What is it?
Sheep are raised for both meat and wool. The number of sheep in the United States peaked at 51 million in 1884. Today, there are approximately 5.5 million sheep in the United States. Sheep account for less than 1 percent of total U.S. livestock. Texas, California, and Colorado are the top three sheep-producing states.
Why is it a concern?
A practice called sheep dipping may expose people to harmful pollutants. To protect sheep from parasites and insects, sheep are led through a lined in-ground trench or steel tank filled with pesticides. Exposure to these pesticides may harm humans.
Sheep may have diseases that can be passed on to people who handle them. Sheep may spread bacteria such as E. coli and salmonella, and cryptosporidium, a parasite. Sheep may carry lice and keds, which are wingless flies that as adults look like ticks.
Who is at risk?
People working with sheep should wear appropriate personal protective equipment such as rubber gloves. Anyone who touches sheep may be at risk for bacterial and other diseases.
Handling sheep poses safety concerns. Sheep may become upset if they are separated from their herd, hear loud noises, or see unfamiliar moving objects. Sheep have a narrow field of vision and can become spooked if handlers suddenly appear. Sheep may jump with enough force to break a handler’s leg. Sheep handlers should avoid turning their backs on rams, who may charge or butt humans.
What pollutants are of greatest concern?
Approximately 20,000 gallons of pesticides were used each year until the sheep dipping process ceased in the 1980s in most places. Two pesticides that were used, toxaphene and lindane, are particularly harmful to humans. They are organochlorine pesticides that may cause cancer, according to the U.S. National Toxicology Program.
Toxaphene and lindane are both persistent organic pollutants (POPs) and endocrine disruptors. POPs are highly toxic chemicals that resist breaking down, which is called persistence. Because they don’t break down, they can build up and harm humans and the environment. Endocrine disruptors are chemicals that may interfere with human hormones.
The production and use of toxaphene was banned in 1990.