by Sally Colby
Many farmers throughout the southeast are still dealing with the aftermath of excessive rain, topped by Hurricane Florence. While Florence had massive impacts on land and people, it’s likely that more storms will hit the southeast and northeast over the coming months.
What goes on when water gets into places it shouldn’t be and stays there for periods of time? “There are numerous sources that can contribute to microbial growth,” said Dr. Chad Roy, director of infectious disease aerobiology at Tulane University. “That is primarily because of water getting into soil.”
Roy explained that microbial cells are numerous in soil, and that a gram of soil contains about 10 billion microorganisms. “The primary way they start to replicate is through water,” he said. “When backed up, water gets into the soil, it absorbs and stays, and essentially activates everything in in the soil. If soils are saturated for long periods of time, it can accelerate growth of microorganisms that you don’t want to grow. A flood essentially does that – it turns on everything in the environment that can grow, and can contribute to massive microbial growth.”
All microorganisms require water in an available form to grow. When water enters areas of a home where it shouldn’t be, active mold grows and causes problems. “The same thing is true on a farmstead that has numerous buildings where water can get in and cause both bacterial and fungal growth,” said Roy. “One thing to keep in mind is when people talk about bacteria and fungi, they think ‘infectious’ – but 99.99 percent of microbial growth that takes place in floods is non-infectious and will not cause an active infection.” However, this microbial growth can cause significant non-infectious health issues.
Roy explained that one of the main hazards with unusually rapid bacteria and fungi growth is the production of volatile organic compounds (VOCs), which he relates to the VOCs emitted from petroleum products such as gasoline. Microorganisms, specifically fungi, grow rapidly in saturated conditions and produce a lot of VOCs. “They can cause discomfort, especially in an enclosed area,” said Roy. “This is for not only humans, but animals that may be in enclosed areas. It’s an irritant, and has a very low threshold for irritation.” VOCs can irritate the nervous system and mucous membranes such as the eyes.
“If you think of all the outbuildings, semi-enclosed areas and husbandry operations, these VOCs can build up,” said Roy. “Because VOCs are gases, it’s very difficult to use the proper PPE to avoid contact. They’re natural products, so it’s very difficult to cancel out the source unless remediation takes place.”
The exposure to VOCs from excess microbial growth is the result of microbes’ presence and transport through the air, moving water and stagnant water. The level of exposure doesn’t have to be high for someone to experience ill health effects, and can occur rapidly after a flood.
“Water is highly contaminated because it’s coming in contact with everything,” said Roy. “It’s a ‘witch’s brew’ with both chemical and biological contaminants.” Some of the contaminants include petroleum products/distillates, agricultural chemicals, pathogenic microbes from the soil, animal/human waste and dead livestock. “It’s very difficult, if not impossible, to understand the concentration that flood waters may hold relative to an occupational exposure,” said Roy. “There’s a high unknown potential for exposure and repeated exposure in flood water to chemical contaminants.”
Roy said it’s important to identify potential wellhead contamination during floods and appreciate all the biological hazards in floodwaters mixed with chemical hazards. “Most wellheads in rural areas have a sanitary seal and cap,” said Roy. “Flood waters, especially stagnant water, that may contain solvents from chemical contamination can compromise that sanitary seal and lead to wellhead fouling and contamination of the well.” Wellheads, especially after the floodwater has recessed, should not be presumed to be free of contamination.
Although farmers keep the proper PPE for routine tasks particular to their farm, it’s nearly impossible to measure the risk or know what PPF is needed for cleanup. “Think about respiratory protection, particulate protection,” said Roy. “An M95 will do no good to protect against VOCs. We’re dealing with generation, transport and exposure all at once. We’re surrounded by floodwaters and can’t assess properly what’s going on with generation, if it’s being transported and what the exposures are in terms of duration as well as concentration.”
Charlotte Halverson, clinical director of AgriSafe, said that an M95 respirator is an excellent choice for many applications, but when there’s exposure to VOCs resulting from a flood there are few options for adequate protection. She usually recommends level P respiratory protection on the N, R, P scale, and a 100 filter or an organic vapor filter with dust caps.
Using the proper hand, arm and foot protection is also essential during cleanup. Cotton-lined gloves soak up moisture, and leather gloves will also absorb and transmit moisture to the skin. Neoprene or nitrile gloves are best. Properly fitted splash goggles that are not directly vented are also important to protect the eyes. Boots should be PVC, and wearers should be willing to discard them after cleanup. Any hats should be plastic so they don’t absorb potentially contaminated liquids.
Halverson said coated PPE clothing may become hot and uncomfortable, so avoid wearing it for a long time. “When possible, take it off when you can,” she said. “There is no breathability. What you need on the outside and what your body needs are different.”
During flood recovery, there’s added danger from carbon monoxide from gasoline generators and propane or charcoal grills. “If they are not ventilated properly, CO2 buildup happens and it can poison people and animals,” said Halverson. She explained some of the symptoms including nagging tension headaches, dizziness, feeling flu-like, chest pain and altered mental states.
Stress management is a critical aspect of flood clean up. Flooding results in significant financial stress for farmers and affects commodity prices, land values and production. “Local services may not be accessible, and getting those services can be quite a battle,” said Halverson. “The environmental stressors of weather and a long clean-up period and continual potential for disease is there. It takes a toll on people physically, especially age-related stressors.”
Halverson reviewed the signs of anxiety that may occur after any disaster. “Excessive and persistent worry that is non-stop and constant for two weeks or longer,” she said. “Inability to concentrate, restlessness, irritability and constantly being unable to focus on anything.” Continuous stress and anxiety increase the risk for illness and injury, and recovery from illness or injury may take longer.
Another issue that comes with disaster cleanup is depression. Signs to watch for include depressed mood, using poor judgment, inability to concentrate, becoming short-tempered, inability to sleep or sleeping constantly, a big change in weight, overusing tobacco or alcohol, and/or doubling up on medications. “We need to be alert and gentle in taking care of each other, and not being afraid to say ‘Are you having a problem, or is there something I can help you with?’” said Halverson.