More than fifty years ago, author Rachel Carson warned in her epic, “Silent Spring,” about the dangers of pesticides. Farming was producing at then record levels and much of this boom was attributed to the use of pesticides and their ability to kill off insects that would normally have consumed larger shares of a harvest.
While pesticides remain essential in agriculture, the government has taken a far more serious role in regulating them, banning some and reducing volumes of others that might be considered carcinogenic or harmful to health in other ways.
But another chemically based threat has recently been identified in the U.S. and a number of other places, including Pueblo.
Plastics, or more specifically the chemical agents that create the ubiquitous material essential in so many things in our daily lives, are now a growing threat.
In Pueblo’s Runyon Lake, state health officials are warning fishers to limit their consumption of rainbow trout to no more than two per month. That amount should be even less for children under age six to no more than six servings per year. A single serving is conserved to be approximately 8 ounces, about the size of palm.
Elevated amounts of a chemical essential in the manufacture of plastic items identified as perfluoro octane sulfonate (PFAS)have been detected in rainbow trout in the lake.
The Colorado Department of Public Health and Environment said consumption of rainbow trout registering dangerous levels of PFAS pose a risk of cancer. Other risks from eating this fish include higher cholesterol levels, liver issues and immune system effects. The chemicals sited by state health is also dangerous in pregnancies.
CDPHE began studying this danger in 2020, sampling fish taken from six lakes spread across the state. In 2023 it discovered levels high enough to issue warnings for fish caught in Pueblo Runyon Lake, Weld County’s Barr Lake and Chatfield Reservoir.
Because millions of tons of plastic are produced each year—it is cheaper than using glass, metal and ceramics and it can be formed into so many shapes—it has become essentially impossible to dispose of completely. Only 5 percent of all plastic is recycled and reused. Much of it, which is almost impossible to detect, has made its way into the food chain where it has become a serious health concern.
Chemicals in the manufacture of plastics can find their way into the food chain. Studies have found traces of plastics in cow milk, beef, pork and chicken. Once ingested, studies have shown that these chemicals can mimic human hormones and increase the risk of infertility, birth deformities and cancer.
The state health warning is not a statewide warning and restricted to only three bodies of water. But the warning for Pueblo, Weld County and Chatfield Reservoir should be taken seriously. Once dangerous chemicals have been detected neither cleaning nor cooking, said state health, “removes these substances.”
Also, state health’s Nicole Rowan said the warning should not inhibit anyone’s enjoyment of fishing. “Fishing,” she said, “is one of the best ways to enjoy Colorado’s natural beauty and spend time with loved ones.” The warning, she added, is simply an advisory to help people make informed decisions about what kinds of fish to eat and where to catch them.
