‘Silent Spring’ got things rolling on DDT use
September 7, 2012 5:06PM
This is Riley Jean Young, 7, with a northern pike she caught on Druce Lake fishing with her grandfather, Kieth Young. "That was one of four northerns she caught and that wasn't the biggest one," said grandpa. "She was yelling 'Grandpa hold on he's going to pull me in!' I was laughing all day," he said. Riley recently moved from unincorproated Antioch Township to Twin Lakes, Wis. | Special to Sun-Times Media
Don’t be silent about cleaning up past mistakes
The United States Fish and Wildlife Service sent out a reminder that September marks the 50th anniversary of the publication of Rachel Carson’s book “Silent Spring” which documented the harmful effects of DDT and other pesticides and helped launch the environmental movement.
It was required reading when I was in high school and wouldn’t you know, it’s been so long, I really don’t remember it. It’s one of those books, like Aldo Leopold’s “A Sand County Almanac,” that I need to read again. Leopold’s book was even better the second time around.
It amazes me how science can just stumble along sometimes and then all of sudden everything comes together and a discovery is made. Carson’s book explained the dangers of DDT to the ecosystem and her work led to the banning of the chemical in the United States.
One of her stories in the book chronicles how ornithologist George Wallace of Michigan State University connected the dots between insecticide use and silencing robins.
A graduate student for Wallace was studying the robins in 1954 that did not involve insecticide use. At the time, Dutch Elm disease was ravaging elms across the country, turning beautiful canopied neighborhoods into treeless landscapes. To fight the disease, the school was spraying the elm trees with DDT.
As he followed the robin’s return each spring, he noticed less birds returning and those that did were dying on campus. Fewer and fewer birds were seen.
He suspected a disease of some sort that affected the nervous system because the insecticide people claimed their product couldn’t hurt birds, even though they had classic poisoning symptoms including loss of balance, tremors, convulsions and then they die.
The researchers found that the robins that did survive were not reproducing. The avenue of exposure was discovered accidently when campus earthworms were fed to crayfish and they all died. They fed the worms to a snake and it developed violent tremors.
Then, another researcher at another university came up with an explanation of the exposure route.
The DDT would cling to the tree leaves and in the fall, the leaves would fall and worms would eat the decaying matter. A bird would eat the worm and the toxins would either kill it or concentrate in the reproductive organs preventing the birds from reproducing.
Carson, who worked for the U.S. Fish and Wildlife Service, highlighted the effects of the indiscriminate use of pesticides following World War II.
What’s also interesting is that in the press release, they note that in June of this year, a woman sent some dead robins to Michigan State University and they found the birds had high concentrations of DDT.
So maybe we haven’t come so far?
As it turned out, the DDT was thought to be coming from the Velsicol Chemical plant on the Pine River, which is now a designated Superfund site. A river cleanup helped reduce the amount of DDT in the fish, but the grounds and adjacent properties (the woman who found the dead birds and sent them to the university lives next door) have higher levels of DDT. Officials are moving forward with a cleanup plan for those areas.
Which leads me back to Waukegan, where this week, they announced a final dredging of the harbor where PCBs still lurk and fish advisories are necessary.
This final cleanup will reduce the amount of the chemical in the water column, reducing the amount in the smaller feeder fish and ultimately reducing the amount in the bigger fish people catch and eat.
Some day, you may well see those fish advisories disappear as the cleanup takes hold.