A new study out of Indiana University found that potent growth hormones given to cattle persist in the environment longer than thought, and can end up in our drinking water:
Study: Environmental Exposure To Hormones Used In Animal Agriculture Greater Than Expected, Indiana University Press Release, 8 May 2015
They only looked at one chemical but lead author Adam Ward said it was representative of many others. “This compound is something of a canary in a coal mine,” he said in this video that accompanied the study:
Some excerpts from the press release:
The study focuses on the environmental fate of trenbolone acetate, or TBA, a highly potent synthetic analogue of testosterone, used to promote weight gain in beef cattle. A majority of beef cattle produced in the U.S. are treated with TBA or one of five other growth hormones approved for use in animal agriculture.
The compound and its byproducts are examples of contaminants of emerging concern called endocrine disruptors.
The metabolite makes its way to streams and rivers via manure that washes from feedlots or is applied to land as fertilizer.
So, if it makes its way to streams and rivers, that means it makes its way into our tap water (see below). And if it’s applied to land as fertilizer, that means it makes its way into our food. Water used for irrigation also contains these chemicals.
TBA metabolites were thought to break down in sunlight. It was found they reassemble at night:
The breakdown products reverted back to 17-alpha-trenbolone in the dark. This means that, instead of permanent removal in sunlight, the compound would be expected to persist in stream environments, returning to its earlier form overnight in the dark.
Stream life experience 50% higher exposure than thought – to just this one chemical. There are hundreds of chemicals we’re dumping into our water:
They show that concentrations of TBA metabolites may be about 35 percent higher in streams than previously thought. And the compounds persist longer, resulting in 50 percent more biological exposure than anticipated. … That’s a problem, Ward said, because even very low concentrations of these powerful endocrine disruptors have been shown to have significant effects on stream life.
While TBA and its metabolites are the focus of the study, Ward said those compounds are representative of many others — suggesting it may be time to update regulatory approaches to better include a wide range of findings from modern research.
Studies by the U.S. Geological Survey and other agencies have found endocrine disruptors to be present in many streams, rivers and lakes, and several similar compounds have even been found in drinking water.
Don’t water treatment plants remove drugs? Some drugs, I discovered, but not all:1
Wastewater treatment plants were never built to deal with [drugs]. … They remove 95 to 98% of pharmaceuticals from the sewage, [yet] many are still biologically active at low concentrations, which means you have to remove a lot of it to see the benefit. “Yet that’s very difficult to do when you’re trying to treat such extraordinarily large volumes as we do with wastewater treatment,” [Joanna Wilson, biologist at McMaster University in Ontario] says.
What’s left in our tap water after treatment is a cocktail of hundreds of drugs, albeit in small amounts. A problem? No one knows for sure:
There really have been no studies that have associated the [pharmaceutical] residues in our water with human health problems.
So there are no regulations:
Right now, the EPA does not have any guidelines about pharmaceuticals in drinking water. So water treatment plants, despite removing most compounds, don’t tend to specifically treat for them.
We’re being exposed to endocrine disruptors and other drugs not just from water, but from food, food packaging, prescription drugs (the diabetes drug metformin was just found to be an endocrine disruptor), dietary supplements, toiletries, even the air. The NOVA article says that new nanomedicines are particularly problematic because they remain stable in water since they’re encapsulated.
“Our studies show that if the nanomedicine comes into the vicinity of a plant, it can be absorbed, and go inside.” If the plant taking up the nanomedicine were grass in a field for example, an herbivore might eat it, and potentially move up the food chain this way.
There’s the problem of bioaccumulation again. These drugs tend to be hydrophobic and will dissolve in the fat tissue of animals. Animal fat, as I often say, is a good source for environmental pollutants.
Both the NOVA article and Ward’s study ended by saying we need to upgrade water treatment plants so they remove more of these drugs, especially given the growing use of them.
1 The Complicated Question of Drugs in the Water, PBS NOVA, 14 May 2014