- Author: UCLA News
Reposted from UCLA Samueli Engineering Newsroom
Drone sensors for deployment into a local ignition event Courtesy of Kevin Schwarm
Using new drone sensing technology, Schwarm has helped contribute to a new way of measuring the emissions of fires — carbon monoxide, carbon dioxide, particulates, volatile organic compounds, etc. — so researchers can gain a deeper understanding of the way wildfires behave.
When controlled properly, the so-called prescribed burns — fires that are intentionally set to clear out vegetation that otherwise could end up fueling larger, more catastrophic fires — can play a key role in maintaining the health of a forest. They help prevent the kinds of wildfires that have wiped out homes and caused devastating losses of lives across California in recent years.
![Researchers fighting fire with fire alongside other researchers at Blodgett Forest in Northern California.](https://samueli.ucla.edu/wp-content/uploads/samueli/Blodgett_pic1-300x200.png)
Since the Gold Rush, however, the amount of plant life in forests in California has proliferated. While this growth is ostensibly good for the health of the forests, the extra vegetation actually increases the risk of extreme wildfires as it provides large amounts of fuel.
Located about 142 miles east of UC Berkeley on the western slope of the central Sierra Nevada, the 4,400-acre Blodgett Forest Research Station has been a living laboratory since 1933. In April, Rob York, an assistant Cooperative Extension specialist and adjunct associate professor of forestry at UC Berkeley, directed a field campaign involving four days of controlled burns. Scientists and forestry experts from other universities, including UCLA and UC Riverside, joined in the effort to reduce wildfire risk.
Working with engineers from OptoKnowledge, Schwarm was a part of several research teams in charge of measuring the emissions of the prescribed burns. They monitored the emissions using a drone that features on-board, optical sensors that can measure levels of airborne carbon monoxide and carbon dioxide. The team also used the data to create aerial maps that correlate the emissions with the fires, as well as other ground and air measurements.
Schwarm, whose doctoral research focuses on optical diagnostics for combustion systems and harsh environments, was responsible for monitoring the data collection, working with the optical sensor equipment and guiding the drone pilots during the tests.
![Uses drone sensing in prescribed burns to prevent wildfires](https://samueli.ucla.edu/wp-content/uploads/samueli/Blodgett_pic4-300x200.png)
at Blodgett Forest
A Maine native who loves the outdoors, Schwarm was initially interested in research involving internal combustion engines when he first visited UCLA in 2017 as a prospective graduate student. After meeting Spearrin and learning about his research on laser diagnostics and combustion systems, Schwarm was intrigued and decided to join Spearrin's research group that fall.
“I found Professor Spearrin's research very compelling, with laser diagnostics providing an avenue for engine research while also remaining an elegantly simple yet powerful measurement tool with wide applicability,” Schwarm shared.
Last fall, Spearrin introduced Schwarm to the multicampus wildfire project. “I found it a very exciting opportunity to use our expertise in combustion diagnostics to play a role in enhancing our understanding of both wildfires and climate change, which could lead to better methods for managing these grave issues,” Schwarm said.
According to Schwarm, the preliminary results from emissions data collected during the field campaign indicate that the drone sensor was very effective in capturing the multi-dimensional gradients of emissions in the fire plumes.
The team has been able to create three-dimensional spatial maps of the emissions concentrations, tracking how they change over time. This finding provides the researchers with insight into how fires behave, such as where the boundaries of the fire are and where new ignition sites emerge.
“This is very exciting as a new sensor capability to provide a deeper level of information for a wide range of applications in wildfire science and management, and we are currently working with the other researchers involved in the burns to place that information into context,” Schwarm said. “This was the first full-scale, real-world test for our drone sensor, and it will serve as a strong foundation for future deployment and expansion of our methods.”
Sara Hubbard contributed to this story.
- Author: Jeannette E. Warnert
A summer of smoke and ash in many parts of California has raised questions about the safety of produce growing on farms and in the garden, eggs laid by chickens who peck around in ash-laden areas, and remediation needed to safely and effectively grow food in the future.
UC Agriculture and Natural Resources brought together experts who have researched the effects of previous fires' fallout and studied soil contaminants to share their insight in a two-hour webinar now available on YouTube.
“The No. 1 health concern during a fire is smoke inhalation, and it's been well documented that wildfire smoke can negatively impact both the heart and the lungs,” said Claire O'Brien, a pharmacology and toxicology doctoral student at UC Davis. “However, the chemicals found in the smoke don't just stay in the air. They can deposit onto plants and into soil and water.”
Although every fire is unique, some generalizations can be drawn from research conducted following previous fires. UC Cooperative Extension food systems advisor Julia Van Soelen Kim detailed a study conducted following the October 2017 wildfires in Sonoma County and across the North Bay.
With the help of UC Master Gardener and community volunteers, the researchers collected over 200 samples of homegrown collard greens, lettuces, kale and chard that were exposed to wildfire smoke and ash. A subset of the samples were analyzed by a private laboratory.
“There was very low concern about chemicals on produce,” Van Soelen Kim said. “No samples had detectable levels of lead, arsenic, mercury or chromium. And that's a huge sigh of relief.” However, analytical results vary by site, site history and by fire event, and few have pre-fire baseline data to compare with.
Van Soelen Kim said basic food-safety practices should be followed when preparing to eat food grown in a home garden, regardless of ash or smoke contamination.
“You should always wash your hands before and after harvesting, and wash your produce in running water to mitigate any kind of potential risk,” she said.
Are backyard chicken eggs safe to eat?
Another study outlined at the webinar used a similar process to determine whether there might be contaminants in the eggs laid by backyard poultry that live and feed in areas exposed to wildfire ash and smoke.
Scientists know from previous research that chickens exposed to lead in their environment can produce eggs with high lead content and that heavy metal content of ash from urban wildfires is higher than from rural wildfire.
“We combined those two pieces of research with what we know that chickens do all day: they peck at the ground for hours on end,” said Todd Kelman, a veterinarian in the School of Veterinary Medicine at UC Davis. “That makes for a pretty good hypothesis that urban wildfire could pose a risk for the production of eggs and poultry that contain heavy metals.”
Kelman and his team put out a call for eggs from backyard poultry and received samples from 344 premises in fire-affected and non-fire-affected areas of California.
Surprisingly, egg samples that contained higher lead levels came from parts of the state that were not directly impacted by ash and smoke.
“Did our data support our hypothesis that proximity to urban wildfire is a driving source for lead in eggs of backyard poultry? The answer is not so much,” Kelman said. “So, is it safe to eat eggs from your backyard poultry? We can't give you a definitive answer to that question. But we do suggest you assess your risk and reduce the risk of contamination.”
Practices that reduce the risk include keeping chickens off the ground, using a chicken feeder that prevents spillage onto the ground and making calcium readily available, for example in the form of oyster shells, because calcium can prevent the absorption of lead. Making sure that chickens are provided uncontaminated water is also an important part of risk reduction.
For confirmation on the safety backyard chickens and their eggs, lab tests for eggs are available for $60 from the California Animal Health and Food Safety Laboratory at UC Davis, or chickens may be submitted to CAHFS for necropsy.
Are soils safe for growing food after a fire?
Fire effects on soil is another consideration in burned areas, said UC Cooperative Extension urban agriculture advisor Rob Bennaton.
“Fires heat topsoil layers. They reduce the amount of living micro-organisms at the site of the burn, and also affect organic matter and nutrients. Ash deposits over time may make soils more alkaline,” he said. “As a result of these combined factors, there are temporary changes in nutrient levels and the capacity for soils to exchange nutrients for optimal plant growth and nutrition.”
With proper land care and management, soils can be remediated over time.
“It won't happen overnight. Soils were developed over millions of years,” he said.
Some ways to improve safety when gardening in fire-affected areas including keeping the soil covered with wood chips or other landscape mulch to reduce airborne soil dust. Use drip irrigation to prevent up splash onto the undersides of growing vegetables. Promote good drainage, especially at the bottom of slopes to prevent the concentration of contaminants.
Lab tests are often needed to determine the soils' post-fire characteristics. “Don't guess, but test,” Bennaton said.
The UC Master Gardener Program can provide technical assistance to help home gardeners find resources for home soil testing, he said.
Additional resources and information shared during the webinar include:
Post-fire soil resources and soil testing information
- UCCE publication on Soils in Urban Agriculture with soil testing & sampling information
- The UC ANR Healthy Soils Website, which has many resources worth reviewing.
- Tips for Interpreting Soil Analysis
- UC Master Gardener of Sonoma County 2018 workshop video “Effects of fire on soil”
Post-fire food safety
- Research on produce safety and backyard chicken egg safety after the 2017 wildfires in California is available on this web page. To view a past webinar recording with these research findings, click this link.
- Poultry wildfire resources from the UC Davis School of Veterinary Medicine:
- Best Practices for Produce Safety After Fire
- Understanding Risk: A community guide for assessing the potential health impacts of locally grown produce exposed to urban wildfire smoke
Firewise and sustainable home landscaping design in the defensible space zone
- Visit the UC Master Gardener Program of Sonoma County firewise landscaping web page.
- For a recent firewise & sustainable design and maintenance video by the Resilient Landscapes Coalition.
Impact of smoke & ash on plants
[This article was first published Nov. 3, 2020]
- Author: Jeannette E. Warnert
A summer of smoke and ash in many parts of California has raised questions about the safety of produce growing on farms and in the garden, eggs laid by chickens who peck around in ash-laden areas, and remediation needed to safely and effectively grow food in the future.
UC Agriculture and Natural Resources brought together experts who have researched the effects of previous fires' fallout and studied soil contaminants to share their insight in a two-hour webinar now available on YouTube.
“The No. 1 health concern during a fire is smoke inhalation, and it's been well documented that wildfire smoke can negatively impact both the heart and the lungs,” said Claire O'Brien, a pharmacology and toxicology doctoral student at UC Davis. “However, the chemicals found in the smoke don't just stay in the air. They can deposit onto plants and into soil and water.”
Although every fire is unique, some generalizations can be drawn from research conducted following previous fires. UC Cooperative Extension food systems advisor Julia Van Soelen Kim detailed a study conducted following the October 2017 wildfires in Sonoma County and across the North Bay.
With the help of UC Master Gardener and community volunteers, the researchers collected over 200 samples of homegrown collard greens, lettuces, kale and chard that were exposed to wildfire smoke and ash. A subset of the samples were analyzed by a private laboratory.
“There was very low concern about chemicals on produce,” Van Soelen Kim said. “No samples had detectable levels of lead, arsenic, mercury or chromium. And that's a huge sigh of relief.” However, analytical results vary by site, site history and by fire event, and few have pre-fire baseline data to compare with.
Van Soelen Kim said basic food-safety practices should be followed when preparing to eat food grown in a home garden, regardless of ash or smoke contamination.
“You should always wash your hands before and after harvesting, and wash your produce in running water to mitigate any kind of potential risk,” she said.
Are backyard chicken eggs safe to eat?
Another study outlined at the webinar used a similar process to determine whether there might be contaminants in the eggs laid by backyard poultry that live and feed in areas exposed to wildfire ash and smoke.
Scientists know from previous research that chickens exposed to lead in their environment can produce eggs with high lead content and that heavy metal content of ash from urban wildfires is higher than from rural wildfire.
“We combined those two pieces of research with what we know that chickens do all day: they peck at the ground for hours on end,” said Todd Kelman, a veterinarian in the School of Veterinary Medicine at UC Davis. “That makes for a pretty good hypothesis that urban wildfire could pose a risk for the production of eggs and poultry that contain heavy metals.”
Kelman and his team put out a call for eggs from backyard poultry and received samples from 344 premises in fire-affected and non-fire-affected areas of California.
Surprisingly, egg samples that contained higher lead levels came from parts of the state that were not directly impacted by ash and smoke.
“Did our data support our hypothesis that proximity to urban wildfire is a driving source for lead in eggs of backyard poultry? The answer is not so much,” Kelman said. “So, is it safe to eat eggs from your backyard poultry? We can't give you a definitive answer to that question. But we do suggest you assess your risk and reduce the risk of contamination.”
Practices that reduce the risk include keeping chickens off the ground, using a chicken feeder that prevents spillage onto the ground and making calcium readily available, for example in the form of oyster shells, because calcium can prevent the absorption of lead. Making sure that chickens are provided uncontaminated water is also an important part of risk reduction.
For confirmation on the safety backyard chickens and their eggs, lab tests for eggs are available for $60 from the California Animal Health and Food Safety Laboratory at UC Davis, or chickens may be submitted to CAHFS for necropsy.
Are soils safe for growing food after a fire?
Fire effects on soil is another consideration in burned areas, said UC Cooperative Extension urban agriculture advisor Rob Bennaton.
“Fires heat topsoil layers. They reduce the amount of living micro-organisms at the site of the burn, and also affect organic matter and nutrients. Ash deposits over time may make soils more alkaline,” he said. “As a result of these combined factors, there are temporary changes in nutrient levels and the capacity for soils to exchange nutrients for optimal plant growth and nutrition.”
With proper land care and management, soils can be remediated over time.
“It won't happen overnight. Soils were developed over millions of years,” he said.
Some ways to improve safety when gardening in fire-affected areas including keeping the soil covered with wood chips or other landscape mulch to reduce airborne soil dust. Use drip irrigation to prevent up splash onto the undersides of growing vegetables. Promote good drainage, especially at the bottom of slopes to prevent the concentration of contaminants.
Lab tests are often needed to determine the soils' post-fire characteristics. “Don't guess, but test,” Bennaton said.
The UC Master Gardener Program can provide technical assistance to help home gardeners find resources for home soil testing, he said.
Additional resources and information shared during the webinar include:
Post-fire soil resources and soil testing information
- UCCE publication on Soils in Urban Agriculture with soil testing & sampling information
- The UC ANR Healthy Soils Website, which has many resources worth reviewing.
- Tips for Interpreting Soil Analysis
- UC Master Gardener of Sonoma County 2018 workshop video “Effects of fire on soil”
Post-fire food safety
- Research on produce safety and backyard chicken egg safety after the 2017 wildfires in California is available on this web page. To view a past webinar recording with these research findings, click this link.
- Poultry wildfire resources from the UC Davis School of Veterinary Medicine:
- Best Practices for Produce Safety After Fire
- Understanding Risk: A community guide for assessing the potential health impacts of locally grown produce exposed to urban wildfire smoke
Firewise and sustainable home landscaping design in the defensible space zone
- Visit the UC Master Gardener Program of Sonoma County firewise landscaping web page.
- For a recent firewise & sustainable design and maintenance video by the Resilient Landscapes Coalition.
Impact of smoke & ash on plants
Urban Agriculture Soil Information
- Author: Trina Tobey
Living in California, we inevitably get smoke from wildfires in our yards and gardens and this year is no exception. Over 7,400 fires and 3.1 million acres have burned across California so far this year, making 2020 an extreme year for fires on top of COVID-19, protests, an election, and heat waves. But how does all of this smoke and ash affect our plants? I did some research and found that there are both positive and negative effects of smoke on plants.
Positive effects of smoke come from the increase of carbon dioxide. Plants extract carbon dioxide from the air and use it in photosynthesis to feed themselves. If the plant has an ample supply of water and there is enough sunlight shining through the smoke for the plant to use the extra carbon dioxide, the plant can produce more food for itself. At moderate levels smoke can diffuse the light, which can be a relief for plants here in the high desert that are normally exposed to very intense light every day. This is good for the plants but also for us humans and animals who depend on oxygen.
Conversely, smoke and ash particles can coat plants inhibiting photosynthesis. Smoke particulates can clog stomatal pores which prevent the gas exchanges required in photosynthesis which decreases the amount of food available to the plant. Smoke that sticks to plants can be bad for the plants but good for us. Plants, especially fuzzy plants, remove these smoke particles from the air by absorbing them into their leaves and stems and by minerals translocated through the roots. Again, this eventually helps clean the environment.
If plants are covered with smoke and ash, both sides of their leaves should be cleaned with water. As for the produce you eat from your garden, simply washing it with water before consuming it should remove any of the residue you might otherwise ingest.
In conclusion, the good news is that your plants will likely not be harmed by the smoke, especially if you give them a bath. The bad news is that the smoke is still hazardous to us humans.
Luckily, we have the plants to help us out by cleaning the air for us.
Humans can find out current air quality conditions online at airnow.gov.
/span>- Author: Ben Faber
California agricultural employers, workers approach smoke concerns differently
UC Davis examines health and safety awareness around mounting threat
University of California - Davis
In 2018, California wildfires burned more than 1.8 million acres and caused smoke to drift hundreds of miles. As the frequency and intensity of wildfires increases with climate change, California agricultural workers are at greater risk of smoke exposure as they often have no option but to work outdoors.
A new study from researchers at the University of California, Davis, finds that while wildfires and smoke exposure are recognized by farmworkers and employers as a growing threat and safety concern, the means to address these concerns differs between the two groups.
"What stood out in this study is the substantial disparities between agricultural employers and farmworkers," said Heather Riden with the Western Center for Agricultural Health and Safety at UC Davis.
Riden, who led the research in partnership with the California Institute for Rural Studies, said that while growers and employers expressed concern about poor air quality at the time of the study in 2018, many had no clear plans or protocols for measuring air quality or managing workers in such conditions. While the public is advised to stay indoors due to poor air quality during a wildfire, agricultural work often continues.
The study also found that when farmworkers were offered protective masks, many found them difficult to use while working due to heat-related discomfort and chafing. Others believed wearing two bandanas over the mouth and nose would provide just as much protection.
Farmworkers' experience is compounded by economic need.
"Many farmworkers will continue working, even in unsafe conditions, to support their families. They don't have many other options," said Riden.
NEW REGULATIONS
Last year, the state Division of Occupational Safety and Health, better known as Cal/OSHA, enacted an emergency regulation requiring employers to take measures to protect workers from wildfire smoke when the Air Quality Index reaches 151 or greater, which is considered unhealthy. Riden said as CAL/OSHA begins to craft permanent regulations, she hopes it takes the study's findings into consideration.
"This highlights the need for better awareness for both agricultural employers and farmworkers about the health risks associated with wildfire smoke," said Riden. "Employers also need training materials and concrete steps they can take to protect workers."
To assist agricultural employers with meeting the requirements outlined in the newly adopted regulation, the Western Center for Agricultural Health and Safety developed training materials and an employer checklist.
###
The study was based on interviews and focus groups with California agricultural employers and workers in the Salinas, San Joaquin and Imperial valleys. Support for the study came from the Centers for Disease Control and Prevention, and the National Institute for Occupational Safety and Health.
For the complete article and amazing pictures check out: https://www.ucdavis.edu/health/california-agricultural-employers-workers-approach-smoke-concerns-differently
Media Contact
Amy Quinton
amquinton@ucdavis.edu
530-752-9843
@ucdavisnews
This content was developed by the Western Center for Agricultural Health and Safety at UC Davis. For more information and to access their wildfire training materials, visit their wildfire training page: https://aghealth.ucdavis.edu/wildfires
![fire hillside fire hillside](/blogs/blogcore/blogfiles/65855.jpg)