LAS VEGAS (KLAS) — Two major Las Vegas events brought big numbers, big money and a significant bump in prescription and illicit drugs to the water flowing into Lake Mead, local research found.

In May, the 8 News Now I-Team reported researchers and students at the College of Southern Nevada’s School of Sciences & Mathematics took part in a global study to investigate the effects of pharmaceuticals on the world’s waterways.

As part of the project, the team took samples up and down the Las Vegas Wash, the 12-mile-long channel that moves treated wastewater out of the Las Vegas Valley and into Lake Mead.

LAS VEGAS, NV – JUNE 18: A general view shows the 21st annual Electric Daisy Carnival at Las Vegas Motor Speedway on June 18, 2017 in Las Vegas, Nevada. (Photo by Steven Lawton/Getty Images)

Researchers continued their study, finding an increase in some medications and drugs during the NFL Draft and the Electric Daisy Carnival.

The draft, which was held in late April on the Las Vegas Strip, brought an estimated quarter-million tourists to the region. EDC, a three-day festival at the Las Vegas Motor Speedway, took place in late May. The festival attracted about 160,000 people each night.

“Two distinctly different groups of people showed up,” Dr. Doug Sims, the school’s dean, said.

Sims leads the grand-funded research, with a mission to find out not only what southern Nevadans — but also what tourists — are leaving behind.

NFL Draft ’22 stage at the Bellagio Fountains. (Mary Jane Belleza/KLAS)

Sims’ research found 28 compounds in the wash, including antidepressants, opioids, and medications to treat acid reflux, allergies, coughs, diabetes, high blood pressure, muscle spasms, nerve pain and shingles.

“It’s important to look at what’s going into the natural environment because what we do as people is going to affect the wider environment or the food web,” he said.

Data from before and after the draft, and EDC, show two specific drug signatures, he said.

During the NFL Draft, Sims noted an influx of anti-depressants and medications to mitigate high blood pressure and cholesterol. The uptick in those chemical compounds is statistically significant compared to the other weekly-compiled data, Sims said.

The amount of MDMA flowing through the Las Vegas Wash on the Monday after EDC was 300 times its level recorded before the festival began, Sims’ research found. (KLAS)

During EDC and the days after, wastewater in Las Vegas contained a notable spike in MDMA, also known as Ecstasy or Molly.

The amount of MDMA flowing through the Las Vegas Wash on the Monday after EDC was 300 times its level recorded before the festival began, Sims’ research found.

Results are expressed in parts per trillion. The levels are not yet harmful to humans, but other organisms do not have the privilege of a high-tech treatment facility. The amount of MDMA in the wash on Monday, May 30, was about 2,100 parts per trillion. Readings decreased after the spike, Sims said.

“Going from 10 parts per trillion MDMA on a normal day to 2,100 parts per trillion on a day during or shortly after that event is clearly a signature of that event itself,” he said.

The wash also saw an uptick in Ketamine and pain medication that same weekend.

“They get up the next morning, take another medication to deaden the pain that they have from partying all night long,” Sims said.

The medications and drugs going into Lake Mead have no effect on our drinking water, which also comes from the reservoir.

“All drinking water treated and delivered by the Southern Nevada Water Authority meets or surpasses Safe Drinking Water Act and health-based standards,” a spokesperson said in a statement in May when the I-Team’s first story aired. “Over the past 20 years, SNWA has also developed and implemented cutting edge methods to monitor our water supply for pharmaceuticals, illicit drugs, and relevant metabolites.”

Dr. Douglas Sims collects samples at the Las Vegas Wash. (KLAS)

Sims hopes his research shows how these compounds affect smaller organisms and creatures that bigger animals, like humans, rely on.

“It’s very low for you and I, but for a fish, that’s a lot of potentially hazardous material,” Sims said.

Over time, as Las Vegas’ groundwater shrinks and the volume of wastewater increases, those trace levels will only multiply. Their effects on plants, small organisms and animals living in the wash and in the lake is unknown.

Las Vegas Metro police arrested 39 people and issued 13 misdemeanor citations during EDC.