Air quality

What is air quality?

Air quality is a term used to describe and measure levels of air pollution and the extent to which the air we breathe is safe for human health. The air around us contains small amounts of pollutants such as nitrogen oxides and particulate matter. Air pollutants are emitted into the atmosphere by various activities such as burning of fossil fuels, industry, farming, using certain products in the home and natural processes. Secondary pollutants that are not emitted also form when other pollutants react in the atmosphere.

Levels of air pollution can vary according to factors such as distance from the source, geography, weather conditions, time of year and time of day.

The main source of air pollution in Salford and Greater Manchester is road transport (vehicles with internal combustion engines). In Salford, this accounts for approximately 77% of nitrogen oxides emissions and 89% of particulate matter emissions.

Whilst the majority of Salford has generally good air quality, there are areas close to busy roads and built up areas where nitrogen dioxide levels are high and do not meet national and European standards.  

Why is air quality important?

Air quality has improved significantly in recent decades in the UK through national and local measures to reduce pollution from transport, industrial and domestic sources. However, air pollution still has negative impacts. For example:

Impacts on health and wellbeing

Air pollution can harm human health, and has the most impact on people who are the most vulnerable in society e.g. the youngest, the oldest, those living in areas of deprivation, and those with existing respiratory or cardiovascular disease.

According to the World Health Organization (WHO), air pollution is the biggest environmental risk to health in the European Union. In 2018, a report by the Committee on Medical Effects of Air Pollutants (COMEAP) in the UK estimated the health burden effect linked to exposure to 2 key pollutants (particulate matter and nitrogen dioxide) to be equivalent to between 28,000 and 36,000 deaths nationally each year. A 2010 report by COMEAP estimated that the impact of public exposure to ‘human made’ particulate matter alone reduced average life expectancy from birth in the UK by around six months.

The Royal College of Physicians produced a report in 2016 examining the public health impact of air pollution, Every breath we take: the lifelong impact of air pollution. This examined the links between long term exposure to air pollutants and illnesses and diseases such as asthma, cardiovascular disease (heart disease and strokes) and even lung cancer.

The Public Health Outcomes Framework provides overarching indicators of factors that effect health and well being in communities, including exposure to fine particulate air pollution (known as PM2.5).

In 2017, 4.5% of all mortality in Salford was estimated to be attributable to human made particulate pollution. This is slightly higher than the average for the north west of 4.1%, but lower than the England average of 5.1%. There are currently no figures available for Salford on the health impact from nitrogen dioxide exposure. These figures are used as an indicator of the local public health impact of air pollution.

Impacts on the environment

Air pollution has a negative impact on the environment by damaging biodiversity, reducing crop yields and contributing to climate change.

Impacts on society

The health problems resulting from exposure to air pollution also have a high cost to society. The Royal College of Physicians report estimates costs to add up to more than £20 billion each year in the UK.

Further information

The Clean Air Greater Manchester website contains lots of information about air quality in our region and its impact on health.

The central government UK AIR website contains a wealth of information about air pollution and monitoring.

The Chief Medical Officer independent annual report of 2017 discusses the health impacts of all pollution.


This page was last updated on 9 April 2019

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