But they have the worst of all superpowers: invisibility.

For example, the catadores,

workers who collect recyclable materials for a living.

Catadores emerged from social inequality, unemployment,

and the abundance of solid waste

from the deficiency of the waste collection system.

Catadores provide a heavy, honest and essential work

that benefits the entire population. But they are not acknowledged for it.

Here in Brazil, they collect 90 percent of all the waste that's actually recycled.

Most of the catadores work independently,

picking waste from the streets and selling to junk yards at very low prices.

They may collect over 300 kilos

in their bags, shopping carts, bicycles and carroças.

Carroças are carts built from wood or metal

and found in several streets in Brazil,

much like graffiti and street art.

And this is how I first met these marginalized superheroes.

I am a graffiti artist and activist

and my art is social, environmental and political in nature.

In 2007, I took my work beyond walls and onto the carroças,

as a new urban support for my message.

But at this time, giving voice to the catadores.

By adding art and humor to the cause, it became more appealing,

which helped call attention to the catadores

and improve their self-esteem.

And also, they are famous now on the streets, on mass media and social.

So, the thing is,

I plunged into this universe and have not stopped working since.

I have painted over 200 carroças in many cities

and have been invited to do exhibitions and trips worldwide.

And then I realized that catadores, in their invisibility,

are not exclusive to Brazil.

I met them in Argentina, Chile,

Bolivia, South Africa, Turkey

and even in developed countries such as the United States and Japan.

And this was when I realized that I needed to have more people join the cause

because it's a big challenge.

And then, I created a collaborative movement called Pimp My Carroça --

(Laughter) -- which is a large crowdfunded event.

Thank you.

(Applause).

So Pimp My Carroça is a large crowdfunded event

to help catadores and their carroças.

Catadores are assisted by well-being professionals and healthcare,

like physicians, dentists, podiatrists, hair stylists, massage therapists

and much more.

But also, they also receive safety shirts, gloves, raincoats and eyeglasses

to see in high-definition the city,

while their carroças are renovated by our incredible volunteers.

And then they receive safety items, too:

reflective tapes, horns and mirrors.

Then, finally, painted by a street artist

and become part of part of this huge, amazing mobile art exhibition.

Pimp My Carroça took to the streets of São Paulo, Rio de Janeiro and Curitiba.

But to meet the demand in other cities, including outside of Brazil,

we have created Pimpx, which is inspired by TEDx,

and it's a simplified, do-it-yourself, crowdfunded edition of Pimp My Carroça.

So now everybody can join.

In two years, over 170 catadores, 800 volunteers and 200 street artists

and more than 1,000 donors

have been involved in the Pimp My Carroça movement,

whose actions have even been used in teaching recycling at a local school.

So catadores are leaving invisibility behind

and becoming increasingly respected and valued.

Because of their pimped carroças, they are able to fight back to prejudice,

increase their income and their interaction with society.

So now, I'd like to challenge you to start looking at and acknowledging

the catadores and other invisible superheroes from your city.

Try to see the world as one, without boundaries or frontiers.

Believe it or not,

there are over 20 million catadores worldwide.

So next time you see one,

recognize them as a vital part of our society.

Muito orbigado, thank you.

(Applause).