According to a new study, a pesticide sprayed in the forests again Brunswick more than 55 years ago in some stream trout in the province, according to a new study.
DDT was sprayed From airplanes throughout the north and central of Brunswick, more than half of the province, between 1952 and 1968 to control the fir earth that feeds on coniferous trees.
And the synthetic insecticide left a residue that has not disappeared.
“I think it is important that people are aware of the fact that this inherited pollutant exists in the current environment at very high concentrations,” said Joshua Kurek, an associate professor of environmental sciences at the University of Mount Allison and main researcher of the study.
Kurek said his research team showed and studied Trout, which he described as one of the most harvested fish in New Brunswick, by Seven Lakes throughout the province.
The harmful environmental effects of DDT were widely known to the public after Rachel Carson’s influential book on pesticides, Silent Spring, It came out in the early 1960s.
New Brunswick stopped spraying DDT at the end of the 1960s, instead with other pesticides, including Fenithion, which was also controversial, but it was discovered that it decompose quickly and did not persist in nature. The province now adopts a more specific approach to control the outbreak worm.
But DDT, although it was not the most used pesticide in the spray program, has persisted on the ground and in the water environment again Brunswick.
High levels of a sprayed insecticide have been found more than half a century ago in the Arroyo trout in several New Brunswick lakes.
When Kurek observed his presence in some populations of Arroyo trout, he discovered DDT in 10 times higher concentrations than the levels identified in Canadian ecological guidelines as healthy for wildlife.
The guidelines say that it would not be expected that up to 14 nanograms of DDT per gram of trout trout cause adverse effects in wildlife that the fish eat.
Five of the Seven Lakes Kurek studied were in areas where DDT was sprayed: Upsalquch, Goodwin, California, Sinclair and the Midds peak mountain.
The remaining two, Anthony and Bennett, were out of the spraying areas and were chosen for DDT comparisons throughout the province, Kurek said.
He said that the dark and fresh atmosphere at the bottom of these lakes is favorable to preserve the DDT.
“Usually, organisms acquire DDT through their diet, what they are eating,” Kurek said.
Insects that live in the lake mud will eat sediments with DDT content. These insects are food for the Arroyo trout, then consumed by Loons, Minks, otters and humans, Kurek said.
“Then, if it is in the trout, it is also in these other organisms, because they are part of the broader food network.”
Kurek described DDT as a “probable” carcinogen.
The International Agency for Cancer Research and the United States Environmental Protection Agency has recognized DDT as a probable human carcinogen.
Low levels of DDT were detected in the trout of the two lakes outside the spray areas, which shows insecticide trips in the environment, Kurek said.
He said that he can travel atmospherically, and that it can be transported from Earth to the nearby water bodies by heavy rains or surface waters.
DDT present in the food network associated with these bioacumulated lakes, or continues to accumulate in the tissues of organisms such as trout, Kurek said.
“And then, as he advances through the food chain, his abundance in organisms is also magnified, so organisms at higher levels in the food chain tend to have higher concentrations of pollutants such as DDT in their tissues,” he said.
Kurek said his next investigation requires sampling more lakes to better understand how the pollutant enters forest floor lakes.
“We want populations of fish that are fine,” he said. “When they have large amounts of contaminants such as DDT in their fabric, they will not work very well.”
A spokesman for the New Brunswick Department of Health said in an email that DDT levels found in Brook trout investigation exceed guide levels for wildlife that they consume trout, but not for humans.
“The patterns developed to protect human health have levels that are many hundred times higher because wildlife consumers, such as rapt birds, have very different diet patterns than humans,” said spokesman Tara Chislett.
Chislett advised New Brunswickers to follow the limits of provincial fish consumption, for several species, including trout.
According to New Brunswick fish consumption guidelines, people 12 years or older can have eight monthly stream trout portions that are shorter than 25 centimeters. Women, babies and pregnant children who breastfeed up to 11 should have only a monthly portion.
With fish that is more than 25 centimeters long, the guidelines recommend that people 12 years or older have more than four monthly portions, while women, babies and pregnant children or breastfeeding of up to 11 years should not eat.
The portion sizes mentioned in the provincial guidelines are 75 grams, 125 milliliters or “a portion of cooked fish that fits the palm of the consumer’s hand.”
The reason for the great gap between the guidelines for human and wild life consumption is that humans only eat fillets, while wildlife would consume the entire fish, therefore, consuming more DDT, Kurek said.
Kurek’s study is published in the magazine reviewed by Pares Plos One.
