farm injuries. Possible approaches might include reconsidering tractor design, how farm equipment interacts with roadways, and how best to educate farmworkers on tractor safety.
The research team also included Tracy Young, injury epidemiologist with the IPRC; Kathy Leinenkugel, Iowa Department of Public Health; and James Torner, a faculty member with the IPRC and professor and head of epidemiology in the UI College of Public Health. The study was funded by the UI Great Plains Center for Agricultural Health.
Farmers and other outdoor workers face hot and humid conditions in the summer, but they can take steps to prevent sun burns and heat stress. Iowa’s Center for Agricultural Safety and Health (I-CASH) and the Great Plains Center for Agricultural Health (GPCAH) have launched a seasonal awareness campaign on skin cancer and heat stress. The campaign includes a poster and radio spots to help spread the word.
Skin Cancer Prevention
Preventing Heat Stress
A new report by UI College of Public Health investigators sheds light on the more than 200 agriculture-related deaths per year that occur in Midwestern states, confirming that farming remains one of the nation’s most dangerous industries and poses particular risks to vulnerable populations such as elderly workers.
The goal of the report, sponsored by the UI Great Plains Center for Agricultural Health, is to facilitate access to agricultural fatality information for anyone interested in agricultural safety and health. The full report and an accompanying slide show are available at: http://cph.uiowa.edu/gpcah/center-projects/surveillance-of-agricultural-injuries-and-fatalities/.
Researchers Amanda Swanton, Tracy Young, Corinne Peek-Asa, Marizen Ramirez, and Fred Gerr studied 1,858 agriculture-related deaths that occurred between 2005 and 2012 in 12 Midwestern states, including Iowa, Illinois, Indiana, Kansas, Michigan, Minnesota, Missouri, North Dakota, Nebraska, Ohio, South Dakota, and Wisconsin.
“Numerous hazards threaten farm workers including exposure to machinery, livestock, chemicals, noise, and physical stress, which can be compounded by the fact that agricultural activities are often performed in rural environments with limited access to medical services,” the authors explain.
Over the period reviewed, there were on average 232 agriculture-related fatalities per year in the Midwest region, an annual rate of 19.94 agriculture-related deaths per 100,000 farm operators. This compares with an overall rate of 3.4 fatal work injuries per 100,000 full-time equivalent workers across all industries in 2012.
The researchers also report that agriculture-related fatalities increase with age. Over three-quarters (77%) of agriculture-related deaths occurred among persons 45 years or older, and 41% occurred in individuals 65 and older. Less than 3% of agriculture-related fatalities occurred among minors less than 16 years old.
Other findings include:
- Agriculture-related fatality is much more commonly experienced by males than females. Of the 1,858 total agriculture-related deaths studied, 95% occurred in males while only 5% occurred in females.
- More than half (51.6%) of individuals who died due to an agriculture-related injury were performing a vehicle- or transportation-related task at the time of the incident. Of these 958 fatalities, 315, or 33%, were due to farm vehicle (e.g. tractor) rollovers.
- Agriculture-related fatalities are most frequent from late spring to early fall. The greatest number of deaths occurred in July (13%), while the lowest number of deaths occurred in December (4%).
- Fatalities most often occurred within 24 hours of the inciting injury, however deaths occurring after 24 hours were more frequent with increasing age. The fact that some older individuals do not die immediately of their injuries suggests that there may be an opportunity for medical intervention to potentially save these lives, however further research is needed.