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• “The problem is that through the urban water cycle, we might be producing more antibiotic-resistant bacteria.”

  James Jensen

  Professor of Civil, Structural and Environmental Engineering

By CHARLOTTE HSU

Published: June 25, 2009

Each day, Americans use tons of personal care products and pharmaceuticals—everything from antibiotics and hormones to perfumes, shampoos and soaps.

People take a pill or wash their hair. Then they move on, giving little thought to what ultimately happens to the chemicals they apply to their bodies or ingest.

As it turns out, many active ingredients end up in the nation’s wastewater collection system, and eventually back in our drinking water, James Jensen, professor in the Department of Civil, Structural and Environmental Engineering told about 100 people who attended his UBThisSummer lecture yesterday.

Whether this contamination is cause for worry is a question scientists are still working to answer, in part because researchers did not begin investigating the subject in large numbers until recently, Jensen said.

“What people have done for many, many years is focused, in particular, on industrial wastewater,” he said. “They’ve also spent quite a bit of time looking at agricultural runoffs into the water. So this is historically what we have done. But very recently—literally the last six or seven years—the focus has shifted a little bit.”

Bath and shower products often end up at water treatment plants after being washed down the drain. Drugs, including illicit substances and over-the-counter or prescribed pharmaceuticals, often are discharged in urine after the body processes them.

While some of the substances are removed at water treatment plants, others are not filtered out and make it back to household taps. Many of the contaminants that end up back in drinking water are miniscule, measured in parts per trillion, Jensen said. While the tiny concentrations in which many of the substances are found make it difficult to understand the effects they could have on the populations consuming them, many contaminants are likely harmless in such doses, he said.

Some people have expressed concern about hormones from contraceptives and hormone replacement therapies entering the water supply.

Jensen and his students found, however, that the total amount of estrogen excreted each day in the United States is about 107 pounds. Estrogen that women naturally produce accounts for the overwhelming amount of the quantity, he added, with pregnant women responsible for about 80 percent of the estrogen waste.

An area of greater concern is the release of antibiotics into the water system and their effect, Jensen said.

Water treatment plants use bacteria, which eat organic material, to help clean water, and researchers have feared that exposing these bacteria to antibiotics will lead to the development of larger populations of bacteria that are resistant to the drug, killing organisms that are not resistant and allowing those that are to multiply and trade genetic material with other nearby organisms.

Jensen said UB researchers have found that the presence of antibiotics does not increase the concentrations of antibiotic-resistant bacteria in wastewater treatment facilities. But, he added, other scientists have found that the presence of antibiotics increases the concentrations of bacteria that can resist multiple types of antibiotics.

When it comes to the water supply, “The reason that antibiotics are so special is because with antibiotics, it’s not so much the exposure to that chemical that we’re worrying about,” Jensen said. “Rather, we’re concerned about the concept of antibiotic resistance. The problem is that through the urban water cycle, we might be producing more antibiotic-resistant bacteria.”