- Last Updated on Thursday, 06 June 2013 15:30
By Nadia M. Whitehead
UTEP News Service
Everyday actions like washing your laundry, brushing your teeth and cleansing your hands with antibacterial sanitizer are all linked to endocrine disrupting compounds (EDCs).
EDCs are chemicals commonly found in household and industrial products that are capable of disrupting hormonal balance within humans and wildlife and leading to reproductive disturbances. They include nonylphenols (NPs) in detergents and pesticides, triclosan in hand sanitizer and toothpaste, and BPA in plastics.
On top of potentially affecting users, there is another problem – the chemicals are constantly washed down the drain and are entering the sewage system.
“If I asked you not to take showers or do your laundry you’d think I was crazy,” said Wen-Yee Lee, Ph.D, associate professor of chemistry at The University of Texas at El Paso. “And you’re right. We cannot stop doing those things, which is why this release is continuous with not one source, but many. It’s a new type of contamination where everyone is involved, not just the industry.”
The chemist recently assembled an interdisciplinary research team of biologists and engineers at UTEP to develop a process to remove EDCs, or compounds of emerging concern, in wastewater treatment plants.
“Wastewater treatment is not designed to remove these types of compounds because these findings are relatively too new to have been built into the process,” said Lee, who has sampled the region’s wastewater pre- and post-treatment. “Right now the removal rate ranges from 60 to 99 percent.”
The EDCs that escape the treatment process ultimately reenter the environment via reclaimed water or drinking water pipes, causing damage to wildlife.
For instance, a study done in Canada spiked an experimental lake with an extremely low dose of birth control – comparable to a single drop of water in a football field. It led to fish feminization, characterized by increased hormone levels, development of organisms with characteristics of both sexes, skewed sex ratios, and near extinction of the fish population.
“The good news is once they stopped treating the lake with it, the fish population gradually came back,” said Lee, who is also a member of the Border Biomedical Research Center (BBRC). “However, the situation we’re facing is different. We are releasing these chemicals constantly.”
That’s why the UTEP team is out to remove them entirely once they hit wastewater treatment facilities.
With the help of Marc Cox, Ph.D., associate professor of biological sciences, Roberto de la Torre-Roche, a former doctoral student in environmental science and engineering, and Cesar Bezcares, a doctoral student in civil engineering, the team has tested water from multiple wastewater treatment facilities – confirming that EDCs and estrogenic activity is present in the region’s wastewater influent and effluent samples.
EDCs identified in the wastewater include NPs, BPA, and estrone and estradiol, which are natural hormones excreted from women.
“We know that these chemicals can cause reproductive problems, but we’re not sure which levels of exposure lead to those effects,” said Cox, who is a co-principal investigator of the study. “In my opinion, it’s better to be cautious and assume they are harmful, so we’re trying to do everything we can to completely remove them from the environment. ”
That’s where Shane Walker, Ph.D., assistant professor of civil engineering, comes in. As another co-principal investigator of the project, he is using the chemical and biological analysis of the wastewater to create a treatment process to remove the EDCs.
Last year Walker and the team constructed a small wastewater testing facility inside a 16-foot trailer to test different removal methods. They found that additional disinfection processes via UV rays and chlorination lead to the removal of EDCs.
This summer they hope to validate their results by expanding the study to six existing municipal wastewater treatment plants in El Paso and Socorro, N.M.
The goal is to develop a sustainable and effective treatment for 100 percent removal of the compounds.
“The problem is that everything we do has an environmental impact. There are many things in our water that we don’t know about yet and have not identified as a potential threat,” said Bezcares, who recently transferred from Purdue University to UTEP to complete his doctoral degree. “We need to identify exactly what’s in our wastewater, how much, and then figure out a process to destroy the compounds.”
Although there are no regulations on the removal of EDCs from water treatment systems, the researchers hope their results will provide water utilities worldwide with an effective treatment process to respond to inevitable regulations in the future.