WALKING THE DOG recently in the Village of Chatham we encountered two boys speaking Spanish to each other. We exchanged greetings in English, but as they headed up the street in the other direction, they giggled loudly, and one of them exclaimed, “Zapatos!”
He had it right. The dog was wearing shoes. Well, technically booties. He wears them every winter, and it’s easy to predict the human reaction based on gender. Men tend to chuckle dismissively, as if to say: Your dog’s a wuss. Women coo and say: That’s so cute. Seldom does anyone remark on the practicality of his footware.
Cold never seems to bother the dog much. He wears booties as a barrier against salt. Even this winter, when snowfalls have been light and infrequent, most sidewalks and roadways are bathed in sodium chloride (NaCl–common table salt) or else some other compound that combines chlorine ions with a different element, like calcium, potassium or manganese. Many of these substances have a corrosive effect on the paw pads of dogs, producing severe pain and causing deep cracks that bleed and make it difficult for the dog to walk.
So should road crews stop using salt and let cars and people slip and slide on the ice, risking damage, injuries and death, all so that doggies’ feet don’t hurt? While ardent dog lovers might nod in assent, no sane person (sorry, ardent dog lovers) would seriously suggest that drastic a remedy. Still, the plight of dogs like ours suggests that these pets may serve as what scientists call a sentinel species.
For more than a decade researchers have looked at the impact de-icing agents used on roads. It’s not a small amount. The generally accepted figure seems to be that road crews around the country spread 10 to 15 million tons of salt each winter season, most of it on roads in the Northeast and Midwest (although states in the Southeast and Mid-Atlantic may wish they had stockpiled more this winter). All this salt, which was dug out of the Earth, goes wherever nature takes it once it washes off the pavement. In high enough concentrations it can deplete or sterilize the soil, robbing it of the ability to support life. When salt seeps into the groundwater we drink, it can make life more expensive–drilling new wells, importing water, etc.–and can threaten human health if high levels of sodium are not detected and addressed. The Town of Schodack in neighboring Rensselaer County had just such a problem a few years ago.
One practical result from studying the impact of salt use on roads was the state requirement that municipalities must store their salt supplies in sheds–those multi-sided buildings with roofs shaped like big, fat cones. Most comply. But once the trucks spread the stuff, no one can predict where it will go or what mischief it will make.
Dogs give us a lot of information if we’ll heed them. For example, they tell us that the state uses a much higher concentration of salt than the village. After a snowstorm, a dog of our acquaintance will walk without concern across a freshly cleared village street. Moments later, the same animal will panic in the middle of a state highway, yelping and lifting one foot after the other, not knowing what to do to stop the pain. The only way to relieve the animal is to whisk it to a snow bank on the side of the road… or use booties.
Salt only works its melting magic up to a concentration of about 23%. At a certain level higher than that, the excess salt can actually cause water to refreeze on the highway. The state does have an incentive to use salt as efficiently as possible; the stuff is expensive. And modern spreaders now disperse salt more effectively than ever. But if the village can clear its roads with less salt, maybe the state has something more to learn.
The state probably can’t slash the amount of salt it dumps on the roads as long as drivers insist on traveling as fast and as far in winter as they do other times of the year. And anyway, salt on the roads doesn’t rank anywhere near the top of the list when it comes to the environmental threats facing the nation.
But aside from the obvious effects of so much road salt–vehicle rust, corrosion of bridges, water pollution, etc.–we still rely on this stuff even though it eats the feet off our pets. Doesn’t that suggest we’re doing something wrong?