The stinky, dusty air of hog barns is generally treated as an annoyance to be ignored.
But people get a lot more demanding about air quality when their pregnant daughters are the ones exposed, says a Prairie Swine Centre researcher.
Improving air quality could become a major concern for commercial hog barns that want to keep their staff.
“That is the kind of question I hear: is this safe for a pregnant woman?” said air quality researcher Bernardo Predicala.
“We don’t have answers.”
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Predicala said the air that permeates most hog barns can be cleaned up about 90 percent using a simple control technique of spraying canola oil.
Hog barn dust carries a cocktail of irritants for the human respiratory system. Beyond the immediate bracing shock of ammonia, hog barn dust also contains microorganisms, chemicals such as hydrogen sulfide and particles of manure and fibre.
All can hurt humans in high levels, but Predicala said long-term low level exposure is a concern too.
The Prairie Swine Centre has found a number of ways to reduce gases and dust in its research barns.
In one experiment, switching the pigs’ feed to a low protein with fermentable carbohydrate diet produced 42 percent less ammonia than normal diets.
Manure treatment additives reduced odour by up to 66 percent and hydrogen sulfide by 14-76 percent.
Removing manure daily with a scraper system reduced 90 percent of the hydrogen sulfide gas being emitted in the barn.
Regularly spraying a canola oil mist knocked about 90 percent of a barn’s airborne dust down, Predicala said.
None of these approaches to controlling gas and dust in barns is free.
But the $1 per marketed pig cost of canola spraying might be a good investment.
“It is a cost, and the reward is not really evident, but you might note a change in the employee turnover rate,” said Predicala.
Employees are expensive to train and replace, so employers should try to provide the best working atmosphere possible.
“In family operations people don’t always have the chance to have a choice, but when the barn uses hired workers, the air quality becomes an issue,” said Predicala.