5 “Harmless” Things in Your Yard that Are Actually Toxic

Updated: May 03, 2021

Keep your family healthier at home—and don't overlook these surprising hazard zones in your backyard.

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Those yard chemicals may not have been tested

Most of us assume that if a product is on the market, it must be safe. But we shouldn’t, says David Hopman, an associate professor of landscape architecture at The University of Texas at Arlington and a past chair of the American Society of Landscape Architects’ Planting Design Professional Practice Network. Of the most common of the 80,000 chemicals used today in the United States, only 7 percent have been fully tested for safety. Many are found in everyday products we use to maintain yards and gardens, so knowing where they lurk can help ensure your outdoor space is a healthier place for your family. Bottom line: “Assume that all chemicals are bad because we just don’t know,” says Hopman.


Shiny black driveway

The sticky black coal tar sealants that give driveways their well-manicured look may contain carcinogenic chemicals called polycyclic aromatic hydrocarbons (PAHs). PAH concentrations in these sealants are hundreds of times higher than those in other major sources, such as exhaust smoke. Research, including a study published in 2014 in Environmental Pollution, found that PAH concentrations in coal-tar-sealcoat runoff remained high for months after application. Since this is a new area of research, scientists can’t say for sure that exposure to driveways containing PAHs causes cancer in people, but they suspect a strong link. Coal tar sealants have been banned in a handful of cities and counties, but no matter where you live, avoid coal tar varieties and stick with natural pavement or an asphalt-based sealant. If you already sealed your driveway this season, keep off it as much as possible. Avoid tracking chemicals into your home by removing your shoes at the door—and vacuum regularly, just in case. Here are 11 sneaky backyard dangers you should be aware of this summer.

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Green weed-free lawn

Ingredients in popular pesticides have been linked to cancer, hormonal changes, and liver or kidney toxicity. Now research points to another surprising peril: mental health hazards. A review of studies published in 2019 in International Journal of Environmental Research and Public Health, found that farmers who work with pesticides are at greater risk for poor mental health, diagnosed mental health disorders such as depression, and increased suicide risk. “You never need to use pesticides and plants grow without fertilizers,” says Hopman. “If you’re doing new construction, then you want to put some organic matter in, but once the plants start growing you don’t need to fertilize.” If you need help keeping weeds at bay, use an all-natural herbicide like corn gluten meal. Apply it in early spring (when forsythia or dogwood first blooms) to prevent annual weeds from reseeding; it also fertilizes your existing grass with nitrogen, so it is healthier (and can crowd out weeds). And beware of companies that purport to be organic; they may use the same chemicals as traditional companies. Here are 10 natural tick repellents that actually work.


Mosquito-free backyard

First the good news: When the mosquito-borne Zika virus began to spread, health authorities were able to employ a process called aerial spraying to treat an area with insecticides safely, quickly, and efficiently, reports the Centers for Disease Control and Prevention (CDC). “There was significant public pushback because some people felt the sprays were more dangerous than the risk for disease, but that isn’t true,” says entomologist Joseph M. Conlon, spokesperson for the American Mosquito Control Association. “Anything is dangerous if you misuse it, but these things have gone through a vetting process. To get it registered by the Environmental Protection Agency (EPA), it has to go through a battery of tests.”

Where mosquitos breed

The bad news? Mosquitoes can still lurk in unsuspecting places in your backyard. “There are 180 mosquito species in the United States and some have very specific habits,” says Conlon. “The ones in your yard breed in containers with standing water: downspouts, pet dishes, non-functioning fountains.” To help prevent mosquito-borne illness, get rid of anything with standing water. You can also use an EPA-registered insect repellant. Look for “an EPA registration number on it,” says Conlon. “That shows you that the product actually works and poses minimal risk.” Don’t miss these trusted mosquito-repelling products.

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Burning waste

Some may view burning trash in their backyard as an efficient way to dispose of it—some countries can even produce heat and electricity by doing so—but the truth is, burning waste in your backyard (especially when much of our trash is plastics) releases dangerous chemicals that pose harm to you and the environment. According to the EPA, exposure to these toxins can cause rashes, headaches, nausea, and asthma, and they can even increase your risk of heart disease. What’s more, burning trash can also produce harmful quantities of dioxins, toxic chemicals that can end up in our crops and water supplies and affect the health of entire communities. Find out more about the 8 scary ways your fireplace could be toxic.

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Swimming pool

When it comes to swimming, parents with young children put drowning at the top of their list of concerns. According to a study published in 2016 in American Family Physician, nearly 4,000 drowning deaths occur annually in the United States; in fact, drowning is the most common injury-related cause of death in children ages one to four years old. But many people don’t realize the problems that pool chemicals such as chlorine and bromine can cause. These are added to pools, hot tubs, and water playgrounds to protect swimmers from the spread of germs and prevent outbreaks. Other chemicals help to disinfect, improve water quality, stop corrosion, and protect against algae growth. But all of these chemicals can injure people when mixed together or when the correct protective equipment is not used when handling them, according to the CDC. Next, be sure to check out the 23 subtle ways your house might be making you sick.