A tire is a ring-shaped component that surrounds a wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide traction on the surface over which the wheel travels. Most tires, such as those for automobiles and bicycles, are pneumatically inflated structures, providing a flexible cushion that absorbs shock as the tire rolls over rough features on the surface. Tires provide a footprint, called a contact patch, designed to match the vehicle's weight and the bearing on the surface that it rolls over by exerting a pressure that will avoid deforming the surface.
A rubber-tyred metro or rubber-tired metro is a form of rapid transit system that uses a mix of road and rail technology. The vehicles have wheels with rubber tires that run on a roll way inside guide bars for traction. Traditional, flanged steel wheels running on rail tracks provide guidance through switches and act as backup if tyres fail. Most rubber-tyred trains are purpose-built and designed for the system on which they operate. Guided buses are sometimes referred to as 'trams on tyres', and compared to rubber-tyred metros.
Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind, volcanic eruptions, and pollution.
Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline (petrol), diesel fuel, fuel oil, biodiesel blends, or coal. According to the type of engine, it is discharged into the atmosphere through an exhaust pipe, flue gas stack, or propelling nozzle. It often disperses downwind in a pattern called an exhaust plume.
Diesel exhaust is the exhaust gas produced by a diesel engine, plus any contained particulates. Its composition may vary with the fuel type, rate of consumption or speed of engine operation, and whether the engine is in an on-road vehicle, farm vehicle, locomotive, marine vessel, or stationary generator or other application.
A diesel particulate filter (DPF) is a device designed to remove diesel particulate matter or soot from the exhaust gas of a diesel engine.
Uniform Tire Quality Grading, commonly abbreviated as UTQG, is a set of standards for passenger car tires that measures a tire's treadwear, temperature resistance and traction. The UTQG was created by the National Highway Traffic Safety Administration in 1978, a branch of the United States Department of Transportation (DOT). All passenger car tires manufactured for sale in the United States since March 31, 1979 are federally mandated to have the UTQG ratings on their sidewall as part of the DOT approval process, in which non-DOT approved tires are not legal for street use in the United States. Light truck tires are not required to have a UTQG. It is not to be confused with the tire code, a supplemental and global standard measuring tire dimensions, load-bearing ability and maximum speed, maintained by tire industry trade organizations and the International Organization for Standardization.
Air pollution in Hong Kong is considered a serious problem. Cases of asthma and bronchial infections have soared due to reduced air quality.
Air pollution is the presence of substances in the atmosphere that are harmful to humans and other living beings, or cause damage to the environment. Air pollution can be chemical, physical or biological. There are many different types of air pollutants, such as gases, particulates, lead and biological molecules. Air pollution can cause diseases, allergies, and even death; it can also cause harm to animals and crops and damage the natural environment or built environment. Air pollution can occur naturally or be caused by human activities.
Ultrafine particles (UFPs) are particulate matter of nanoscale size (less than 0.1 μm or 100 nm in diameter). Regulations do not exist for this size class of ambient air pollution particles, which are far smaller than the regulated PM10 and PM2.5 particle classes and are believed to have several more aggressive health implications than those classes of larger particulates. Although they remain largely unregulated, the World Health Organization has published good practice statements regarding measuring UFPs.
Air Pollution in Mexico City has been of concern to the city's population and health officials for decades. In the 20th century, Mexico City's population rapidly increased as industrialization brought thousands of migrants from all over the world. Such a rapid and unexpected growth led to the UN declaring Mexico City as the most polluted city in the world in 1992. This was partly due to Mexico City's high altitude, which causes its oxygen levels to be 25% lower. Carbon-based fuels also do not combust completely. Other factors include the proliferation of vehicles, rapid industrial growth, and the population boom. The Mexican government has several active plans to reduce emission levels which require citizen participation, vehicular restrictions, increase of green areas, and expanded bicycle accessibility.
Particulates or atmospheric particulate matter are microscopic particles of solid or liquid matter suspended in the air. The term aerosol refers to the particulate/air mixture, as opposed to the particulate matter alone, though it is sometimes defined as a subset of aerosol terminology. Sources of particulate matter can be natural or anthropogenic. They have impacts on climate and precipitation that adversely affect human health, in ways additional to direct inhalation.
The health of a mother directly affects the fetus during pregnancy. High levels of pollution where pregnant women reside can have adverse health effects on fetuses.
In Turkey, air pollution is the most lethal of the nation's environmental issues, with almost everyone across the country exposed to more than World Health Organization guidelines. Over 30,000 people die each year from air pollution-related illnesses; over 8% of the country's deaths. Air pollution is particularly damaging to children's health. Researchers estimate that reducing air pollution to World Health Organization limits would save seven times the number of lives that were lost in traffic accidents in 2017.
The air pollution in Delhi, the capital territory of India, was found to be the worst of any major city in the world in an August 2022 survey of 7,000 world cities by the US-based Health Effects Institute. The air pollution in Delhi also affects the surrounding districts. Air pollution in India is estimated to kill about 2 million people every year and is the fifth largest killer in India. India has the world's highest death rate from chronic respiratory diseases and asthma, according to the World Health Organization. In Delhi, poor air quality has irreversibly damaged the lungs of 2.2 million children.
Berlin’s Environmental Zone, also known as Berlin’s Umweltzone, refers to a region within the city of Berlin and has been deemed a low-emissions zone. This zone permits only vehicles that have an environmental badge, or a green sticker, to enter. The policy was put into place in January 2008 due to the high density of Berlin’s inner city being affected by pollutants such as fine dust (PM 10) and nitrogen dioxide (NO2) threatening human health.
Usage of electric cars damages people’s health and the environment less than similar sized internal combustion engine cars. While aspects of their production can induce similar, less or different environmental impacts, they produce little or no tailpipe emissions, and reduce dependence on petroleum, greenhouse gas emissions, and deaths from air pollution. Electric motors are significantly more efficient than internal combustion engines and thus, even accounting for typical power plant efficiencies and distribution losses, less energy is required to operate an electric vehicle. Manufacturing batteries for electric cars requires additional resources and energy, so they may have a larger environmental footprint in the production phase. Electric vehicles also generate different impacts in their operation and maintenance. Electric vehicles are typically heavier and could produce more tire and road dust air pollution, but their regenerative braking could reduce such particulate pollution from brakes. Electric vehicles are mechanically simpler, which reduces the use and disposal of engine oil.
Rubber pollution, similar to plastic pollution, occurs in various environments, and originates from a variety of sources, ranging from the food industry processing chain to tire wear. Synthetic and natural rubber dust and fragments now occur in food, airborne as particulates in air pollution, hidden in the earth as soil pollution, and in waterways, lakes and the sea.
Particulate pollution is pollution of an environment that consists of particles suspended in some medium. There are three primary forms: atmospheric particulate matter, marine debris, and space debris. Some particles are released directly from a specific source, while others form in chemical reactions in the atmosphere. Particulate pollution can be derived from either natural sources or anthropogenic processes.
Air Quality Expert Group (AQEG) is an official committee of scientific advisers who provide independent advice on air pollutants to the UK government's Department for Environment, Food and Rural Affairs (Defra). The group is drawn mostly from academia and consists of about a dozen atmospheric chemists and other environmental scientists. AQEG also advises government officials and ministers on air quality issues, suggests priority areas for future work, and advises on changes in international policy. AQEG was created in 2001, consolidating the work of a number of previous advisory groups including the Quality of Urban Air Review Group, Airborne Particles Expert Group, and Expert Panel on Air Quality Standards.
