Health Dangers in Your Hose: Are You Watering Your Garden With Endocrine Disruptors and Toxic Chemicals?
What says summer like running through the sprinkler, eating a homegrown tomato off the vine, or drinking right from the garden hose? Unfortunately, those summer experiences might come with toxic chemicals like lead, bisphenol A (BPA), phthalates, and even flame retardants. That's what the Ecology Center found out when it tested a number of different common garden products recently.
The finding that your hose might be the most dangerous tool in your garden was not necessarily what the Ecology Center expected to find.
“We've been looking at a wide range of products where there is a credible connection to having human exposure and we know that consumer products are a very significant source of exposure to many of these chemicals,” explained John Gearhart, the Ecology Center's research director. “We've looked at everything from baby products to toys to things as big as vehicles and building materials.”
They had not yet examined garden products, and a few people had asked about them. “We started off trying to do a broader assessment and we did screen a range of products, but overwhelmingly we found that the garden hoses were of most concern.”
What is so dangerous about an innocent-looking hose? To start, one in three of the hoses tested had levels of lead that exceeded drinking water standards. And water sampled from one hose was 18 times the levels allowed in drinking water! Only there is nothing illegal about this, because hoses are not regulated by the same laws that limit lead leached by plumbing fixtures into drinking water. (Since, you know, no one is ever going to drink out of a hose or use it to water plants they might eat.) Brass, often used in plumbing fixtures, is an alloy that can contain up to 8 percent lead. In addition to its uses in brass fixtures, lead is also sometimes used as stabilizers or pigments, particularly in yellow or green hoses. Lead is a neurotoxin and children are more vulnerable to lead poisoning than adults.
The good news is that the state of California took action against three major manufacturers of water hoses over lead content in their products in 2003 and settled in 2004. Under the settlement, the companies Teckni-Plex, Inc.; Plastic Specialties and Technologies, Inc. Teknor Apex Company; and Flexon Industries Corporation were to limit the lead content in their products. (The details are on this page, toward the bottom.) While the Ecology Center did not test any of these brands for lead leaching, presumably gardeners who purchased their hoses since 2007, when the settlement terms fully took effect, can skip worrying about lead – and instead only worry about other chemicals like BPA and phthalates.
For anyone familiar with polyvinyl chloride (PVC), nicknamed “poison plastic,” it should come as no surprise that PVC hoses contain phthalates and leach them into the hose water. According to Gearhart “most vinyl hoses are going to have phthalate plasticizers in them.” Phthalates, used as plasticizers, are endocrine disruptors, and some studies link them to liver cancer. Levels of one phthalate, DEHP, was found in the hose water at a rate of four times the amount permitted in drinking water. Several phthalates have been banned in children's toys, but they are still used in garden hoses and garden gloves.
Another concern found was BPA, an endocrine disruptor that has gotten a lot of publicity recently due to campaigns to ban it from use in baby bottles and sippy cups. Nowadays, consumers have wised up, and many plastic water bottles are marketed as “BPA-free.” The hose industry has faced no such scrutiny, it seems. This endocrine-disrupting chemical was found at a level 20 times higher than what is considered a safe amount in drinking water by the National Science Foundation.
Aside from these harmful chemicals, a few products were also found to contain flame retardants and the heavy metals cadmium and antimony. Gearhart was surprised to find flame retardants in a water hose, but when the researchers found bromine in their tests, they looked further to find its source, and it came from brominated flame retardants. The hoses that tested positive for flame retardants were made from recycled materials, making Gearhart wonder if the manufacturer had recycled flame retardant plastics into garden hoses.
It's easy to evaluate the impacts of toxic chemicals when they are in drinking water, but it becomes far more complex once they are in your garden. For each chemical, one must consider how quickly they break down, and what they break down into, whether they bind to soil or to water, and whether they are taken up into plants. If they are taken up into plants, the next question is, which part – roots, leaves, fruits, or seeds? And finally, are there children in your garden (or perhaps even adults) who will have a lot of contact with the soil or even eat it?
So what can you do if you are a gardener? If you can afford it, replace your hose. The Ecology Center's Healthy Stuff Web site offers a list of safe garden hoses, many of which are made from natural rubber. But for those who cannot replace their hose quickly, Gearhart offers a few tips. First of all, no drinking out of the hose! Second, store your hose in the shade. And third, let your hose run for a few moments before using it to water your plants.
Another strategy? Don't water your plants unless you need to. Wait until the soil is dry an inch below the surface or until your plants are slightly wilted in the evening before watering, and check the weather to see if rain is in the forecast. To help your soil conserve moisture, add a thick layer of mulch – at least three inches. This will have other benefits in addition to conserving moisture, as it encourages the growth of beneficial microbes, breaks down to enrich your soil, and prevents soil from splashing on your plants during waterings, thus preventing soil-borne plant diseases.
If you are worried that your soil is already contaminated with toxins, it's easy and inexpensive to test for heavy metals like lead but more complicated and expensive to test for other chemicals. The University of Massachusetts provides soil testing for lead for only $10. If you find your soil is contaminated, the solution might be as simple as planting sunflowers. Sunflowers are just one of many plants useful in a strategy called phytoremediation, in which plants help remove or break down toxins in the soil. The good news about sunflowers is that they are easy to grow in even the worst soil – and they are beautiful. However, if you go that route, be sure to toss your sunflowers out after they've grown, because if you put them in your compost pile, you'll return the toxins back to your soil.