Waste-Watcher's Guide to Safer Horsekeeping

Here's how to handle and dispose of potentially harmful products found around the barn. By Laurie Bonner for EQUUS magazine.
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Here's how to handle and dispose of potentially harmful products found around the barn. By Laurie Bonner for EQUUS magazine.

You couldn't do without them--the medical supplies, the fly sprays, the dewormers, the rodent-control products, the pesticides--but sometimes you don't quite know what to do with them, either. The product-warning labels make it perfectly clear that these beneficial horse-care and property-upkeep items can be hazardous in the wrong places, in the wrong recipients, in the wrong amounts. So what do you do with used medical materials, expired drugs, empty pesticide containers and the like? Simply tossing them in with your run-of-the-mill trash can be dangerous to the people and/or animals who may encounter them, as well as to the environment. In some cases, improper hazardous-waste disposal is a violation of the law. For the sake of your family and neighbors, your animals and indigenous wildlife, and your soil and water resources, here's how to be sure that your horse-related hazardous wastes end up where they can do no harm.

Syringe Needles
Risk: "Sharps" is the regulatory term for used hypodermic and intravenous needles, scalpels, lancets and other medical devices that penetrate tissue. Human hospitals and medical facilities must follow strict sharps-disposal rules, developed to protect health-care workers who administer dozens of injections per day in settings with a high risk of contracting diseases from errant needlesticks. Also, to protect sanitation workers from accidental injury, most state and local jurisdictions have laws prohibiting disposal of medical sharps in ordinary household trash.

In barns where syringes are kept on hand for routine injections, those laws may not always be followed. "People are discarding them into the garbage," says Roberta M. Dwyer, DVM, MS, an associate professor at the University of Kentucky's Maxwell H. Gluck Equine Research Center, who reports having seen needles tossed into open trash barrels and even muck piles at more than one horse show.

"The danger is that they can stick whoever collects the trash," she says, but any person or animal in the area is at risk of a puncture wound. "If the needle was used on a human, you can get hepatitis C, HIV and any number of bacterial infections," Dwyer says, "but even with needles used on horses, there is still a concern of bacterial infection, especially if the needle had been in contact with unclean substances, like manure."

Solution: Though you'll need to check with your county waste system for details of your local sharps policy, most disposal systems are based on the two-step protocol suggested by the U.S. Environmental Protection Agency (EPA):

After use, drop the needle into a strong plastic or metal container. Specially designed sharps-disposal containers are available from pharmacies and medical-supply companies, but sturdy plastic bottles, such as bleach or laundry-detergent jugs, are also serviceable. Do not use glass, because it is breakable, or lightweight plastic containers that can be crushed and punctured if dropped or stepped on. Label the container clearly, using words such as "Sharps: Do not recycle," and keep it away from children and animals.

When the container is full, seal the lid with duct tape, and dispose of it according to your local ordinance. Often, the sealed bottle can be put in the regular trash (not the recycling bin). Some jurisdictions require that used sharps be disposed of through the public health department, and you may be required to take your container to a drop-off station for biohazardous waste. Medical and other health-care facilities must have sharps-disposal procedures in place, and your veterinarian or even your physician might be willing to take your needle container for disposal.

Health-care workers are instructed to not recap the needle after use but instead to drop it straight into the disposal container. That policy was developed when the Centers for Disease Control (CDC) discovered in the early 1990s that 25 percent of needlestick injuries occurred while someone was trying to replace the cap on a used needle.

"In hospitals, the sharps container is right by each bed, and the worker can give the injection and drop the needle in two steps away," says Dwyer. The average stable doesn't have a disposal container at every stall, however, and the greater danger comes from holding an exposed needle while working with horses. "If you carry your sharps box with you, then you can just drop the needle in when you're done," Dwyer suggests, "but otherwise, carefully recap it, and carry it out to the disposal container."

Mercury Thermometer
Risk: Mercury, a silvery liquid elemental metal, has long been used in thermometers, sensor switches and various medical instruments because it expands and contracts evenly and consistently when exposed to slight temperature variations. Unfortunately, mercury is also a potent neurotoxin. An acute mercury exposure can cause a range of symptoms including malaise, vomiting, diarrhea, chest pain, pulmonary edema and gastrointestinal hemorrhage, sometimes leading to death; chronic exposure can cause tremors, memory loss, insomnia, emotional instability and depression.

"Mercury ranks near the top of the list of our most dangerous pollutants," says Michael Murray, PhD, staff scientist with the National Wildlife Federation. When elemental mercury gets into lakes and rivers, it can be transformed into methylmercury, which accumulates in fish and any people and animals who subsequently feed on the fish. According to the EPA, one gram of mercury is enough to create dangerous levels of methylmercury in every fish in a 20-acre lake. A typical mercury fever thermometer contains almost that amount--about 0.7 grams.

Although most environmental mercury pollution comes from industrial sources, a 1996 EPA report to Congress estimated that ordinary fever thermometers had contributed about 17 tons of mercury to municipal solid waste per year in the early 1990s. If those thermometers are broken in landfills, mercury seeps into the groundwater; if incinerated, the mercury vaporizes and falls back to the land with precipitation. Every two years, the CDC releases a priority list of pollutants posing the highest risk to human health, base on toxicity as well as their environmental concentration; out of 275 substances listed in 2001, mercury ranked third behind arsenic and lead.

Because of these dangers, mercury thermometers may eventually be outlawed. In September 2002, Michigan became the 10th state to ban or restrict the sale of mercury thermometers, and more than a dozen cities, including Boston, Chicago and San Francisco, have enacted similar ordinances. The Mercury Reduction Act, a proposed federal ban on the sale of mercury thermometers, was unanimously passed in the U.S. Senate in August 2002 but did not pass in the House of Representatives before Congress adjourned in November of that year.

Solution: Fluorescent tubes, barometers, thermostats and a variety of other household items often contain mercury, but ordinary glass fever thermometers are probably the most common source in horse barns. If a thermometer gets broken, it's important to gather up as much of the mercury as possible while minimizing contamination of the surrounding area. The EPA, thermometer manufacturer Becton Dickinson and the National Wildlife Federation offer similar guidelines for cleaning up spilled mercury: If the spill occurs in a building, close interior doors to contain the mercury to a single room, and open outdoor windows and doors to increase ventilation. Run a fan for a minimum of an hour to push air out, and if weather permits, leave the windows open for a minimum of two days.

Pick up the mercury droplets with an eyedropper or heavy paper, such as playing cards or index cards. Do not try sweeping them; broom or brush bristles break the mercury into smaller droplets that scatter and contaminate the cleaning tools. Vacuuming is another bad idea because the rush of heated air vaporizes the mercury. Avoid using cleaning solutions that contain ammonia or chlorine, which form toxic gases when combined with mercury.

Place the mercury, the broken thermometer glass and the cleanup tools in a sealed container. A glass jar with a tight-fitting lid works well, as do three zippered plastic bags sealed one inside the others.

Ask your local health department, solid-waste facility or veterinarian or physician about mercury-disposal guidelines in your area. In most areas, mercury must be delivered to a hazardous-waste collection site or to a company that recycles mercury.

You may also want to consider turning in your unbroken thermometers. Digital thermometers for equine use are already available and more will likely come on the market as mercury instruments are phased out of medicine.

Unused Pharmaceuticals
Risk: Periodically sorting through the medicine chest to clear out expired and unneeded drugs is a basic chore of good stable management. But once you've collected an assortment of old bute, leftover antibiotics and forgotten dewormers, what then? If you're like most people, you probably just toss them in the trash. In 1996 the Pittsburgh Poison Center published the results of a survey that asked 500 people how they dispose of expired medicines; the overwhelming majority either put them in the household garbage (54 percent) or flushed them down the toilet (35.4 percent).

Yet neither of these methods is ideal. Medications in the trash are still within reach of children and animals who are at greatest risk of being poisoned by them. According to the National Safety Council, accidental ingestion of pharmaceuticals and vitamins by children under 6 prompted 465,771 calls to U.S. poison-control centers in 2000 and was by far the leading cause of incidents in that age group. Flushing unwanted medication into the septic/sewage system eliminates the problem of ingestion by children and animals, but it may contribute to contamination of our waterways. In 1999 the EPA published a special report on a class of pollutant only recently receiving attention: pharmaceuticals and personal-care products (PPCPs), drugs and other substances, such as sunscreens and deodorants, that enter the lakes and rivers in tiny amounts by way of household toilets, sinks and shower drains. While some of these substances are washed or dumped directly into the water, others are deposited "postconsumer," meaning that unmetabolized portions as well as bioactive metabolites0 are excreted by users into the sewage system.

Wastewater treatment plants, designed to eliminate larger and more obvious types of pollution, do not effectively remove all of these trace chemicals. While each household by itself contributes minuscule quantities of particular drugs, the collective amount becomes significant when the nation is taken as a whole. U.S. consumers bought $130 billion worth of pharmaceuticals in 2001 alone, an amount that has increased steadily each year since 1970, according to Pharmaceutical Research and Manufacturers of America. Only 1 or 2 percent of that expenditure went for veterinary pharmaceuticals, but potential for adverse environmental impact may be greater for domestic animals because animal wastes do not go through standard sewage treatment and the substances they carry can be conveyed directly into surface and groundwaters.

Researchers are quick to point out that the effects of these substances in the water are so far largely unknown. "It certainly is not a currently measurable threat to human health from drinking water exposure," says Christian Daughton, PhD, chief of the EPA's environmental chemistry branch in Las Vegas, "but it may be a threat to ecological health, and of course that would eventually intertwine with human health." Some of the more serious concerns are that combined low levels of numerous types of antibiotics entering the water could foster increasing bacterial resistance to standard therapeutic drugs or change the balance of the microbial community and also that hormones and steroids could alter reproduction or behavior of aquatic organisms. Also, although individual PPCPs exist in the environment in extremely low concentrations, the combination of chemicals from different therapeutic classes in the diverse "soup" could be adding up to a significant threat to aquatic life. "The effect of chronic exposure to multiple substances over time is extremely difficult for toxicologists to study," Daughton says. "We just don't know."

Solution: Although pharmaceutical management, including disposal methods, is closely regulated for drug manufacturers, says Daughton, "this country doesn't have unified recommendations or guidance for health-care facilities, pharmacies or consumers." That leaves several options:

Return them, if you can. The ideal way to dispose of unwanted drugs is to find a pharmacy willing to add the drug waste of consumers to their own established programs for disposal or recycling of unsold drugs. Formal "take-back" programs for consumers are beginning to appear in countries such as Canada, Australia, Italy and France, says Daughton.

Flush them down the toilet. From the standpoint of poison control, flushing is the fastest and easiest way to dispose of drugs. In fact, many medical facilities were once required to dispose of unwanted pharmaceuticals through the sewer, and some states still require disposal to sewage. Since the late 1990s, however, environmental concerns have caused more states to require health facilities to use other means, such as incineration. Flushing remains a legal option for the consumer.

Trash them. In the absence of exchange programs, putting old drugs in the municipal trash (or better yet, municipal hazardous-waste disposal programs) is the best choice from the standpoint of controlling pollution. If small children or animals could possibly get into your trash, consider taking measures to secure the drugs, such as duct-taping the containers shut or placing medications in trash cans with tight-fitting lids and placing them roadside only just before pickup. Household trash, which is typically either incinerated or buried, is still not a perfect way to keep drugs out of the waterways, but, says Daughton, "I personally think it is better to put them into a regulated municipal trash system rather than into the sewer."

Another way to minimize the impact of PPCP pollution is to reduce pharmaceutical use in the first place. Researchers are striving to design drugs that are absorbed more efficiently and that work more effectively at smaller doses. But until that distant day when we might have "perfect" drugs, the best way to minimize PPCP pollution is to be mindful and judicious in your use of medications, particularly antibiotics and hormones. Of course, you'll still need to stock some drugs in your barn, but administer them only with your veterinarian's guidance. In some cases administering less might save you money, help protect the environment and even improve your horse's health.

Risk: Pest-control products are common in barns, from fly sprays for the horses to herbicides sprayed on weeds to poisonous baits set out for mice. Some of these substances can be highly toxic, but any product ought to be safe when used as directed.

Fly sprays, for example, usually contain pyrethrins, a family of insecticidal compounds derived from chrysanthemum flowers, and their synthetic counterparts, pyrethroids. Although these substances are powerful insecticides closely regulated by the EPA, their concentration in a bottle of fly spray is too small to be terribly toxic. "The pyrethrins have a very wide safety range, and many of these products are very safe," says Jill Richardson, DVM, a veterinary poison information specialist with the American Society for the Prevention of Cruelty to Animals (ASPCA) Animal Poison Control Center. Nevertheless, pyrethrins, like many pesticides, can be highly toxic to fish, so care needs to be taken to prevent fly sprays from getting into streams or ponds.

Bait poison put out in barns for rodent control is most likely to attract dogs, but horses have been known to eat it when given the chance. "We've had calls [at the animal poison control center] about horses who had eaten rat poison," Richardson says. Although it's unlikely for an animal as large as a horse to consume a lethal dose, Richardson says that some of them did ingest enough to become seriously ill.

Remember, too, that products safe for one species in your barn might be dangerous for another. "Many horse dewormers might be toxic to dogs," Richardson says. "If your horse spits out the dewormer, and your Jack Russell terrier jumps in and swallows it, the dog could be getting 240 times the recommended canine dose of the drug from just one milliliter of the equine drug." Also, some fly and/or flea control products may be safe for dogs and horses but lethal to cats.

Solution: Using these products safely usually means simply being aware of potential ill effects and taking appropriate steps to minimize risks. Follow label instructions. The EPA has detailed guidelines for the use, storage and disposal of a wide range of dangerous chemicals included in many common manufactured goods. All products containing these substances are required to have labels with detailed instructions on how to handle them. If you need to clean up spills, treat accidental ingestion or dispose of empty containers or unused product, you'll find the how-to specifics on the label. You may also find phone numbers for further information.

Use products carefully. Follow dosage directions, and take steps to prevent unintended exposures. Place bait poisons where you're sure no dog, cat or bored horse can reach them. Also, avoid using spray-on insecticides or herbicides where their residues can get into animals' food or wash into ponds and streams.

Store them safely. Keep all poisonous substances in their original containers with the labels intact; if you must transfer something into a different container, never use one that originally held food. Ideally, poisonous substances would always be kept in a locked cabinet, but at least they need to be kept in a place where children and animals can't reach them. Also, choose a storage site where leaks or spills cannot contaminate feed or water.

Recognizing the potential risks in commonplace horse-care products is step one in running a safer stable. Step two is putting practices in place that reduce opportunities for accidents to as near to zero as is humanly possible. "People are not always careful," says Richardson, and sometimes they take shortcuts without thinking hard enough about the possible consequences. But it doesn't take much extra effort to handle toxic substances with care, and the results can help ensure the health and well-being of all of your charges, as well as the farm itself.

This article originally appeared in the February 2003 issue of EQUUS magazine.