Lower Thames Crossing PM2.5

PM2.5 (Particulate Matter 2.5) is something many are very concerned about when it comes to the proposed Lower Thames Crossing, and rightly so.

What is PM2.5 or Particulate Matter 2.5?

The air around us is made up of lots of different types and sizes of particles, these are particulate matter. These particulates are measured in micrometres in diameter. To put that into perspective the average human hair measures around 50-75 micrometres in diameter, and the particulate matter we’re talking about measures 2.5 micrometres in diameter.  Now we get an idea of just how tiny these particulate are!

When we are referring to PM2.5 in regard to LTC in general we are talking about tiny particles that come from things like brake dust, tyre wear, road wear etc.


What’s the problem with PM2.5?

PM2.5 are particles so tiny they can get into your lungs and then into your bloodstream and are very dangerous.  Exposure to PM2.5 can cause illnesses like asthma, COPD, coronary heart disease, stroke, and lung cancer. There is also evidence that links PM2.5 to low birth weight, diabetes and diseases such as Alzheimer’s and Parkinson’s

According to figures published by NHS England, an average of 5% of deaths in those aged over 30 can be attributed to PM2.5 air pollution. That’s 1 in every 20 deaths. Sadly, you will probably also be familiar with the fact that a coroner ruled that air pollution contributed to the death of 9 year old Ella Kissi-Debrah in London in Feb 2013.

PM2.5 is also very harmful to the environment and gets into the water supply.

If you breathe air you should care


What are the limits for PM2.5?

Updated 24/09/2021
The World Health Organization updated their PM2.5 guidelines on 22nd Sept 2021).  British legal limits for PM2.5 and nitrogen dioxide were now four times higher than the new World Health Organization (WHO) guidelines. That said, there’s no safe level of air pollution. Even the WHO’s recommended limit does not guarantee you suffer no harm.

Hold your breath

What is PM2.5 like in our area?

In 2018, 115 out of 317 local authorities (36%) had unsafe levels of PM2.5 that were over the annual level recommended by the WHO. This is obviously prior to WHO’s latest update to their guidelines in Sept 2021, so these figures are likely to been even worse now.

According to the British Lung Foundation Task Force for Lung Health – Thurrock, Gravesham, Havering, Dartford and the surrounding areas all had PM2.5 levels that breach WHO limits (again prior to the latest update from WHO).

The Mayor of London has committed London to comply with WHO standards for PM2.5 by 2030.  Remember the northern section of the proposed LTC route falls within the London Borough of Havering.


What about PM2.5 limits in regard to LTC?

As per our previous update on LTC – the toxic triangle  professor Karen Lucas publicly stated, whilst working for HE (as an independent advisor to the community impacts workstream for LTC) that the whole proposed LTC route would fail against WHO limits.  However, WHO standards on PM2.5 are not enshrined in UK law.

Professor Karen Lucas Tweet July 2019

How can we get WHO standards on PM2.5 into UK law?

For some time we and many other campaigners have been pushing for WHO standards for PM2.5 to be enshrined into UK law, and the route to do that is by getting it into the Government’s Environment Bill.

Frustratingly, the Government keep delaying this bill.  Environment Minister Rebecca Pow pledged in January 2021 that “…we will achieve Royal Assent before COP26”. Her Lords counterpart Lord Goldsmith reiterated this welcome commitment in June, reassuring peers that “it is absolutely our intention that the Bill be passed before COP26”. He went so far as to stress that missing this deadline would “weaken our hand in these extraordinarily important climate and environment negotiations”.

There was good news on 6th Sept 2021 when the Lords voted for the Environment Bill to include WHO standards for PM2.5 to be met by 2030.

However, the Lords Amendment now means that it has to go back to the Commons for MPs to vote again.



Please either email your MP directly* or use the handy and quick British Lung Foundation form NOW.

Let them know you want:

The Environment Bill back in the House asap, and that you want them to vote in favour of including WHO standards for PM2.5 to be met by 2030 into the Environment Bill when the time arrives for them to vote.



* Click here if you are unsure who your MP is, or are in a different area to those listed below




British Lung Foundation PM2.5 Infoclick here

Green Alliance blog on Environment Bill delayclick here

TCAG letter to Mayor of London about LTC PM2.5click here

What can I do?click here

BBC News – Air pollution: Even worse than we thought – WHO (Sept 2021) – click here

Evening Standard – Global recommended limits for air pollution tightened to combat health threats – click here

Client Earth – Why tighter air pollution guidelines should trigger immediate action from governments – click here