Maceo Martinet Studies Rio Grande and Riparian Groundwater for Presence of Pharmaceutically Active Compounds

Maceo Martinet photoHave you ever wondered what exactly is in the Rio Grande water? Maceo Martinet, a graduate student in the Biology Department, did and was surprised by the results. Martinet's interest was first piqued by a report published in the journal Environmental Science and Technology in 2002. The article reported results from the first nationwide reconnaissance of the occurrence of pharmaceuticals, hormones and other organic wastewater contaminants in 139 streams across 30 states.

“The report startled me because 80 percent of the streams sampled contained one or more of a suite of contaminants, which have a wide suite of origin, from residential, industrial to agricultural,” said Martinet. “Based on the results of that report, I decided to look at what types of personal care products and pharmaceutical compounds are present along the Rio Grande.”

Martinet set out to address two questions in his project: how is the Albuquerque Wastewater Treatment Plant (WTP) effluent altering the nutrient chemistry of the river and shallow alluvial groundwater; and what types and at what concentrations are personal care product compounds present in Albuquerque's WTP?

The effects of human activities on local, regional and global biogeochemical cycles have become an issue of growing concern and increased research, says Martinet in a recent research paper titled “Presence of Pharmaceutically Active Compounds in the Rio Grande and Riparian Groundwater.”

The presence of such contaminants in our rivers is a result of human and veterinary use of pharmaceuticals and personal care products (PPCP) from prescription drugs to fragrances and sunscreen agents, says Martinet. Martinet received funding for his research from the Water Resources Research Institute at New Mexico State University.

Martinet gathered samples using a syringe with an inline filter from five river sites upstream and downstream of the Albuquerque wastewater treatment plant discharge. He sent the samples to MWH Laboratories in California for analysis of a suite of 19 pharmaceuticals and endocrine disruptor compounds.

“With the help from WRRI [Water Resources Research Institute], I was able to submit five samples to a lab in California,” said Martinet. “I sampled Albuquerque's wastewater discharge effluent at three times, dusk, mid-day and evening. I also sampled the shallow groundwater above and below the point of discharge about 30-40 feet from the bank of the Rio Grande. There were some interesting results that came back from the lab.”

Not only did the results indicate the presence of antibiotics and nonprescription drugs, insecticides and other compounds, but the insecticide DEET, the anti-microbial ingredient triclosan and several other fire retardant and plastic derived compounds were found at similar concentrations to those reported in the national reconnaissance study (Kolpin et al., 2002).

“One feature of this small data set that is curious is that the concentration of DEET in the shallow groundwater was roughly an order of magnitude greater than that coming out of the wastewater treatment plant, and that DEET in groundwater downriver from the treatment plants discharge was almost twice that of upriver,” said Martinet. “This indicates that potentially DEET could be concentrating within the soil matrix via absorption to clay or other minerals.”

According to the results, concentrations of the PPCP compounds were all in the parts per trillion range, except for DEET, which was found in the parts per billion range. Martinet says in one study (Kummerer, 2001), 80 different drugs were found in WTP, surface waters, ground water and drinking waters. Overall, he detected seven of 15 categories from the Kummerer study in his research.

Martinet also was able to establish the fact that the WTP is significantly altering the nutrient chemistry of the river and shallow riparian groundwater. As the Rio Grande passes the WTP, the waters become enriched in nitrate, phosphate and ammonium. In his final report, he says little information is available on the effects the PPCP compounds have on organisms and processes, but new research suggests chronic exposure to certain PPCPs, even at low concentrations can have biological effects on crustaceans, algae and bacteria.

“I would love to do more work in addressing this question along the Rio Grande but only if I can secure funding to pay for the analytical costs,” said Martinet. “I am looking for new grants, which can help me address this question of what is the occurrence of pharmaceuticals and health care products along the Rio Grande.”

This article was originally published in "UNM Today: Campus News and Information" ( on June 22, 2005 by Steve Carr (505/277-1821).