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Air pollutionWorldwide

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Worldwide

204. Air pollution

Air pollution is the presence of gases, particles or other substances in the air at concentrations that can harm human health, the environment or ecosystems. Road traffic contributes to air pollution through exhaust emissions and through non-exhaust sources such as brake wear, tyre wear and road dust.

Important traffic-related pollutants include nitrogen oxides, particulate matter, carbon monoxide and volatile organic compounds. Some pollutants are emitted directly by vehicles, while others can form in the atmosphere through chemical reactions. Vehicle-emission standards, cleaner technologies and traffic-management measures are used to reduce these emissions.

Air pollution
Black smoke emitted from a vehicle exhaust on a road in Kamonyi District. (Rwanda)
Wikimedia.org • Emmanuelkwizera • CC BY-SA
What is air pollution?

Air pollution is contamination of the air by gases, particles or other substances that can adversely affect human health, the environment or ecosystems.

How does road traffic cause air pollution?

Vehicles produce pollutants through fuel combustion, exhaust systems, brake wear, tyre wear and road-surface interaction. Moving traffic can also resuspend dust already present on the road.

Which air pollutants are associated with road traffic?

Important traffic-related pollutants include nitrogen oxides, particulate matter, carbon monoxide and volatile organic compounds. Their relative importance depends on the vehicle, fuel and driving conditions.

What is nitrogen dioxide?

Nitrogen dioxide (NO2) is an air pollutant associated particularly with combustion processes and road traffic. High concentrations are commonly found near busy roads and densely trafficked urban areas.

What is particulate matter?

Particulate matter consists of tiny solid particles or liquid droplets suspended in the air. Road traffic can produce particles from exhaust, brakes, tyres and road surfaces.

Is CO2 the same as ordinary air pollution?

No. Carbon dioxide is primarily regulated as a greenhouse gas because of its contribution to climate change. Local air-quality pollution generally focuses on substances such as nitrogen dioxide, particulate matter, ozone and other pollutants that directly affect air quality and health.

Do electric vehicles cause air pollution?

Fully electric vehicles produce no combustion-engine exhaust emissions while driving, but they can still contribute to non-exhaust particulate emissions through tyres, brakes and road wear.

Can air pollution be worse near busy roads?

Yes. Concentrations of traffic-related pollutants can be higher close to heavily trafficked roads because many emissions occur close to ground level and near where people live and travel.

What is a low-emission zone?

A low-emission zone is an area where access by more polluting vehicles is restricted in order to reduce traffic-related air pollution. Access criteria may depend on factors such as fuel type, vehicle category and emission standard.

How can traffic-related air pollution be reduced?

Measures include cleaner vehicles, stricter emission standards, effective emission-control equipment, low-emission zones, public transport, cycling and walking, as well as traffic-management measures that reduce unnecessary congestion and emissions.

1 Worldwide 2 Motorway 3 Expressway 4 Residential area 5 Built-up area 6 Zone 7 Speed limit 8 Minimum speed 9 Advisory speed 10 Footpath 11 Bike path 12 Shared-use path 13 Separated path 14 Pedestrian warning 15 Tunnel 16 Bridge 17 Cycling street 18 Pedestrian zone 19 Speed bump 20 Toll road 21 Customs 22 One-way traffic 23 Quay 24 Slope 25 Bus lane 26 Bus stop 27 Dead end 28 Stop sign 29 Give way 30 Roundabout 31 Priority road 32 Road narrowing 33 Priority over oncoming traffic 34 Give way to oncoming traffic 35 Pedestrian crossing 36 Railway crossing 37 Mandatory direction 38 Turn prohibition 39 School area 40 Overtaking 41 Crossing animals 42 Slippery road 43 Rockfall 44 Aircraft 45 Curve 46 Chevron 47 Wrong-way driving 48 Roadworks 49 Crosswind 50 Height limit 51 Width limit 52 Length limit 53 Weight limit 54 Radar speed sign 55 Selective barriers 56 Low-emission zone 57 Intersection direction sign 58 Priority at the next junction 59 Traffic lights 60 Traffic lights warning 61 Pedestrian lights 62 Road markings 63 All-way stop 64 Junction layout 65 Climbing lane 66 Bike box 67 Left-hand traffic 68 Speed feedback 69 Driving licence 70 Location marker 71 Road number 72 Countdown markers 73 Public toilet 74 Rest area 75 Traffic mirror 76 Emergency telephone 77 International border 78 Pedestrian underpass 79 Cycling route 80 End of restriction 81 Parking 82 No parking 83 No stopping 84 Parallel parking 85 Park and ride 86 Kiss and ride 87 Alternate-side parking 88 Parking meter 89 Parking disc 90 Disabled parking 91 Traffic management 92 Merging 93 Reversing 94 U-turn 95 Carpool 96 Traffic jam 97 Detour 98 Uncontrolled crossroad 99 Road surface 100 Advisory cycle lane ... 101 Verge 102 Ring road 103 Ramp 104 Exit 105 Emergency lane 106 Rush-hour lane 107 Traffic calming 108 Information point 109 Horse riding 110 Provisional licence 111 Hazardous cargo 112 Emergency exit 113 Runaway truck ramp 114 Radio service 115 Oversize load 116 Lane 117 Cycle highway 118 Tyre inflation station 119 ATM 120 Bed and breakfast 121 Dock 122 Cable car 123 Café 124 Motorhome wastewater disposal 125 Ferry 126 Carsharing 127 Chairlift 128 City limit 129 Cyclist crossing 130 Tram crossing 131 Gantry 132 Distance board 133 Truck ecotax 134 Breakdown bay 135 Hiking 136 Hospital 137 Hostel 138 Hotel 139 Greenway 140 Parking garage 141 Pavement parking 142 Parking zone 143 Passing place 144 Pedestrian overpass 145 Picnic site 146 Playground 147 Restaurant 148 Road church 149 Road closed 150 Road open 151 Ski route 152 Winter equipment zone 153 Tourist attraction 154 Viewpoint 155 Horn 156 Axle weight limit 157 Licence plate 158 Charging station 159 Dangers 160 Weather 161 Flooding 162 Blind summit 163 Tunnel category 164 Temporary sign 165 Overhanging trees 166 Dip 167 Turn on red 168 High voltage 169 Tram lane 170 Rail safety 171 Equestrian trail 172 Horse 173 Identity card 174 Fire risk 175 Local traffic 176 Pedestrian 177 Cyclist 178 Moped 179 Motorcycle 180 Car 181 Truck 182 Bus 183 Police 184 Ambulance 185 Taxi 186 Police signals 187 Rescue lane 188 Tailgating 189 Bicycle parking station 190 Gravel road 191 Tram lights 192 European emission standard 193 Public road 194 Roadway 195 Street 196 Pothole 197 Median strip 198 Public property 199 Private property 200 Private road 201 Public square 202 Path 203 Particulates 204 Air pollution 205 Interchange 206 Intersection 207 Box junction 208 Rush hour 209 Filling station 210 Road code 211 Two-way traffic 212 Tram stop 213 Train station 214 2+1 Road 215 2+2 Road 216 Passing lane 217 Reversible lane 218 Street gutter 219 Road debris 220 Cargo bike 221 Lane splitting 222 Forestry vehicle 223 Construction vehicle 224 Semi-trailer truck 225 Trolleybus 226 Speed pedelec 227 Delivery vehicle 228 Idling 229 Tow truck 230 Four-wheel drive 231 No vehicles 232 Road users 233 Driver 234 Passenger 235 Bicycle 236 Motorcycle equipment 237 Tram 238 Train 239 Railcar 240 Rail track 241 Public transport 242 Caravan 243 Trailer 244 Tow hitch 245 Emergency vehicle 246 Fire truck 247 Siren 248 Convoy 249 Emergency vehicle lighting 250 Tractor 251 Agricultural machinery 252 Electric bicycle 253 Electric vehicle 254 Pedelec 255 Quadricycle 256 Microcar 257 All-terrain vehicle 258 Van 259 Recreational vehicle 260 Scooter 261 Trikke 262 Personal mobility device 263 Skateboard 264 Segway 265 Kick scooter 266 Roller skates 267 Mailman 268 Hitchhiker 269 Baby 270 Toddler 271 Child 272 Adult 273 Elderly 274 Disability 275 Handcart 276 Horsecart 277 Livestock 278 Rickshaw 279 Skier 280 Snowmobile 281 Motor vehicle 282 Commercial vehicle 283 Crossing guard 284 Motorail 285 Garbage truck 286 Snowplough 287 Street sweeper 288 Parking violation 289 km/h 290 mph 291 Speedometer 292 National speed 293 Play street 294 Rumble strip 295 Speed cushion 296 Ride height 297 Funeral procession 298 Dirt road 299 Driving 300 Start-stop system 301 Manual transmission 302 Automatic transmission 303 Throttle 304 Tachometer 305 Steering wheel 306 Power steering 307 Visual scanning 308 Mirror 309 Two-second rule 310 Stopping distance 311 Braking distance 312 Fuel 313 Fuel economy 314 Fuel gauge 315 Petrol 316 Diesel 317 Diesel exhaust fluid 318 Car insurance 319 First aid kit 320 Fire extinguisher 321 High-visibility clothing 322 Towing rope 323 First aid 324 Guardrail 325 Cable barrier 326 Concrete step barrier 327 Bollards 328 Barriers 329 Residents card 330 Manoeuvres 331 Zipper method 332 Three-point turn 333 Vehicle lights 334 Street lights 335 Dipped beam 336 High beam 337 Fog lights 338 Front fog lights 339 Rear fog lights 340 Side lights 341 Turn signals 342 Hazard lights 343 Dashboard lights 344 Bicycle lighting 345 Bicycle bell 346 Headlight flashing 347 Seat belt 348 Child restraints 349 Head restraints 350 Airbag 351 ABS 352 Esp 353 Traction control system 354 Helmet 355 Bicycle helmet 356 Hands-free 357 Smartphone 358 GPS 359 Vehicle 360 Brake 361 Handbrake 362 Brake fluid 363 Tyres 364 Tyre code 365 Winter tyres 366 Tyre pressure 367 Snow chains 368 Bicycle tyre 369 Continuous track 370 Gross Vehicle Weight 371 Gross Vehicle Weight Rating 372 Weigh station 373 Cargo 374 Car body 375 Trunk 376 Roof rack 377 Windscreen 378 Emergency hammer 379 Car battery 380 Traction battery 381 Suspension 382 Shock absorber 383 Spring 384 Exhaust 385 Exhaust gas 386 Soot 387 Catalytic converter 388 Engine 389 Petrol engine 390 Diesel engine 391 Electric motor 392 Timing belt 393 Glow plug 394 Cylinder 395 Engine oil 396 Coolant 397 Maintenance 398 Spare tyre 399 Flat tyre 400 Jack 401 Vehicle inspection 402 Key 403 Dashboard 404 Windscreen wiper 405 Doors 406 Glovebox 407 Visibility 408 Snow 409 Ice 410 Rain 411 Freezing rain 412 Fog 413 Hail 414 Sunlight 415 Sunglasses 416 Salt 417 Air conditioning 418 Hydroplaning 419 Loose chippings 420 Blind spot 421 Distraction 422 Emotions 423 Road rage 424 Health 425 Epilepsy 426 Night blindness 427 Visual impairment 428 Fatigue 429 Defects 430 Traffic violation 431 Alcohol 432 Alcohol control 433 Ignition interlock device 434 Breath test 435 Breath analysis 436 Blood alcohol content 437 Blood test 438 Saliva test 439 Drugs 440 Medication 441 Penalties 442 Speeding 443 Smoking 444 Traffic enforcement camera 445 Section control 446 Double curve 447 Accident 448 Injuries 449 Nosebleed 450 Falls 451 Damage 452 Breakdown 453 Total loss 454 Multiple-vehicle collision 455 Warning triangle 456 International Driving Permit 457 Traffic rules 458 Driving school 459 Traffic signs