Livestock farmers and their employees are urged to be aware of the dangers posed by decomposing livestock manure. This is after six people died recently on an American dairy farm from reportedly inhaling what is suspected to have been hydrogen sulphide (H2S) gas.
By Lloyd Phillips, Senior Journalist at African Farming and Landbouweekblad
America’s cattle industry is reportedly in shock and mourning after six men, including a father and his 17-year-old schoolgoing son, succumbed to what is suspected to have been hydrogen sulphide (H2S) gas emitted from stored, decomposing cattle manure. The incident occurred on the Prospect Valley Dairy farm in Colorado’s Keenesburg district.
The North American The Bullvine website, which reports on dairy farming news, explains that a contracting team had been performing routine maintenance on an underground manure pit without incident throughout the day of 20 August. Towards the end of the day, one worker remained in the pit when there was a sudden, unexplained release of concentrated H2S into the pit.
The worker reportedly collapsed immediately from inhaling the gas. His five colleagues, including the 17-year-old school learner accompanying his father, reportedly rushed into the confined space to rescue the victim. They too reportedly quickly succumbed.
Dr David Douphrate, an associate director of the High Plains Intermountain Center for Agricultural Health and Safety at the Colorado State University, confirmed in an interview with CBS News that the H2S emitted from decomposing livestock manure “is highly toxic” and “can be lethal”. In an enclosed environment, such as a storage pit, victims can succumb to H2S in only a few breaths.
Also read: Irrigating with animal manure water
Hydrogen Sulphide Is Heavier Than Air
The Bullvine reports that although H2S is commonly identified by its odour of rotten eggs, at high and deadly concentrations the human nose can no longer smell this potential warning. An added risk is that it is heavier than air, so it pools invisibly in manure pits, trenches and other depressions. Even facilities largely empty of livestock manure can still harbour potentially dangerous H2S.
Prolonged exposure to and inhalation of reportedly only 10 parts per million (ppm) of H2S can cause eye irritation, headaches and fatigue. Approximately 100 ppm of H2S can cause coughing, altered breathing and loss of consciousness. At approximately 500 ppm, H2S can cause rapid unconsciousness.
Concentrations of H2S can reportedly rapidly increase 50 to 100 times when livestock manure is agitated or pumped.
Other potentially harmful gases released from decomposing livestock manure include ammonia (NH3), methane (CH4) and carbon dioxide (CO2).
Dairy, piggery and other livestock operations often also have open reservoirs or dams to store liquid livestock manure, or slurry. This is a valuable source of organic fertiliser for cropping operations, pastures and cover crops, and can also be used in biodigesters to generate renewable energy.
Farmers are reminded that these reservoirs can also generate and harbour toxic gases, especially if situated in a depression or if the content is below capacity. Slurry dams also pose drowning risks for people and animals, particularly if the surface is crusted over and appears solid.
Comprehensive Safety Measures Must Be In Place
Safety measures recommended by various sources include:
- Using portable multi-gas detectors.
- Linking these detectors wirelessly to smartphone and other alert systems.
- Ensuring that confined spaces have ventilation systems that are supported by back-up power supplies.
- Equipping workers with self-contained breathing apparatus and with rope-linked extraction harnesses.
- Securely fencing and locking manure storage facilities.
- Having appropriate emergency action plans and resources in place.
- Never attempting to rescue people without first wearing a self-contained breathing apparatus yourself.
The victims of the Prospect Valley Dairy farm incident are named as Jorge Sanchez Pena (36), Alejandro Espinoza Cruz (50), Oscar Espinoza Leos (17), Ricardo Gomez Galvan (40), Noe Montanez Casanas (32) and Carlos Espinoza Prado (29).
