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Statistics estimate 36,000 people are homeless in Los Angeles, but the city isn’t providing bathrooms to most of them. As the NBCLA I-Team has found, the tons of human waste landing on city streets are creating an urgent public health threat.

In one act caught on camera, a homeless man is seen waking up on South Hope Street. He unbuckles his belt, walks over to the front door of a business, pulls down his pants, and defecates right on the door mat in broad daylight.

“We are not in a third world country,” said Maria Janossy, who works in the building where the incident happened.

Next to a West Los Angeles homeless encampment, a man urinated on a cop car.

“The public restrooms won’t let us go to the bathroom because we’re homeless,” said Jennifer, who lives in an encampment under the 101 Freeway in Hollywood.

When asked where the homeless at her encampment go to the bathroom, she responded, “in bottles, on the side of buildings, right here on the curb.”

As far back as 2012, the LA County Health Department warned that “piles of feces and urine” on the sidewalks posed an “immediate threat to public health.”

Last year, a city of LA report said “the shortage of public restrooms” for the homeless was a leading cause of a Hepatitis A outbreak.

“My car has been defecated on, not once but twice,” said Mar Vista resident Roman Samiley.

Samiley and his family live a half a block from an encampment.

“I’m scared of the public health hazards,” he said.

“Everyone’s at risk at some level,” Dr. Jeffrey Klausner of UCLA School of Public Health said.

The public can be at risk because the feces and urine that's now on LA sidewalks could end up on residents' shoes and tracked into homes, and offices, Klausner said.

“People’s shoes or clothes can be contaminated. Then they inadvertently touch their shoes, touch their eyes, they touch their mouth,” he said. “We can get gastroenteritis, norovirus.”

Such a public health risk can be a big cost to taxpayers, as teams must dispose of urine and piles of feces. The city of LA pays a private firm, Clean Harbors, to clean up human waste and needles. The bill for this was almost $1.9 million last year, more than double the amount from the year before, and six times the amount compared to the year before that.

“The city should be putting porta potties out at every encampment,” Klausner said.

The World Health Organization, or WHO, recommends at least one toilet for every twenty people in populated areas like Los Angeles. But most of the city’s hundreds of encampments are nowhere near a public toilet.

In fact, LA has only 16 mobile toilet stations for its 36,000 homeless people.

To make matters worse, the city hauls away the mobile toilets at night, leaving the homeless no choice but to go on the streets.

“I mean if you’re allowing the homeless to set up tents, they should at least have a bathroom,” Janossy said.

When asked why the city hasn’t provided toilets for the homeless, Mayor Eric Garcetti said there’s simply not enough money.

Garcetti admits the lack of toilets is a crisis for his city.

“We simultaneously have to clean up streets, clean up this crap, and build housing,” Garcetti said. “And if I had the money to do all three, we wouldn’t be in this place.”

Garcetti said he might put money in his upcoming city budget for more toilets for the homeless, but wouldn't say how much.

In the meantime, public health experts, and LAPD officers suggest if residents are walking in an area where people might be going to the bathroom on the streets, take off your shoes before entering your home or office, so you don’t track bacteria or viruses inside.