Is the air in Chorley within legal limits?

For 2024 calendar year, DEFRA reports PM2.5 in Chorley as 8 µg/m³ — within the UK statutory annual limit of 20 µg/m³ for PM2.5. NO2 is 22 µg/m³ — within the UK statutory annual limit of 40 µg/m³ for NO2. These are the maximum modelled annual-mean concentrations DEFRA uses for compliance assessment.

How does Chorley compare with the WHO air quality guideline?

The World Health Organization's 2021 annual guidelines are 5 µg/m³ for PM2.5 and 10 µg/m³ for NO2 — stricter than the UK statutory limits. Chorley's PM2.5 (8 µg/m³) is 1.6× the WHO PM2.5 guideline, and its NO2 (22 µg/m³) is 2.2× the WHO NO2 guideline.

What is PM2.5 and why does it matter for health?

PM2.5 is fine particulate matter under 2.5 micrometres — small enough to reach deep into the lungs and bloodstream. Long-term exposure is linked to higher rates of respiratory and cardiovascular disease. In Chorley the annual mean is 8 µg/m³ (2024 calendar year).

Where does this Chorley air quality data come from?

Every figure is taken directly from DEFRA UK-AIR — Air quality annual mean by Local Authority (NO2 & PM2.5), 2024 (2024 calendar year), produced by Department for Environment, Food & Rural Affairs (DEFRA) and published under the Open Government Licence v3.0. GeraClinic shows the DEFRA values verbatim; only the WHO-multiple ratios are derived, and they are labelled.

Air quality in Chorley

PM2.5 moderate · 8 µg/m³NO2 elevated · 22 µg/m³

Maximum modelled annual-mean concentrations · DEFRA UK-AIR 2024 calendar year

What is the air quality in Chorley?

In 2024 calendar year, the maximum modelled annual-mean PM2.5 in Chorley was 8 µg/m³ (1.6× the WHO guideline of 5 µg/m³) and NO2 was 22 µg/m³ (2.2× the WHO guideline of 10 µg/m³). PM2.5 is moderate and NO2 elevated. Source: DEFRA UK-AIR, 2024 calendar year.

Source:DEFRA UK-AIR — Air quality annual mean by Local Authority (NO2 & PM2.5), 2024·as of 2024 calendar yearupdated annually (last: 20 June 2026)

Pollutant levels — Chorley (DEFRA 2024 calendar year)

Chorley — DEFRA UK-AIR annual-mean concentrations, 2024 calendar year
Pollutant	Annual mean	WHO 2021 guideline	UK limit	UK status
PM2.5 (fine particulates)	8 µg/m³	5 µg/m³ (1.6×)	20 µg/m³	Compliant
NO2 (nitrogen dioxide)	22 µg/m³	10 µg/m³ (2.2×)	40 µg/m³	Compliant

DEFRA publishes the maximum modelled annual-mean concentration within each local authority for limit-value compliance. The WHO multiple (×) is a transparent ratio of the DEFRA value to the WHO 2021 annual guideline.

Air quality in nearby local authorities

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Related health data on GeraClinic

Frequently asked questions

Is the air in Chorley within legal limits?: For 2024 calendar year, DEFRA reports PM2.5 in Chorley as 8 µg/m³ — within the UK statutory annual limit of 20 µg/m³ for PM2.5. NO2 is 22 µg/m³ — within the UK statutory annual limit of 40 µg/m³ for NO2. These are the maximum modelled annual-mean concentrations DEFRA uses for compliance assessment.
How does Chorley compare with the WHO air quality guideline?: The World Health Organization's 2021 annual guidelines are 5 µg/m³ for PM2.5 and 10 µg/m³ for NO2 — stricter than the UK statutory limits. Chorley's PM2.5 (8 µg/m³) is 1.6× the WHO PM2.5 guideline, and its NO2 (22 µg/m³) is 2.2× the WHO NO2 guideline.
What is PM2.5 and why does it matter for health?: PM2.5 is fine particulate matter under 2.5 micrometres — small enough to reach deep into the lungs and bloodstream. Long-term exposure is linked to higher rates of respiratory and cardiovascular disease. In Chorley the annual mean is 8 µg/m³ (2024 calendar year).
Where does this Chorley air quality data come from?: Every figure is taken directly from DEFRA UK-AIR — Air quality annual mean by Local Authority (NO2 & PM2.5), 2024 (2024 calendar year), produced by Department for Environment, Food & Rural Affairs (DEFRA) and published under the Open Government Licence v3.0. GeraClinic shows the DEFRA values verbatim; only the WHO-multiple ratios are derived, and they are labelled.

Worried about air pollution in Chorley?

Long-term exposure to PM2.5 and NO2 is associated with higher rates of respiratory and cardiovascular disease. A GeraClinic care navigator can explain what these DEFRA figures mean for you, assess your individual risk, and connect you with specialist care — fully online.

Talk to a GeraClinic care navigator

Contains public sector information published by Department for Environment, Food & Rural Affairs (DEFRA) and licensed under the Open Government Licence v3.0. Source: DEFRA UK-AIR — Air quality annual mean by Local Authority (NO2 & PM2.5), 2024 (2024 calendar year, published 2025).