Dogs Absorb Lawn Chemicals

Dogs are ingesting, inhaling and otherwise being exposed to garden and lawn chemicals that have been associated with bladder cancer, according to a new study.

The paper, which will appear in the July issue of Science of the Total Environment, also found that wind could carry the chemicals to untreated properties. The researchers also found that dogs, once contaminated by the chemicals, can transfer them to their owners.

The chemicals are common herbicides containing the following: 2,4-dichlorophenoxyacetic acid (2,4-D), 4-chloro-2- methylphenoxypropionic acid (MCPP) and/or dicamba.

"The routes of exposure that have been documented in experimental settings include ingestion, inhalation and transdermal exposures," lead author Deborah Knapp of Purdue University's Department of Veterinary Clinical Sciences, told Discovery News.

"In the case of dogs," she added, "they could directly ingest the chemicals from the plant, or they could lick their paws or fur and ingest chemicals that have been picked up on their feet, legs or body."

Scottish terriers, West Highland white terriers, Shetland sheepdogs, beagles and wire hair fox terriers are all at particular risk, the researchers suggest, because these breeds have a high genetic propensity for bladder cancer.

Knapp and her colleagues first conducted an experimental grass plot study that involved spraying various defined patches with the chemicals under different conditions. These included spraying the herbicides on plots that were green, dry brown, wet or recently mowed. The researchers next measured how much of the chemicals remained on the grass up to 72 hours post treatment.

Co-author Angus Murphy, also from Purdue, explained that dead or dying plant material does not readily absorb the chemicals, "so the herbicide can remain longer on the surface of the plant."

He continued, "If an excessive amount of herbicide is applied, then the capacity of the target plant to take up the compound may be overwhelmed."

In a second experiment, the researchers analyzed urine samples of dogs from households that either used herbicides or didn't. The majority of dogs from homes that used the chemicals were found to have these same herbicides in their urine. Some dogs from untreated homes also had the chemicals in their urine.

Knapp explained that wind could cause the herbicides to travel up to 50 feet away from the application site. Neighbors who use the chemicals might therefore impact other individuals in the area.

"There are industry guidelines for restricting lawn chemical application based on wind speed, although homeowners may not be aware of these," Knapp said.

Once contaminated, dogs can pass the chemicals on to their owners and to others. The study only looked at dogs, but the researchers suspect that cats and other pets could also be affected.

"Dogs can pick up the chemicals on their paws and their fur," Knapp said. "They can then track the chemicals inside the house, leaving chemicals on the floor or furniture. In addition, if the dog has chemicals on its fur, the pet owner could come in contact with the chemicals when they pet or hold the dog."

John Reif, a professor emeritus of epidemiology at the Colorado School of Public Health, told Discovery News, "The paper presents important information since exposure to 2,-4-D, a widely used broad leaf herbicide, has been associated with increased risk of cancer in pet dogs and humans."

Reif added, "This study has potentially important implications for human health since it demonstrates widespread exposure to pet dogs. The likelihood that children, who share the local environment with their pets, are similarly exposed to these chemicals is high and thus additional studies should be conducted to evaluate this possibility."

The researchers suggest that if owners still must use herbicides, they should follow manufacturer guidelines, allow gardens and lawns to dry before allowing pets out, wash their dog's feet each time the dog comes inside, and consider treating the back yard one week before the front (or vice versa) so that pets will have an area of less potential chemical exposure available to them.

Dogs exposed to garden and lawn chemicals may have a higher risk of bladder cancer.

April 22, 2012 --

Leap for joy, it's Earth Day! And with lawn grass America's biggest crop, even beating out corn, it's time to green-up your grass. A study by NASA's Earth Observatory estimated that grassy lawns blanket approximately 50,000 square miles of the United States. No reason not to make this much landscaping Earth-friendly. Lawns absorb carbon dioxide, filter runoff water, and fight erosion. But gas-powered lawn mowers and synthetic fertilizers and insecticides can contaminate the environment and contribute to climate change. A few changes in technique can trim costs, spare time, and help a lawn grow truly green.

Pest Control Grass has few serious insect pests, but if you choose to plant a garden, be prepared to battle hungry bugs. But you don't have to carpet bomb your future food with synthetic chemicals to get a good crop. Planting a variety of species can discourage one particular pest from taking over. A bit of biodiversity in the foliage department also provides habitat for beneficial predatory insects. Some plants don't need any help. Plants like spearmint, onions, garlic, mums and chrysanthemums produce chemicals that keep bugs at bay. Planting a few in the mix in the garden can protect the other crops. Some species of chrysanthemums are even used to produce a pesticide known at pyrethrin. Pyrethrin sprays are hardy enough to even kill fire ants, but sprays that mix the synthetic additive piperonyl butoxide or PBO are not considered organic by most practitioners even though the product may be advertised as such. For fire ants though, having natural predators in the neighborhood, such as dragon flies and other native ants, works best. Phorid flies from the genus Pseudacteon, make a living out of eating fire ant brains. The females lay an egg in a worker ant and when the egg hatches the maggot eats the ant's brain and then lives inside the empty head until becoming an adult and flying away. If you don't have phorid flies, citrus oil sprays also work to control fire ants; whereas grits or Malt-O-Meal do not.

Guano the Great (Natural Fertilizer) Some of the world's best fertilizer comes from seabird poo, or guano. The birds' fish-rich diets lead to a naturally nutrient rich fertilizer. Grass is especially hungry for nitrogen, and seaweeds, guano, and fish emulsion, though stinky, has plenty of it. Many lawn and garden centers sell these products as well as specially formulated organic lawn fertilizers. Organic fertilizers can cost more in the short term, but because they are applied less often they save money over the years. They only need to be put down once in the spring and fall. As they decompose they naturally time-release nutrients into the grass. Organics also don't shock roots and harm earthworms, even if over-applied, since most of the nutrients aren't immediately available. Over time the organics will help build up the soil and the community of microorganisms living in it, which means less need for fertilizer in the future.

Kill Weeds With Corn Meal America's second largest crop, corn, can help protect the number one crop, grass, from weed invaders. Corn gluten meal can stop weeds while they are only seeds. But it can take up to four years of proper application to wipe out the weeds' seeds. Dogs, livestock and wildlife feel no ill effects from corn gluten meal. Also, the meal doesn't affect plants once they have sprouted, so it is safe for the grass and garden. Once the weeds are up, a spray of concentrated vinegar can shrivel them up without leaving a toxic residue. The younger the plant, the more effective the vinegar. Kitchen vinegar isn't strong enough to kill weeds. It will only give the rabbits a nice vinaigrette salad to enjoy, if you toss croutons out along with it. When all else fails, just pull the weeds by hand. But keep in mind that weeds tell stories about your lawn's chemistry. For example, dandelions, love slightly acidic soil, whereas grass likes slightly basic soil. So working to drop your lawns pH can save some weeding.

Mow, Mow, Mow the Lawn How you mow the lawn can make a big difference in saving time and money along with the Earth. Leaving grass higher helps to shade out young weeds. Contrary to popular belief, cutting grass short doesn't result in more time between mows. Grass tends to spring up after being mowed short. Longer grass puts less energy into regrowing and more into building roots and spreading. The type of mower makes a big difference too. An old-fashioned reel mower produces no emissions, uses no costly fuel and has few moving parts to break. They also leave a layer of finely cut grass behind to serves as mulch. Most gas and electric mowers are now equipped with blades that chop the grass into mulch as well. The mulch helps keep soil moist as it decomposes and returns its nutrients to the soil.

Say No to Wimpy Lawns Frequent watering results in a wimpy lawn with short roots that can't fend for themselves in a drought. When a lawn dries out between irrigation, the grass sends roots deep into the earth searching for a drink. Deeps roots mean the grass can survive a long dry spell with less water. A dry surface also makes life harder for young weeds.

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Eat What You Grow A yard can also become edible. Landscaping with fruit trees and other edible plants turns a yard into a beautiful sources of fresh healthy food. Some communities have even started making whole parks of edible food.

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While other communities have cracked down on rebel gardeners who put raised beds in their front yards.

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Here, corn grows above broccoli as a young cantaloupe vine makes a break for it.

The Year-Round Greenhouse If you want to give up the lawn for good, a greenhouse can provide crops nearly all year long in most parts of the U.S. Building with found and reused materials saves money and keeps construction waste out of the landfills. Extending the growing season with a greenhouse also provides cheap veggies at the same time that prices are rising in the grocery store.

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Give Up and Go Fishing Perhaps soil isn't your thing. Ditch the dirt entirely and dig a pond. Ponds provide habitat to frogs and fish. Birds also appreciate the never ending drinking fountain, especially in the middle of a dry summer. Beneath the rippling surface of the pond, tomorrow's dinner splashes. Many people raise koi in their home ponds, but edible species like catfish and blue gill can do well in a small pond as well. This 1400 gallon pond, built by hand, is deep enough to provide fish a refuge during the winter.

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