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Health Impacts of poor air quality and government measures to tackle air quality emissions from cars. 

The effects of air pollution on health varies widely between individuals and sub-groups of the population.  In particular air pollution is known to affect the elderly, children, and those suffering from chronic respiratory diseases (e.g. bronchitis and asthma) and heart disease. 

The effects of these exhaust gases are described in more detail below: 

CO - Carbon monoxide reduces the blood’s oxygen-carrying capacity which can reduce the availability of oxygen to key organs. Extreme levels of exposure, such as might occur due to blocked flues in domestic boilers, can be fatal. At lower concentrations CO may pose a health risk, particularly to those suffering from heart disease. 

NOx - Oxides of nitrogen is the total amount of nitrogen dioxide (NO2) and nitric oxide (NO); NO quickly reacts in the atmosphere to form NO2.  Exposure to NO2 at roadside concentrations can have adverse effects on health, particularly among people with respiratory illness. The Committee on the Medical Effects of Air Pollutants has identified that the evidence associating exposure to NO2 with health effects has strengthened substantially in recent years. NOx also contributes to smog formation, and acid rain, can damage vegetation, contributes to ground-level ozone formation and can react in the atmosphere to form fine particles (‘secondary particles’). 

PM – Particulate matter. Exposure to fine particles has an adverse effect on human health, particularly among those with existing respiratory disorders. Particulate matter is associated with respiratory and cardiovascular problem. 29,000 equivalent deaths a year in the UK are attributable to fine particulate pollution.   

HC - Hydrocarbons contribute to ground-level ozone formation leading to risk of damage to the human respiratory system. Some kinds of hydrocarbons, in addition, are both carcinogenic and indirect greenhouse gases. 

The European Union Ambient Air Quality Directive sets maximum permissible levels for roadside concentrations of pollutants thought to be harmful to human health and the environment. The UK meets almost all these levels, however, achieving the air quality standards for nitrogen dioxide presents the greatest challenge, especially in urban areas the government is committed to meeting those standards in as short as time as possible. 

Emissions of these air quality pollutants from road vehicles have been reduced by improving the quality of fuels and by setting increasingly stringent emission limits for new vehicles, which has encouraged the fitting by manufacturers of appropriate technology. As an example, it would take 50 new cars to produce the same quantity of particulate matter per kilometre as a vehicle made in 1970. Over the last twenty years increasingly stringent emission limits have been set at a European level, starting with the "Euro1" limits in 1993.

Since September 2015 virtually all newly registered cars have had to meet the Euro 6 standard, further details are shown in Table 1.  Emissions of NOx will be further reduced due to the strengthening of test procedures with the adoption of real driving emissions (RDE).  RDE step 1, (Euro 6d-Temp) is compulsory for new models registered from September 2017 and all new cars registered from September 2019.   RDE step 2 (Euro 6d), which sets an even tighter margin between the laboratory limits and real world performance, will apply in January 2020 for new models and then from January 2021 for all cars.

Information on the level of air pollutant emissions recorded for new models of cars at their type approval test is listed in the data table, alongside the CO2 and fuel consumption figures. Unlike the CO2 and fuel consumption figures, the figures for air pollutant emissions should not be used to directly compare different models of vehicle. The figures for these emissions are indicative rather than absolute, and emissions of them will vary within an acceptable range between individual production vehicles for each model. 

As well as being required to meet strict emission limits before a vehicle enters into service, all vehicles must be able to meet these limits whilst they are in service (unless specifically exempted).

Changes to the MOT test which affects emissions standards for diesel vehicles were introduced in the UK on 20 May 2018. If a vehicle’s emissions limit is listed on the manufacture’s plate (which is usually found on the bottom inside of a vehicle’s door frame) then a vehicle’s emissions at its next MOT will need to meet the maximum level listed on the plate. If no emissions value is listed on the plate then the vehicle will be tested, as it previously would have been, to the default limit set for the age of the vehicle. For all Euro 6 vehicles the default limit will be 0.7m-1 compared to the current 1.5m-1. 

A vehicle will fail its MOT if any emissions control system or component has been removed or tampered with. One example of such a component which must be in working order is the Diesel Particulate Filter (DPF).

It is an offence under the Road Vehicles (Construction and Use) Regulations (Regulation 61a(3)) to use a vehicle which has been modified in such a way that it no longer complies with the air pollutant emissions standards it was designed to meet. The potential penalties include a maximum fine of £1,000 for a car.