Unbearable stench evoking rotten eggs and vomit has hovered for days in Brighton Park

CHICAGO (CBS) -- Residents in the Brighton Park neighborhood say they have been dealing with a unbearable smell for the past couple of days.

The cause of the stench is unknown, and now residents are calling on the city to get to the bottom of it. CBS 2's Marybel González could smell it herself right when she arrived in the area.

The strong odor comes in waves. Residents said it was so awful that they weren't even able to enjoy the beautiful weather outside this week.

"It smells like garbage; like rotten food – pretty much like someone just threw up in your neighborhood," said Brighton Park resident Felipe Lopez.

Lopez said the stench has been lingering in the neighborhood since Monday.

"It was unbearable to be outside," he said. "You couldn't even open the doors, and you couldn't do anything outside."

And he is not the only one dealing with the stink. Dozens of other residents chimed in online – posting in a community group. They described the smell of one of rotten eggs and vomit – even saying it made them dizzy.

"It's not even just my neighborhood - from three blocks away," Lopez said. "So people from Sawyer even further down to Archer are saying they're smelling this as well."

Ald. George Cardenas (12th) said his office has heard about the smell too.

González: "Any idea of where this could be coming from? Are there any theories on it?"

Cardenas: "My ward superintendent believes that it could be coming from a couple of sources. There's a company that does garbage disposal - that could be one of those – and there's also a couple of factories there south of 48th that could be culprits."

But neighbors say the stench is one they've never smelled before in their industrial community – at least not one this strong.

"I've been here for about 20 years, and I've never had a smell like this – especially not for two or three days that it lingers," Lopez said.

The source of the smell is still a mystery, so Ald. Cardenas says he's getting the city's Department of Public Health involved.

"So we don't know," Cardenas said. "The idea is to send an inspector to, for all intents and purposes, kind of sniff around."

Ald. Cardenas is asking people to call his office and report any strong smells so they can better pinpoint the areas