Air Quality

Environmental briefing note for WDPS members

Air quality in and around Wheathampstead

Ever wondered about how clean the air is in and around Wheathamstead ?

Ever wondered what you are inhaling and how it might affect you ?

Well, here’s how to find out as well as some information you might find helpful.

Wheathampstead photo - poor air quality


A convenient way to find out and track air quality is to download AccuWeather’s Plume Labs app onto your mobile device.  Just go to the app store, find Plume and download the app.  It is free.

Once you have downloaded the app you can enter your location e.g. Wheathampstead.  Then you will be able to see a measure of the quality of the outside air you are breathing on an hourly basis as well as a forecast for three days ahead.  You can also enter other locations, for example a holiday destination anywhere on the globe.

Here’s the real-time air quality information that Plume provides with examples of measurements:

AQI (i.e. Air Quality Index) e.g. “24 AQI Moderate”   This index combines measurements of the following which the app provides.

NO2 (i.e. Nitrogen Oxide) e.g. “12”

PM2.5 (Particulate Matter –  fine particulate matter) e.g  “23”

PM10 (Particulate Matter – particulate matter e.g. “15”

O3 (i.e. Ozone) – a secondary pollutant created in the atmosphere through chemical reactions and sunlight e.g. “25”

So what?  What does it all mean for you?

You may have no health issues or you may be among the more sensitive groups which include children, the elderly and those with known health vulnerabilities.  So let’s look at how Plume Labs AQI is interpreted and its potential implications for your health:


Descriptor and range

Meaning and advice


Excellent 0-20

The air quality is ideal for most individuals: enjoy normal outdoor activities


Fair/Moderate 21-50

The air quality is generally acceptable for most individuals. However, sensitive groups may experience minor to moderate symptoms from long-term exposure


Poor 51-100

The air has reached a high level of pollution and is unhealthy for sensitive groups. Reduce time spent outside if you are feeling symptoms such as difficulty breathing or throat irritation.


Unhealthy 101-150

Health effects can be immediately felt by sensitive groups. Healthy individuals may experience difficulty breathing and throat irritation with prolonged exposure. Limit outdoor activity.


Very unhealthy 151-250

Health effects will be immediately felt by sensitive groups and they should avoid outdoor activity. Healthy indiividuals are likely to experience difficulty breathing and throat irritation. Consider staying indoors and rescheduling outdoor activities


Dangerous 250+

Any exposure to the air, even for a few minutes, can lead to serious health effects on everybody. Avoid outdoor activities.

By looking at the Plume app which gives hourly AQI measurements, you can, for example, choose the best time of the day to go for a run or to cycle.   The app gives tips for runners, cyclists, those with babies and those going for picnics according to the hourly AQI.

So, what is Wheathampstead’s air quality usually like ?

At the moment the air quality in and around Wheathampstead is usually “Excellent/Good” or “Fair/Moderate”.   The annual average AQI is 23. The AQI on the best day of the past year was 8. However, the worst peak of the year was an AQI of 93 meaning that the air quality was well into the “Poor” category. 

These values may or may not change in future – we must keep our eyes and ears open to developments in and around Wheathampstead which have the potential to worsen our air quality. We should mount vigorous arguments to prevent them going ahead. Only recently it was necessary to oppose the development of a giant incinerator to the West of Wheathampstead which could have had serious air quality implications for Wheathampstead residents. Fortunately, that proposal has now lapsed.

What are the main sources of air pollution affecting Wheathampstead and what can we do ?

The largest source of nitrogen dioxide (NO2) is emissions is from combustion in diesel light duty vehicles (cars and vans). There has been significant growth in these vehicle numbers over the last 10 years. NO2 is the main pollutant of concern around airports such as London Luton Airport and emanates from aircraft engines, airport operations and movements and surface road traffic. DEFRA has estimated that NO2 contributes to shortening lives by an average of around 5 months.

Actions to reduce NO2 emissions include:  car manufacturers to adopt ever tighter emissions standards, stop using diesel vehicles; drive less; clean air zones and related pollution pricing structures; fly less; limit the growth of airports and related road traffic especially close to already densely populated areas.

Particulate Matter comprises micron sized particles and is assessed in three main size fractions; PM10, PM2.5 and PM0.1. Particulate Matter can be composed of particles from combustion products; from abrasion of engine components, brakes and tyres on road surfaces, generated during construction and agricultural processes, as well as components generated by chemical reactions in the air. However, much particulate matter in urban pollution hotspots, particularly those close to roads, derives from traffic sources and comprises soot, part-burnt diesel and petrol compounds that form benzene-based carcinogens, heavy metals, silica, bitumen, rubber and other organic waste matter from road surfaces.  Particulate emissions from jet exhausts are almost all PM2.5 and are of concern as airports expand.

Actions to reduce PM emissions include

  • avoid ‘open burning’ of landscape debris, rubbish etc. and use composting more;
  • drive less, work from home more; 
  • shop on-line; 
  • walk or cycle when you can; 
  • drive smart i.e. no idling, accelerate smoothly, avoid hard braking; 
  • go for a less polluting, more efficient vehicle when you change.

Ozone (O3) is often called photochemical “smog” and is harmful to breathe. Ozone aggressively attacks lung tissue by reacting chemically with it. When ozone is present, there are other harmful pollutants created by the same processes that make ozone. The ozone layer found high in the upper atmosphere (the stratosphere) shields us from much of the sun’s ultraviolet radiation. However, ozone air pollution at ground level where we can breathe it (in the troposphere) causes serious health problems. Ozone develops in the atmosphere from gases that emanate from tailpipes, smokestacks and many other combustion sources.

Actions to reduce polluting ozone include: as above plus use water-based solvents or those with low volatile compound (VOC) content; use water-based paints or those labelled zero VOC; paint with a brush rather than a sprayer; store solvents like paint thinners in airtight containers; use an electric lawn mover instead of a petrol one.