Cars in Pakistan generate plenty of pollution, making the masses vulnerable to illness and disease. Pollution is when something is added to the environment, which is harmful or poisonous to living things. Smoke in the air is a type of pollution as it is bad for the lungs when inhaled. Air pollution is caused by harmful gases such as carbon monoxide, sulphur dioxide, nitrogen dioxide and very small particles of carbon. Most of the pollution around us is caused by vehicles, factories and live stock.Air pollution causes many types of diseases, e.g. human beings can develop asthma due to air pollution. Air pollution can also cause inflammation of the lungs, known as lung fibrosis and infections, leading to chronic obstructive pulmonary disease. Accumulation of smoke in the lungs can cause a disease known as emphysema due to active or passive inhalation of smoke. Lung cancer can also be caused by air pollution. Moreover, various sorts of cancers are initiated by highly toxic gases being inhaled indiscriminately. Lastly, air pollution can lead to heart disease, including heart attack and stroke.Air pollution is a mixture of natural and man made substances in the air we breath, such as fine particles produced by the burning of fossil fuels, a reactive form of oxygen that is a primary component of urban smog and noxious gases such as sulphur dioxide, nitrogen oxide, carbon monoxide and chemical vapours. Carbon monoxide can lead to death as well. Carbon monoxide, nitrogen oxides, and hydrocarbons are released when fuel is burned in an internal combustion engine and when air/fuel residuals are emitted through the vehicle tailpipe due to poor performing engines or low quality fuels. Gasoline vapours also escape into the atmosphere during refuelling and when fuel vaporises from engines and fuel systems caused by vehicle operation or hot weather. Motor vehicle pollution also contributes to the formation of acid rain and adds to the greenhouse gases that cause climate change. Pollutants emitted directly from vehicles are not the only cause for concern. On warm, sunny days, hydrocarbons react with oxides of nitrogen to create a secondary pollutant, the ozone. In many urban areas, motor vehicles are the single largest contributor to ground-level ozone, which is a common component of smog. Ozone causes coughing, wheezing and shortness of breath, and can bring on permanent lung damage, making it a cause of crucial public health problems. Vehicle emissions control is the study of reducing the motor vehicle emissions — emissions produced by motor vehicles, especially internal combustion engines. Emissions of many air pollutants have been shown to have a variety of negative effects on public health and the natural environment. Emissions that are principal pollutants of concern include the following. Hydrocarbons are a class of burned or partially burned fuel, which is toxic. Hydrocarbons are a major contributor to smog, which can be a major problem in urban areas. Prolonged exposure to hydrocarbons contributes to asthma, liver disease, lung disease and cancer. Regulations governing hydrocarbons vary according to type of engine and jurisdiction; in some cases, ‘non-methane hydrocarbons’ are regulated, while in other cases, ‘total hydrocarbons’ are regulated. Technology for one application (to meet a non-methane hydrocarbon standard) may not be suitable for use in an application that has to meet a total hydrocarbon standard. Methane is not directly toxic but is more difficult to break down in a catalytic converter, so in effect a ‘non-methane hydrocarbon’ regulation can be considered easier to meet. Since methane is a greenhouse gas, interest is rising in how to eliminate emissions of it. Carbon monoxide (CO) is a product of incomplete combustion. It reduces the blood’s ability to carry oxygen and overexposure (carbon monoxide poisoning) may be fatal. Carbon monoxide poisoning is a killer in high concentrations. Nitrogen oxides (NOx) are generated when nitrogen in the air reacts with oxygen at high temperature and pressure inside the engine. NOx is a precursor to smog and acid rain. NOx is a mixture of NO, N2O, and NO2. NO2 is extremely reactive. It destroys resistance to respiratory infection. NOx production is increased when an engine runs at its most efficient (i.e. hottest) part of the cycle. Particulate matter is soot or smoke made up of particles in the micrometer size range: particulate matter causes negative health effects, including but not limited to respiratory disease and cancer. Sulphur oxide (SOx) is a general term for oxides of sulphur, which are emitted from motor vehicles burning fuel containing sulphur. Reducing the level of fuel sulphur reduces the level of sulphur oxide emitted from the tailpipe. Volatile organic compounds (VOCs) are organic compounds, which typically have a boiling point less than or equal to 250 °C; for example chlorofluorocarbons (CFCs) and formaldehyde. Volatile organic compounds are a subsection of hydrocarbons that are mentioned separately because of their dangers to public health. Motor vehicle inspection is common and mandatory in several countries around the world but not in India and Pakistan. Vehicle inspection is a procedure mandated by national or subnational governments in many countries, in which a vehicle is inspected to ensure that it conforms to regulations governing safety, emissions, or both. Inspection can be required at various times, e.g., periodically or on transfer of title to a vehicle. Few countries announced the Clean Air Act in different years: the UK in 1956, New Zealand in 1972 and US in 1963. The Clean Air Act is a federal law that requires countries to develop and enforce regulations to protect the public from airborne contaminants known to be hazardous to human health. Motor vehicles are significant sources of pollution that can damage the environment and pose public health issues. Everyone has a stake in limiting pollution. Who is responsible for ending pollution? Our government? It should announce the Clean Air Act, implement inspecting both commercial and private vehicles and make vehicle inspection mandatory. This would benefit the government, generating and earning billions of rupees every year by inspecting the vehicles and setting a pre-code fee of inspection. In this way, hundreds of thousands of Pakistani nationals will get jobs working at the inspecting stations. Currently there no vehicle inspections, no emission checks and thus the vehicles are absorbing more petrol. By inspecting vehicles, the government will save billions of rupees every year, stopping the lavish spending of petrol. Such a change in policy will have multiple impacts on our environment, stop the negative impact on health and limit the over expenditure of people due to the deleterious outcomes of the pollution caused by vehicles, increasing the revenue of the cash strapped government. The writer is a freelance columnist