manufacturers are based here. Most families have at least one car. But lots of vehicles

emit lots of harmful fine dust. Rajko Zschiegner lives at this intersection. He'd like to drive

less, but that's easier said than done.

"Public transport just doesn't take you where you want to go. Then you have no choice but

to take the car. Because Stuttgart lies in a valley, cycling is also really exhausting."

Stuttgart is the fine-dust capital of Germany. The tiny particles emitted in car exhaust

can damage the heart and lungs. Zschiegner measures levels of the particulates around

his home at a station he put together himself.

The data he collects is passed on to the website luftdaten.info. There users can check to see

how high levels are in real-time in their neighborhood and throughout the city. When

they rise, Zschiegner leaves his car at home.

Zschiegner's measuring equipment came from OK Lab Stuttgart, which also provided online

instructions on how to build it from scratch. It's made up of a processor and wireless chip,

a USB power supply source and two plastic pipes that shield it from the weather. Total

cost: around 30 euros.

"Just put it together and stick it in the pipe. Hardware is ready to go. There's still

some software stuff, but it isn't hard to get it running. You don't have to program

anything yourself."

Jan Lutz, the head of OK Lab Stuttgart, set up Luftdaten.info two years ago after discovering

that just 5% of the city's inhabitants leave cars at home, even after fine dust alarms

are issued.

That bothered him. So he decided to do something to wake people up to the danger, by making

the data more visible and accessible.

"It's a way to help people change their consumer and mobility behaviors. This area has been

shaped strongly by automobiles. We have to do something and continue to develop our products.

This should provide a little impetus for people to just stop and think: 'hey, what are we

doing here?"

The state government in Stuttgart has already announced that in 2018, on days when fine

dust levels climb too high, it will ban a certain type of Diesel cars.

Urban climatologist Ulrich Reuter is responsible for the city's official measuring stations.

He's generally in favor of the self-installed fine dust sensors -- though he does have a

few reservations.

"It's certainly a good measure for raising consciousness if the devices are used properly.

But there is a danger that data could be falsely interpreted."

"How?"

"Well, say one person measures on the street, another in a courtyard. One says his spot

is heavily polluted, the other says 'here where I live there's little pollution'. But

only because the two locations really can't be compared at all."

TC: 03:37 The private measuring station movement isn't

confined to Stuttgart. People in other regions are using them too. 400 have been set up so

far in all.

"We're getting really positive feedback at the transregional level. People are enthusiastic

and want to build one straight away."

The group has received inquiries from as far afield as South Africa. OK Lab Stuttgart has

now entered into a cooperation with the organization Open Data Durban, which tracks air and water

quality there. In many of South Africa's cities, traffic is posing the same environmental challenges

that it does in Stuttgart.